B Lymphocytes depletion therapy for autoimmune hepatitis

Abstracts Accepted to 2012 CDDW/Annual CASL Winter Meeting

Oral Presentations:

• CAG Paper Session – The Biological Processes that Culminate in IBD Abstracts 1 – 2 • CAG Clincial Paper Session Abstracts 3 – 8 • CAG/CCFC Student Prize Paper Presentations Abstracts 9 – 14 • CASL Viral Hepatitis Paper Session 1 Abstracts 15 – 20 • CAG Paper Session - Epithelia out of Control:

Cellular Mechanisms of Colon Cancer Abstracts 21 – 22 • CASL Viral Hepatitis Paper Session 2 Abstracts 23 – 28 • CAG Paper Session - Neurogastroenterology: Who is Talking to Whom? Abstracts 29 – 31 • CAG Paper Session - Resolution of Inflammation:

Towards Better Therapies for Inflammatory Diseases Abstracts 32 – 32 • CASL Paper Session 3 Abstracts 33 – 38 • CAG Paper Session - Irritable Bowel Syndrome: Advances in Basic Research Abstracts 39 – 41 • CAG Paper Session - The GI Microbiome: Digestive Diseases and Beyond Abstracts 42 – 43 • CASL Paper Session 4 Abstracts 44 - 49

Poster Presentations:

Poster Session 1: • Acute Liver Injury and Hepatotoxicity Abstracts 50 - 51 • Chronic Liver Disease Including Alcoholic,

Cholestatic, and Metabolic Disease Abstracts 52 - 63 • Clinical Practice Abstracts 64 - 84 • Cytokines and Intracellular Signals Abstracts 85 - 90 • Epidemiology and the Burden of Illness Abstracts 91 – 99 • Fatty Liver Disease (Alcohol-related and Non-alcoholic) Abstracts 100 - 100 • Fibrogenesis, Portal Hypertension, Complications of Cirrhosis Abstracts 101 - 106 • Gastro Intestinal Oncology Abstracts 107 - 124 • Hepatobiliary Neoplasia Abstracts 125 - 126

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Poster Session 1 cont’d: • Hormones, Transmitters, Growth Factors Abstracts 127 – 128 • Immunobiology and Liver Transplantation Abstracts 129 – 132 • Immunology and Inflammatory Bowel Disease Abstracts 133 – 160 • Intestinal Disorders Abstracts 161 – 181 • Nutrition, Obesity and Aging Abstracts 182 - 190

Poster Session I1: • Clinical Practice Abstracts 191 - 211 • Epidemiology and the Burden of Illness Abstracts 212 - 219 • Esophagus, Gastric and Duodenal Ulcer Disorders Abstracts 220 - 236 • Immunology and Inflammatory Bowel Disease Abstracts 237 - 276 • Microbiology and Parasite-Host Interactions Abstracts 277 - 287 • Motility and Nerve-Gut Interactions Abstracts 288 – 294 • Pancreatico-Biliary Disease Abstracts 295 – 303 • Pediatric Liver Disease Abstracts 304 – 307 • Viral Hepatitis Abstracts 308 – 330

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CAG Paper Session - The Biological Processes that Culminate in IBD Friday, February 24th, 08h00-10h00 A1 G9A PROMOTES T CELL DEPENDENT COLITIS BY RESTRAINING TH17 AND REGULATORY T CELL DEVELOPMENT F. Antignano1, S. Wang1, J. Han2, M. Oudhoff1, M. Hughes1, M. Gold1, T. Fung1, K. McNagny1, M. Levings2, C. Zaph1 1. The Biomedical Research Centre, Vancouver, BC, Canada; 2. Children and Family Research Institute, Vancouver, BC, Canada. Aims: G9a is a histone lysine methyl transferase with specific mono- and di-methyl activity towards histone H3 lysine 9. We have previously shown that G9a expression in CD4+ T cells is required for Th2-polarization in vitro and in vivo. Concomitantly, loss of G9a in CD4+ T cells results in lineage-promiscuous expression of IL-17 under neutral and Th2-polarizing conditions. In recent work, we have found that G9a-/- T cells also overproduce IL-17 under Th17-polarizing conditions. Several studies have investigated the role of IL-17 in intestinal inflammation with some claiming a protective role and others a pathogenic role. In an example of the former, one study found that T cells were both the source and target of IL-17 required for protection in a mouse model of T cell transfer colitis. Therefore, using this mouse model of colitis, in the present study we examined the consequences of G9a deletion and the resulting enhanced IL-17 production. Methods: In T cell transfer colitis, CD4+CD25-CD45Rb+ T cells, isolated from naïve donor mice, are adoptively transferred to Rag-/- mice (T and B-cell deficient strain). In the absence of Tregs in Rag-/- mice, donor T cells promote colonic inflammation in response to intestinal microflora. Results: We found that transfer of G9a-deficient T cells fails to cause the weight loss and colonic inflammation typical of the model. Furthermore, T effector-cell production of gamma-interferon (IFNγ) was significantly reduced and colonic Il17 was enhanced in T cell transfer experiments using G9a-/- T cells. In addition, compared to wild-type (WT) controls, a higher proportion of G9a-deficient T cells express Foxp3 and more Foxp3 mRNA was detected in colon tissue. Thus, G9a also restrains Treg cell development. However, we found that the frequency of natural Treg (nTregs) cells are not altered in T cell specific (CD4Cre) G9a-/- mice suggesting that only inducible Tregs (iTregs) are altered in the absence of G9a. Indeed, in vitro culture of G9a-/- T cells using conditions that promote Treg development (TGFβ) results in a higher frequency of Foxp3+ cells. As a potential mechanism, we found that G9a-/- T cells display enhanced sensitivity to TGFβ in vitro requiring 20-fold lower concentrations of TGFβ to promote Treg development than WT cells. In addition, unlike WT Tregs, G9a-/- Tregs maintain Foxp3 expression after withdrawal of TGFβ. Conclusions: Our results identify G9a as an important epigenetic modifier of Treg cell fate since G9a limits both Th17 and Treg development. Thus, G9a is a potential therapeutic target for diseases with dysregulated T cell responses such as inflammatory bowel diseases.

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A2 THE ROLE OF NADPH OXIDASE GENES IN VERY EARLY-ONSET IBD S. Dhillon1, R. Fattouh2, C. Guo2, J. Brumell1, A. Muise1 1. Institute of Medical Science, University of Toronto, Toronto, ON, Canada; 2. Program in Cell Biology, The Hospital For Sick Children, Toronto, ON, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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CAG Clinical Paper Session Friday, February 24th, 10h30-12h00 A3 A MULTICENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED PHASE2B STUDY OF USTEKINUMAB IN PATIENTS WITH MODERATELY TO SEVERELY ACTIVE CD:RESULTS THROUGH WK36 FROM THE CERTIFI TRIAL B. Feagan1, C. Gasink2, L. Gao2, M. Blank2, J. Johanns2, C. Guzzo2, B. Sands3, S. Hanauer4, S. Targan5, P. Rutgeerts6, S. Ghosh7, W. de Villiers8, R. Panaccione7, G. Greenberg9, S. Schreiber10, S. Lichtiger3, W. Sandborn11 1. Robart Research Inst, London, ON, Canada; 2. Janssen R&D, Malvern, PA; 3. Mt Sinai Med Ctr, New York, NY; 4. U Chicago, Chicago, IL; 5. Cedars Sinai Med Ctr, Los Angeles, CA; 6. U Hosp Gasthuisberg, Leuven, Belgium; 7. U Calgary, Calgary, AB, Canada; 8. U Kentucky Med Ctr, Kentucky, KY; 9. Mt Sinai Hosp, Toronto, ON, Canada; 10. U Hosp Schleswig-Holstein, Kiel, Germany; 11. U California San Diego, La Jolla, CA. Aims: UST was evaluated in pts with mod-to-sev CD previously failing anti-TNFs. Methods: Pts with CDAI score 220-450 were randomized to IV PBO or UST 1,3,or 6mg/kg at wk0.Primary endpt was clin response at wk6.At wk8,wk6 responders & nonresponders who received IV UST were separately rerandomized to SC90mg UST or PBO maintenance at wks8&16.During maintenance,steroid tapering was mandated and assessments were at wk22.Pts were followed until wk36. Results: Of 526pts randomized,baseline mean CDAI was 324;49.6% were on steroids(incl budesonide);48.8% failed ≥2 anti-TNFs and primary/secondary non-response or intolerance criteria were met by 30.4%,72.2%&33.5% of pts,resp.At wk6,39.7% in the 6mg/kg USTgrp were in clin response vs 23.5% PBO(p=0.005).All 3 doses had sig changes vs PBO at wk6 in CRP,IBDQ,meanCDAI,70 pt drop, and lactoferrin/calprotectin. In maintenance,among pts in clin response to UST at wk6,41.7%(30/72) on UST were in remission at wk22 vs 27.4%(20/73)PBO(p=0.029);69.4% vs 42.5% remained in clin response(p<0.001) and 30.6%(22/72) on UST were in steroid-free remission at wk22 vs 17.8%(13/73)PBO(p=0.048).Among pts on systemic steroids at baseline(n=35 UST;26 PBO),median dose was 20mg. At wk22,median dose[IQrange] was 5mg[0,15] on UST vs 10mg[2.5,20] PBO(p=NS),and 5mg[0,19] vs 15mg[2.5,20] at wk36(p<0.05).Through 36wks,proportions of AEs, SAEs, and infections in the UST&PBO grps were similar during both induction & maintenance.The only malignancy was a basal cell skin Ca.There were no major adverse CV events, deaths,serious opportunistic infections or TB. Conclusions: In mod-to-sev CD pts previously failing anti-TNFs,UST induced & maintained clinical response. Sig greater proportion of wk6 responders achieved clinical remission & steroid-free remission at wk22 on SC UST vs SC PBO.IV&SC UST were well tolerated through wk36.

PBO UST1mg/kg UST3mg/kg UST6mg/kg UST Combined N 132 131 132 131 394

Clin Responsea Wk 6 23.5% 36.6%* 34.1% 39.7%* 36.8%* Wk 8 17.4% 32.1%* 31.8%* 43.5%* 35.8%*

Clin Remissionb Wk6 10.6% 16.0% 15.9% 12.2% 14.7% Wk8 10.6% 17.6% 18.2% 18.3% 18.0%*

a≥100pt reduction in CDAI;bCDAI<150;*P<0.05 vs.PBO by CMH

A4 SURVEILLANCE COLONOSCOPY IN AVERAGE RISK CANCER SCREENING PROGRAMS WILL DOUBLE COLONOSOCOPY REQUIREMENTS IN 10 YEARS. A MATHEMATICAL MODEL OF PROGRAM GROWTH. D. Leddin DALHOUSIE UNIVERSITY, Halifax, NS, Canada. Aims: Many Provinces are planning, or have introduced, average risk-screening programs using fecal occult blood testing. A majority of those testing positive will have polyps or cancer. Once pathology is detected guidelines dictate surveillance endoscopy times. We have developed a mathematical model, which will allow prediction of demand for surveillance colonoscopy if current guidelines are followed. Methods: Development of the Model: The number of people participating in the program is variable, as is the positivity rate of the test. The product of these variables generates the number of new patients coming for colonoscopy each year. In order to evaluate the growth of surveillance colonoscopy we held these variables steady. Once a patient undergoes colonoscopy there are four possible outcomes. The test may be normal and the patient is removed from the program for 10 years. The patient may have cancer and will require a repeat colonoscopy three years after the index scope. Those with high-risk polyps require colonoscopy one year after the index scope, intermediate risk will be scoped 3 years later, and low risk 5 years later. We assumed that all follow up scopes in high, intermediate, and low risk generated low risk polyps only and these patients were therefore transferred to follow up endoscopy five years after their first follow up scope. The model was developed on a spreadsheet and all variables can be adjusted to calculate colonoscopy growth requirements under various assumptions and conditions. Results: Growth Prediction: Assuming no growth in the number of positive occult blood tests being referred each year, and a 60 % pathology detection rate (high risk polyps10%, cancer 10%, intermediate risk polyps 20%, and low risk polyps 20%) the model predicts that by 10 years the number of returning patients will equal the number of new patients. At a conservative 60% pathology detection rate colonoscopic resources will need to grow by a minimum of 10% per year (Figure 1) to meet program needs. This estimate does not include colonoscopies required to screen the first-degree relatives of those found to have polyps or cancer many of whom will also require colonoscopy. Conclusions: This model allows prediction of growth based on current guidelines and will help guideline writers estimate the impact of various surveillance policies on resource demand. Program planners and hospital administrators need to understand that once an average risk program begins it has inherent growth driven by the need for surveillance. Using conservative estimates an annual growth rate of 10% should be anticipated.

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A5 DEVELOPMENT OF AN OBJECTIVE SKILL ASSESSMENT TOOL FOR COLONOSCOPY: A DELPHI APPROACH C. Walsh1, S. Ling1, N. Khanna2, M. Cooper1, S. Grover1, G. May1, T. Walters1, L. Rabeneck1, R. Reznick3, H. Carnahan1 1. University of Toronto, Toronto, ON, Canada; 2. University of Western Ontario, London, ON, Canada; 3. Queen's University, Kingston, ON, Canada. Aims: Ensuring competency remains a seminal objective of endoscopy training programs, professional organizations and accreditation bodies; however, no widely accepted measure of endoscopic competence currently exists. Using Delphi methodology, this study aimed to determine expert consensus regarding items required on a checklist and global rating scale designed to assess the competence of clinicians performing colonoscopy. Methods: Checklist and global rating items were initially generated from a systematic literature review and survey of core committee members. An international Delphi group of endoscopy experts was established, composed of panellists with strong publication records in the area of endoscopy assessment and/or performance or leaders in endoscopy as evidenced by their roles as opinion makers within organizations. During each Delphi round experts rated potential checklist and global rating items, on a 1 to 5 Likert scale, for their importance as an indicator of the competence of trainees learning to perform colonoscopy. In addition, panellists were asked to identify up to 10 checklist and global rating items that they viewed to be critical indicators of endoscopic competence. After each round responses were summarized by an expert panel, analyzed, and resent to the group in an online survey. Checklist and global rating items were removed from subsequent rounds if they had received a mean rating < 4 and < 5 panellists had assigned a critical rating. The process continued until consensus was reached and items were reduced to a number feasible for use in the clinical setting. Items that ≥ 80% of experts rated as ≥ 4 were included in the final instrument. Results: 55 experts agreed to be part of the Delphi panel: 43 gastroenterologists, 10 surgeons, and 2 endoscopy managers. Participants had completed an average of 632 (range: 50-2600) colonoscopies over the previous year. 67 checklist and 34 global rating items were generated through a systematic literature review and survey of committee members. An additional 2 checklist and 4 global rating items were added by the Delphi panel. 5 rounds of surveys were completed with response rates ranging from 67 to 100%. 7 global ratings and 19 checklist items were included in the final tool. Conclusions: Delphi methodology allowed for the determination of consensus regarding essential items to be included in a tool designed to measure competence in performing colonoscopy. As a next step, we are assessing the measurement properties of the tool in both the clinical and simulated setting.

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A6 PREDICTORS OF THE NEED FOR SECOND INTESTINAL RESECTION IN CHILDREN WITH CROHN’S DISEASE E. Benchimol1, M. Boualit3, J. Wong2, J. Colombel3, C. Gower-Rousseau3 1. Children's Hospital of Eastern Ontario, Ottawa, ON, Canada; 2. Institute for Clinical Evaluative Sciences, Ottawa, ON, Canada; 3. Université Lille, Lille, France. Aims: Early intestinal resection was previously considered a poor prognostic marker in Crohn’s disease (CD). A French study found that surgery performed within 1y of diagnosis in children with CD was not associated with the need for a second surgery1. The aim of this study was to assess whether earlier first surgery and younger age at diagnosis was prognostic of need for a second surgery, using The Ontario Crohn’s and Colitis Cohort. Methods: A validated administrative data algorithm2 identified all children <17y diagnosed 1994-2007 in Ontario with CD with minimum 2 year follow-up period who underwent a first intestinal resection. Multivariable Cox proportionate hazard models assessed whether time from diagnosis to first surgery was predictive of undergoing a second surgery, controlling for confounders: age at diagnosis, gender, income quintile, and rural/urban status at diagnosis. Results: Of 1917 children diagnosed with CD from 1994 to 2007, 28.8% (n=553) underwent a first intestinal resection. Median age of diagnosis was 14y (IQR 11-15), median time to first surgery was 2.1y (IQR 0.5-4.6) and median follow-up duration was 5.4y (IQR 2.8-8.5) following first surgery. Of these, 29% (n=163) patients underwent second surgery, with risk of second surgery/censoring of 14% at 2y, 25% at 5y, and 36% at 10y. Earlier time from diagnosis to first surgery was not associated with second surgery (HR for a 1y decrease 1.05, 95%CI 0.99-1.12). Only younger age at diagnosis (HR for a 1y decrease 1.06, 95%CI 1.01-1.11) and rural residence at diagnosis (HR 1.58, 95%CI 1.05-2.37) were associated with second surgery. Due to significant statistical interactions between follow-up time and the independent variables, analysis was stratified by years of follow-up. Earlier time to first surgery only predicted second surgery at the second (HR 1.10, 95%CI 1.01-1.19) and third (HR 1.11, 95%CI 1.02-1.21) years of follow-up, and then became non-significant in years 4-14 of follow-up. Earlier age at diagnosis was predictive of second surgery in all subgroup analyses, except if only 1y of follow-up. Rural status was predictive of second surgery only in those with 11-14y of follow-up (HR range 1.58-1.59), but not shorter follow-up time (HR range 1.16-1.48). Conclusions: Younger age at diagnosis and rural residence, but not early resection, were associated with increased likelihood of undergoing second surgery, when controlling for other sociodemographic confounders. Due administrative data limitations, clinical predictors could not be assessed. This is the largest study to assess risk of second surgery in CD and confirmed findings from France. <P>References: 1Boualit, Gastroenterol 2011;140:S38, 2Benchimol, Gut 2009;58:1490-7.

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A7 COMPUTER BASED VIRTUAL REALITY COLONOSCOPY SIMULATION IMPROVES REAL LIFE COLONOSCOPY PERFORMANCE K. McIntosh, N. Khanna, J. Gregor Division of Gastroenterology, Department of Medicine, University of Western Ontario, London, ON, Canada. Aims: The advancement of computer technology has led to the development of several virtual reality colonoscopy simulators. The potential benefits as a training tool include the ability to do an unlimited number of procedures with no risk of procedural related complications. Our aim in this study is to determine whether virtual reality simulator training translates into improved patient based colonoscopy performance. Methods: We enrolled 17 residents between PGY2 and PGY4 with no prior colonoscopy experience. They were assigned to be in either the simulator trained group (n=10) or the non-simulator trained control group (n=7). The simulator group completed an average of 16 hours (range 12 - 20) on the Simbionix GI Mentor II colonoscopy simulator prior to patient based colonoscopy. We then evaluated both groups on their first 5 patient based colonoscopies, giving the residents a 15 minute time limit to reach the cecum. Objective outcome measures included the insertion time, depth of insertion and the number of assists required. Preset criteria for assisting fellows included making no forward progress with the scope over a period of 2 minutes. Subjective outcome measures included ratings of pain, attention to discomfort, and technique by the proctor, endoscopy nurse, and patient on a 5 point Likert scale. Results: Within the allotted time, the average distance reached was the hepatic flexure by the simulator group and the transverse colon by the controls (p=0.12). The simulator group required significantly less assists than the control group (1.94 vs. 3.46, p=0.0004), inserted the scope further unassisted (43 cm vs. 25cm, p=0.007), and reached the cecum more often (26% vs. 9%, p=0.052). The simulator group received higher ratings of competence by both the proctors (2.28 vs. 1.86 out of 5, p=0.03) and the endoscopy nurses (2.56 vs. 2 out of 5, p=0.006). There were no significant differences in proctor, nurse or patient rated pain or attention to discomfort. Conclusions: In the initial stages of training, patient based colonoscopy performance is superior in simulator trained residents compared to non-simulator trained residents. The residents completing simulator training were all highly satisfied with the experience and this study indicates that at least 16 hours of training may be required for optimal benefit. As well, the method of providing “assists” to residents for challenging parts of the colonoscopy and returning the scope to them worked extremely well. Employing this technique, allowed the novice residents to perform successful and efficient colonoscopies with a high degree of patient satisfaction.

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A8 INCREASED FREQUENCY OF RISK ALLELES IN A COHORT OF HEALTHY FIRST DEGREE RELATIVES OF CROHN'S DISEASE PATIENTS: A REPORT OF THE CCFC MICHAEL J. HOWARTH GEM PROJECT D. Kevans1, M. Silverberg1, W. Xu2, A. Paterson3, P. Beck4, C. Bernstein4, A. Bitton4, L. Dieleman4, B. Feagan4, A. Griffiths4, H. Huynh4, K. Jacobson4, G. Kaplan4, D. Krause4, K. Madsen4, J. Marshall4, P. Moayyedi4, R. Panaccione4, M. Ropeleski4, E. Seidman4, K. Siminovitch4, D. Snider4, A. Stadnyk4, H. Steinhart1, D. Turner4, B. Vallance4, T. Walters4, K. Croitoru1 1. Zane Cohen Centre for Digestive Diseases, Mount Sinai Hospital, Toronto, ON, Canada; 2. Department of Public Health Sciences, University of Toronto, Toronto, ON, Canada; 3. Genetics and Genome Biology Program, The Hospital for Sick Children Research Institute, Toronto, ON, Canada; 4. GEM Project Team, Toronto, ON, Canada. Aims: First degree relatives (FDRs) of patients with IBD are at increased risk of developing the condition. The GEM Project is a CCFC funded multi-centre study assessing etiological factors in Crohn’s Disease (CD) by studying healthy FDRs of CD subjects. While epidemiological studies have suggested increased genetic susceptibility to IBD in healthy FDRs of CD probands, large scale genotyping of this group has not previously been performed. The aim of this study was to define the CD-associated risk alleles in healthy FDRs of CD. Methods: 870 independent, Caucasian, healthy FDRs were recruited to the GEM project. GEM-FDRs were genotyped for 28 CD-associated SNPs and compared to independent, matched CD (n=870), UC (n=725) and healthy control (n=982) groups from Mount Sinai. A NOD2 risk score was generated to compare the risk of carrying > 1 NOD2 risk allele vs. no risk allele. Using the weighted summary of risk alleles of 15 CD-associated SNPs an overall CD genetic risk score (CDRS) was calculated. Results: Comparing GEM-FDRs and healthy controls (HCs) significant differences in allele frequency were observed for: rs2066847 (NOD2, SNP13), p=1.12 x 10-6; rs3828309 (ATG16L1), p=4.3 x 10-5; and rs2241880 (ATG16L1), p=3.4 x 10-5. Frequency of NOD2 risk allele carriage was greater in FDR vs. HC groups: 1 risk allele, 25% vs. 17% respectively; two risk alleles, 4% vs. 1% respectively. NOD2 risk score was greater in FDR vs. HC groups: OR 1.82, p=9.15 x 10-8. The CDRS for the FDR cohort (19.24) was higher compared to HC (18.45, p=2.2 x 10-6) and UC (18.91, p=0.06) groups, however lower than CD cohort (20.22, p=3.32 x 10-8). Conclusions: We have demonstrated that healthy GEM-FDRs are significantly enriched for CD-associated risk alleles compared with healthy controls. This group therefore is an ideal cohort in which to study the genetic influence of CD-associated risk alleles on microbial and other environmental events involved in the initiation of CD.

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CAG/CCFC Student Prize Paper Presentations Friday, February 24th, 13h00-14h30 CAG Student Prize A9 INTESTINAL MICROBIOTA REGULATE BARRIER FUNCTION AND INTESTINAL TH17 IMMUNITY IN THE NON-OBESE DIABETIC MOUSE. K. Brown1, B. Vallance2, J. Dutz2, D. Gibson1 1. University of British Columbia, Okanagan Campus, Kelowna, BC, Canada; 2. Child and Family Research Institute, Vancouver, BC, Canada. Aims: We have previously shown that non-obese diabetic (NOD) mice have dysfunctional intestinal barriers similar to humans with Type 1 Diabetes (T1D). Th17 cells, originally thought to be pro-inflammatory, have recently been shown to be tolerogenic in the small intestine. Their differentiation is promoted by segmented filamentous bacteria, which confers protection in a T1D model. Since the composition of the intestinal microbiota has been shown to be altered in individuals with T1D, we hypothesize that intestinal microbiota regulate intestinal barrier function and intestinal immunity which contributes to diabetes pathogenesis. The aim of this study is to determine the role of microbiota in regulating intestinal barrier function as well as intestinal Th17 immune responses in the NOD mouse model of T1D. Methods: Non-obese diabetic (NOD) mice spontaneously develop T1D, whereas non-obese resistant (NOR) mice do not. We employed a fecal-oral transfer method in which stool from donor NOD mice was orally gavaged into antibiotic-treated NOR mice and vice versa. This created four groups of 'chimeric' mice: NOD mice with NOD microbiota, NOD with NOR, NOR with NOR, and NOR with NOD. This was used as a model to determine the role of microbiota in mediating intestinal immune responses, intestinal barrier function, and T1D onset. We measured intestinal permeability through FITC-dextran studies and assessed tissues for proteins involved in maintaining intestinal tight junctions. Intestinal tissues were evaluated for inflammatory cytokines and markers of T cell subsets, including Th17 cells. Results: NOR microbiota significantly improves intestinal barrier function in NOD mice, and NOD microbiota decreases barrier function in NOR mice. There is a heightened inflammatory status in the intestinal tissues of NOD mice characterized by an increase in TNF-α and IFN-γ, as well as an increase in chemokines and chemokine receptors involved in T cell migration: Cxcl9, Ccr7, and Cxcr4. Th17-associated cytokines are decreased in NOD mouse intestinal tissues. Conclusions: Microbiota contribute to intestinal pathologies of T1D by mediating intestinal immune responses and intestinal barrier function.

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CAG Student Prize A10 MODULATION OF INTERLEUKIN-8 SECRETION FROM INTESTINAL EPITHELIAL CELLS VIA A GIARDIA CYSTEINE PROTEASE J. Cotton1, A. Bhargava1, J. Ferraz1, P. Beck2, A. Buret1 1. Inflammation Research Network, Calgary, AB, Canada; 2. Gastrointestinal Research Group, Calgary, AB, Canada. Aims: The expression and secretion of the potent neutrophil (PMN) chemoattractant interleukin-8 (CXCL8) by intestinal epithelial cells (IECs) is an early event in acute intestinal inflammation. Current research suggests that certain parasitic organisms can attenuate the induction of acute inflammatory responses. Giardia duodenalis is a non-invasive protozoan parasite of the upper small intestine that can exceed parasite burdens of 106 trophozoites per centimetre of gut. Despite this heavy parasite load, the intestinal mucosa in the majority of Giardia-infected individuals is devoid of signs of overt inflammation. Furthermore, individuals in the developing world that are chronically infected with G. duodenalis have reduced inflammatory scores and are protected against diarrheal disease. The Giardia genome contains at least 20 cathepsin-like genes, most of which have an unknown function(s). The aim of this study was to determine whether G. duodenalis modulates the secretion of CXCL8 by IECs and if this is attributed to Giardia cathepsin-like proteases. Methods: Ex vivo human small intestinal mucosal biopsy tissues and in vitro colonic monolayers (Caco-2 and HCT-8) were co-incubated with G. duodenalis trophozoites (Assemblage A isolates NF, or WB, or Assemblage B isolate GS/M) for 2 hours and subsequently administered pro-inflammatory interleukin (IL)-1β (1.0 ng/mL : 4h), recombinant CXCL8 (rCXCL8) (1.0 ng/ml : 4h), or Salmonella typhimurium (MOI 100:1 : 5h). Samples were processed for various activity assays, qPCR, and Western blotting. Results: Co-incubation of ex vivo human small intestinal biopsy tissues or in vitro monolayers with G. duodenalis trophozoites results in attenuation of IL-1β-induced CXCL8 secretion in an isolate independent manner. Supernatant levels of CXCL8 are also significantly reduced in polarized (HCT-8) and non-polarized (Caco-2) monolayers co-incubated with G. duodenalis trophozoites and subsequently administered S. typhimurium. G. duodenalis trophozoites incubated in the presence or absence of Caco-2 monolayers reduce supernatant levels of rCXCL8. Cysteine protease activity is detected in supernatants when G. duodenalis trophozoites are incubated in the presence and absence of Caco-2 monolayers. Activity based probes show that Giardia trophozoites secrete two cysteine proteases. Inhibition of G. duodenalis-secreted cysteine proteases using the broad-spectrum cysteine protease inhibitor E-64d or the cathepsin-B specific inhibitor CA-074 prevents Giardia-mediated cleavage of CXCL8. Conclusions: A Giardia cathepsin B-like cysteine protease cleaves human CXCL8. This protease may represent a novel anti-inflammatory compound.

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CCFC Student Prize A11 COMMENSAL AND PROBIOTIC BACTERIA INFLUENCE COLITIS SEVERITY IN NOD1-/-;NOD2-/- MICE J. Natividad1, V. Petit2, X. Huang1, G. de Palma3, J. Jury1, Y. Sanz3, D. Philpott4, C. Garcia Rodenas2, K. McCoy1, E. Verdu1 1. McMaster University, Hamilton, ON, Canada; 2. Nestle Research Center, Lausanne, Switzerland; 3. Spanish National Research Council, Valencia, Spain; 4. University of Toronto, Toronto, ON, Canada. Aims: Intestinal bacteria regulate host function and immunity and may contribute to the pathogenesis of inflammatory bowel disease (IBD) in genetically susceptible hosts. Multiple susceptibility genes, including polymorphisms in Nucleotide oligomerization domain (Nod)-like receptor family have been associated with IBD. Here we investigate whether commensal bacteria and the probiotic strain Bifidobacterium breve NCC2950 affect intestinal barrier function and responses to intestinal injury in mice deficient for the Nod1 and Nod2 gene. Methods: Specific-pathogen free (SPF) Nod1-/-;Nod2-/- mice and mice gnotobiotically derived with Altered Schaedler Flora (ASF) were used. SPF Nod1+/-;Nod2+/- littermates (generated by crossing SPF Nod1-/-;Nod2-/- and germ-free C57BL/6 mice) and ASF Nod1+/-;Nod2+/- mice were used as controls. SPF mice were gavaged daily with 109-CFU Bifidobacterium breve NCC2950 for 14 days before colitis induction. Denaturing Gradient Gel Electrophoresis (DGGE) and real time PCR (RT-PCR) were used to assess fecal microbiota. Intestinal permeability was assessed by in vitro and in vivo techniques. Expression of epithelial apical junction proteins, mucin and antimicrobial proteins was assessed by quantitative RT-PCR and immunofluorescence. Acute (5 days) intestinal injury was induced by Dextran Sulfate Sodium (DSS) in drinking water. Results: Under SPF conditions, Nod1-/-;Nod2-/- mice had increased paracellular permeability, a six-fold and eight-fold lower colonic E-cadherin and antimicrobial RegIII-γ RNA expression respectively, compared to Nod1+/-;Nod2+/- littermate controls. These changes were associated with increased colitis severity and higher histological scores in Nod1-/-;Nod2-/- mice compared to Nod1+/-;Nod2+/- mice. DSS-treated Nod1-/-;Nod2-/- mice had an 73% and 174% increase in colonic IL-12p70 and TNF-α expression respectively, compared to Nod1+/-;Nod2+/- controls. B. breve supplementation to SPF Nod1-/-

;Nod2-/- mice as well as ASF colonization of Nod1-/-;Nod2-/- mice, normalized RegIII-γ expression and decreased severity of acute DSS colitis. Conclusions: The intestinal microbiota influences colitis severity in Nod1-/-;Nod2-/- mice. Preventive administration of B. breve NCC2950 to SPF mice increases antimicrobial peptide secretion and attenuates subsequent colitis. Colitis is also attenuated by colonization of Nod1-/-;Nod2-/- mice with a microbiota devoid of pathogens and opportunistic bacteria. The results suggest that specific probiotics with well-determined mechanisms of action, or microbiota imprinting strategies, may prove effective to prevent intestinal inflammation in a genetically predisposed host.

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CCFC Student Prize A12 A NOVEL STRATEGY TO REDUCE THE SEVERITY OF INTESTINAL INFLAMMATION BY DISRUPTING 5-HT7 RECEPTOR SIGNALING J. Kim1, B. Bridle1, J. Ghia1, H. Wang1, Y. Wan1, P. Hedlund2, W. Khan1 1. McMaster University, Hamilton, ON, Canada; 2. The Scripps Research Institute, La Jolla, CA.

NOT PUBLISHED AT AUTHORS REQUEST

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Honorable Mention A13 INTESTINAL SMOOTH MUSCLE CELL PROLIFERATION DECREASES GDNF PRODUCTION T. Han, S. Lourenssen, M. Blennerhassett Queen's Univ., Kingston, ON, Canada. Aims: In TNBS-induced experimental colitis, smooth muscle cells (SMC) initiate proliferation, which normally ceases upon resolution of inflammation. However, intestinal stricturing is a sporadic outcome in this model associated with continued proliferation of SMC and minimal innervation. In the early postnatal rat intestine, myenteric neurons depend on glial-cell line derived neurotrophic factor (GDNF) for survival and axon outgrowth, with GDNF primarily expressed by smooth muscle cells in vivo and in primary cultures in vitro. Since the effect of continued proliferation of adult SMC on GDNF expression is unknown, but might affect expression of this major neurotrophin, we studied this in smooth muscle cell lines from the adult rat colon. Methods: Circular smooth muscle cells (CSMC) from the mid-descending colon of adult rats were cultured to passage 2 (P2) or 10 (P10). qPCR and western blotting were used to evaluate GDNF mRNA and protein. As a bioassay for neurotrophic factor expression, myenteric neurons were isolated from neonatal intestine and plated onto confluent cultures of adult CSMC for 48 hr, with evaluation of neuronal survival by immunocytochemistry for HuD and SNAP-25, to detect neurons and axons, respectively. Alternatively, conditioned medium (CM) from P2 or P10 CSMC was added to cultures of neonatal neurons for 48 hr and evaluated similarly. Results: The initiation of tissue culture caused expression of GDNF in adult CSMC, with qPCR showing a 5-fold increase in mRNA by 48 hr in vitro. However, these levels decreased with extended growth in vitro, with analysis of western blotting showing a 3-fold decrease in expression per cell (IOD per CSMC) in P10 cultures relative to P2. Neuronal survival was increased by 225+6% (p<0.05 vs control) when co-cultured on P2 CSMC, while P10 CSMC were only able to increase neuron survival by 123+16% (p>0.05). Addition of the positive control of GDNF peptide (50 ng/mL) to P10 CSMC enhanced neuronal survival to a level similar to that seen with P2 CSMC, implying a critical absence of this diffusible factor. In support, CM from P2 CSMC significantly increased neuron survival by 210+25% after 48 hr, while P10 CM was ineffective (114+20%; p<0.05 relative to control DMEM). Conclusions: The onset of proliferation of CSMC initially increases expression of GDNF, but this declines with increasing passage number in vitro. This translates into a failure to support myenteric neuronal survival and growth, correctable by addition of exogenous GDNF. In vivo, a decrease in GDNF expression by extensively proliferating SMC (as in chronic inflammation) may reduce their capacity to support enteric neuronal survival and innervation of target tissue, which could contribute to the pathology of stricture formation. Supported by CCFC and NSERC, and a graduate scholarship (TYH) from CIHR.

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Honorable Mention A14 PHYSIOLOGICAL AND PATHOLOGICAL EXOCYTOSIS IN ACINAR CELLS IN HUMAN PANCREAS SLICES T. Liang1, S. Dolai1, N. Karimian1, M. Cattral2, E. Winter2, H. Gaisano1 1. University of Toronto, Department of Medicine, Toronto, ON, Canada; 2. Toronto General Hospital, Toronto, ON, Canada. Aims: Acute pancreatitis (AP) is a necro-inflammatory disease of the exocrine pancreas which causes very high morbidity and mortality, at considerable financial costs to the healthcare system. Much animal work directed at AP has employed dispersed acini assays, leading to a number of postulated mechanisms. However, there is no effective specific treatment for AP because these postulated disease mechanisms could not be directly tested on human pancreatic tissue. We developed the human pancreas slice preparation to examine genuine pancreatic acinar cell biology and the mechanisms of AP in their true native in situ state for the first time. Methods: These human pancreas sample firstly infused with 37°C low-melting agarose gel, then excised, trimmed and sliced very thinly (~100μm) with a vibratome. Agarose gel renders the soft pancreas organ sufficiently firm to enable vibratome slicing, with its porous matrix providing ready access to buffer and ensuring optimal tissue oxygenation and nutrition, thus preserving acinar cell health for long periods. We now deployed the slice preparation to examine pancreas exocrine function by amylase secretion assay and real-time exocytosis imaging. Results: Amylase secretion. Human pancreatic slices were stimulated (1 slice per tube) with different concentrations of CCh as indicated for 1hr. Amylase release was calculated as % of total amylase content of each slice. We saw dose-dependent CCh-stimulated amylase secretion even at low 1 µM CCh, maximal reached at 10 µM CCh, which is notably more sensitive than mouse pancreas slices, and dose-dependent supramaximal inhibition of secretion at 100 µM CCh and 2 mM CCh. FM1-43 imaging of Apical and basolateral exocytosis. We had reported using lipophilic dye FM1-43 on dispersed acini which partitions into and fluoresce in lipid membranes and hence lighting up the plasma membrane (PM) and progressively deeper layers of fusing zymogen granules. We observed maximal 10 µM CCh stimulation caused apical exocytosis in acini within pancreas slices. Supramaximal 2 mM CCh stimulation blocked apical exocytosis and progressively increased green FM1-43 staining along the basolateral PM of several adjacent acinar cells that border the interstitial space. This indicates basolateral exocytosis, with emptying of zymogens into the interstitial space expected to lead to interstitial pancreatitis, previously postulated to account for the increased severity of AP. Conclusions: These results demonstrating for the first time our use of live human pancreas slices to direct clinical relevance since cholinergic stimulation is the primary stimulant of human exocrine pancreas.

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Viral Hepatitis Session 1 Friday, February 24, 13h00-14h30

CASL Student Research Prize A15 OCCLUDIN, CD81 AND CD5 ARE CRUCIAL FOR HCV INFECTION OF T CELLS, WHILE CLAUDIN-1 AND SR-B1 ARE DISPENSABLE M. Sarhan, T. Michalak Memorial University, St.John's, NF, Canada. Aims: Infection of T cells with wild-type HCV, although occurring at low levels, has been well documented. The phenomenon of HCV persistence might be attributed to HCV latency in immune cells including T cells. However, factors involved in HCV entry and replication in T cells are not yet identified. To determine if the previously proposed HCV receptors may play a role in T cell infection, we characterized the expression of CD81, SR-B1, CD5, claudin-1 (CLDN-1), and occludin (OCLN) in HCV-susceptible and nonsusceptible lymphoid cells in comparison to hepatoma-derived cells (Huh7.5 and HepG2 cells) and primary human hepatocytes (PHH). Moreover, we identified their level of expression before and after exposure to HCV. Methods: HCV-susceptible Molt4, Jurkat, affinity-purified human T cells, total PBMC and HCV-resistant PM1and CEM T cells were examined for the expression of different HCV candidate receptors in comparison to hepatoma-derived cells and PHH as well as 293-HEK cells. Results: All cells except HepG2 cells express CD81. Although, SR-B1 mRNA was expressed by all cells examined, only HCV-nonsusceptible T cells (PM1 and CEM) as well as hepatoma-derived cells, PHH and 293-HEK cells expressed SR-B1 protein. Interestingly, OCLN was expressed only by HCV-susceptible T cells, however, the level of expression was significantly lower than hepatoma derived cells, PHH and 293-HEK cells. CLDN1 was not expressed by all lymphoid cells tested except the HCV-nonsusceptible PM1 cells. CD5 was only expressed by HCV-susceptible lymphoid cells and no protein was expressed by hepatoma-derived cells, PHH and 293-HEK cells. Blocking of CD81 or CD5 using mAb decreased the susceptibility of T cells to HCV infection. Further, knocking down CD5 and OCLN using shRNA-encoding lentiviral particles were associated with inhibition of HCV infection of T cells. Consequently, infection of T cell lines with plasma-derived HCV downregulated CD81 and OCLN but upregulated CD5, but no change was detected in the level of expression of SR-B1 mRNA. Conclusions: While no association was found between the expression of CLDN-1 or SR-B1 and HCV infectivity of T cells, OCLN, CD81 and CD5 were found to be indispensable, suggesting a role of these molecules in HCV lymphotropism. In addition, in vitro infection of T cells with HCV tends to downregulate CD81 and OCLN which may prevent T cells superinfection, but upregulates CD5 which may offer resistance of infected T cells to apoptosis. Our findings reveal specific cellular factors used by HCV to inhabit T cells which may affect the future strategies for HCV treatment.

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A16 STABILIZATION OF THE HEPATITIS C VIRUS GENOME BY AN UNCONVENTIONAL MICRORNA-TARGET RNA INTERACTION S. Sagan, E. Machlin, P. Sarnow Stanford University, Stanford, CA. Aims: Hepatitis C virus (HCV) infection is a rapidly increasing global health problem with over 170 million people infected worldwide. A highly-abundant, liver-specific microRNA, miR-122, interacts with two sites within the 5’ non-coding region (NCR) of the HCV genome. This is an unusual microRNA interaction in that it promotes HCV RNA accumulation. This interaction is important for maintaining HCV RNA levels in both HCV-infected cells and in the liver of infected chimpanzees, making miR-122 an attractive antiviral target. In fact, antisense locked nucleic acid inhibitors of miR-122 have currently gone through Phase II clinical trials for the treatment of HCV (Santaris Pharma a/s). Thus, it is imperative to gain information on the mechanism of this interaction and how the complex between miR-122 and the viral RNA differs from the microRNAs normal cellular targets. In addition, further elucidation of this complex will help identify novel antiviral targets. Methods: Viral RNA decay assays were performed by treating HCV RNA-electroporated Huh-7 cells with a polymerase inhibitor during sequestration or supplementation of miR-122. The effect of supplementation with exogenous miR-122 mimetics was compared to supplementation with an irrelevant microRNA mimetic. In addition, the effect of sequestration of miR-122 using complementary locked nucleic acids (LNAs) was compared with that of sequestering an irrelevant microRNA using complementary LNAs. Additionally, we have explored novel methods for purification of the unique miR-122:HCV RNA complexes from Huh-7 cells. Results: We find that cells supplemented with miR-122 mimetics had slowed viral RNA decay compared to cells supplemented with control microRNA mimetics. In contrast, sequestration of miR-122 using complementary LNAs, results in a faster rate of viral RNA decay than in the presence of a control LNA. In addition, we find that small tags can be tolerated in miR-122:HCV RNA complexes for affinity purification and analyses of these complexes from Huh-7 cells. Conclusions: Our recent findings that miR-122 interacts with the 5’ terminus of the HCV genome and produces 3’ overhanging extensions suggests novel hypotheses regarding its mechanism of action. Binding of miR-122 to the 5’ terminus of the HCV genome may protect the HCV genome from attack by nucleases or cellular sensors of viral RNA. Our results support a model whereby miR-122 protects or stabilizes the HCV genome. Affinity purification and analyses of miR-122:HCV RNA complexes will further elucidate the host or viral factors associated with this complex and will identify novel antiviral targets to limit HCV accumulation.

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A17 DENDRITIC CELLS ACTIVATION DURING ACUTE HCV S. Pelletier, E. Said, P. Ancuta, J. Bruneau, N. Shoukry Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Hôpital St-Luc, Montréal, QC, Canada. Aims: Dendritic cells (DCs) are the major antigen-presenting cells (APCs) of the immune system. They capture and process antigens and migrate between sites of infection and lymph nodes to initiate adaptive T cell responses. DCs rapidly differentiate into mature DCs in response to various “danger” signals like toll like receptor (TLR) ligands. This maturation process involves up-regulation of several co-stimulatory molecules to optimize antigen presentation and T cell activation. The role and function of DCs in chronic HCV infection remains highly controversial. Various groups have reported that DCs are defective in chronic HCV in particular in response to TLR ligands, while others have demonstrated that they are functional. We have previously studied the role of NK cells during acute HCV but the role of DCs during the acute phase has not been studied yet. Methods: To examine the function of myeloid DCs (mDC) we have optimized a flow cytometry based method to study the frequency, maturation status, cytokine production and endocytic capacity of mDCs in response to a TLR4 ligand (LPS) and a TLR8 ligand (ssRNA40). mDC were studied in a cohort of intravenous drug users exposed to HCV. Three groups were studied: acute HCV with chronic evolution (n = 8), acute resolving HCV (n = 5) and healthy donors (n = 7). Three time points were studied: early acute (2 months after estimated time of infection), late acute (8 months) and follow-up (1-2 years). Results: We observed a trend towards a lower frequency of CD86+ cells in spontaneous resolvers and consequently a significant up-regulation of CD86 after LPS and ssRNA40 stimulation compared to chronics during the early acute phase. In addition, spontaneous resolvers had an overall higher production of TNFa after ssRNA40 stimulation compared to chronics and this was even more significant during the follow-up phase. Finally, we observed increased TNFa, IL-12 and IL-6 production by spontaneous resolvers after ssRNA40 stimulation during the early acute phase compared to healthy donors and we also observed a trend compared to chronics. Conclusions: In conclusion, mDCs from spontaneous resolvers have an overall higher functional potentiel compared to chronics, but also compared to healthy donors especially during the early acute phase. In perspective, we expect to establish a correlation between NK and DC function as these two cell types activate each other in a reciprocal manner.

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A18 COMPARATIVE STUDY OF TWO HEPATITIS C VIRUS STRAINS IN RESPONSE TO EXOGENOUS INTERFERON TREATMENT IN CHIMERIC MICE R. Chen1, C. Wilkins2, M. Gale Jr2, L. Tyrrell1 1. Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada; 2. Department of Immunology, University of Washington, Seattle, WA. Aims: In donor-matched SCID/beige-uPA chimeric mice (Nat Med. 2001): 1. To compare the study of interferon (IFN) responses induced by 2 clinical isolates of HCV with distinct sensitivities to IFN-based therapy (responder versus null-responder); 2. To study, in parallel, the responses of these 2 HCV strains to exogenous IFN treatment. Methods: The mice, repopulated with single donor human hepatocytes, were divided into 3 groups. Mice in the 1st group were infected with a genotype (gt)-2 HCV strain isolated from a patient who achieved a SVR after pegIFN & ribavirin treatment. In the 2nd group, mice were infected with gt-1 HCV from a patient in whom pegIFN and ribavirin produced less than 1 log drop in viral titers (a null responder). Four weeks after infection, half number of mice in each group received a treatment with IFNα or saline for 2 weeks. A 3rd group of mice were mock infected followed by the treatment of IFN or saline. Results: Both HCV strains produced stable viremia. Surprisingly, unlike the previous results in our SCID-uPA mice which lack the beige trait (PLoS Pathogen. 2006), we did not detect a strong IFN response in mice chronically infected with either HCV strain based on gene-expression analysis. This result was further confirmed in mice produced with hepatocytes from 2 other donors but infected with the same gt-1 HCV strain. Upon treatment with IFN, no significantly declined viremia was observed in the mice infected with gt-1 HCV strain. This is consistent with the non-responsiveness observed in the patient. However, in the mice inoculated with the gt-2 HCV strain, IFN treatment for 2 weeks reduced viral serum levels up to 3-4 logs - similar to the result seen in the patient. Comparative gene expression analysis results indicated that both strains of HCV were able to significantly suppress the level of IFN stimulated genes (ISGs). Interestingly, the responder strain had a similar level of suppression of ISGs as the null-responder strain. Conclusions: In our SCID/beige-uPA chimeric mice produced with the 3 donors in this study, 2 different strains of HCV failed to induce a significant IFN response; Two HCV strains isolated from 2 patients with distinct outcomes to IFN-based treatment were studied. Upon exogenous IFN treatment, the viremia changes in mice infected with the 2 viral strains were consistent with the responses seen in the patients treated with pegIFN & ribavirin; Comparative gene expression analysis results indicated that both strains of HCV were able to suppress ISG expression at comparable levels, indicating that other viral factors play important roles in determining the outcomes of IFN-based therapy since the hepatocytes used in this study were from a single donor.

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A19 PROMOTER ANALYSIS OF IL-28B/IFNλ3 AT THE RS12979860 SNP B. Thomas, M. Joyce, K. Fischer, L. Tyrrell Li Ka Shing Institute of Virology, Dept. of Medical Microbiology and Immunolgy, University of Alberta, Edmonton, AB, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A20 VX-222/TELAPREVIR IN COMBINATION WITH PEGINTERFERON-ALFA-2A AND RIBAVIRIN IN TREATMENT-NAÏVE GENOTYPE 1 HCV PATIENTS TREATED FOR 12 WEEKS: ZENITH STUDY, SVR12 INTERIM ANALYSIS A. Di Bisceglie1, M. Sulkowski2, E. Gane3, I. Jacobson4, K. Alves5, M. Koziel5, C. De Souza5, T. Kieffer5, S. George5, M. Rosario5, R. Kauffman5, D. Nelson6 1. Saint Louis University School of Medicine, Saint Louis, MO; 2. Johns Hopkins University, Baltimore, MD; 3. Auckland City Hospital, Auckland, New Zealand; 4. Weill Cornell Medical College, New York, NY; 5. Vertex Pharmaceuticals Incorporated, Cambridge, MA; 6. University of Florida College of Medicine, Gainesville, FL. Aims: ZENITH is assessing safety and efficacy of VX-222 with telaprevir (T), either alone (DUAL), with ribavirin (R) (TRIPLE) or with peginterferon (P) and ribavirin (QUAD) in chronic HCV genotype 1 treatment-naïve patients. Methods: A Wk 24 interim analysis of the QUAD regimen is shown. QUAD patients received either VX-222 100 mg (Arm C, n=29) or 400 mg (Arm D, n=30) plus T 1125 mg bid, P 180 μg/wk, and R 1000-1200 mg/day for 12 wks. Patients with undetectable HCV RNA at Wks 2 and 8 were eligible to stop all treatment at Wk 12; those with detectable HCV RNA received 24 wks of PR. Results: No viral breakthrough was observed in either QUAD arm. 11/29 and 15/30 patients from arm C and D, respectively, were eligible to stop treatment at Wk 12. Of those, 82% (9/11) and 93% (14/15), respectively achieved SVR12, the remaining 3 patients relapsed. 16/29 (arm C) and 13/30 (arm D) patients did not meet the short duration criteria and received 24 wks of treatment; in addition, 2 patients in each arm discontinued treatment prior to the Wk 2 and/or Wk 8 assessment. 83% (15/18) and 87% (13/15) of patients who were not eligible for short duration treatment achieved SVR12; of the remaining 5 patients, 1 relapsed after discontinuing treatment at Wk 1, 1 had detectable HCV RNA after discontinuing treatment at Day 4, 2 discontinued the study with undetectable HCV RNA, and 1 patient’s SVR12 assessment was unavailable. Overall, SVR12 was 83% (24/29) and 90% (27/30) in arms C and D, respectively. Most frequent AEs were: fatigue 56% (mild 69%), nausea 49% (mild 72%), diarrhea 48% (mild 89%), anemia 37% (mild 36%), pruritus 34% (mild 65%), and rash 31% (mild 72%). Severe AEs occurring in at least 2 patients were: neutropenia (5.1%), hypomagnesemia (3.4%), and anemia (3.4%). Three patients (10%) in each arm discontinued all study drugs due to AEs during the overall treatment phase; 2 patients in each arm discontinued treatment before Wk 12, 1 patient in each arm discontinued treatment while on PR only. Conclusions: In this interim analysis, QUAD VX-222/T/PR therapy was associated with a high rate of antiviral activity (SVR12) in genotype 1 treatment-naïve patients and a safety profile similar to that of T/PR, with, however a higher rate of mild GI events. There was no on-treatment viral breakthrough and 38-50% of patients were able to receive only 12 wks of therapy. Overall, SVR12 was 83-90%.

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CAG Paper Session - Epithelia out of Control: Cellular Mechanisms of Colon Cancer Friday February 24, 15h00-17h00 A21 DIFFERENTIAL EXPRESSION OF NUCLEOPHOSMIN (NPM1) IN ADENOMAS AND COLORECTAL CANCERS (CRC), AND ITS POTENTIAL ROLE IN TUMORIGENESIS J. Wong, M. Hasan, S. Chan, D. Schaeffer, D. Owen, I. Tai University of British Columbia, Vancouver, BC, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A22 SHP-2 PROTECTS INTESTINAL EPITHELIAL CELLS AGAINST ONCOGENIC STRESS BY INDUCING SENESCENCE. G. Coulombe, C. Leblanc, N. Rivard Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: SHP-2 (Src homology-2 domain-containing phosphatase 2) is a tyrosine phosphatase ubiquitously expressed. Previous work done in SHP-2-/- fibroblasts demonstrated its implication in proliferation as well as in many signaling pathways such as the Ras-Raf/MEK/ERK, PI3K/AKT and Jak/STAT pathways known for their function in this process. Although SHP-2 is highly expressed in the intestinal epithelium, its role in the proliferation of intestinal epithelial cells has never been investigated. Methods: Recombinant lentiviruses encoding anti-SHP-2 short hairpin RNA (shRNA) were developed to stably suppress SHP-2 mRNA levels in human non immortalized intestinal epithelial crypt cells (HIEC). Using the Cre/loxP system, mice with intestinal epithelial cell-specific SHP-2 deletion were generated (SHP-2IEC-KO) and these mice were bred with APCMin/+ mice (SHP-2IEC-KO/APCMin/+). Western blots were performed in intestinal mucosa enrichments from mice or total cell extracts. Proliferation was evaluated by BrdU incorporation or by immunofluorescence against PCNA protein. Results: 1- Protein levels of SHP-2 were markedly reduced in HIEC stably expressing a shRNA targeting SHP-2, in contrast to HIEC expressing a control shRNA. 2- SHP-2 silencing in HIEC rapidly resulted in G1 arrest and in increased levels of the cell cycle inhibitor p21. 3- This proliferation arrest was associated with senescence as visualized by the detection of senescence-associated β-galactosidase activity as well as by the increase of p53 and phospho-histone H2AX levels. 4- SHP-2IEC-KO mice were born at the expected Mendelian ratio and no difference in body weight was observed at birth. 5- As visualized by PCNA staining, cell proliferation was not altered in the colon of mutant mice aged of one day while a marked increase was observed in mice aged of two weeks and one month, in comparison to control mice. 6- Signaling pathways known to regulate colonic cell proliferation such as the Jak/STAT3 and the Wnt/β-catenin pathways were hyperactivated in the intestinal epithelium of young SHP-2IEC-KO mice. 7- Finally, SHP-2 epithelial deficiency severely enhanced intestinal tumor load in ApcMin/+ mice. Conclusions: Our results demonstrated that the loss of SHP-2 expression induces senescence in normal human intestinal epithelial cells in culture; by contrast, SHP-2 deficiency in mouse intestinal epithelium promotes intestinal crypt cell proliferation and formation of polyps in the absence of the tumor suppressor APC. These results suggest that SHP-2 may negatively control mitogenic signals in intestinal epithelial crypt cells, hence protecting the cells against oncogenic stress.

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Viral Hepatitis Session 2 Friday, February 24, 15h00 - 16h30 A23 FUTILITY RULES IN TELAPREVIR COMBINATION TREATMENT N. Adda1, L. Gritz1, T. Kieffer1, D. Bartels1, S. De Meyer2, F. Tomaka3, L. Bengtsson1, I. Jacobson4, R. Kauffman1, G. Picchio3 1. Vertex Pharmaceuticals Incorporated, Cambridge, MA; 2. Tibotec BVBA, Beerse, Belgium; 3. Tibotec Incorporated, Titusville, NJ; 4. Weill Cornell Medical College, New York, NY. Aims: Futility rules during peginterferon (P) and ribavirin (R) treatment of hepatitis C prevent needless additional drug exposure in patients who have little chance of achieving a sustained virologic response (SVR). Treatment with telaprevir (T) in combination with PR required the re-evaluation of futility rules with an additional need to minimize the evolution of telaprevir-resistant HCV variants in patients who may not respond to therapy. Preliminary futility rules had been established based on Phase 2 studies. Methods: Retrospective data analyses from the three Phase 3 trials were performed for patients assigned to treatment with 12 weeks of telaprevir with PR followed by either 12 or 36 additional weeks of PR (treatment-naïve, N=903) or 36 weeks of PR (treatment-experienced, N=266). We correlated on-treatment HCV RNA levels and SVR to define the optimal HCV RNA thresholds (>100 IU/mL or >1000 IU/mL) and timepoints (Weeks 4, 6, 8,12) to identify patients unlikely to achieve SVR. Results: In the three Phase 3 trials, 1.6% (14/903) of treatment-naïve patients, 0.7% (1/145) of prior relapsers, no (0%, 0/49) prior partial responders, and 14% (10/72) of prior null responders had HCV RNA levels >1000 IU/mL at Week 4. None of the 25 patients with HCV RNA levels >1000 IU/mL at Week 4 achieved an SVR with continued PR treatment (telaprevir was discontinued per protocol). Furthermore, 24/25 of these patients reached their HCV RNA nadir at or prior to Week 4, typically at Week 2, with subsequent increase in HCV RNA levels by Week 4. Among 16/903 treatment-naïve patients and 7/266 treatment-experienced patients who had HCV RNA levels between 100 and 1000 IU/mL at Week 4, 22% (5/23) achieved an SVR with continued treatment. Conclusions: Clinical data from Phase 3 trials showed that a futility rule of >1000 IU/mL at Week 4 best identified patients unlikely to achieve an SVR; no patients who met this criteria achieved an SVR with continued peginterferon/ribavirin treatment. Furthermore, the vast majority of these patients had reached their HCV RNA nadir and were experiencing viral breakthrough by Week 4. An additional futility rule of >1000 IU/mL at Week 12 replaced the previously established futility rule of <2 log10 decrease in HCV RNA levels. Therefore, the recommended futility rules benefit both treatment-naïve and treatment-experienced patients by preventing unnecessary exposure to telaprevir and peginterferon/ribavirin treatment in those who are unlikely to achieve a sustained virologic response.

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A24 REALIZE TRIAL FINAL RESULTS: TELAPREVIR-BASED REGIMEN FOR GENOTYPE 1 HEPATITIS C VIRUS INFECTION IN PATIENTS WITH PRIOR NULL RESPONSE, PARTIAL RESPONSE OR RELAPSE TO PEGINTERFERON/RIBAVIRIN S. Pol1, S. Zeuzem2, E. Lawitz3, M. Diago4, S. Roberts5, R. Focaccia6, Z. Younossi7, G. Foster8, A. Horban9, P. Pockros10, P. Andreone11, R. van Heeswijk12, S. De Meyer12, D. Luo13, G. Picchio13, M. Beumont12 1. Assistance Publique-Hôpitaux de Paris, Hôpital Cochin, Paris, France; 2. Johann Wolfgang Goethe University Medical Center, Frankfurt am Main, Germany; 3. Alamo Medical Research, San Antonio, TX; 4. Hospital General de Valencia, Valencia, Spain; 5. Department of Gastroenterology, Alfred Hospital, Melbourne, VIC, Australia; 6. Emilio Ribas Infectious Diseases Institute, São Paulo, Brazil; 7. Center for Liver Disease, Inova Fairfax Hospital, Falls Church, VA; 8. Queen Mary University of London, Institute of Cell and Molecular Science, London, United Kingdom; 9. Medical University of Warsaw, Wolska, Warsaw, Poland; 10. Scripps Clinic and The Scripps Research Institute, La Jolla, CA; 11. Università di Bologna, Bologna, Italy; 12. Tibotec BVBA, Beerse, Belgium; 13. Tibotec Inc., Titusville, NJ. Aims: REALIZE evaluated telaprevir (T) in combination with peginterferon/ribavirin (PR) in well-characterized prior PR treatment-failure patients, including non-responders (null- and partial-responders) and relapsers. Methods: REALIZE was a randomized, international, multicentre, double-blind, placebo-controlled trial to evaluate the efficacy, safety and tolerability of T (750 mg q8h) plus P (180 μg/week) and R (1000-1200 mg/day) compared with PR alone in genotype 1 HCV-infected patients with prior PR treatment failure. The treatment arms (randomized 2:2:1, stratified by viral load and type of prior response) were: 1) T/PR for 12 weeks, followed by PR for 36 weeks (T12PR48); 2) PR for 4 weeks followed by T/PR for 12 weeks, then PR for 32 weeks (Lead-in T12PR48); 3) PR for 48 weeks (PboPR48). The primary objective was to evaluate the superior efficacy of the T/PR arms for non-responders and relapsers compared to PR. Secondary objectives included the evaluation of a lead-in, and efficacy in prior null- and partial-responders separately. ESAs were not allowed for anemia management. Results: 70% of patients were male, 93% were Caucasian, 26% had cirrhosis, and 89% had baseline HCV RNA ≥800,000IU/mL. Adverse events (AEs) reported most frequently with telaprevir were fatigue, pruritus, rash, nausea, influenza-like illness, anemia, and diarrhea. The most common reasons for premature telaprevir discontinuation due to AEs were rash (4%) and anemia (3%). Conclusions: T-based therapy had a superior efficacy than PR in all prior treatment-failure populations studied. A lead-in did not significantly impact SVR rates. The safety profile in prior treatment-failure patients was consistent with that in treatment-naïve patients.

Prior Relapsers Prior Partial-responders Prior Null-responders

n/N (%) SVR

Virological failure/stopping

rule Relapse SVR

Virological failure/stopping

rule Relapse SVR

Virological failure/stopping

rule Relapse

T12PR48 (with or without Lead-in)

245/286 (86)* 3/286 (1) 19/273

(7) 55/97 (57)* 18/97 (19) 17/75

(23) 46/147

(31) 76/147 (52)* 17/66 (26)

PboPR48 16/68 (24) 18/68 (26) 30/46

(65) 4/27 (15) 19/27 (70) 0/4 (0) 2/37 (5) 31/37 (84) 3/5 (60)

*P<0.001 compared to PboPR48

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A25 SUSTAINED VIROLOGIC RESPONSE RATES AND VIRAL RESISTANCE PROFILES IN PATIENTS TREATED WITH A TELAPREVIR-BASED REGIMEN REGARDLESS OF LIVER FIBROSIS STAGE A. Di Bisceglie1, P. Marcellin2, J. Sullivan3, M. Fried4, T. Kieffer3, G. Dusheiko5, E. Martin3, D. Nelson6, C. Wright3, S. George3, L. Bengtsson3, D. Bartels3, G. Everson7, N. Adda3 1. Saint Louis University School of Medicine, Saint Louis, MO; 2. University of Paris Clichy, Clichy, France; 3. Vertex Pharmaceuticals Incorporated, Cambridge, MA; 4. University of North Carolina at Chapel Hill, Chapel Hill, NC; 5. Royal Free and University College, London, United Kingdom; 6. University of Florida, Gainesville, FL; 7. University of Colorado Denver, Aurora, CO. Aims: ADVANCE and ILLUMINATE were Phase 3 randomized studies that evaluated the safety and efficacy of telaprevir (T) in combination with PR in treatment-naïve genotype 1 HCV patients. In this pooled analysis of ADVANCE patients and ILLUMINATE patients (T12PR N=903, PR N=361), we evaluated the effects of liver fibrosis stage on response to treatment and occurrence of telaprevir-resistant variants. Methods: We compared the virologic response rates of T12PR therapy (ADVANCE/ILLUMINATE) and PR therapy (ADVANCE) between patients with no/minimal or portal fibrosis (F0-F2) and patients with bridging fibrosis or cirrhosis (F3-F4). In patients treated with T12PR who failed to achieve a sustained virologic response (SVR), the presence of low- or high-level resistant variants, determined by viral population sequencing, was analyzed by pretreatment fibrosis stage. Results: Efficacy outcomes after T/PR treatment were improved over PR, regardless of fibrosis stage (see table). In patients who failed to achieve SVR and had sequence data available (n=156), resistant variants occurred at similar rates and with similar resistance phenotypes between fibrosis stages (low-level: 38% in F0-F2, 43% in F3-F4; high-level: 38% in F0-F2, 44% in F3-F4). In patients with detectable resistant variants after failure and with follow-up sequence data available (n=105), median time-to-loss of resistant variants was 9 months in F0-F2 and 10 months in F3-F4. Conclusions: Telaprevir-based therapy improved SVR rates compared to PR alone regardless of liver fibrosis stage (+29%, F0-F2; +30%, F3-F4). Within a treatment group, virologic failure and relapse rates were higher in patients with bridging fibrosis or cirrhosis than in those with no/minimal or portal fibrosis. T12PR patients who failed to achieve SVR had similar resistance profiles and median time-to-loss of resistant variants, regardless of the pre-treatment liver disease stage.

Liver Fibrosis Stage Treatment eRVR, n (%)

EOT, n (%)

SVR, n (%)

Relapse†, n (%)

VF, n (%)

T12PR (N=681) 444 (65) 602 (88) 520 (76) 38 (6) 39 (6) No/Minimal or Portal Fibrosis (F0-

F2) PR (N=288) 25 (9) 189 (66) 134 (47) 50 (26) 84 (29)

T12PR (N=222) 121 (55) 181 (82) 139 (63) 26 (14) 27 (12)

Bridging Fibrosis or Cirrhosis (F3-F4)

PR (N=73) 4 (5) 40 (55) 24 (33) 14 (35) 31 (42)

†Denominator is number of patients with HCV RNA undetectable at EOT

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A26 RESPONSE-GUIDED TELAPREVIR COMBINATION TREATMENT IN GENOTYPE 1 CHRONIC HEPATITIS C PATIENTS WHO HAD PRIOR RELAPSE TO PEGINTERFERON ALFA-2A/RIBAVIRIN N. Adda1, A. Muir2, B. Adiwijaya1, F. Poordad3, L. Gritz1, L. Bengtsson1, D. Luo4, G. Picchio4, R. Kauffman1 1. Vertex Pharmaceuticals Incorporated, Cambridge, MA; 2. Duke Clinical Research Institute, Durham, NC; 3. Cedars-Sinai Medical Center, Los Angeles, CA; 4. Tibotec BVBA, Beerse, Belgium. Aims: Phase 2 (PROVE3 and Study 107) and Phase 3 (ADVANCE, ILLUMINATE, and REALIZE) telaprevir (T) studies have indicated that pts with relapse to a prior peginterferon/ribavirin (PR) therapy had high on-treatment response and sustained virologic response (SVR) rates, comparable to the SVR rates in treatment-naïve pts. The aim of this post-hoc analysis was to determine whether a response-guided telaprevir treatment regimen is warranted in pts with relapse to prior PR therapy. Methods: A post-hoc analysis of SVR and relapse rates was performed in pts with prior relapse according to treatment duration and undetectable HCV RNA at weeks 4 and 12 (eRVR), and compared with treatment-naïve pts. Additionally, a viral dynamic model was developed to predict SVR rates by different PR treatment durations in both treatment-naïve and prior relapse pts. Results: Baseline characteristics and demographics in prior relapsers who had eRVR were similar to treatment-naïve pts. In addition, early viral responses at weeks 4 and 12 were similar between T12PR48 in prior relapsers and T12PR24 in treatment-naïve pts. Relapse rates in treatment-naïve pts with eRVR were 6% (T12PR24) and 1% (T12PR48) in ILLUMINATE. In prior relapsers, the overall relapse rate was 7% in REALIZE. In prior relapsers with eRVR, the relapse rate was 7% (2/28) and 0% (0/24) in T12PR24 pts in PROVE3 and Study 107, respectively. The model predicted that the differences in SVR rates between T12PR regimens with and without response-guided PR duration in both treatment-naïve pts and in prior relapsers were similar (1-2%), consistent with observed clinical data. Conclusions: Among prior relapse pts who had eRVR and were treated with 24-week telaprevir combination treatment, SVR rates were comparable to or higher than those in treatment-naïve pts, and relapse rates were low. Modeling predictions and the observed clinical data support the use of response-guided therapy (24 weeks of treatment for pts with eRVR; 48 weeks of treatment for pts without eRVR) in prior relapsers. SVR Rates in Treatment-naïve Patients and Prior Relapsers with eRVR

T12PR24 n/N (%) T12PR24 n/N (%)

Treatment-naïve ADVANCE 189/212 (89) NA

ILLUMINATE 149/162 (92) 140/160 (88) Prior Relapse

PROVE3 25/28 (89) NA Study 107 24/24 (100) NA REALIZE NA 207/218 (95)

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A27 TELAPREVIR COMBINATION WITH PEGINTERFERON ALFA-2A/RIBAVIRIN IN HCV/HIV COINFECTED PATIENTS: 24-WEEK TREATMENT INTERIM ANALYSIS K. Sherman1, J. Rockstroh2, D. Dieterich3, V. Soriano4, P. Girard5, S. McCallister6, N. Adda6, B. Adiwijaya6, L. Mahnke6, M. Sulkowski7 1. University of Cincinnati College of Medicine, Cinicinnati, OH; 2. University of Bonn, Bonn, Germany; 3. Mount Sinai School of Medicine, New York, NY; 4. Hospital Carlos III, Madrid, Spain; 5. Hôpital St Antoine, Paris, France; 6. Vertex Pharmaceuticals Incorporated, Cambridge, MA; 7. Johns Hopkins University School of Medicine, Baltimore, MD. Aims: In an ongoing 2 Part, randomized, double-blind, placebo-controlled, parallel-group, Phase 2 trial of telaprevir (T) in combination with peginterferon/ribavirin (PR) in genotype 1 HCV treatment-naïve pts with HIV infection, a Wk 24 interim analysis was performed. Methods: Pts in each part were randomized: 1) T 750mg q8h + P 180μg/wk + R 800mg/day for 12 wks followed by PR for 36 wks (T/PR groups) and 2) PboPR for 48 wks. T dose was 1125mg q8h when the antiretroviral therapy (ART) regimen included efavirenz. In Part A, pts had no concurrent ART. In Part B, pts were on stable, predefined ART with either an efavirenz- or atazanavir/ritonavir-based regimen. Results: 60 pts received at least 1 dose of study drug, 13 in Part A, 47 in Part B. 44 pts reached Wk 24 on study drug. Mean age was 46 years. 88% were male, 27% were Black/African American, 68% had subtype 1a, 3.3% had cirrhosis. At baseline, 92% and 81% of Part A and B pts had HCV RNA ≥800,000 IU/mL; mean CD4 counts were 690 and 562 cells/mm3, respectively. 2 pts had HCV RNA vBT on T (n=1 EFV, n=1 ATV/r). None had HIV RNA vBT. Absolute CD4 counts declined from baseline in both groups, but CD4% was unchanged. Overall, in T/PR groups versus Pbo, abdominal pain, vomiting, nausea, pyrexia, dizziness, depression and pruritus occurred ≥10% difference; bilirubin AEs were more frequent in ATV/r pts (27% vs 0%) as was indirect hyperbilirubinemia. No severe rashes were reported. 3 T/PR pts in Part B had an AE (cholelithiasis, jaundice, hemolytic anemia [SAE]) that led to discontinuation of 1 or more study drugs. Telaprevir PK was similar across ART regimens. The PK of ART when co-administered with telaprevir led to changes consistent with prior DDI studies in healthy volunteers. Conclusions: In this interim analysis, substantially higher on-treatment responses were observed in pts treated with a T/PR compared to Pbo. Undetectable HCV RNA at Wks 4 and 12 occurred in 63% of T/PR pts compared to 4.5% in Pbo. Bilirubinemia was seen in patients receiving T/PR with an ATV/r-based regimen; otherwise, safety and tolerability of T/PR was comparable to that previously observed in HCV monoinfected pts.

Part A No ART Part B EFV/TDF/FTC

Part B ATV/r + TDF + FTC Total

n (%) T/PR N=7

PR48 N=6

T/PR N=16

PR48 N=8

T/PR N=15 PR48 N=8 T/PR

N=38 PR48 N=22

Undetectable HCV RNA at Wk 4 (RVR) 5 (71) 0 (0) 12 (75) 1 (12) 9 (60) 0 (0) 26 (68) 1 (4.5)

Undetectable HCV RNA at Wk 12 (cEVR) 6 (86) 2 (33) 14 (88) 2 (25) 11 (73) 3 (38) 31 (82) 7 (32)

Undetectable HCV RNA at Wks 4 and 12 (eRVR) 4 (57) 0 (0) 12 (75) 1 (12) 8 (53) 0 (0) 24 (63) 1 (4.5)

Undetectable HCV RNA at Wk 24 6 (86) 2 (33) 12 (75) 4 (50) 10 (67) 6 (75) 28 (74) 12 (55)

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A28 INTRAOCULAR COMPLICATIONS DURING ANTIVIRAL THERAPY FOR HEPATITIS C ARE COMMON AND MORE FREQUENT IN PATIENTS WITH HYPERTENSION, DIABETES, MIXED CRYOGLOBULINEMIA: A PROSPECTIVE, LONGITUDINAL STUDY G. Sebastiani1, S. Vujosevich2, E. Midena2, D. Tempesta3 1. McGill University Health Centre, Montreal, QC, Canada; 2. University of Padova, Padova, Italy; 3. Dell'Angelo Hospital, Venice, Italy. Aims: Treatment with pegylated interferon-alpha (PEG-IFNα) and ribavirin is still regarded as the standard of care for hepatitis C. It is expected that even the new therapeutic regimens for HCV genotype 1 based on direct antiviral agents will be IFN-based still for some years. Ophthalmological complications during therapy with IFN have been occasionally described as case reports or retrospective data, with discordant results. Prospective, longitudinal data about frequency and clinical significance of ophthalmological events are lacking. Methods: We investigated the prevalence of ophthalmological complications during antiviral therapy in 97 consecutive naïve HCV patients. 44.7% of patients were treated with PEG-IFNα 2b, 55.3% with PEG-IFNα 2a. Ophthalmological examination was performed by a single ophthalmologist before therapy (baseline), at 3 and 6 months (3T and 6T, respectively) of therapy and 3 months after end of therapy (3ET). The drop-out rate was 10.5%. All patients underwent the baseline and 3T examination, 89.5% underwent 6T and 3ET examination. Results: Overall, 30.5% of patients developed a “de novo” ophthalmological event. At baseline, 30.1% of patients had hypertension and/or diabetes (“at risk” subgroup) and had an abnormal ophthalmological examination more frequently than the subgroup “without risk” (27.6% vs. 4.4%, p=0.001). As shown in the Table, patients belonging to the “at risk” group had a significantly higher prevalence of ophthalmological events throughout the therapy. Presence of mixed cryoglobulinemia at baseline (29.9% of cases) vs. absence was also significantly associated with the frequency of ophthalmological events during therapy at 3T (50% vs. 25.5%, p=0.01) and at 3ET (26.3% vs. 9.3%, p=0.01). The most frequent ophthalmological complications were cotton wool spots (60%) and retinal haemorrhages (35%). In one (3.4%) “at risk” patient, who developed retinal venous occlusion at 6T, the therapy was discontinued. All other patients continued the therapy. No significant difference in the frequency of ophthalmological complications between the two PEG-IFNs was observed. Conclusions: Ophthalmological complications are frequent during treatment with PEG-IFNα and ribavirin, especially in patients with hypertension, diabetes, and in those with mixed crioglobulinemia, who may develop serious complications. Ophthalmological monitoring should be recommended in patients with hypertension, diabetes, mixed cryoglobulinemia.

Baseline 3T 6T 3ET Group \"at risk\" (n=29) 20% 75.7% 72.7% 14.3%

Group \"without risk\" (n=68) 6% 18.1% 29% 11.1% P 0.02 <0.0001 <0.0001 0.8

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CAG Paper Session - Neurogastroenterology: Who is Talking to Whom? Saturday February 25, 11h00-12h30 A29 TASK-LIKE CONDUCTANCE REGULATES VAGAL AFFERENT NEURON EXCITABILITY AND IS INCREASED IN DIET INDUCED OBESITY S. Park, M. Beyak GIDRU, Queen's University, Kingston, ON, Canada. Aims: We have recently shown that diet induced obesity decreases the excitability of vagal afferent nodose ganglion neurons (NGN), and this may result in decreased satiety signaling, however the mechanism of this is unknown. Two-pore-domain potassium channels (K2P) are K+-selective ‘background’ or ‘leak’ channels that stabilize the membrane potential. A major subfamily of K2P channels underlying these leak currents are the TASK channels. We characterized TASK-like currents based upon biophysical and pharmacological properties and examined their role in regulation of excitability in NGN, and tested the hypothesis that these are altered by diet induced obesity. Methods: Nodose ganglia were harvested from male C57Bl6/J mice, dissociated and whole cell patch clamp recordings on NGN were performed 18-24 h later. Leak currents were isolated by blocking Na+, Ca+, as well as voltage gated K+ channels, and solutions in which K+ was the only charge carrier were used. Obesity was induced by feeding a high fat diet (60%kCal from fat) for 12 weeks. Results: rtPCR revealed the presence of mRNAs of all K2P channels tested (KCNK2, 3, 4, 5 and 6) in NGNs. In voltage clamp experiments, voltage ramps (-110 to 50 mV, 400 ms, Vh=-60mV) were applied to the cells. Isolated TASK-like currents are approximated by GHK current equation that predicts a curvature of the I-V relationship in asymmetric K+ conditions. Mean leak conductance (gLeak) was 0.219 ± 0.028 nS (n=10) and the reversal potential of passive region (-120 -60 mV) was -75.3 ± 4.5 mV (n=10), approximating the predicted Nernst value (EK=-85.6 mV). TASK currents are increased by extracellular alkaline pH and are also activated by the anesthetic halothane. Alkaline pH and halothane increased gLeak by 0.213 ± 0.083 nS (n=5) and 0.172 ± 0.039 nS (n=6), respectively. Current clamp experiments assessed the effect of TASK activation on excitability. Resting membrane potential (mV) was significantly hyperpolarized by halothane (control, -48.5±1.1, n=8 vs. halothane, -54.1±1.5, n=8, P < 0.0020). Input resistance (MΩ) was significantly reduced in the presence of halothane (control, 428.3±77.3, n=8 vs. Halothane, 162.9±31.1, n=8, P < 0.0066). The rheobase (pA) was significantly increased in the presence of halothane (control, 47.5±7.0, n=8 vs. halothane, 103.8±16.0, n=8, P < 0.0062). Finally, the magnitude of the leak conductance was compared in NGN from lean and obese mice. Mean leak conductance (gLeak) was 0.178±0.021 nS (n=6) in NGN from lean mice while it was significantly increased (0.352±0.029nS, n=7) in NGN from obese mice (p=0.0007). Conclusions: TASK-like leak conductance regulates NGN excitability. This current is increased in NGN from obese mice, and this may explain the reduction in excitability of satiety sensing gut vagal afferent nerves. (Supported by CIHR)

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A30 THE ANXIOLYTIC PROBIOTIC L. RHAMNOSUS (JB-1) FACILITATES AFFERENT VAGAL DISCHARGE A. Perez-Burgos1, B. Wang1, B. Mistry1, J. Bienenstock1, W. Kunze2 1. McMaster Brain-Body Institute St Joseph’s Healthcare, Hamilton, ON, Canada; 2. The Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada. Aims: Brain function may be altered by ingesting certain symbiotic microorganisms; an effect that may be very important therapeutically. Bravo et al.1 reported that ingestion of Lactobacillus rhamnosus (JB-1) induces alterations in mRNA expression of GABA A & B receptors in widespread regions of the mouse brain. JB-1 also reduced anxiety- like behavior. Severing the vagus nerve subdiaphragmatically before feeding the probiotic eliminated the central actions of JB-11. We have previously shown that when JB-1 is applied to the luminal epithelium jejunal motility is moderated within minutes2; and this effect may be mediated by an increase in excitability of myenteric intrinsic primary afferent neurons. In contrast, L. salivarius has no effect on motility or enteric neuron excitability. We postulated that JB-1 but not L. salivarius would affect vagal nerve afferent firing and recorded from the mesenteric nerve bundles to elucidate the nature of this signal. Methods: We recorded multi- and single-unit activity from the mesenteric afferent nerve bundles innervating ex vivo segments of mouse jejunum. Segments were cannulated at the oral and anal end, and serosal and luminal compartments separately perfused with carbogen gassed Krebs buffer. Recordings were made after drawing a single nerve bundle into a glass suction pipette. Probiotics were added to the Krebs perfusing the luminal compartment. Subdiaphragmatic vagotomies were carried out in some animals prior to the recording experiments. Results: JB-1 increased the constitutive firing rate of the mesenteric afferent bundle at an effective concentration of 9 log cfu/ml. Average multiunit discharge increased from 10.8±2 to 14.2±3 Hz (n=7), but L. salivarius (n=5) or medium alone (n=6) were ineffective. The increase in constitutive firing rate was also replicated with single unit analysis. In addition, we found that only JB-1 augmented multiunit discharge responses to distension evoked by applying 30 hPa intraluminally. With Krebs only in the lumen, distension increased the multiunit firing frequency by 228±31% (n=7) above baseline; however, after the addition of the JB-1, distension further increased the firing frequency significantly by 319±91% (n=7). Vagotomy abolished all of the JB-1 evoked effects. Conclusions: Our results show that JB-1 affect vagal signaling by enhancing both constitutive and distension-evoked spike discharge. This work provides the first recordings of potentially anxiolytic and hedonic signals that are caused to be relayed toward the CNS via the vagus nerve by a psychoactive probiotic. 1. Bravo, J. A. et al. Proc Natl Acad Sci 108, 16050, 2011 2. Wang, B. et al. FASEB J 24, 4078, 2010

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A31 A NOVEL METHOD TO MEASURE GASTROINTESTINAL TRANSIT IN MICE D. Reed, J. Lu, S. Collins, P. Bercik Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada. Aims: Altered gastrointestinal transit is a feature of many gastrointestinal and systemic disorders (e.g. GI infections, diabetes mellitus). To date, analysis of intestinal transit in animal models has been hampered by a need to euthanize the animal at a given time point to remove the intestine and localize the tracer substance. This study explores the development of a novel in vivo method to determine gastrointestinal transit in mice. Methods: Metallic beads (diameter of 0.79mm) were used as a marker for intestinal transit. BALB/c mice (n=10) were gavaged with beads 3 hours before fluoroscopic imaging. Barium (40% dilution, 100-200 µl) was gavaged 3 hours and 10 min prior to imaging. Each mouse was fluoroscoped for 20 seconds and images recorded for off-line analysis. Immediately after completing the fluoroscopy exam, mice were euthanized. The GI tract, from the stomach to the rectum, was removed and one investigator localized each bead within the GI tract. A second blinded investigator localized the beads by analyzing the fluoroscopic images. A bead was given a numeric score depending on its location within the GI tract (range 0: stomach to 5: expelled from GI tract) and a total score was calculated by adding the individual bead scores. The total scores obtained from the 2 investigators were compared. Results: Metallic beads were easily identified in each animal. Barium was consistently seen outlining the stomach, proximal small bowel and cecum, identifying position of beads localized in these gut segments. Beads seen in fecal pellets indicated their localization in mid to distal colon. Total scores ranged from 16 to 24. There was a good correlation between fluoroscopic and anatomical (post-mortem) localization of pellets (Pearson correlation, r= 0.77, p<0.01). Differences between investigators’ scores for individual beads occurred in differentiating a bead in distal small bowel versus proximal colon. Conclusions: Fluoroscopic localization of small metallic beads shows good correlation with their anatomical position within the GI tract. Longer imaging protocols, that allow detection of high frequency slow wave-driven contractions within the small bowel, may further improve discrimination of whether a bead is located in the distal small bowel or colon. This novel imaging method enables repetitive measurements of GI transit in vivo, and will be useful to investigate dysmotility in animal models of disease.

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CAG Paper Session - Resolution of Inflammation: Towards Better Therapies for Inflammatory Diseases

Saturday February 25, 13h30-15h00 A32 THE PRO-INFLAMMATORY CYTOKINE, INTERLEUKIN-6, ENHANCES THE POLARIZATION OF ANTI-INFLAMMATORY ALTERNATIVELY ACTIVATED MACROPHAGES M. Fernando, G. Leung, D. McKay University of Calgary, Calgary, AB, Canada. Aims: Alternatively activated macrophages (AAMs), differentiated by exposure to interleukin (IL)-4 and IL-13, can inhibit chemically-induced colitis in mice. However, little is known regarding how the cytokine milieu affects the AAM phenotype and function. IL-6 is a multi-functional cytokine whose expression is up-regulated in enteric inflammation, and so we sought to determine the effect of IL-6 on AAMs. Methods: Murine bone-marrow and human blood-derived macrophages were differentiated into AAMs by 48h exposure to IL-4+IL-13 (20ng/mL) ± IL-6 (10ng/ml). The effect of other IL-6-family cytokines (i.e. IL-11 and LIF) and STAT-3 activators (i.e. IL-10) was assessed. The expression of arginase1, Ym1, RELMα and nitric oxide, TNFα and IL-10 production in murine macrophages were examined by Q-PCR, immunostaining, western blotting and various assays (arginase activity, inducible nitric oxide synthase activity, ELISA). Changes in human AAMs markers, CD206 (mannose receptor) and CCL18, were assessed by Q-PCR and western blotting. The ability of fibroblast conditioned medium (FΦCM) to modify an AAM phenotype was also assessed. Results: Murine and human macrophages polarized to AAMs in response to IL-4+IL-13. Fibroblast CM enhanced the expression of AAMs, but only if IL-4+IL-13 were present. Neutralization of IL-6 in the FΦCM reduced its ability to enhance an AAM phenotype, while recombinant IL-6, time- and dose-dependently enhanced IL-4+IL-13 induction of AAMs. IL-6 was more effective than IL-11 and LIF, and IL-10 in synergizing with IL-4+IL-13 in the induction of AAMs as gauged by all of the canonical markers. The possibility that IL-6 induced AAMs via the autocrine affect of IL-10 was dismissed using macrophages from IL-10 knock-out mice. Functionally, AAMs co-stimulated with IL-6 displayed reduced LPS-induced nitric oxide and TNFα production, giving these macrophages the characteristics of the quiescent intestinal macrophage. Conclusions: These results show that IL-6, in the presence of IL-4+IL-13, significantly amplifies the polarization of murine and human AAMs and suppresses responses to extracellular bacterial stimuli, namely LPS. These data indicate that IL-6 from fibroblasts, or other cells, can participate in the in vivo differentiation of AAMs and/or the resident gut macrophages, which are similar in function to AAMs. Finally, the data indicate the folly of dogmatically characterizing immune molecules - IL-6 is often regarded as pro-inflammatory, yet it has the ability to induce and maintain AAMs, a cell with anti-inflammatory properties that can contribute to wound healing.

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CASL Paper Session 3 Saturday, February 25 13h30 - 15h00 A33 ISOLATION OF THE HUMAN BETARETROVIRUS AND DEMONSTRATION OF INTEGRATION SITES IN PATIENTS WITH PRIMARY BILIARY CIRRHOSIS W. Wang1, S. Wasilenko1, S. Indik2, G. Wong1, A. Mason1 1. Medicine, University of Alberta, Edmonton, AB, Canada; 2. Research Institute for Virology and Biomedicine, University of Veterinary Medicine Vienna, Vienna, Austria.

NOT PUBLISHED AT AUTHORS REQUEST

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A34 DEFINING ABNORMAL METABOLISM IN PRIMARY BILIARY CIRRHOSIS. B. Meng1, W. Wang1, S. Liu2, A. Mason1 1. University of Alberta, Edmonton, AB, Canada; 2. Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China. Aims: Primary biliary cirrhosis (PBC) is associated with the formation of anti-mitochondrial antibodies (AMA) reactive with pyruvate dehydrogenase E2 complex (PDC-E2). Previous electron microscopy studies of PBC biliary epithelium have shown increased numbers of swollen mitochondria with abnormal cristae as well as aberrant location of PDC-E2 on the cell surface. To better understand the mitochondrial derangements, we have studied the transcriptional patterns and metabolic changes in BEC from patients with PBC and control subjects. To date we have found evidence of activation of glycolysis and oxidative phosphorylation in PBC BEC with increased (i) expression of glycolytic pathway enzymes, (ii) uptake and usage of glucose, (iii) lactate production, (iv) ATP production and (v) oxygen consumption. We hypothesize that PBC BEC have a unique metabolic phenotype associated with abnormal distribution of PDC-E2 in cells. To further characterize the phenotype, proteomic studies were performed using liver samples from PBC, PSC and other control patients. Methods: Four liver samples from PBC patients, PSC patients and cryptogenic cirrhosis patients were labelled by CyDye DIGE Fluor and assessed by 2D gel analysis. Approximately 1900 spots were detected on each gel and differentially expressed proteins were identified and characterized using MALDI-TOF/TOF. Results: To date, 46 proteins have been identified. Compared to patients with PSC, PBC patients had increased expression of two proteins associated with glycolysis (PEPCK [GTP], ADH4) as well as 4 isoforms of ATP synthase, a component of the F1 complex in mitochondria. These data are consistent with previous metabolic profiling of PBC biliary epithelium and support the hypothesis of increased glycolysis and oxidative phosphorylation. Moreover, two proteins associated with amino acid biogenesis (BHMT isoform CRA_b and TGM6) were increased in PBC liver; these data are also consistent with the glycolytic phenotype found in cancers where the glycolytic metabolites are used for generating amino acids and proteins. TGM6 (transglutaminase) is also a known autoantigen associated with celiac disease, which is in keeping with the hypothesis that autoantigens are aberrantly expressed and therefore “seen” in the immune system. Altered ANXA2 expression was observed in PBC liver that directly impacts on AE activity in cholangiocytes, which is known to have a role in the pathogenesis of PBC. A protein kinase TRRAP involved in HTLV-1 infection process was found to be up-regulated in PBC liver. Conclusions: In summary, our results unveil several proteins implicated in the pathogenesis of PBC that require further validation and investigation.

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A35 B LYMPHOCYTES DEPLETION THERAPY FOR AUTOIMMUNE HEPATITIS G. Marceau1, P. Lapierre2, K. Béland1, R. Yang1, F. Alvarez1 1. CHU Sainte-Justine / Université de Montréal, Montreal, QC, Canada; 2. INRS - Institut Armand-Frappier, Laval, QC, Canada. Aims: Autoimmune hepatitis (AIH) is a disease of unknown etiology, characterized by a loss of tolerance against liver antigens resulting in a chronic but fluctuating course with progressive destruction of the hepatic parenchyma. Considered a T cell-mediated disease AIH is nonetheless characterized by the presence of autoantibodies. Recent evidence of B cell depletion in clinical settings have highlighted the role of B cells in perpetuating an organ specific inflammation and the usefulness of B cell targeted therapy in AIH. In type 2 AIH, the T and B cell responses target the same antigen, and an overlap of B and T cell epitopes has been shown. Consequently we propose the hypothesis that autoimmune B cell response play a major role in the development and/or maintenance of AIH. Methods: In order to verify B cells role, we depleted B lymphocytes during active liver inflammation in a type 2 AIH mouse model. Briefly, female C57BL/6 mouse were injected with DNA coding for human liver antigens targeted in AIH patients (CYP2D6/LCHC1). At five and seven months after DNA vaccination, depleting anti-CD20 antibodies (Genescript) were injected in the tail vein and circulating B cells monitored by flow cytometry (anti-CD19). Serum was used to monitor alanine transferase (ALT) levels and antigen specific and total immunoglobulins (ELISA). Liver inflammation was evaluated with a modified Ishak histological activity index. Results: A single injection of antibodies resulted in a rapid and efficient depletion of circulating and splenic B cells (<5% remaining two days post-injection). The levels of circulating B cells remained low for over a month (40 days). In a month, liver-specific autoantibodies titers decreased in B cell depleted mice compared to their untreated mates. In addition, serum ALT levels normalization (p<0.05) as well as resorption of liver inflammation (p<0,01) was observed. Long term B cell depletion (over three months with two injections) also resulted in a decrease in overall circulating antibodies (40% of starting levels). Conclusions: Overall B cell depletion in our mouse model of type 2 AIH resulted in a rapid remission of disease. Normalization of ALT levels and absence of major liver infiltrates suggest a modification of the T cell compartment following B cells depletion. Effects on T cells reactivity toward liver antigens as well as the duration of remission following treatment need to be assessed. This project may lead to a new and innovative treatment for AIH patients. It will also contribute to a better understanding of the underpinning mechanisms responsible for the break of immune tolerance in AIH.

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A36 INTRANASAL DESENSITISATION AS A NEW TARGETED TREATMENT FOR TYPE 2 AUTOIMMUNE HEPATITIS IN A MURINE MODEL K. Beland1, R. Yang1, B. Faye2, M. Gagnon1, G. Marceau1, P. Lapierre3, F. Alvarez1 1. Gastroenterology, hepatology & nutrition, Department of Paediatrics, CHU Sainte-Justine, University of Montreal, Montreal, QC, Canada; 2. Université de Strassbourg, Strassbourg, France; 3. INRS-Armand-Frappier, Laval, QC, Canada. Aims: Autoimmune hepatitis (AIH) is a disease of unknown aetiology that can be fatal if not treated. Currently available immunosuppressive drugs (cyclosporine, prednisone and azathioprine) are effective to obtain remission of liver inflammation, but serious side effects are associated to each of them. New specific immunotherapies, based on autoantigen desensitisation, have shown promising results in other models of autoimmune diseases and could be applied to AIH. Aims of this study are to evaluate the effectiveness and elucidate the mechanisms of intranasal desensitisation using a murine autoantigen (mFTCD) in a mouse model of type 2 autoimmune hepatitis. Methods: C57BL/6 female mice were xenovaccinated with plasmids coding for human type 2 AIH autoantigens (CYP2D6 and FTCD). Prior to liver inflammation development (5 months post-vaccination) or during chronic active hepatitis (7 months post-vaccination), mice were treated with either 100ug of intranasal mFTCD or mock treatment daily for 3 consecutive days. Mice were sacrificed at 8 months. Liver inflammation was evaluated using modified Ishak score. Serum ALT levels and autoantibodies were monitored monthly and then each week after treatment. Phenotype and function of splenocytes and liver-infiltrating lymphocytes were characterised. Results: Liver inflammation was significantly improved as soon as two weeks post-treatment (p=0,0053) and this improvement was sustained for at least two months. Intranasal treatment was effective when applied at the initiation of inflammation or during hepatitis (p=0,0446). Conversely, autoantibodies against mFTCD were significantly increased following autoantigen nasal administration (p<0,0001) while their isotypes remained unchanged. Pattern of cytokines secreted by recovered T cells was similar in the two groups, as well as their proliferating capacity. In the liver, regulatory T cells were lower in the treated group (p=0,0432) while B regulatory cells (B10 cells) showed an upward trend. Conclusions: Intranasal desensitisation is an effective treatment for the remission of inflammation in the liver during AIH in our model. Mechanisms by which this remission takes place are still to be elucidated and skewing of Th1/Th2 profiles or induction of anergy does not seem to be implicated. While Tregs population may only reflect the inflammatory status of the liver, IL10 secreting B-cells could be involved in the remission process.

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A37 EVALUATION OF PHLEBOTOMY AS A TREATMENT FOR NON-ALCOHOLIC FATTY LIVER DISEASE M. Beaton, S. Chakrabarti, M. Levstik, P. Marotta, P. Adams London Health Sciences Centre, London, ON, Canada. Aims: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in the western world. It is the hepatic manifestation of the metabolic syndrome and is strongly tied to the features of this disorder. Unfortunately, short of sustained weight loss and management of other metabolic risk factors, there are no specific therapies for NAFLD. Elevated iron indices have been well described in NAFLD and in patients with the metabolic syndrome, suggesting a link between the pathogenesis of these conditions. Iron depletion via phlebotomy has been shown to improve enzymes in NAFLD. Little is known, however, about its long term effect on liver histology, the gold standard in evaluating treatment of NAFLD. As well, the benefit of iron depletion on other aspects of the metabolic syndrome such as insulin resistance has not been well characterized. A prospective study of phlebotomy as a treatment for NAFLD was conducted at our centre. We sought to determine if systemic iron depletion improved liver disease and components of the metabolic syndrome in patients with NAFLD. Methods: Patients with biopsy proven NAFLD underwent baseline evaluation to determine severity of metabolic and liver disease. Phlebotomy was carried out to achieve near iron depletion (serum ferritin ≤50 or Hgb 100). Repeat liver biopsy, anthropometric and biochemical measurements were performed 6 months following the end of treatment. Primary outcome was an improvement in histologic features of NAFLD, as assessed using the nonalcoholic fatty liver disease activity score (NAS). Results: 31 patients with biopsy proven NAFLD completed follow up. 61% (N=19) male, mean 49 (27-69) years. Mean baseline serum ferritin 384µg/L (60.5-1461), ALT 64U/L (28-158), Fasting Glucose 6.5mmol/L (4.2-12.9) and HOMA-IR 2.95 (0.9-9.6). BMI was in the obese range for most patients, mean 33 (23-45). Phlebotomy therapy resulted in a statistically significant improvement in total NAS activity score (0.63±1.75, p=0.034) but did not result in significant improvement in the individual histologic features of lobular inflammation (0.20±1.03, p=0.364), steatosis (0.27±0.78, p=0.116), hepatocyte ballooning (0.17±0.70, p=0.307) or fibrosis (0.30±0.95, p=0.138). Regarding anthropometric and biochemical markers of NAFLD severity, only serum ALT significantly improved with phlebotomy (12.3±24.3, p 0.011). No improvement was seen in measures of insulin resistance or other measures of the metabolic syndrome. Conclusions: This study is the first prospective trial to date evaluating liver histology pre and post phlebotomy therapy in a large number of NAFLD patients. Despite the common coexistence of NAFLD and elevated iron indices, iron reduction therapy does not conclusively result in improvement of liver or metabolic disease in this condition.

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A38 PERFORMANCE OF NON-INVASIVE MARKERS FOR LIVER FIBROSIS IS MAJORLY AFFECTED BY AETIOLOGY OF LIVER DISEASE, EARLIER FIBROSIS STAGES AND NORMAL TRANSAMINASES: A STUDY OF 2411 CASES G. Sebastiani1, P. Halfon2, L. Castera3, S. Pol4, A. Mangia5, V. Di Marco6, M. Pirisi7, M. Voiculescu8, M. Bourliere9, A. Alberti10 1. McGill University Health Centre, Montreal, QC, Canada; 2. Hospital Ambroise Pare, Marseille, France; 3. Université Denis Diderot Paris VII, Clichy, France; 4. Cochin Hospital, Paris, France; 5. Hospital Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy; 6. University of Palermo, Palermo, Italy; 7. Università del Piemonte Orientale, Novara, Italy; 8. Fundeni Clinical Institute, Bucharest, Romania; 9. Hôpital Saint Joseph, Marseille, France; 10. University of Padova, Padova, Italy. Aims: Staging of liver fibrosis is of paramount importance for prognosis and management of patients with chronic liver diseases (CLDs). Non-invasive markers for liver fibrosis have been proposed as surrogates of liver histology but their implementation in clinical practice is still debated due to concerns about their performance. Among them, the most studied are AST-to-Platelet Ratio Index (APRI) and Fibrotest-Fibrosure® (FT). Evaluation of the factors that might account for discrepancy between these markers and the gold standard liver biopsy is still needed. Methods: 2411 patients with compensated CLD (HCV=75.1%, HBV=10.5%, NASH=7.9%, HIV/HCV=6.5%) were consecutively enrolled in 9 Centers. APRI and FT were tested against liver biopsy, considered the gold standard. The performance of non-invasive markers for significant fibrosis and cirrhosis (≥F2 and F4, respectively) was expressed as area under the curve (AUC). Results: The performance (AUC) of non-invasive markers is reported in the Table. APRI showed its best performance in HCV monoinfected cases. In HBV and NASH cases, APRI showed a performance that was lower than in HCV cases for both ≥F2 and F4 (p<0.0001). Performance of FT was good in all aetiologies for both ≥F2 and F4, except for ≥F2 in NASH (AUC=0.64). Both APRI and FT showed an overall lower performance to diagnose ≥F2 as compared to F4. A subgroup analysis was conducted in 595 HCV cases with normal ALT, who had a significant lower prevalence of ≥F2 as compared to the whole study population (29.5% vs. 45.3%, p<0.0001). The performance of non-invasive markers was lower in HCV cases with normal ALT vs. whole HCV group (APRI: AUC=0.71 vs. 0.77, p=0.05 for ≥F2; AUC=0.73 vs. 0.83, p<0.0001 for F4; FT: AUC=0.70 vs. 0.77 for ≥F2, p=0.04; AUC=0.73 vs. 0.79, p=0.05). Conclusions: Aetiology of liver disease (HBV and NASH), earlier stages of liver fibrosis and normal ALT in HCV are major factors affecting the performance of APRI and FT. In these clinical settings, non-invasive markers for liver fibrosis cannot substitute liver biopsy and should be used cautiously.

Whole study population HCV HBV NASH HIV/HCV ≥F2 0.74 0.77 0.69 0.63 0.74

APRI F4 0.80 0.83 0.66 0.60 0.75 ≥F2 0.76 0.77 0.74 0.64 0.76

Fibrotest-Fibrosure® F4 0.79 0.79 0.73 0.89 0.79

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CAG Paper Session - Irritable Bowel Syndrome:Advances in Basic Research Sunday February 26, 08h00-10h00 A39 β2 ADRENERGIC RECEPTORS ARE A NOVEL TARGET FOR TREATMENT OF STRESS INDUCED PAIN IN A MODEL OF POST-INFECTIOUS IRRITABLE BOWEL SYNDROME R. Guerrero-Alba, F. Ochoa-Cortes, I. Spreadbury, S. Vanner Queen's University, Kingston, ON, Canada. Aims: Chronic stress is associated with visceral hyperalgesia in patients with irritable bowel syndrome (IBS). We have previously shown that chronic stress elevates stress hormones which markedly increases nociceptive signaling in colonic dorsal root ganglia (DRG) neurons, using a mouse model of post-infectious IBS (Gastroenterology, In press). The present study aimed to examine cellular mechanism involved in this response. Methods: C57BL/6 mice were subjected to 1-hour water avoidance stress (WAS) daily for 9 consecutive days. For in vitro studies, T9 -T13 DRGs were dissociated from control mice and incubated with stress hormones (epinephrine 5 nM, corticosterone 1 µM) in the presence or absence of an antagonist of the β2 adrenergic or corticosterone receptor. Colonic DRG neuronal excitability was measured using perforated patch clamp techniques (change in rheobase and action potential firing) and voltage clamp studies were used to identify associated changes in ionic currents underlying action potential electrogenesis. Parallel molecular studies were conducted to examine changes in mRNA and protein levels of the β2 adrenergic receptor and Nav channels. Results: Incubation of dissociated DRG in corticosterone and epinephrine induced hyperexcitability of DRG neurons (rheobase decreased 51%, p<0.05; action potential discharge increased 95%, P<0.01); this effect was blocked by an antagonist of the β2 adrenergic receptor (butoxamine) or the corticosterone receptor (mifepristone), but not by α adrenergic receptor blockade. In whole animal studies, hyperexcitability of DRG neurons induced by 9 days of WAS was also blocked by β2 adrenergic (butoxamine i.p.) or the corticosterone receptor (s.c.) antagonists. In voltage clamp studies, stress hormones enhanced voltage gated Nav1.7 currents (P<0.05) and suppressed IA (P<0.0001) and IK+ (P<0.05) currents. Furthermore, stress hormones increased mRNA transcript (59%, P=0.007) and protein (125%, P<0.05) for the β2 adrenergic receptors on DRG neurons. These hormones also increase Nav 1.7 mRNA transcript (45%, P=0.002) and protein expression (55%). Conclusions: This study demonstrates that chronic stress and the resulting stress hormones epinephrine and corticosterone induce hyperexcitability of nociceptive DRG neurons which is mediated by activation of β2 and corticosterone receptors. The increased neuronal excitability is associated with corresponding changes in voltage gated Na+ and K+ currents. Furthermore, stress hormones increase the expression β2 adrenergic receptor and Nav1.7 channels and these transcriptional changes could lead to sustained signaling following stress. Together, these data suggest that β2 adrenergic receptors may provide a novel target for the treatment of visceral pain in selected patients with IBS.

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A40 ENTERIC PATHOGEN-MEDIATED DISRUPTION OF THE INTESTINAL MICROBIOTA IN THE DEVELOPMENT OF CHRONIC GASTROINTESTINAL DISEASE: A NOVEL MODEL USING GIARDIA DUODENALIS J. Beatty1, S. Akierman1, K. Rioux2, P. Beck2, A. Buret1 1. Department of Biological Sciences, University of Calgary, Calgary, AB, Canada; 2. Department of Medicine, University of Calgary, Calgary, AB, Canada. Aims: Irritable Bowel Syndrome (IBS) is the most common functional bowel disorder in the developed world. The causes remain obscure. Recent reports indicate post-infectious IBS (PI-IBS)-symptoms in upwards of 36% of patients previously subject to acute enteric infections, the severity of which being largely dependent on the initial infectious agent. The protozoan parasite Giardia duodenalis has become one of the key pathogens leading to such post-infectious abnormalities. Disruptions of species distribution in the intestinal microbiota of patients with IBS have been reported, but remain poorly characterized. The normal intestinal microflora exists in biofilm communities, and the effects of enteropathogens on the biofilm phenotype of human intestinal microflora have yet to be assessed. In an attempt to determine whether or not such effects may be implicated in the development of post-infectious IBS, this study examines how acute exposure to Giardia duodenalis may alter human intestinal microflora biofilms. Methods: Representative multi-species bacterial biofilms were cultured anaerobically (72h) on the Calgary Biofilm Device (MBECTM, Innovotech) from human intestinal mucosal biopsies collected during routine colonoscopies, in the presence or absence of live G. duodenalis. Biofilms were quantified with T-RFLP, CFU, XTT assays. Confocal Scanning Laser Microscopy (CSLM), Scanning Electron Microscopy (SEM), and Wheat Germ Agglutinin (WGA) served as biofilm phenotype markers. Caco-2 intestinal monolayers were used to assess the effects of Giardia-modified biofilms on epithelial integrity. Results: T-RFLP analysis of Giardia-exposed biofilms indicates a drastic switch from normal species distribution seen in control biofilms. Cell counts and XTT assays revealed that Giardia promotes the planktonic growth phase of bacteria. SEM and WGA staining indicate that Giardia inhibits the polysaccharide production typical of bacterial biofilms. Lastly, ELISA revealed monolayers co-incubated with biofilms (3h) exposed to Giardia (24h) exhibited greater levels of apoptosis, compared to those incubated with control biofilms. Conclusions: Our study successfully grew multispecies microflora biofilms from human intestinal biopsies. The findings indicate that acute exposure to G. duodenalis modifies the structure and species composition of these bacterial communities. Furthermore, we demonstrate that biofilms modified by Giardia promotes enterocyte apoptosis, a key pathogenic event in many intestinal disorders. OUr study highlights the implications of enteropathogen-induced abnormalities of microflora biofilms in chronic bowel diseases.

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A41 MECHANISMS OF THE PROTEASE-INDUCED INCREASE IN TRANSEPITHELIAL RESISTANCE IN INTESTINAL EPITHELIAL CELLS A. Wadhwani, M. Dicay, W. MacNaughton University of Calgary, Calgary, AB, Canada. Aims: We have previously shown that apical addition of serine proteases like trypsin to intestinal epithelial cell (IEC) monolayers reduces epithelial permeability as shown by increased transepithelial resistance (TER) and reduced FITC-dextran flux. This effect of trypsin is independent of activation of protease-activated receptors, but the underlying mechanism is unknown. Given the central role of epidermal growth factor receptor (EGFR) in epithelial cell biology and homeostasis, we hypothesized that trypsin increases TER by activating members of the EGFR family. Because we also hypothesized that inflammation-induced increases in epithelial permeability were due to an imbalance between proteases and endogenous serine protease inhibitors (serpins), we measured the expression of serpin A1 in inflamed colonic tissue obtained from mice with DSS colitis. Methods: TER of confluent SCBN monolayers and mouse colonic tissue was measured in Ussing chambers. To determine a role for EGFR and associated signaling pathways, cells were pretreated with inhibitors of EGFR (PD153035), ErBb2 (AG879), ERK-1/2 (PD98059), PI3K (LY294002) and MMPs (marimastat, MMT), or a neutralizing anti-TGFα antibody, prior to apical application of trypsin or EGF. Transepithelial flux of FITC-dextran was measured following treatment with PD153035 or AG879 and trypsin. Mucosal expression of serpin A1 (α1-anti-trypsin) was measured using western blots and immunohistochemistry in colons from 7 day DSS mice and untreated controls. Results: Apical trypsin increased TER in SCBN cells by 300% (p<0.05) within 60 min. PD153035 or AG879 caused a dose-dependent decrease in trypsin-induced ΔTER (p<0.05), with IC50s of 0.38 and 2.73 μM, respectively. PD98059, LY294002 and MMT also significantly reduced trypsin-induced ΔTER. Apical EGF increased TER by 80%. Anti-TGFα Ab reduced trypsin-induced TER by ~50%. Pretreatment of cells with PD153035 or AG879 prevented trypsin-induced reduction of dextran flux. Soybean trypsin inhibitor decreased TER in mouse colon in vitro, suggesting that luminal serine proteases maintain barrier function. Also, as observed on western blots, mucosal expression of serpin A1 (α1-anti-trypsin) is increased in mouse colitis. Constitutive serpin A1 immunoreactivity was observed in epithelial cells in the mouse colon. Expression in the mucosa was increased at 7 days of 2.5% DSS and appeared to be present in infiltrating leukocytes. Conclusions: Our data show that trypsin increases TER via processing membrane-bound TGFα and activation of EGFR, ErBb2, ERK-1/2, PI3K and MMPs in vitro. In addition, the serine protease inhibitor serpin A1 is overexpressed in inflamed mouse colon. Serine proteases may strengthen epithelial barrier whereas overexpression of endogenous protease inhibitors may contribute to barrier dysfunction in inflammation.

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CAG Paper Session - The GI Microbiome: Digestive Diseases and Beyond Sunday February 26, 13h15-15h15 A42 REPOOPULATING THE GUT: USE TO SYNTHETIC STOOL TO CURE RECURRENT C.DIFFICILE INFECTION E. Petrof1, G. Gloor2, S. Vanner3, J. Weese4, E. Allen-Vercoe5 1. Queen's University, Kingston, ON, Canada; 2. University of Western Ontario, London, ON, Canada; 3. Queen's University, Kingston, ON, Canada; 4. University of Guelph, Guelph, ON, Canada; 5. University of Guelph, Guelph, ON, Canada. Aims: To determine whether a synthetic stool preparation, comprised of bacteria isolated in culture from stool of a healthy donor, would be effective as an alternative to fecal transplant therapy for treatment of recurrent C.difficile infection Methods: Sixty-two bacterial isolates were recovered from the fecal material of a healthy young donor using strict anaerobic conditions, purified isolates were identified by 16S rRNA gene sequencing, and a mixture of over 30 different strains of intestinal bacteria were selected for the final synthetic stool formulation. The mixture was administered by colonoscope to two patients who had a history of previous CDI and who had failed multiple courses of standard antibiotic therapy for recurrent CDI. The study protocol was approved by the Human Research Ethics Boards at Queen’s University and the University of Guelph. Full genomic bacterial DNA was obtained from each patient stool sample (pre-treatment, and post-treatment (day2, week2, week4)), and the V6 rRNA region amplified and subsequently sequenced on the Ion Torrent 314 and 316 chip platform. Community composition analysis of patient stool samples was performed, and samples compared to the composition in the RePOOPulate (synthetic stool) mixture. Principle component analysis was carried out in the QIIME package using multiple sequence alignments generated by clustalw2. Results: The microbial profiles of the two patients were both very distinct from each other and from the synthetic stool preparation. The two pre-treatment patient samples showed strikingly different diversities, with patient 1 having a highly diverse initial microbiome and patient 2 showing less Shannon diversity. Shortly after having received the synthetic stool, the second patient received antibiotics for cellulitis but still did not develop CDI. At 4 weeks the synthetic stool OTUs (operational taxonomic units) still composed over 60% of the OTUs in patient 1. In patient 2, the synthetic stool OTUs composed over 84% of the microbiome until antibiotic treatment, at which point they still made up 39% of the OTUs at week 4. Both patients were cured of recurrent CDI after receiving the synthetic stool preparation, and after more than 3 months of follow-up, remain symptom free. Conclusions: Use of synthetic stool may be a safe and effective alternative to the use of fecal transplant therapy for the treatment of recurrent CDI. Bioinformatic analyses demonstrate that the intestinal microbial profile of the patients reverts to features of the synthetic stool in each case.

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A43 OUTCOME AFTER PELVIC POUCH SURGERY IS ASSOCIATED WITH DIFFERENCES IN THE MICROBIOME AS CHARACTERIZED BY 16S PYROSEQUENCING A. Tyler1, N. Berard3, B. Kabakchiev1, R. Milgrom2, S. Halder2, Z. Cohen2, R. McLeod2, D. Krause3, M. Silverberg2 1. University of Toronto, Toronto, ON, Canada; 2. Zane Cohen Centre for Digestive Diseases, Mount Sinai Hospital, Toronto, ON, Canada; 3. Department of Medical Microbiology, University of Manitoba, Winnipeg, MB, Canada. Aims: Ileal inflammation affecting the pelvic pouch following ileal pouch-anal anastomosis(IPAA) in patients with ulcerative colitis(UC) is a common yet poorly understood phenomenon. Patients with ileostomies rarely develop inflammation, suggesting that microbial elements within the lumen are required for disease. This study used culture-independent techniques to evaluate the microbial composition of pouch and afferent limb biopsies from patients with variable pouch outcomes. Methods: Patients with confirmed UC or familial adenomatous polyposis (FAP) who had a colectomy and IPAA, with ileostomy closure ≥1 year prior to study enrolment were recruited from Mount Sinai Hospital at the time of follow-up endoscopy. Retrospective and cross-sectional clinical/endoscopic information was collected at the time of enrolment and patients were classified into 4 groups: FAP/no pouchitis(FAP), UC/no pouchitis(NP), UC/pouchitis(P) and UC/CD-like phenotype(CDL). P was defined based on the PDAI and PAS. CDL diagnosis was based on presence of afferent limb inflammation or fistula. 2 biopsies were collected and snap-frozen in liquid nitrogen (1 afferent limb and 1 pouch). Microbial DNA was extracted and sequenced using the 454 GS FLX Titanium Sequencing system with primers specific for the V1-V3 hypervariable region of 16S rRNA gene. Sequences were quality trimmed and aligned to a SILVA reference database using mothur, with a minimum bootstrap cutoff of 60%. Where possible, sequences were assigned to the genus level and patients were considered positive for genera with counts >0. Dichotomized results were analyzed using Fisher’s exact test and FDR correction for multiple testing. Results: 245 patients were recruited to the study of whom 79 were selected for analysis with complete data available (18 FAP, 21 NP, 20 P, 20 CDL). Analysis at the genus level showed that Bacteroides was detected more frequently in the pouch and afferent limb of FAP and NP patients compared to P and CDL(p=0.0005 and 0.001 respectively). Parabacteroides(p=0.01), Moryella(p=0.04) and Sutterella(p=0.03) were detected significantly less often in the P and/or CDL groups in the pouch, while Blautia(p=3.2x10-5) and Dorea(p=0.02) were less frequent in P and CDL groups in the afferent limb. Conclusions: Differences in microbial composition are associated with outcome following IPAA. Further study may allow us to identify the role these organisms play in pouch pathogenesis, and to identify interactions occurring between microorganisms and host endogenous elements such as genotype and development of anti-microbial antibodies.

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CASL Paper Session 4 Sunday, February 26, 13h30 - 15h00 A44 THE NATURAL HISTORY OF PATIENTS WITH CIRRHOSIS, ASCITES AND SPONTANEOUS BACTERIAL PERITONITIS. G. Ra, C. Tsien, F. Wong University of Toronto, Department of Gastroenterology, Toronto General Hospital, Toronto, ON, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A45 MEDICAL INJURIES DURING HOSPITALIZATION AMONG PATIENTS WITH CIRRHOSIS: A POPULATION BASED STUDY A. Shaheen, D. Tanyingoh, E. Dixon, G. Kaplan, R. Myers Liver Unit, Division of Gastroenterology and Hepatology, University of Calgary, Calgary, AB, Canada. Aims: Medical injuries during hospitalization constitute an important preventable cause of morbidity and mortality. The burden of medical injuries among patients with cirrhosis has not been described despite their frequent requirement for admission. Our objectives were to compare the incidence of medical injuries between cirrhotic patients and controls, and to assess the effect of these injuries on in-hospital mortality, length of stay (LOS), and hospital charges. Methods: We analyzed the Nationwide Inpatient Sample database (1993-2008) to identify all patients with cirrhosis and a random sample of non-cirrhotic controls hospitalized in the United States. The Patient Safety Indicators (PSIs) developed by the Agency for Healthcare Research and Quality were used to identify medical injuries. The incidence of these events was compared among cirrhotic patients and controls using Poisson regression, and their influence on health outcomes was determined using multivariate regression. Results: Between 1993 and 2008, we identified 4,135,826 admissions among patients with cirrhosis and 11,004,530 controls. The unadjusted incidence of medical injury among cirrhotic patients was 2.57% compared to 2.69% among controls (P=0.03). For most PSIs, the adjusted incidence of medical injuries was higher among cirrhotic patients. Specifically, patients with cirrhosis had a higher risk of death among low mortality diagnosis-related groups (age/sex-adjusted incidence rate ratio [IRR] 2.18; 95% confidence interval [CI] 1.78-2.66), death after surgery (1.63; 1.47-1.82), and post-operative sepsis (1.74; 1.45-2.08), hemorrhage (1.55; 1.35-1.77), respiratory failure (1.30; 1.12-1.50), and wound dehiscence (1.40; 1.22-1.59). On the other hand, patients with cirrhosis were less likely to develop infections due to medical care (IRR 0.82; 95% CI 0.75-0.91), postoperative venous thromboembolism (0.52; 0.48-0.56), accidental puncture during surgery (0.71; 0.64-0.79), and decubitus ulcer (0.74; 0.70-0.80). Among patients with cirrhosis, most medical injuries were associated with increased mortality, LOS, and charges. Events with the greatest influence on mortality were post-operative respiratory failure, sepsis, and metabolic derangements (excess attributable mortality, 41-51%). Excess mean LOS and hospital charges ranged from 2.4 to 11.8 days and from ~$12,000 to $67,000, respectively. Conclusions: Patients with cirrhosis have an increased risk of many medical injuries during hospitalization. Injuries incurred during hospitalization pose a significant threat to cirrhotic patients and have important societal costs.

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CASL Student Research Prize A46 XANTHINE OXIDASE INHIBITION ATTENUATES BRAIN EDEMA IN IN RATS WITH LIVER FAILURE C. Bosoi, C. Parent-Robitaille, M. Tremblay, C. Rose Neuroscience Research Unit, Hôpital Saint-Luc (CRCHUM), Université de Montréal, Montreal, QC, Canada. Aims: Liver disease leads to hyperammonemia, a central component in the pathogenesis of hepatic encephalopathy (HE). There is increasing evidence that systemic oxidative stress may exacerbate the neuropsychological effects of hyperammonemia in patients with liver disease. With new, highly sensitive imaging techniques, brain edema is commonly being observed in patients with cirrhosis and HE. Bile duct ligated rats, six-week after intervention, present with brain edema, hyperammonemia and also an increase in plasma reactive oxygen species (ROS) along with an increase in xanthine oxidase activity. In order to better understand the relationship between oxidative stress and ammonia and their role in the pathogenesis of brain edema, we evaluated the effect of xanthine oxidase inhibition in rats with cirrhosis. Methods: Cirrhosis was induced in rats by bile duct ligation (BDL) for 6 weeks. BDL and SHAM-operated rats received 100 mg/kg/day of allopurinol (xanthine oxidase inhibitor) during the last 10 days before sacrifice. As control groups, separate BDL and SHAM-operated rats received equivalent volume of saline. AST and ALT were measured at the end of the treatment period to assess liver function. Ammonia and ROS were assessed in arterial plasma using a commercially available kit and a DCFDA-fluorescent technique respectively. Brain water content was measured in the frontal cortex using the specific gravimetric technique. Results: Arterial ROS and ammonia levels were significantly increased in BDL vs SHAM-operated rats (p<0.001). BDL rats treated with allopurinol demonstrated a significant decrease in systemic ROS as well as ammonia levels vs non-treated BDL rats (1.70 ± 0.53RFU vs 4.97 ± 1.38RFU, p<0.05, 37.9 ± 13.8µM vs 101.1 ± 10.1µM, p<0.001, respectively), reaching values similar to those seen in SHAM-operated rats. Brain water content increased in BDL vs SHAM-operated rats and normalised in allopurinol treated BDL rats (77.20 ± 0.08% vs BDL: 78.46 ± 0.28%, p<0.05). Liver function markers, AST and ALT, increased in BDL rats compared to their respective SHAM-operated controls (p<0.001) and were not attenuated following allopurinol treatment. Conclusions: Allopurinol treatment decreased systemic ROS and attenuated brain edema as well as arterial ammonia levels. The effect of allopurinol demonstrates oxidative stress plays a role in ammonia metabolism and in the pathogenesis of brain edema. Our results suggest antioxidant treatment directed towards inhibiting ROS production could be beneficial in lowering ammonia and treating HE. Additional studies are warranted to evaluate the implication of oxidative stress in ammonia metabolism.

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A47 GLUTATHIONE DEPLETION LEADS TO BRAIN EDEMA IN PORTACAVAL-SHUNTED RATS C. Bosoi, C. Parent-Robitaille, M. Tremblay, C. Rose Neuroscience Research Unit, Hôpital Saint-Luc (CRCHUM), Université de Montréal, Montréal, QC, Canada. Aims: The pathogenesis of hepatic encephalopathy (HE) is multifactorial. Even though ammonia is the central component in the pathogenesis of HE, oxidative stress is believed to play a role in exacerbating the neuropsychological effects of ammonia in patients with liver disease. With new, highly sensitive imaging techniques, brain edema is observed in HE patients. We previously demonstrated that portacaval shunted hyperammonemic rats do not develop oxidative stress or brain edema. In order to define a synergistic effect between hyperammonemia and systemic oxidative stress, the present study investigates the role of oxidative stress in the pathogenesis of brain edema in PCA rats following glutathione depletion by diethyl maleate (DEM). Methods: In the first set of experiments, we evaluated the effect of DEM in PCA and SHAM-operated control rats by injecting DEM at a dose of 0.4 and 1 mg/kg/day intraperitoneally for 10 days starting at day 18 after surgery. Rats were sacrificed at day 28 and oxidative stress was evaluated by arterial malon-dialdehyde (MDA, commercial kit). In the second set of experiments, 1 mg/kg/day DEM was used to induce oxidative stress. Ammonia (commercial kit) as well as other different oxidative stress markers: reactive oxygen species (DCFDA fluorescence technique), and 4-hydroxy-2-nonenal (HNE, Western blot) were assessed in arterial plasma and frontal cortex tissue. Brain water content was measured in the frontal cortex using a specific gravimetric technique. Results: DEM at 1 mg/kg/day (not 0.4 mg/kg/day) induced a significant increase in MDA levels in PCA rats. No increase in MDA was detected following either dose of DEM in SHAM-operated controls. Ammonia levels in both DEM-treated and non-treated PCA rats were significantly increased vs respective sham-operated controls (p<0.001) and remained unchanged between non-treated and DEM-treated PCA groups (p>0.05). An increase in brain water content was observed in DEM-treated PCA rats vs non-treated PCA rats (PCA+DEM: 78.45 ± 0.13% vs PCA: 77.38 ± 0.11, p< 0.001). Although no significant changes in reactive oxygen species were observed, there was an increase in plasma levels of HNE in DEM-treated PCA rats compared to non-treated PCA rats. No significant changes in any oxidative stress markers were observed in the frontal cortex. Conclusions: DEM treatment in PCA rats induced systemic oxidative stress but not central oxidative stress. This, imposed on hyperammonemia, was accompanied by the onset of brain edema in rats with PCA. Oxidative stress and brain edema were not detected in SHAM-operated rats, which were not hyperammonemic. Our findings suggest a synergistic effect between hyperammonemia and systemic oxidative stress is implicated in the pathogenesis of brain edema in hepatic encephalopathy.

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A48 SARCOPENIA IN PATIENTS WITH HEPATOCELLULAR CARCINOMA J. Meza-Junco1, A. Montano-Loza2, C. Prado1, J. Lieffers1, V. Baracos1, V. Bain2, M. Sawyer1 1. Cross Cancer Institute, Edmonton, AB, Canada; 2. University of Alberta, Edmonton, AB, Canada. Aims: Sarcopenia is the deficiency in muscle mass defined as two standard deviations below the gender-specific means, with reduction in the number of motor units and atrophy of muscle fibers. It is also associated with advanced malignant disease; however, it is not well studied or understood in patients with different types/stages of cancer and on different treatments. This study aimed to establish sarcopenia frequency and if it predicts mortality in a cohort of cirrhotic patients with hepatocellular carcinoma (HCC). Methods: Fifty-one patients with HCC and cirrhosis who were consecutively evaluated for liver transplant and had a computed tomography (CT) scan at the 3rd lumbar vertebrae were selected. Data were recovered from medical charts, skeletal muscle cross-sectional area was measured by CT and sarcopenia was defined using previously published gender-specific cutoffs. Results: Forty patients were males (78%), mean age was 57±6 years (range, 42-69). During a median follow-up of 14±2 months (range, 2-66 months), 24 patients (47%) died, 7 (14%) had a liver transplant, and 20 (39%) were alive. Cirrhosis etiology was hepatitis C (67%), alcohol (14%), hepatitis B (14%), and others (5%). Sarcopenia was present in 15 patients (29%). Twenty-nine patients (57%) received treatment with chemo/radio embolization (TACE/TARE), 12 (24%) ablation (radiofrequency/alcohol), 5 (10%) combined treatment (TACE + ablation), and 5 (10%) best supportive care. By univariate Cox analysis presence of encephalopathy (HR 10.59; 95% CI 2.08-53.84, P=0.004), INR (HR 6.90; 95% CI 1.26-37.70, P=0.03), MELD score (HR 1.17; 95% CI 1.05-1.30, P=0.004), Child-Pugh (HR 2.77; 95% CI 1.41-5.42, P=0.003), tumor size (HR 1.82; 95% CI 1.02-3.25, P=0.04), TNM stage (HR 1.84; 95% CI 1.11-3.07, P=0.02), treatment type (HR 0.57; 95% CI 0.34-0.96, P=0.04), and sarcopenia (HR 2.84; 95% CI 1.26-6.39, P=0.01) were associated with increased risk of mortality. By multivariate Cox regression analysis (including MELD, Child-Pugh, TNM, treatment type, and sarcopenia), only TNM (HR 1.79, 95% CI 1.06-3.06, P=0.03), and sarcopenia (HR 2.54, 95% CI 1.03-6.29, P=0.04), were independently associated with early mortality. Median survival for sarcopenic patients was 16±7 months, compared to 29±4 months in non-sarcopenic (P=0.008). Conclusions: Sarcopenia is presented in almost one third of patients with HCC and cirrhosis, and constitutes a strong and independent risk factor for mortality in these patients.

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A49 PCSK9 EXPRESSION REFLECTS CHOLESTEROL METABOLISM IN HCC M. Bhat1, M. Deschenes1, V. Marcus1, J. Bouteaud1, S. Negi1, R. Aikin1, J. Kwan1, R. Amre1, M. Hassanain1, P. Siegel2, P. Metrakos1 1. McGill University Health Centre, Montreal, QC, Canada; 2. Goodman Cancer Centre, Montreal, QC, Canada. Aims: The current management of Hepatocellular carcinoma (HCC) is limited by the lack of adequate screening biomarkers and therapeutic strategies for advanced disease. In recent years, therapeutic avenues to curtail cancer metabolism have been studied. The proprotein convertase PCSK9 is solely produced in the liver, and is upregulated in the context of liver regeneration. It enables internalization of the LDL-receptor, thereby affecting cholesterol metabolism and modulating local and serum cholesterol levels. The aim of this study was to determine whether PCSK9 expression was altered in HCC. Methods: Forty patients undergoing partial hepatectomy or liver transplantation for HCC were consented for use of HCC tissue to construct a tissue microarray (TMA). The TMA consisted of HCC, cirrhosis, interface between HCC and cirrhotic background, viral hepatitis, normal liver and HCC cell line cores. Slides were cut from the TMA, and stained for PCSK9. Two liver pathologists independently reviewed the staining, and graded cores as not or weakly staining (0-1), moderately staining (2), and strongly staining (3) for PCSK9. Serum PCSK9 levels were also obtained from a separate cohort of patients with HCC and cirrhosis. Results: Results: 32.5% of HCC samples were weakly staining for PCSK9, 46.3% were moderately staining, and 21.1% were strongly staining for PCSK9. 30.9% of cirrhosis samples, obtained just adjacent to the interface between tumour and cirrhotic background, stained strongly for PCSK9, 45.6% were moderately staining, and 23.5% were weakly staining for PCSK9. Patients with HCC tumour that stained strongly for PCSK9 had improved survival after transplantation (p=0.0055) as compared to weakly staining tumours. There was no correlation between staining intensity and aetiology of liver disease or grade of tumour. Serum PCSK9 levels were significantly decreased among patients with HCC as compared to those with chronic liver disease without HCC (p=0.033). Patients with cirrhosis had higher mean PCSK9 values as compared to chronic liver disease patients without cirrhosis (p=0.048). Conclusions: The decreased expression of PCSK9 in HCC and increased expression in surrounding liver tissue may indicate that HCC modulates its local microenvironment to enable constant energy supply. Alternatively, this could reflect the degree of tumour differentiation. The decreased serum levels of PCSK9 in HCC patients further confirm this finding. There has recently been a move in oncology research to evaluate the modification of energy supply to a tumour as a therapeutic strategy to suppress its growth. Further confirmation at the mRNA level is required to confirm the altered expression of PCSK9, and determine whether it is a potential therapeutic target for HCC.

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Poster Session 1 Satruday, February 25, 17h00-18h30 Acute Liver Injury and Hepatotoxicity

A50 USE OF THE MELD SCORE TO PREDICT PROGRESSION TO FULMINANT HEPATIC FAILURE AFTER ACETAMINOPHEN POISONING S. Bouchard1, C. Fournier1, M. Sylvestre2, J. Villeneuve1 1. Centre Hospitalier Universitaire de Montréal, Montreal, QC, Canada; 2. Centre de recherche du CHUM, Montreal, QC, Canada. Aims: Acetaminophen poisoning is the most common cause of drug-induced liver injury. In a small proportion of patients, there is a risk of progression to fulminant hepatic failure (FHF) that may require transfer to a tertiary care center and possibly evaluation for liver transplantation. The aim of this study was to identify predictive factors of progression to FHF in a cohort of patients with acetaminophen poisoning. Methods: We performed a retrospective analysis of all cases of acute acetaminophen poisoning in our hospital during a 48 months period (March 2005 to February 2009). Patients studied had a clear history of acetaminophen overdose or a toxic serum acetaminophen concentration. Patients’ demographic, clinical characteristics and in-hospital evolution were evaluated as well as multiple laboratory values at regular intervals after the initial time of intoxication. The predictive ability of INR, creatinine, bilirubin, MELD score, platelets levels and AST was evaluated by multivariate analysis and the use of ROC curves. Results: 55 patients with acute acetaminophen poisoning were studied (49% men, average age 36,4 +/- 13,82 years). 54,5% of patients were transferred to our center from a referring community hospital. The average ingested dose was 39.4 g and the time to NAC averaged 24.1 h +/- 20.3. 37 patients developed severe hepatotoxicity (ATL > 1000) and 12 (22%) eventually developed FHF. Among the 12 patients with FHF, 8 patients met the King’s College criterias for liver transplantation. None were transplanted and 3 patients died. The MELD score at day 1 to 3 after poisoning was associated with the development of FHF (OR 1.42 95% CI 1.18-2,02; p=0.0073). At day 1 post-poisoning (24-48h), a MELD score of 34 or higher had high sensitivity (80%) and specificity (97.1%) for predicting evolution to FHF. At day 2 post-poisoning, a MELD score of 24 or higher had a 89% sensitivity and 61% specificity for predicting FHF. At day 3, a MELD score of 29 or higher had a 100% sensitivity and 85% specificity for predicting FHF. INR level at day 1 to 3 after poisoning also had a positive association with FHF (OR 1.67 95% CI 1.28-2.34 ; p≤0.001), although the predictive ability of INR was lost when INR and MELD were studied together in a regression model. Bilirubin, creatinine, platelets et AST levels were not statistically associated with the developement of FHF. Conclusions: In our cohort of acute acetaminophen poisoning, the MELD score had the best value in predicting the risk of FHF, with high sensitivity, specificity and NPV. Therefore, it may be helpful in identifying quickly patients needing transfer to a tertiary center.

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A51 THE PREGNANCY PARADOX: A CASE OF ACUTE FATTY LIVER DISEASE OF PREGNANCY J. Goy1, Z. Kassam2, M. Matsos3, G. Joseph4, S. Ganguli2 1. Department of Medicine, Internal Medicine Residency Program, Hamilton, ON, Canada; 2. Department of Medicine, Division of Gastroenterology, McMaster University, Hamilton, Ontario, Hamilton, ON, Canada; 3. Department of Medicine, Division of Rheumatology, McMaster University, Hamilton, Ontario, Hamilton, ON, Canada; 4. Department of Medicine, Divisions of Obstetrical Medicine and Nephrology, McMaster University, Hamilton, Ontario, Hamilton, ON, Canada. Aims: Acute Fatty Liver of Pregnancy (AFLP) is a rare hepatic and obstetrical emergency characterised by jaundice, encephalopathy, coagulopathy and renal failure in the third trimester of pregnancy. AFLP carries a reported maternal mortality as high as 18% and neonatal mortality as high as 58%. Accordingly, it is important to differentiate AFLP from other causes of liver disease in pregnancy. Methods: A comprehensive chart review of the case was undertaken including assessment of laboratory and radiographic results. A subsequent literature review of the topic was conducted Results: : A previously healthy 36 year old G2 P1 patient presented in active labour with acute jaundice and gave birth to a stillborn child at 382 weeks gestation after an uneventful pregnancy. Post-partum she was found to have an INR 9.2, PTT 95, bilirubin 221 without evidence hemolysis, ALT 242, AST 249, ALP 743, albumin 25, platelets 90, creatinine 183 in addition to grade 2 hepatic encephalopathy and mild hypoglycaemia (CBS 3-4). She was treated with fresh frozen plasma, however, suffered a post-partum hemorrhage on transfer to a tertiary care center ICU. She was treated with fluid resuscitation, transfusion and subsequently furosemide for pulmonary edema. CT scan of the abdomen was conducted showed severe fatty infiltrates of the liver and a moderate amount of ascites but no evidence of hepatic hematoma, infarct or laceration. Subsequent abdominal ultrasound with doppler flow studies and MRCP conducted when her liver tests transiently worsened were non-contributory. Clinically and biochemically the patient improved with conservative therapy without the need for liver transplant. The patient was eventually discharged and chose to undergo LCHAD deficiency testing. Conclusions: Given its high mortality rates, clinicians must consider AFLP in woman in the third trimester of pregnancy with abnormal liver tests. AFLP can be distinguished from HELLP syndrome by its acute onset as well as the prominent presence of coagulopathy, synthetic dysfunction, hypoglycaemia and absence of hemolysis. Early recognition of AFLP is critical in facilitating ICU transfer and initiating the coordinated care of obstetrical medicine, gastroenterology, perinatology and hepatology services from a liver transplant center.

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Chronic Liver Disease Including Alcoholic, Cholestatic, and Metabolic Disease

Poster of Distinction A52 DETECTION AND QUANTIFICATION OF HEPATIC STEATOSIS USING THE FATTY LIVER INDEX: AN EXTERNAL VALIDATION STUDY M. Borman1, A. Pollett2, R. Kirsch2, G. Pomier-Layrargues3, M. Beaton4, M. Levstik4, A. Duarte-Rojo5, D. Wong5, P. Crotty1, M. Elkashab6, R. Myers1 1. University of Calgary, Calgary, AB, Canada; 2. Mt. Sinai Hospital, Toronto, ON, Canada; 3. l'Université de Montréal, Montréal, QC, Canada; 4. University of Western Ontario, London, ON, Canada; 5. Toronto Western Hospital, Toronto, ON, Canada; 6. The Toronto Liver Centre, Toronto, ON, Canada. Aims: Accurate, non-invasive tools for the identification of hepatic steatosis are needed in order to identify individuals at risk for progressive liver disease. The fatty liver index (FLI) has been proposed as a screening tool for fatty liver. Our objective was to validate the FLI for the detection and quantification of hepatic steatosis in an obese population. Methods: In this multi-centre study, patients with chronic liver disease and BMI ≥28 kg/m2 underwent liver biopsy; FLI was calculated using biochemical and anthropometric data. The performance of the FLI for diagnosing hepatic steatosis compared with liver biopsy was assessed using areas under receiver operating characteristic curves (AUROC). Steatosis was graded according to the percentage of hepatocytes with lipid droplets and the NAFLD Activity Score (S0, < 5%; S1, 5-33%, S2, 34-66%; and S3, > 66%). A novel model for the prediction of significant (≥10%) steatosis was developed using logistic regression. Results: 250 patients were included: 65% were male, the median BMI was 33 kg/m2. Overall, the median FLI was 90 (interquartile range [IQR] 78-97; range 27-100). In patients with S0, S1, S2 and S3 steatosis, the median (IQR) FLI was 80 (61-94), 89 (77-97), 94 (82-98) and 91 (82-98) respectively. FLI was weakly correlated with the percentage of steatosis (ρ=0.29, P <0.00005) and steatosis grade (ρ=0.28, P <0.00005). The median FLI was higher among patients with significant steatosis (92 [IQR 83-97] vs. 83 [67-95]; P=0.0002). For the prediction of significant steatosis, the AUROC of the FLI was 0.65 (95% CI 0.57-0.72). According to an optimal FLI cut-off of 83 (defined according to the maximal sum of sensitivity and specificity), the FLI was 75% sensitive, 51% specific, and had positive and negative predictive values of 75% and 51% respectively. Overall, the ability of the FLI to discriminate between individual grades of steatosis was poor (Obuchowski measure = 0.62). Independent predictors of significant steatosis were serum triglycerides, glucose, alkaline phosphatase (ALP), and waist circumference (all P <0.05). A novel model including these factors outperformed the FLI for the prediction of significant steatosis (AUROC 0.76 vs. 0.65; P=0.002). Conclusions: In a cohort of obese patients, the FLI is poorly predictive of significant steatosis and has limited utility for steatosis grading. A novel model based on serum triglycerides, glucose, ALP, and waist circumference may have a role as a non-invasive predictor of steatosis, but requires validation.

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Poster of Distinction A53 IRON INDICES DO NOT PREDICT DISEASE SEVERITY OR RESPONSE TO PHLEBOTOMY IN NAFLD M. Beaton, S. Chakrabarti, M. Levstik, P. Marotta, P. Adams London Health Sciences Centre, London, ON, Canada. Aims: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in the western world. Despite this significant disease burden, short of sustained weight loss and management of metabolic risk factors, there are no specific therapies for NAFLD. Elevated iron indices are well described in NAFLD and iron depletion via phlebotomy has been shown to improve liver enzymes in this condition. While this suggests a relationship between the these disorders, studies to date have yielded conflicting results regarding whether iron plays a significant role in the severity of liver disease in NAFLD. Liver histology is the gold standard for determining the efficacy of treatment for NAFLD. We conducted a prospective study of phlebotomy as a treatment for NAFLD and sought to determine whether pretreatment iron indices correlated with the histologic severity of liver disease and whether they predicted a response to phlebotomy therapy. Methods: Patients with biopsy proven NAFLD underwent phlebotomy to achieve near iron depletion (serum ferritin ≤50 or Hgb 100). All patients underwent liver biopsy prior to and 6 months following the end of treatment. Severity of liver disease was measured using the nonalcoholic fatty liver disease activity score (NAS). This consists of individual scores for steatosis, hepatocyte ballooning and inflammation which contribute to total NAS, with a separate score for fibrosis. Iron indices measured were serum ferritin concentration and hepatic iron concentration (HIC). HIC was determined from liver tissue by high resolution inductively coupled plasma mass spectrometry (HR ICP-MS). Results: 31 patients with biopsy proven NAFLD completed follow up. 61% (N=19) male, mean 49 (27-69) years. Mean baseline serum ferritin 384µg/L (60.5-1461), ALT 64U/L (28-158), HIC 16.5μmol/g (1.6-84), total NAS 3.8 (1-7), Fibrosis 1.6 (0-4). Pre-treatment serum ferritin concentration was associated with increased steatosis on liver biopsy (r 0.395, p=.031). However, neither serum ferritin nor HIC were associated with any other features of disease activity or hepatic fibrosis. Regarding prediction of response to phlebotomy, pre-treatment HIC was predictive of improvement in total NAS (r 0.404, p=0.027). However, neither serum ferritin nor HIC were predictive of improvement in any individual measures of disease activity or fibrosis. Conclusions: This study is the first prospective trial to date evaluating liver histology pre and post phlebotomy therapy in a large number of NAFLD patients. Despite the common coexistence of NAFLD and elevated iron indices they do not reflect the severity of underlying liver disease as measured by the NAS, nor do they predict improvement in liver histology with iron reduction therapy.

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Poster of Distinction A54 AUTOIMMUNE HEPATITIS - LONG-TERM OUTCOMES FROM A DEDICATED CLINICAL PRACTICE J. Mosko, A. Dinani, G. Hirschfield University of Toronto, Toronto, ON, Canada. Aims: Autoimmune hepatitis (AIH) is uncommon and there are relatively few reported large North American cohorts. Our goal was to review the clinical history of patients seen with AIH in our liver clinic. Methods: Chart review and analysis of patients with a clinical diagnosis of AIH seen from 1978-2010. Results: Of 180 patients treated for AIH to date, the mean age at diagnosis was 44 (12-86 years), 75% were female, and 31% non-Caucasian (12% African Americans, 12% Asian, 7% other). 28% had a smoking history whilst 37% had a co-existing autoimmune disease, the most common being hypothyroidism, SLE and IBD, and 26% gave a family history of autoimmune disease. Confirmed overlap with PSC was seen in 6%, whilst confirmed overlap with PBC in 3%. Of the female patients, 13% reported a pregnancy either at diagnosis or during their disease course (26 total pregnancies). Review of clinical characteristics revealed that 64% were symptomatic at diagnosis with 36% of patients presenting with jaundice (average MELD at diagnosis 11). Labs at presentation included a median (range) AST of 239 (19-5600), ALT of 264 (16-5600), ALP of 132 (31-1112) and IgG of 25 (1-100). 69% were ANA +ve (24% <1:40, 17% 1:40-1:80 and 59% >1:80), 47% SMA +ve (50% <1:40, 22% between 1:40-1:80 and 28% >1:80) and 13% AMA +ve. Baseline biopsy revealed cirrhosis in 37% (activity level 0-2 in 63%, 3-4 in 37%). The median pre-treatment IAIHG score was 14 with a median post-treatment score of 16. 82% of patients were started on therapy at diagnosis including 21 receiving steroids alone, 116 receiving steroids and an immunomodulator (Aza/6MP/MMF), and 6 receiving an immunomodulator only. Of those receiving steroids and an immunomodulator, 9% were treated with MMF. Follow-up revealed that 72% of treated patients experienced a clinical remission (disappearance of symptoms, normal serum aminotransferases, bilirubin and IgG levels, normal hepatic tissue or inactive cirrhosis). 43% (78/180) of patients experienced one or more clinical relapse (increase in transaminase >3x ULN and/or increase in IgG >20g/L). Average patient follow-up was 9 years and at completion of follow-up, 46% of patients were on therapy, 16% in clinical remission off treatment, 7% deceased, 6% had been transplanted and 1% developed HCC. Factors at presentation found to be predictors of death or liver transplant included age at diagnosis (p=0.003) and MELD score (p=0.03). The absence of clinical remission (p=0.04) predicted poor outcome. Conclusions: We demonstrate low transplant rates for AIH in our practice but confirm age, severity at presentation and the absence of clinical remission as predictors of poorer outcomes.

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A55 HIGH PREVALENCE OF GASTROINTESTINAL SYMPTOMS IN PRIMARY BILIARY CIRRHOSIS S. Pollifrone, S. Sidani, C. Letendre, M. Bouin, C. Vincent CRCHUM St Luc Hospital, Montreal, QC, Canada. Aims: INTRODUCTION: A high prevalence of gastrointestinal symptoms is reported in cirrhotic patients. Primary Biliary Cirrhosis (PBC) is an auto-immune disease responsible for cirrhosis. Prevalence of GI symptoms in PBC patients is unknown. AIMS: To determine the prevalence of GI symptoms in PBC patients. Methods: METHODS: PBC outpatients were prospectively recruited at the Hepatology unit in a tertiary hospital center between september 2010 and september 2011. All patients accepting to participate in the study completed questionnaires of gastrointestinal symptoms (esophageal, gastric and bowel symptoms according to Rome III criteria) and a questionnaire of extra-digestive symptoms. The frequency of each symptom was measured. Demographic data and Child-Pugh scores were collected for each patient. Results: RESULTS: Forty eight PBC patients (92% females) were included (mean age: 60.3 +/- 8.7 yrs). The Child-Pugh score was A in 87% of cases. The overall prevalence of GI symptoms was 98%. With the following distribution of symptoms: esophageal (63%), gastroduodenal (83%), bowel (87%) and anorectal symptoms (71%). Bloating was the most prevalent symptom with 79% of cases. Two or more symptoms were shown in 63% of patients for esophageal symptoms, 80% for gastric symptoms, 86% for bowel symptoms and 50% for anorectal symptoms. The ROME criteria for IBS were found in 17% of patients. Finally, the prevalence of extra-GI symptoms was 98%. The most prevalent extra-GI symptom was sleeping difficulties (60%) and fatigue was present in 48% of patients. Conclusions: CONCLUSION: According to the data we collected, it seems that GI symptoms are very prevalent in PBC patients. This study underlines the importance of screening these patients for GI complaints, which could be a major issue in the improvement of their quality of life.

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A56 IRON OVERLOAD IS RARE IN PATIENTS HOMOZYGOUS FOR THE H63D MUTATION M. Kelley, N. Joshi, Y. Xie, M. Borgaonkar Memorial University, St. John's, NF, Canada. Aims: Hereditary hemochromatosis (HH) is one of the most common inherited disorders affecting individuals of northern European descent. While previous research has suggested that the H63D HFE mutation is associated with significantly elevated transferrin saturation levels and abnormal transaminase levels the true penetrance of this mutation is still unclear. The goal of this study was to assess the proportion of H63D homozygotes who have or develop laboratory abnormalities consistent with iron overload during the study period. Methods: This was a retrospective study of all individuals in Newfoundland homozygous for the H63D mutation identified between 1999, when genotyping began, through to 2009. Using electronic health records the serum ferritin, iron, transferrin saturation, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) performed closest to the time of genetic testing were recorded for each patient. Follow-up lab values were recorded up to February 2011. Age, gender, liver biopsy results and treatment with phlebotomy were also documented. Iron overload was classified using previously published definitions from the HealthIron study. SPSS version 17.0 software was used for descriptive statistics and to compare means using one-way ANOVA. Results: Between 1999 and 2009, 170 individuals tested positive for H63D/H63D in Newfoundland. One hundred and sixteen (68.2%) were male and 54 (31.8%) were female. The mean age at diagnosis was 48.9±13.0. The mean length of follow-up was 4.2±2.6 years. At the time of genotyping 28.8% had an elevated ferritin (mean 501±829) and 15.9% had an elevated transferrin saturation (mean 0.45±0.18). There was no significant change in the mean ferritin level over time. At genotyping 94 individuals had data available to classify iron overload status. One (1.1%) had iron-overload-related disease, 2 (2.1%) had documented iron overload, 11 (11.7%) had provisional iron overload, and 80 (85.1%) had no evidence of iron overload. Sixty individuals had follow-up data available and of these 1 (1.7%) had iron-overload-related disease, 3 (5.0%) had documented iron overload, 11 (18.3%) had provisional iron overload and 45 (75.0%) had no evidence of disease. No one developed new iron-overload-related disease in follow-up and only one individual developed new documented iron overload. Conclusions: H63D homozygosity was associated with an elevated mean ferritin level that did not change significantly over time. Despite this elevated ferritin only one H63D homozygote had iron-overload-related disease. The H63D mutation does predispose individuals to having a higher ferritin level however the penetrance of the genotype appears to be low.

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A57 PROBABILITY OF C282Y-LINKED HEMOCHROMATOSIS DECREASES AS LIVER TRANSAMINASES INCREASE IN PARTICIPANTS WITH HYPERFERRITINEMIA IN THE HEIRS STUDY P. Adams1, M. Speechley1, J. Barton2, C. McLaren3, G. McLaren3, J. Eckfeldt4 1. University of Western Ontario, London, ON, Canada; 2. Southern Iron Disorders Center, Birmingham, AL; 3. University of California, Irvine, CA; 4. University of Minnesota, Minneapolis, MN. Aims: Hemochromatosis is considered by many to be an uncommon disorder, although the prevalence of HFE C282Y homozygosity is relatively high in Caucasians. Liver disease is one of the most consistent findings in advanced iron overload due to hemochromatosis. Liver clinics are often thought to be ideal venues for diagnosis of hemochromatosis, but diagnosis rates are often low. Methods: The Hemochromatosis and Iron Overload Screening (HEIRS) Study screened 99, 711 primary care participants in North America for iron overload using serum ferritin and transferrin saturation measurements and HFE genotyping. In this HEIRS substudy, serum levels of hepatic transaminases (ALT, AST) were compared between 186 C282Y homozygotes and 1,367 non-homozygotes with an elevated serum ferritin (men > 300 µg/L, women > 200 ug/L). The probability of being a C282Y homozygote was determined for AST and ALT ranges. Results: Mean ALT and AST levels were significantly lower in C282Y homozygotes than non-homozygotes. The probability of being a C282Y homozygote increased as the ALT and AST levels decreased. Conclusions: Patients with hyperferritinemia are more likely to have C282Y-linked hemochromatosis if they have normal liver transaminase levels. This paradox could explain the low yields of hemochromatosis screening reported by some liver clinics.

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A58 URSODEOXYCHOLIC ACID (UDCA) IN TREATMENT OF NONALCOHOLIC STEATOHEPATITIS (NASH): A SYSTEMATIC REVIEW OF RANDOMIZED CONTROLLED TRIALS L. Win, K. Tsoi, H. Witt-Sullivan, K. Khan McMaster University, Hamilton, ON, Canada. Aims: NASH is an epidemic and can progress to cirrhosis. Many drugs including UDCA have been studied for NASH but the efficacy data is non-conclusive. The aim of this study is to systematically review all published randomized studies looking at the effectiveness of low-dose UDCA (LD-UDCA) and high-dose UDCA (HD-UDCA) in the treatment of NASH. Methods: A comprehensive search of MEDLINE and EMBASE (to May, 2011) for fully published, English-language randomised studies evaluating the efficacy of UDCA for NASH compared to placebo/vitamins was done. Primary outcome was any improvement in liver histology after UDCA in patients with biopsy-proven NASH. Secondary outcomes were normalization of liver biochemistries, improvement in liver biochemistries and fibrosis markers, or changes in steatosis by imaging. Results: After the initial search yielded 488 results, 475 were excluded by screening titles/abstracts. Thirteen studies were retrieved in full text and of those, 7 studies met eligibility criteria for analysis. Five looked at the efficacy of LD-UDCA (10-15mg/kg/day) and only two assessed HD-UDCA (23-35 mg/kg/day) in the treatment of NASH. Duration of treatment ranged from 6 weeks to 2 years. Two studies of LD-UDCA (n=221) with histologic outcomes showed a significant improvement in steatosis but no significant changes in other features of NASH. One study with HD-UDCA (n=186) showed significant improvement in lobular inflammation only but not overall liver histology score. One study with LD-UDCA (n=30) showed no significant changes in hepatic density value on imaging. Two studies with LD-UDCA (n=104) showed no difference in ALT normalization and one study with LD-UDCA (n=48) showed a significant increase in AST normalization in UDCA group. One study with HD-UDCA (n=126) showed ALT normalization in 24.5% with UDCA and only 4.8% in placebo group. One study with HD-UDCA (n=126) and 5 studies (n=335) with LD-UDCA showed improvement in liver biochemistries. HD-UDCA significantly reduced serum fibrosis markers in one study. Conclusions: This systematic review shows that most studies of UDCA for NASH are heterogeneous in their outcomes which precludes a meta-analysis and makes interpretation of the overall evidence challenging. LD-UDCA and HD-UDCA may improve liver biochemistries but changes in histologic features of NASH are conflicting. The benefit of UDCA in the treatment of NASH remains questionable, but merits further studies.

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A59 COPPER CONUNDRUM: A CHALLENGING CASE OF WILSON’S DISEASE N. Forbes1, J. Nadarajah2, Z. Kassam1, S. Goodwin1, M. Tarnopolsky1, K. Woodward1, D. Morgan1 1. McMaster University, Hamilton, ON, Canada; 2. University of Ottawa, Ottawa, ON, Canada. Aims: Wilson's disease (WD) is a hereditary condition of copper deposition characterized by multi-organ involvement, mainly resulting in hepatic, neurologic and psychiatric manifestations. WD prevalence ranges from 10-60 cases per million, and by virtue of its rarity as well as its diverse clinical presentation, WD may be challenging to diagnose. Methods: A comprehensive chart review of the case was undertaken, including assessment of radiographic, biochemical and pathological results. A subsequent literature review of the topic was conducted. Results: A 34-year-old man from India was admitted following an acute dystonic episode. Past history revealed a six-year history of tremor and a two-year history of neuropsychiatric disturbances, which had been previously diagnosed as spinocerebellar ataxia, depression and bipolar disorder. Specifically, the patient had progressive mood lability, disinhibition and aggression, along with slurred speech, gait instability, restlessness and rigidity. Physical examination revealed dysarthria, increased tone, hyperreflexia, dysdiadochokinesia and truncal ataxia. No Kayser-Fleischer rings were observed on routine physical examination, but the patient was unable to be positioned for a slit-lamp examination. There were no stigmata of acute or chronic liver disease. Laboratory investigations revealed low serum ceruloplasmin (0.05 g/L), low serum copper (3.4 μmol/L), and elevated 24-hour urinary copper (1.8 μmol), strongly indicative of WD. Transaminases, synthetic liver function and platelet count were unremarkable. Abdominal ultrasound showed coarse echogenicity suggestive of cirrhosis without ascites. Liver biopsy revealed grade 2-3 fibrosis, but was negative for copper staining; other metabolic, granulomatous, neoplastic, viral and toxic processes were ruled out. Brain MRI showed generalized atrophy along with metallic deposition in the brainstem and basal ganglia. Confirmatory genetic tests are pending. The patient was treated with penicillamine, but developed a drug fever and was switched to trientine. His 24-hour urinary copper increased ten-fold to 17.7 μmol after three weeks of therapy. The patient's hypertonicity, ataxia and mood improved gradually while on treatment. Conclusions: Given its rarity and variable clinical manifestations, clinicians must maintain a high index of suspicion for WD. Biochemical markers remain the diagnostic mainstays, and although liver biopsy can be helpful, it does not rule out WD if negative for copper staining, particularly in advanced disease. Ultimately, young patients presenting with unexplained neuropsychiatric symptoms or cirrhosis should be investigated for WD, as morbidity is lower when it is detected early and chelating therapy initiated promptly.

A60 THE UTILITY OF TRANSIENT ELASTOGRAPHY IN MONITORING OF WILSON'S DISEASE A. Chopra, M. Ma University Of Alberta, Edmonton, AB, Canada. Aims: Transient elastography (Fibroscan; EchoSens, Paris, France) is a non invasive technique involving the acquisition of pulse-echo ultrasound signals to measure liver stiffness in adults and children. Transient elastography values increase proportional to the progression in the histological stage of fibrosis. Patients with Wilson’s disease can be difficult to monitor due to the variability of urine copper excretion and the liver biochemical profile does not reflect disease progression accurately. We present a spectrum of distinct cases of Wilson’s disease illustrating the usefulness of transient elastography as a potential useful tool to monitor Wilson’s disease. Methods: 4 patients with liver biopsy and ATP7B gene proven Wilson’s disease were monitored with standard of care and transient elastography yearly. These patients have been followed from 2008 to 2011. Their clinical course, response to therapy (zinc, penicillamine, or trientine) and compliance were assessed with clinical presentation, detail history, liver tests and repeat liver transient elastography measurements. Transient elastography was performed as per standard protocol. Results: Four Wilson’s disease cases (3 males and 1 female) with a mean age of 29.75 +/-6yrs (range 21-37yrs) were reviewed. These patients had hepatic and neurologic/psychological manifestations. Neurological manifestations seen were difficulty with speech articulation, abnormal posturing and fine motor involvement. Psychiatric manifestations included symptoms of aggression and depressed mood. One patient was on zinc therapy on presentation, and had a history of treatment noncompliance (Patient 1). Another patient had a history of noncompliance due to social situation (Patient 2). These 2 patients had early cirrhosis and transient elastography changes correlated with history of compliance. The other two patients (patients 3 and 4) were compliant and transient elastography results remained stable. Conclusions: Wilson’s disease can present with many diverse characteristics and monitoring can be difficult. Transient elastography appears to be an effective method to monitor liver disease progression in Wilson’s disease patients. Patient Characteristics And Transient Elastography Results

Patient 1 (F) Patient 2(M) Patient 3(M) Patient 4 (M) Fibroscan1(KPa) 35.3 23.4 9.1 6 Fibroscan2 (KPa) 21.3 15.4 9.1 5.7 Fibroscan 3 (KPa) 21.3 19 7 5.5 Fibroscan 4 (KPa) 33.3 22 5 4

ALT (U/L) Mean 84+/-10 Mean 40 +/- 5 Mean 27 +/- 10 Mean 35+/-10 Serum Copper Mean 4.3 Mean 5.9 Mean 8 Mean 12

Urine Copper (umol/24h) Mean 12 Mean 9 20->0.7 9.5->undetectable Kpa-Kilopascals, U/L-units per litre, umol/24h-micromol per 24 hours.

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A61 SPONTANEOUS RUPTURE OF HEPATOCELLULAR CARCINOMA (HCC) A. Dinani, E. Greenwald McMaster University, Hamilton, ON, Canada. Aims: A 69 year old male with a history of alcohol-related cirrhosis, Childs B complicated by multifocal HCC presented to the ER with 3 day history of feeling unwell, abdominal distention and diffuse abdominal pain. Recent MRI showed a cirrhotic liver with multiple lesions, largest measuring 6.2 x 4.1x 4.9cm in segment 4A. He denied any fever, chills or recent sick contacts. There were no signs of overt bleeding, confusion or day/night reversal or pedal edema. Methods: On examination, he appeared in obvious distress. Vital signs were suggestive of hypovolemia with a BP of 70/42 and HR 142bmp. He was resuscitated with 3 litres of normal saline and his BP increased to 94/46 and HR remained unchanged. His abdomen was diffusely tender, markedly distended with shifting dullness. There were no peritoneal signs. Routine laboratory tests were as follows: Hg 143 g/L, WBC 24.8 x109/L and platelets of 563 x 109/L. His electrolytes were normal, TBil 23umol/L, INR 1.9, Cr 112umol/L and lactate of 11.5 mmol/L. His MELD score was 17. Results: He was admitted to the ICU and a central line was placed. Diagnostic paracentesis revealed frank blood in the peritoneal cavity. His repeat Hg was 77 g/L. 2 units of packed red blood cells were transfused and the patient became more hemodynamically stable. He underwent a CT scan, which revealed a large amount of dense peritoneal fluid consistent with hemoperitoneum and a large segment 4 mass bulging the capsule. The liver appeared cirrhotic and there were multiple small arterial phase enhancing lesions consistent with multifocal HCC. He underwent an abdominal angiogram and successful transcatheter arterial embolization (TAE) and coiling of the branches of the right and left common hepatic arteries. His vitals and Hg remained stable and he was transferred back to the general medical floor. He required multiple large volume paracentesis despite diuretic therapy and consequently a pig-tail catheter was inserted. He was discharged home with outpatient Palliative Care follow up. Conclusions: Spontaneous rupture of HCC is uncommon in western countries. In Asia and Africa, however, spontaneous rupture is the initial presenting symptom in up to 10% of patients with HCC. Patients usually present with sudden onset of severe abdominal pain and massive hemoperitoneum. The mechanism of rupture is unclear; thought to be a combination of hypervascularity and necrotic nature of the tumour combined with precipitating factors to include increased intravascular pressure, intrahepatic venous obstruction and hyperaemic liver circulation. By far the most commonly identified risk factor is direct pressure of the tumour against the capsule, as was the case in our patient. Treatment in the past was traditionally surgical, however, recent data suggest that TAE has become the initial treatment of choice. The success rate of hemostasis with TAE ranges from 53-100%.

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A62 FAMILIAL HYPOBETALIPOPROTEINEMIA-INDUCED NONALCOHOLIC STEATOHEPATITIS (NASH) - CASE REPORT AND LITERATURE REVIEW. M. Lam1, J. Singham1, R. Hegele2, M. Riazy1, M. Hiob1, G. Francis1, U. Steinbrecher1 1. University of British Columbia, Vancouver, BC, Canada; 2. Robarts Research Institute, London, ON, Canada. Aims: We present here a patient with a novel apoB mutation, V703I. Methods: ApoB immunoblotting was performed on fasting plasma from the patient. DNA was extracted from plasma samples and subsequently from all first-degree relatives, and sent to the Cardiovascular Genetics Lab in London, Ontario. Direct automated sequencing revealed two different mutations in the APOB gene, R463W and V703I. Results: Our patient had liver enzymes abnormalities, increased echogenicity of the liver consistent with steatosis, along with low LDL cholesterol at 0.24 mmol/L and extremely low apoB level at 0.16 g/L. ApoB immunoblotting on fasting plasma showed only a band at the expected apoB100 position. Genetic sequencing revealed our patient to be heterozygous for two mutations (R463W and V703I). R463W has been described to be associated with FHBL. Genetic sequencing of his immediate relatives revealed an asymptomatic brother and father with V703I mutation. His mother and sister are symptomatic with low serum LDL and have R463W mutation. Conclusions: V703I mutation alone is a non-damaging mutation. However, it is possible that it has a contributory role to a more aggressive phenotype in the presence of R463W.

A63 A METANALYSIS OF NUTRITIONAL SUPPLEMENTATION FOR MANAGEMENT OF HOSPITALIZED ALCOHOLIC HEPATITIS R. Antar2, P. Ghali1, P. Wong1 1. McGill University, Montreal, QC, Canada; 2. University of Ottawa, Ottawa, ON, Canada. Aims: Alcoholic liver disease (ALD) carries a high risk of morbidity and mortality. Malnutrition accompanies this condition and may be both a consequence of and a contributor to the pathology. This can be explained by free radical damage and increased risk of infection that occur because of a lack of anti-oxidants, mainly vitamins and proteins. Many trials have investigated the benefits of providing supplemental nutrition in management of patients with ALD. This is a metanalysis of the available evidence. Methods: A systematic review was carried-out by two independent observers, who each searched through the Cochrane, Medline, EMBASE and Google Scholar databases, without restriction on language. Included trials had to compare a special nutritional therapy versus a normal balanced diet, in hospitalized patients with alcoholic hepatitis. Only randomized clinical trials (RCT) were included. A manual search was also performed on the major hepatology journals including Hepatology, Journal of Hepatology and Gastroenterology published within the last 10 years and on the references listed by relevant articles. Results: Seven RCTs were identified, including 262 patients with ALD. Selected studies were of moderate to high quality using the Jadad scale. Pooled analysis of the studies revealed no statistical difference in mortality between the 2 groups (OR 0.80, 95% CI: 0.42-1.52). In addition, nutrition did not significantly improve ascites (OR 1.29; CI 0.52 - 3.20) or any biochemical tests. However, encephalopathy showed a significant improvement or resolution (OR 0.24; CI 0.06 - 0.93). A funnel plot for the log ORs did not show any asymmetry and the I2 test was 0%, hence the data not heterogeneous. Conclusions: Nutritional supplementation provided no mortality difference in patients with ALD. Neither ascites nor biochemical tests significantly improved. However, encephalopathy did significantly ameliorate, and therefore should not be discouraged in that setting. Characteristics and comparability of the included RCTs

Study # of Patients # of Study Days Experimental Nutrition Route of

Nutrition Control

Nutrition Nasrallah et

al. 1980 35 (18 control, 17 study) 28 Amino-acids, MVI IV Hospital diet

Naveau et al. 1985 37 (19 control, 18 study) 28 40 kcal/BW, MVI, glucose, fat, amino-

acids IV Hospital diet

Calvey et al. 1985

64 (22 control, 21 conventional protein, 21 BCAA formula) 21 2000 kcal, carbohydrate, MVI, 65g

protein vs. 25g BCAA + 40g protein PO or IV (if PO

not possible) Hospital diet

Achord 1987 28 (14 control, 14 study) 21 860 kcal, amino-acids IV Hospital diet Simon et al.

1988 32 (17 control, 14 study) 28 Dextrose, amino-acids, lipids, MVI IV Hospital diet

Bunout et al. 1989 36 (19 control, 17 study) 28 50 kcal/ BW, dextrose, casein (protein),

lipids PO Hospital diet

Kearns et al. 1992 31 (15 control, 16 study) 28 167 kJ/kg, 1.5g protein/kg PO Hospital diet

BCAA = branched chain amino-acids; MVI = multivitamins; BW = bodyweight; IV = intravenous; PO = oral

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Clinical Practice

A64 CANADIAN COLON CLEANSING SCALE (CCCS): A VALIDATED INSTRUMENT FOR ASSESSING QUALITY OF COLON CLEANSING REGIMENS FOR COLONOSCOPY O. Cruz Pereira1, S. Vanner1, A. Rostom2, L. Hookey1 1. Queen's University, Kingston, ON, Canada; 2. University of Calgary, Calgary, AB, Canada. Aims: Optimum colon cleansing is essential to the efficiency, safety and effectiveness of colonoscopy. To identify the optimum cleansing regimen we need a validated colon cleansing scale. The Ottawa Bowel Preparation Scale (OBPS) is the best tool currently available but its value is now limited by recent advances in technology for washing and emerging data suggesting greater emphasis should be placed on the right colon as interval neoplasm occur more in the right side, possibly due to flat lesions and higher prevalence of right sided film with new low volume cleansing regimens. Thus, we sought to create a new sensitive and validated colon cleansing scale that can by taking into account these recent advances. Methods: The OBPS was initially modified and presented to a focus group of 10 gastroenteroIogist and 4 GI fellows. Two fundamental issues were identified: 1) Does total fluid collected correlate with OBPS and 2) does the right sided segment score correlate with total OBPS? To examine these questions, we analyzed unpublished data from three completed colon cleansing trials examining Pico-salax and polyethylene glycol solution (PEG) in which OBPS and total fluid collected was recorded during screening colonoscopies of adults. The correlation between the segmental score in the right colon and the total OBPS and the total fluid suctioned and the OBPS was calculated using a Pearson correlation coefficient. Results: Data from 590 patients was analyzed. In all three studies we found that total fluid collected correlated and right segment score strongly correlated with OBPS (see table). Based on these data, input from the focus group, and the emerging data about neoplasms and bowel preparations, we concluded that the scoring of the right colon should be weighted more than the middle and left by separating segment scores into right colon and remainder of colon; negative points should be awarded for right colonic film; extent of washing and suctioning could be measured as total fluid suctioned; and that this scale should not be applied to cases where water is used for insufflation. Conclusions: We have identified key features which will increase the accuracy of a new colon cleansing scale. The next step is to refine these elements in a segmental scoring system with the aid of our focus group and then prospectively evaluate its reliability and validity in a clinical study.

STUDY CORRELATION COEFFICIENT N Split dose Study 1 OBPS to total fluid OBPS to right side score 0.429* 0.812* 220

Component Study 2 OBPS to total fluid OBPS to right side score 0.528* 0.785* 87 95 Breakfast Study Picosalax 3 OBPS to total fluid OBPS to right side score 0.358* 0.851* 202

Breakfast Study PEG 3 OBPS to total fluid OBPS to right side score 0.518* 0.861* 73 *p<0.0001 1 Flemming et al. GIEndscopy. In press. 2 Vanner and Hookey. CJG. In press. 3 Melicharkova et al. CJG abstract 2011.

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A65 FACTORS INFLUENCING PREMATURE END OF PPI PRESCRIPTION IN CHRONIC NSAIDS USER AT RISK OF GASTROINTESTINAL COMPLICATIONS. I. Le Ray1, F. Vauzelle-Kervroëdan2, M. Bardou1 1. CIC-P INSERM 803, CHU de Dijon, Dijon, France; 2. Ethypharm, Saint Cloud, France. Aims: Gastroprotection with a PPI is recommended for patients at risk for gastrointestinal (GI) complication (older than 65 years, with a past history of GI ulcer or receiving antiplatelet agents) receiving a nonsteroidal anti-inflammatory drug (NSAID), especially when it is on a chronic basis. Whereas it is well known that patient's compliance diminishes during the course of treatment, maintenance of PPI prescription by the physician, another factor potentially influencing GI protection has been less studied. This study aimed at assessing maintenance of PPI prescription in chronic at-risk NSAIDs users and factors potentially associated with PPI disruption Methods: We used a validated electronic database (LPD, Cegedim) covering a representative panel of general practitioners in France. Included patients received NSAID prescription for at least 2 years from 2007, without more than 180 days-long interruption, associated with an initial concomitant prescription of a PPI. Kaplan Meier curves were used to explore the probability of still being treated by PPI at 12 and 24 months from index prescription. Risk factors for PPI disruption were described by univariate and multivariate Cox analyses. The GI complications rates were compared using Student's t-test. Results: A total of 1856 at-risk patients were included. Patients were mostly female (63.8%) and older than 65 years (74.4%). Most frequent comorbidities were hypertension (55.1%) and hypercholesterolemia (40.8%). Median number of NSAID prescriptions during study period was 8 (min 2, max 24). The probability of being still prescribed a PPI concomitantly to NSAID was 77.5% [95%CI 75.6-79.4] and 68.3% [66.1-70.4] one and two years after study inclusion respectively. Risk factors for PPI disruption were: change in NSAID molecule (OR 2.01, 95% CI:1.69-2.39, p<0.001), female gender (OR 1.20; 1.01-1.42, p<0.05), absence of GI side effects (OR 1.26; 1.01-1.58, p<0.05). The number of co-prescribed drugs had a protective effect (OR 0.94[0.91-0.96], p<0.001). PPI co-prescription was reintroduced in 50% of the case within the next 6 months following its stop. As no specific reason to reintroduce PPI was reported by the practitionners in about 70% of the cases, it is likely that interruption was unintended. GI complications rate was significantly higher for patients without adequate PPI prescription (17.8% vs 12.8%, OR 1.48; 1.12-1.98, p=0.007). Conclusions: This study shows that adequate PPI prescription is obtained for only two-thirds of chronically NSAID-treated at-risk patients initially receiving a PPI. It is of real concern as PPI disruption appears to be associated with an increased GI complications rate.

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A66 WAIT TIMES FOR DIAGNOSTIC COLONOSCOPY AMONG PATIENTS WITH COLORECTAL CANCER: A COMPARISON WITH CANADIAN ASSOCIATION OF GASTROENTEROLOGY TARGETS M. Sey, J. Gregor, P. Adams, N. Khanna, C. Vinden, D. Driman, N. Chande University of Western Ontario, London, ON, Canada. Aims: Timely access to colonoscopy has been a nationally recognized issue in Canada. Prior studies have documented significant wait times for a variety of indications. However, none have specifically examined wait times for colonoscopy among patients with colorectal cancer. Our aim was to examine wait times for diagnostic colonoscopy among patients with colorectal cancer and compare it to Canadian Association of Gastroenterology (CAG) wait time targets. Methods: A retrospective review of all cases of colorectal cancer diagnosed with out-patient colonoscopy in 2010 in London, Ontario was performed. Wait times from date of referral to consultation and colonoscopy was reviewed and compared to maximal wait times established by CAG stratified by indication. Cancer staging at the time of diagnosis was compared to colonoscopy wait times. Wait times for pre-operative endoscopic ultrasound and magnetic resonance imaging for rectal cancer staging were also examined. Results: 108 colorectal cancer patients were diagnosed with out-patient colonoscopy during the study period. 35%, 39%, 40%, 50%, 50%, 45% of patients exceeded CAG maximal wait times for the indications of anemia, hematochezia, high likelihood of cancer based on imaging or physical exam, new onset change in bowel habits, screening colonoscopy, and follow up for positive screening fecal occult blood test, respectively. Higher cancer stage was associated with shorter wait times, likely as a result of triaging. Only 59% of potentially treatable stage 1-3 colorectal cancers met wait time targets. Mean wait times for endoscopic ultrasound and MRI for pre-operative rectal cancer staging were 33 and 28 days, respectively. Conclusions: Long wait times for diagnostic colonoscopy among patients with colorectal cancer remains an issue with a significant proportion of cases not meeting CAG maximal wait time targets.

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A67 SURVEY OF PHYSICIAN PRACTICES IN THE PREVENTION OF VENOUS THROMBOEMBOLISM (SPOT) J. Sam, R. Thanabalan, G. Nguyen Mount Sinai Hospital Centre for Inflammatory Bowel Disease, University of Toronto, Toronto, ON, Canada. Aims: Hospitalized inflammatory bowel disease (IBD) patients are at an increased risk of venous thromboembolism (VTE). We aimed to determine physician perceptions of VTE risks and self-reported practices regarding VTE prophylaxis in hospitalized IBD patients among North American gastroenterologists. We also sought to identify patient factors that may influence prophylaxis. Methods: All gastroenterologists who are current members of the American Gastroenterological Association (AGA) and who have cared for IBD patients in the past 12 months were included. A questionnaire was developed to assess physician’s perceptions of VTE risks among IBD inpatients, and to assess practices in VTE prophylaxis for hospitalized IBD patients and other factors that may influence the decision to provide prophylaxis. The questionnaire was administered via an online survey engine (Novi-Survey). Results: A total of 95 gastroenterologists participated in this study, with a mean of 13.8±11.6 years in practice. The majority of participants (80%) practiced in an academic setting. Forty-four percent had >50% IBD patients in their practice, and 95% had provided care for IBD inpatients. Most physicians (84%) reported having had IBD patients develop VTE. Though the majority (84%) was aware that hospitalized IBD patients have a higher risk of VTE compared to non-IBD patients, 23% did not routinely assess patients for signs and symptoms of VTE on admission to hospital. Only 60% cared for IBD patients in hospitals that had protocols for VTE prophylaxis, and 43% were aware of any published guidelines for VTE prophylaxis in hospitalized IBD patients. While 4% believed that any rectal bleeding is a contraindication to VTE chemoprophylaxis in hospitalized IBD patients with flares, 14% never administered prophylaxis to IBD inpatients with flares. VTE prophylaxis was deemed unnecessary in young (<40 years) and ambulatory IBD inpatients by about 6% and 20% of respondents, respectively. About 24% believed that hospitalized IBD patients in remission without high-risk comorbidities do not require VTE prophylaxis. There was no consistent agreement on the duration of anticoagulation for a first unprovoked VTE in an IBD patient. Conclusions: There are discrepancies in VTE prophylaxis in IBD patients among gastroenterologists. As the greatest relative risk of VTE occurs in hospitalized IBD patients <40 years, these patients should receive prophylaxis, as should hospitalized IBD patients in remission. Rectal bleeding is not a contraindication to prophylaxis. Pharmacological VTE prophylaxis should be offered to almost all hospitalized IBD patients. Standardized protocols and societal guidelines for VTE prophylaxis need to be developed to improve health outcomes for IBD inpatients.

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A68 FACTORS ASSOCIATED WITH SHORT WITHDRAWAL TIME AND POLYP DETECTION RATE DURING COLONOSCOPY D. Yik, R. Enns, J. Telford, L. Halparin, E. Lam, J. Amar, A. Ramji, B. Bressler St. Paul's Hospital, Vancouver, BC, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A69 UTILITY OF DOUBLE BALLOON COLONOSCOPY IN PATIENTS WITH PRIOR INCOMPLETE CONVENTIONAL COLONOSCOPY A. Alfadda, J. Love, P. Kumar, S. Heitman University of Calgary, Calgary, AB, Canada. Aims: Double balloon colonoscopy (DBC) can be used to accomplish cecal intubation and endoscopic intervention in patients with previously failed conventional colonoscopy. Although high success rates have been previously reported using this technique, the worldwide literature is relatively limited. We evaluated the utility of DBC at a Canadian tertiary care centre. Methods: All DBC procedures performed in Calgary, Alberta Canada were retrospectively reviewed. Patient demographics, procedure indication, cecal intubation rate, mean procedure time, need for fluoroscopy, types of therapeutic interventions performed and immediate and late complications were determined after review of the procedure reports and patient charts and following telephone follow-up. Results: Between January 2008 and October 2011 a total of 47 DBCs were performed on 38 patients. The mean age of the patients was 64 yr (range 49-80 yr) of which 58% (22/38) were female. The indication for DBC in 68% (26/38) of the patients was failure to reach the cecum with conventional colonoscopy. The rest were done to stabilize and/or improve positioning for therapeutic intervention in a redundant colon even though the cecum had been visualized. Cecal intubation was successful in 88% (23/26) of patients when it couldn’t be reached with conventional colonoscopy. All 3 of the failed cases were due to a fixed angulation in the sigmoid colon. There were 2 failures among the 12 patients who had DBC to stabilize the colon. Both were due to poor preparation and were completed with a 2nd attempt. Therefore, 92% (35/38) of patients ultimately underwent successful DBC. The mean total procedure time was 44 mins (range 21-85 mins). All patients underwent the procedure with conscious sedation using comparable doses of medication as used during conventional colonoscopy. Fluoroscopy was used in 12 of the 47 procedures (26 %). Therapeutic interventions were performed in 45% (21/47) of the procedures which included polypectomy, clipping, argon plasma coagulation, and tattooing. There were no early or late complications documented in the medical record or reported by the patients during a telephone follow-up. Conclusions: DBC is highly effective for completing endoscopic visualization of the entire colon and for performing therapeutic intervention when conventional colonoscopy has been unsuccessful. Our failures occurred in patients with fixed angulations and in those with poor bowel preparation. The procedure can be done in a reasonable amount of time, is safe and can generally be done without fluoroscopy.

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A70 PROVINCIAL VARIATIONS IN GASTROINTESTINAL ENDOSCOPY (GIE) FEE-FOR-SERVICE PAYMENTS ACROSS CANADA: 2008-2009 D. Armstrong, S. Khanna Division of Gastroenterology & Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A71 GASTROINTESTINAL ENDOSCOPY IN CANADA: NATIONAL TRENDS FROM 2004-5 TO 2008-9. D. Armstrong, S. Khanna Division of Gastroenterology & Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada. Aims: Gastrointestinal (GI) endoscopy is central to the management of many GI conditions. However, wait times for consultation and investigation with gastroenterologists are prolonged and it is proposed that this may be due to limitations on access to GI endoscopy because of financial and human resource constraints. This study aimed to evaluate changes in Canadian endoscopy service delivery over the last 4 years for which data are available. Methods: National and provincial data on upper endoscopy (EGD), colonoscopy (Colo) and sigmoidoscopy (Sig), published by the Canadian Institute for Health Information (CIHI) in the National Physician Database, were extracted for two, 12-month periods (2004-5 & 2008-9) to determine changes in procedural numbers, over a 4-year period, with reference to changes in the overall population. Data are presented as: (a) overall number of procedures, and (b) number of procedures per capita (95% CI). Results: Data were available for all provinces except P.E.I. and the territories. Between 2004-5 and 2008-9, there was a 4.30% increase in the Canadian population. During the same period, 434,693 more procedures were performed; this was an overall increase of 31.8% in the number of GI endoscopy procedures performed per capita (Table), encompassing increases of 44.2% (Newfoundland), 53.8% (Nova Scotia), 13.0% (New Brunswick), 15.2% (Quebec), 49.3% (Ontario), 12.9% (Manitoba), 15.4% (Saskatchewan), 8.20% (Alberta) and 21.9% (British Columbia). Conclusions: The number of GI endoscopies performed, per capita, in Canada increased significantly from 2004-5 to 2008-9 although there was significant interprovincial variation in the extent of these increases. The greatest increase, seen for colonoscopy (55.0%), may reflect adoption of formal colon cancer screening programs but EGD also increased (16.4%), in all provinces except New Brunswick and Alberta; sigmoidoscopy decreased (18.4%) in all provinces except Nova Scotia. Improving Canadians' access to care for digestive diseases may require greater resources but the significant increase in GI endoscopies suggests that there is also a need for robust endoscopy quality assurance programs to ensure that resources are managed appropriately across all jurisdictions. GI endoscopy procedural numbers

2004-2005 2008-2009 Change (%) Procedure # (total) # (per capita) 95% CI # (total) # (per capita) 95% CI per capita

EGD 406,792 0.0128 0.0128 to 0.0128 492,888 0.0149 0.0149 to 0.0149 + 16.41 Colo 599,175 0.0189 0.0189 to 0.0189 969,307 0.0293 0.0292 to 0.0294 + 55.03 Sig 154,236 0.0049 0.0049 to 0.0049 132,701 0.0040 0.0040 to 0.0040 - 18.37

TOTAL 1,160,203 0.0366 0.0365 to 0.0367 1,594,896 0.0482 0.0481 to 0.0483 + 31.80 Population 31,704,900 33,068,000 + 4.30

Source: National Physician Database - http://www.cihi.ca/

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A72 VIDEOCAPSULE VERSUS ENTEROSCOPY IN PATIENTS WITH OBSCURE GI BLEEDING: PLANNED INTERIM ANALYSIS OF AN OUTCOMES RCT A. Barkun1, D. Segarajasingam2, S. Hanley1, K. Waschke1, P. Burtin3, J. Parent1, S. Mayrand1, C. Fallone1, G. Jobin4, M. Martel1 1. Gastroenterology, McGill University, Montreal, QC, Canada; 2. Gastroenterology and Hepatology, Royal Perth Hospital, Perth, WA, Australia; 3. Service de gastro-entérologie, CHU, Anger, France; 4. Hôpital Maisonneuve-Rosemont, Université de Montréal, Montreal, QC, Canada. Aims: Videocapsule endoscopy (VCE) is associated with increased detection of mucosal lesions in patients with obscure gastrointestinal bleeding compared to Enteroscopy (E). Its clinical relevance is debated with few high quality outcomes trials. Methods: We randomly allocated adult patients with occult bleeding (iron deficiency anemia >6 months needing transfusion/ iron with repeated occult blood positive testing), or with overt bleeding (>1 episode of melena/ hematochezia within 6 months with hemoglobin drop) to VCE or E (of the push-type in most cases) after a negative initial work-up (single or repeated gastroscopy and colonoscopy examinations with or without small bowel radiology). The main outcome was recurrence, persistence of bleeding using standardized a priori criteria over 1 year. Cross-overs were permitted after the main outcome was reached. Results: 79 patients (68.5+/-14.5yrs, 36.7% female) included over a 5-year period. 40 were allocated to VCE and 39 to PE. Overall, 76.0% presented with overt bleeding. At baseline, 24.1% were taking ASA, 11.4% an anticoagulant, and 2.5% on NSAID; 76.7% of patients had had a nuclear scan, and 37.0% an angiography. No marked clinically meaningful between-group imbalances were noted. One or multiple lesions were detected in 72.5% of the VCE group compared to 48.7% for E of patients (p=0.03). They were thought to be related to bleeding in 79.3% and 35.0% (p=0.002) in the VCE and E patients respectively. The mean duration of follow-up was 289.0+/-118.8 days, with 50.0% requiring a blood transfusion (42.5% in VCE vs 57.9% E, p=0.174) with a mean of 2.9+/-5.0 units (2.8 +/- 4.3 and 3.0+/-5.6 units in the VCE and E groups, respectively, p=0.645), 40.0% patients in the VCE group and 53.9% in the PE were hospitalized for bleeding or continuing bleeding (p=0.218) (mean stay: 11.0 +/-11.9 and 18.5 +/-28.2 days respectively, p=0.219). Overall 5.1% had surgery related to the GI bleed (5.0% in VCE and 5.1% in E, p=0.979). 35.4% of patients have crossed over (amongst these, 48.7% from E to VCE Four patients died in the VCE group and none in the E (P=0.043). Conclusions: VCE results in increased diagnostic detection of lesions related to bleeding. The subsequent impact on clinical care was not significantly greater in this trial although trends favoured the VCE group. Recurrence rates were high in both groups. Following an initial work-up that includes the performance of gastroscopy and colonoscopy, a VCE exam may be a more efficacious next management step than is an enteroscopy.

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A73 THE “NATURAL HISTORY” OF DECLINED OUTPATIENT REFERRALS E. de Boer1, S. Veldhuyzen van Zanten2 1. University of Alberta Hospital, Edmonton, AB, Canada; 2. Leids Universitair Medisch Centrum, Leiden, Netherlands. Aims: Wait times to outpatient gastroenterology services has been a well-documented problem in Canada. It is a serious problem in the Edmonton zone; ranking the second worst after mental health according to a 2005 survey. Over the past 24 months, a comprehensive wait time management program has been developed, tested and evaluated by the GI Division at the University of Alberta (UofA-GI) Hospital in Edmonton. The aim of this study was to evaluate “the natural history” of outpatients who were referred for Gastroenterology (GI) problems to the UofA-GI and declined. Methods: Included patients were declined in the period January-June 2010 for one of the following indications: abdominal pain, rectal bleeding, FOBT+ stools and iron deficiency. For each patient data were obtained about consultations by other GI/surgeons working in the region, clinically relevant diagnoses and number and type of GI related X-rays. A clinically relevant diagnosis was defined as a diagnosis that would change the medical management of the patient in question. Data were obtained through our electronic medical record which is linked to the regional patient information system. The period included 12 months following the rejection of the referral and 24 months preceding the referral. Results: The sample size was 230 patients. 83 patients had the indication ‘abdominal pain’, 59 ‘rectal bleeding’, 48 FOBT+ stools and 40 patients iron deficiency anemia. In total 47.8% (110/230) of patients was seen by another gastroenterologist or surgeon after decline. In 9.1% (21/230) a significant diagnosis was made. In the abdominal pain group 12% (10/83) had a significant diagnosis: 5 adenomas, 1 inflammatory polyp, 1 Crohn’s disease, 1 Barrett esophagus, 1 gastric ulcer, 1 inguinal hernia with SB obstruction. In the rectal bleeding group 5.1% (3/59) had a significant diagnosis: 2 adenomas, 1 ulcerative colitis. In the FOBT+ group 6.3% (3/48) had a significant diagnosis: 3 adenomas. In the iron deficiency group 12.5% (5/40) had a significant diagnosis: 1 colon cancer, 3 adenomas, 1 celiac disease. A lot of GI related X-rays (abdominal X-ray, ultrasound, CT-scan, UGI, SBFT and barium enema) were ordered. 40% of patients has at least one or more GI related X-ray before decline, after decline this percentage increased further to 55%. Conclusions: Approximately 50% of declined patients is seen by other gastroenterologists or surgeons and in 10% a clinically important diagnosis is made. This patient group undergoes a lot of GI related X-rays both before and after decline.

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A74 DYNAMIC PATIENT POSITION CHANGES DURING COLONOSCOPE WITHDRAWAL AND ADENOMA DETECTION: A PROSPECTIVE RANDOMIZED TRIAL E. Kim, G. Ou, I. Hemmati, R. Enns, B. Bressler, A. Ramji, L. Halparin, E. Lam, J. Amar, H. Ko, S. Whittaker, J. Telford University of British Columbia, Vancouver, BC, Canada. Aims: An important indicator of colonoscopy quality is adenoma detection rate. East et al. published a randomized crossover study of dynamic position changes during colonoscope withdrawal and reported improved polyp detection. Our objective was to confirm these results by assessing polyp detection in patients undergoing colonoscopy with prescribed position change during colonoscope withdrawal and compared to usual care. Methods: The authors undertook a randomized controlled trial of prescribed position change during colonoscope withdrawal. Inclusion criteria included: Age ≥ 40 years. Exclusion criteria included: Inpatient status, inflammatory bowel disease, polyposis syndrome, prior colon resection, incomplete colonoscopy, poor bowel preparation, and musculoskeletal disorders. Patients were randomized to either “static” colonoscope withdrawal (usual care) or “dynamic” position change: right colon examined in left lateral decubitus, transverse colon in supine, and splenic flexure/left colon in right lateral decubitus. Nine gastroenterologists at St. Paul’s Hospital performed all colonoscopies. Primary outcome was number of polyps detected. Secondary outcomes were polyp size, location and pathology, and other variables that may affect polyp detection rate. The mean polyp detection rate was compared in the two groups using the Student’s t-test. The sample size required to detect a 20% difference in polyp detection rate with 80% power and a p-value of 0.05, was 338 subjects in each group. Interim analysis was performed after approximately 100 subjects were randomized. This study was approved by the IRB. Results: From July through September 2011, 58 subjects were randomized to the dynamic and 68 to the static groups. The mean age was 60 (SD 10) years and 50.8% were women. The mean number of polyps detected per subject was 1.6 (SE 0.19) in the dynamic group and 1.3 (SE 0.25) in the static group. There was no difference in total polyp detection between the two groups (p=0.39). Conclusions: The interim analysis did not show a difference in polyp detection with prescribed dynamic position change compared to usual care. The study will continue to accrue subjects to meet the required sample size.

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A75 ENTERAL NUTRITION FOR INDUCTION OF PEDIATRIC CROHN’S DISEASE: A ONE-YEAR FOLLOW-UP. J. Turcotte, J. Turner, E. Wine, R. Persad, H. Huynh Stollery Children's Hospital, University of Alberta, Edmonton, AB, Canada. Aims: Despite the fact that enteral nutrition (EN) is a recognized therapy for induction of remission in pediatric Crohn’s disease (CD), long-term data and outcomes regarding this approach are lacking. The aim of our study was to determine the one-year outcome of pediatric patients treated with EN for induction of CD. Methods: Using the Pediatric Inflammatory Bowel Disease (IBD) Database at the University of Alberta, we performed an audit of all pediatric patients diagnosed with CD over the last five years (2005-2010) given EN for first induction of remission. Eighty three patients were diagnosed with CD over that period, with 38 first treated using EN. Six were excluded for incomplete data. Results: Thirty patients were Caucasians; 59% were males. Most patients had ileo-colonic disease (63%), perianal disease was present in 31% of patients; no patient had exclusive colonic disease. Mean age at diagnosis was 12.6±3.1 years, with a mean pre-disease duration of 153 days. The mean Pediatric Crohn’s Disease Activity Index (PCDAI) at diagnosis was 32±12 (range 13-63). The majority of these patients were treated with a polymeric formula (97%), with nasogastric tube feeds, oral feeds or a combination of both. The mean caloric intake was 58 calories/kg/day (35-82). Patients were treated for six to twelve weeks. At their first follow-up visit, patients had a mean reduction of nineteen points in their PCDAI scores (mean PCDAI score 13±10). Patients had gained a mean weight of 1.7kg and height of 0.5cm from diagnosis. Only three patients (9%) had failed induction with EN and had been treated with steroids. At one year post-diagnosis, nine patients (28%) had required steroids at some point during the past year. Most patients (81%) were on maintenance therapy with an immunomodulator (mostly azathioprine), while five patients were on an anti-TNF antibody. The mean PCDAI score at one-year was five, with a mean reduction of 27 points. Both weight and height had improved, with mean change of 8.8 kg and 4.7 cm respectively. Conclusions: EN in pediatric patients with CD appears to be effective as an induction therapy with most patients achieving remission. A minority of patients had flares requiring steroids. Furthermore, at one year post diagnostic, maintenance therapy with an immunomodulator following EN appears to be effective in supporting disease remission in most patients, with a significant reduction in the PCDAI score.

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A76 DOES PET SCAN MEASURE UP TO COLONOSCOPY? K. Grzywacz, J. Rebeuh, T. Sophie, C. Faure CHU Sainte Justine, Montreal, QC, Canada. Aims: Positron Emission Tomography (PET) scans detect enhanced abnormal glucose metabolism. As gastroenterologists in a large pediatric tertiary care center we are often confronted with the question of whether a colonoscopy is indicated in patients who present with increased uptake in the digestive tract on PET scan. We sought to compare colonic findings on PET with endoscopy, the gold standard. Methods: We performed a retrospective review of all body PET scans over a period of 4 years (2008-2011) and identified patients with small bowel and/or colonic enhancement, with approval from our institution. We then isolated patients who had undergone endoscopy and studied the macroscopic findings. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) were calculated for the following anatomic areas: rectosigmoid, descending, transverse, ascending colon, caecum (including ileocecal valve) and terminal ileum (TI). Results: 162 pediatric patients (90 males, 72 females), median age 13 years (range 1month-20 years), had at least 1 PET for all indications at Sainte Justine University Hospital. Forty-six patients showed enhancement of the digestive tract (small bowel and or colon). Nineteen patients had a colonoscopy (3 excluded due to greater than 3 month delay between PET and colonoscopy). The sensitivity was less than or equal to 50% for the colon, but 100% in the TI. Specificity ranged from 58.3-100% for the colon and over 90% in the TI. PPV was very variable in all anatomic segments, and NPV showed a narrower range excluding the rectosigmoid , see table. Conclusions: Given our variable results we conclude that PET is not an efficient tool in detecting small bowel and colonic disease, however our study is limited by the small number of patients who underwent colonoscopy. Furthermore when PET findings are normal, disease is unlikely to be visualized on endoscopy. Overall the TI had the most reliable values.

Rectosigmoid Descending Colon Transverse Colon Ascending Colon Caecum and Ileocecal valve TI Sensitivity 25% 50% 50% 0 25% 100%Specificity 100% 92.8% 92.8% 64% 58.3% 90.9%

PPV 100% 50% 50% 0 16.7% 66% NPV 57.1% 92.8% 92.8% 81.8% 70% 100%

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A77 TOLERABILITY AND EFFICACY OF PEG3350 WITHOUT ELECTROLYTES FOR BOWEL PREPARATION IN THE PEDIATRIC POPULATION. A. Lambrinakos-Raymond1, T. Ngan1, S. Forget2, D. Lévesque2, V. Morinville2, A. Sant'Anna2, E. Seidman3, T. Sigman2, N. Ahmed2 1. McGill University, Montreal, QC, Canada; 2. Montreal Children's Hospital, Montreal, QC, Canada; 3. McGill University Health Centre, Montreal, QC, Canada. Aims: To describe our experience with the efficacy and tolerance of PEG 3350 without electrolytes as a 1 day bowel preparation for colonoscopy in the pediatric population. Methods: As part of a quality assurance initiative, patients were asked to complete a questionnaire regarding the tolerability of their bowel preparation and physicians were requested to evaluate the adequacy of visualization at colonoscopy. Patients who received PEG3350 without electrolytes followed a 1 day protocol. The dose was weight based; patients were prescribed 6g/kg if under 40kg, or 238g if over 40kg. The preparation was diluted in 2L of a sports drink to be taken at around noon over a 4 hour period or less the day prior to colonoscopy. Diet consisted of a full liquid diet for 2 days prior to the procedure, and a clear liquid diet the day prior to procedure. Patients were encouraged to drink plenty of clear fluids after the PEG 3350 administration. In addition, patients were instructed to take another 17g/hour up to 2 times, each dissolved in 250ml of liquid, followed by another litre of clear fluids if stools were not watery clear by early evening. Results: 32 patients (16 male) with the mean age of 12 years (range: 4-17years) took the preparation between July and September 2010. 24 patients (75%) were able to successfully complete the entire preparation. Bowel preparation with the 1 day PEG 3350 regimen was considered effective, with (at a minimum) more than 90% of the mucosa being well visualized, in 31 patients (96.8%). 23 patients (71.9%) stated that they would repeat the same bowel preparation, 4 patients (12.5%) stated that they would not (but only in 2 patients was it secondary to the preparation itself) and 5 patients (15.6%) did not answer the question. The preparation was rated as tasting “ok” or “good” by 24 patients (75%), poor by 2 patients (6.3%) and 6 patients (18.8%) did not respond. The most common side effects were flatulence (43.8%), nausea (40.6%) and abdominal pain (37.5%). Conclusions: The 1 day PEG 3350 without electrolytes bowel preparation is an effective and well-tolerated regimen for colonoscopy in the pediatric population.

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A78 PERI-OPERATIVE MANAGEMENT OF CROHN’S DISEASE: CURRENT PRACTIVE PATTERNS T. Perry, B. Dicken, L. Bistritz University of Alberta, Edmonton, AB, Canada. Aims: Crohn’s disease requiring surgery is a complex problem for gastroenterologists and surgeons. In the absence of strong evidence or clinical practice guidelines regarding peri-operative medication use for Crohn’s, practice pattern varies. We present survey data of the current management of peri-operative Crohn’s disease in Canada. Methods: A case-based survey was distributed via e-mail to members of the Canadian Association of Gastroenterology and the Canadian Association of General Surgeons. One case presented a scenario of active Crohn’s disease, and the other, a case of fibrostenotic Crohn’s disease. Questions regarding when to discontinue Crohn’s medications pre-operatively, and if/when they should be started post-operatively were included. Opinions regarding the risk of post-operative complications including wound healing and infection related to Crohn’s medications were also sought. Results: Twelve gastroenterologists and 60 surgeons responded to the survey. In the setting of active Crohn’s disease, most respondents would continue 5-ASA drugs (57.5%), antibiotics (63%), and steroids (57.5%) until the day of surgery, while fewer would continue azathioprine (39.7%) or methotrexate (34.3%)until the day of surgery, and only 21.9% would continue anti-TNF drugs up to the day of surgery, with the remainder preferring to discontinue anti-TNF agents up to 6 weeks pre-operatively. The majority of respondents thought the risk of complications were very low for 5-ASA(56.2%) and antibiotics (71.2%). Azathioprine and methotrexate were thought to increase the risk of post-operative complications by 23.3% and 24.7%, respectively. Steroids (45.2%)and anti-TNF agents (28.8%) were thought to be associated with increased post-operative complications. 5-AS (42.5%), antibiotics (41.4%) and steroids (37%) were likely to be started within the first 2 weeks post-op by most respondents, while 20.5% of patients on azathioprine, 31.5% on methotrexate, and 31.5% on anti-TNF therapy for active Crohn’s would not be restarted at all post-operatively. Response patterns were similar for the fibrostenotic Crohn’s disease scenario. In terms of the benefits of post-operative medical therapy, 28.7% thought 5-ASA drugs reduced the risk of recurrence, 19.2% for antibiotics, 26% for azathioprine, 13.7% for methotrexate, 6.8% for steroids, and 32.8% for anti-TNF agents. Conclusions: Respondents were most concerned with post-operative complications associated with anti-TNF drugs and steroids, which could be why these agents were more likely to be discontinued pre-operatively. Many respondents would not consider post-operative medical therapy in these patients, possibly because opinions as to their effectiveness were not high. More evidence-based guidelines are needed to guide practice in this area.

A79 IS PROTON PUMP INHIBITOR USE ASSOCIATED WITH IRON DEFICIENCY IN PATIENTS WITH NORMAL ENDOSCOPY?A QUALITY IMPROVEMENT STUDY. A. Kohansal, J. Flemming, S. Gruchy, K. Peltekian, D. Sheppard Dalhousie University, Halifax, NS, Canada. Aims: Proton pump inhibitors(PPI's) are among the most commonly prescribed medications in the world, and the treatment of choice for several gastrointestinal illnesses. While generally safe medications, side effects have been associated with PPI use. A possible side effect is iron deficiency. The proposed mechanism is reduced gastric acid interfering with the absorption of ingested non-heme iron. However, significant iron deficiency associated with PPI use remains clinically unproven. We performed a retrospective case-control study to further investigate this subject. The primary goal was to compare the population of iron deficient patients without a clear endoscopic or histopathologic cause to a control group of patients without iron deficiency. Methods: We reviewed outpatient charts of referrals for assessment of anemia to an urban gastroenterology practice, in the period between 2003-11. A total of 445 charts were reviewed, with initial referring diagnoses of anemia,iron deficiency, or overt GI bleed. Cases with confirmed iron deficiency, defined as a ferritin of equal or less than 40 ng/ml were extracted. Cases with upper and lower endoscopy and no endoscopic or histopathologic findings that could be designated as a cause of iron deficiency were identified. The ratio of patients with documented use of PPI's versus patients not on therapy was calculated. Strict inclusion and exclusion criteria are detailed in Figure 1. A control group, defined as "non iron deficient" based on documented ferritin level of >60 ng/ml was identified. Results: Of the 445 reviewed patients, 52 met the selection criteria. 58% (30/52) were on PPI treatment. 41 cases were selected as controls. 32% (13/41) of the controls were on PPI treatment. The odds ratio of iron deficiency in patients on PPI was 2.93 (CI =1.2459 to 6.9237) P value= 0.0138. Conclusions: There is a positive association between PPI use and iron deficiency in patients without an endoscopic or histopathological cause. There is a statistically significant difference in PPI use between iron deficient and control groups. These findings warrant further study with a larger sample size and a multivariate analysis of factors such as age, medical history, and medications. Table 1-Baseline characteristics of the cases and controls

Variable Iron def. pts Controls P value Age, mean(SD) 58.96 (11.84) 68.08 (10.81) 0.0001

Gender, n (%) Female Male 29 (55.77) 23 (30.33) 20(49.78) 21(51.22) 0.50 on ASA 12 (23.08) 18 (43.90) 0.03

on NSAID 9 (17.31) 4 (9.76) 0.29 Iron Sat%, mean (SD) 20.35 (42.05) 23.34 (16.69) 0.66

EGD 52 (100) 26 (63.41) 0.0047 Colonoscopy 52 (100) 24 (58.54) 0.0030

+ve EGD 0 (0) 13 (31.71) 0.0074 +ve Colonoscopy 0 (0) 14 (34.15) 0.0059

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COLONOSCOPY IS INDICATED TO INVESTIGATE AN INCIDENTAL CT FINDING OF ILEOCOLONIC WALL THICKENING W. Ho, N. Saloojee University of Ottawa, Ottawa, ON, Canada. Aims: The growing availability of cross-sectional imaging such as computed tomography (CT) has resulted in an increasing number of cases in which incidental ileocolonic thickening is seen. Whether to further pursue investigation with colonoscopy is a common clinical dilemma. The aim of this study was to determine the yield for significant pathology when colonoscopy is used to investigate an incidental CT finding of ileocolonic thickening. Methods: In a tertiary referral centre, we prospectively collected 68 cases in which colonoscopy was performed to evaluate an incidental finding of ileocolonic thickening. Exclusion criteria were a previous diagnosis of inflammatory bowel disease, lack of colonoscopy within 180 days, clinically obvious gastrointestinal pathology such as ileus, pancreatitis, or fistula, or radiological evidence of a mass. Results: 31 patients met inclusion criteria. Abdominal pain (81%) was the most frequent reason for obtaining a CT, followed by bright red blood per rectum (6.5%). Inflammatory bowel disease (25.8%), infection (25.8%), and malignancy (19.4%) were the three most common imaging impressions as to the likely diagnosis. Twenty patients (64.5%) had a normal colonoscopy while 9 patients (29%) had a significant pathology such as ischemia (19.3%), malignancy (6.5%), or inflammatory bowel disease (3.2%). Patients under the age of 50 all had a normal colonoscopy. Conclusions: Although the majority of patients had normal endoscopic findings, colonoscopy should be performed in patients with ileocolonic wall thickening seen on CT. Nearly thirty percent of such patients had significant pathology.

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A81 CASE-SERIES: UTILITY OF HEMOSPRAYTM IN MANAGEMENT OF BENIGN UPPER AND LOWER GI BLEED OF VARIOUS ETIOLOGIES S. Moosavi, A. Barkun McGill University, Montreal, QC, Canada. Aims: HemosprayTM is a truly novel endoscopic hemostatic technology that has been recently approved in Canada for management of benign upper and lower GI bleed. We herewith present a case series of 4 patients with upper or lower GI bleed of different etiologies, emphasizing various HemosprayTM indications. These cases highlight our emerging clinical experience in endoscopic management of GI bleed with HemosprayTM . Methods: A retrospective chart review of 4 patients with GI bleed of different etiologies, treated with HemosprayTM at the McGill University Health Centre, Montreal, QC, Canada were carried out. These patients highlight the implication of HemosprayTM in management of various etiologies of GI bleed. Results: All 4 subjects (3 males, age range 56-82 yrs) presented with GI bleeding. The underlying bleeding etologies included colonic polypectomy, ERCP-associated sphincterectomy, peptic ulcer, and esophageal stricture dilatation. The final case highlights the prophylactic utility of HemosprayTM in a patient who underwent bougieanage dilatation for esophageal stricture that led to mucosal tear at risk for subsequent bleeding. Immediate hemostasis was achieved in 2 of 3 acutely bleeding patients. However, in ERCP-associated sphicterectomy, the initial application of HemosprayTM did not achieve a desirable hemostasis, partly due to poorly adapted delivery system of ERCP scope, and required further endoscopic intervention to optimally terminate bleeding. Moreover, the bile flow from the sphincterotomy opening appeared to be halted by the powder accumulation at the common bile duct opening that was re-established through repeat cannulation. All but 1 patient received less than 1 capsule of HemosprayTM (i.e.20 gm per patient; 30 gm in the 4th patient). No further rebleeding was reported up to a mean follow-up of 32 days following optimal hemostasis with HemosprayTM (range of 7 - 65 days). The patient with prophylactic application of HemosprayTM for the management of mucosal tear secondary to balloon dilatation was restarted on full anticoagulation within the next 2 days. Other patients were not on Anti-coagulants or Anti-platelet treatments. Conclusions: HemosprayTM appears to be a safe and effective method in managing common etiologies of both upper and lower GI bleeds. Although the optimal target patient groups are unclear, its mechanism of action probably works best in those with active bleeding. Caution may need to be exercised when attempting hemostasis with HemosprayTM through a side-viewing scope or near the biliary tree. More extensive experience and controlled trials are required to better characterize the most optimal use of this promising, novel hemostatic therapy that has the potential for revolutionizing the endoscopic approach to management of selected patients with both upper and lower GI bleeding.

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A82 GASTROINTESTINAL(GI) HEMORRHAGE IN PATIENTS UNDERGOING EXTRACORPOREAL MEMBRANE OXYGENATION (ECMO) K. Muthiah, D. Moffatt, D. Freed, C. White University of Manitoba, Winnipeg, MB, Canada. Aims: Institution of ECMO for advanced life support in patients with prolonged respiratory failure and cardiogenic shock is increasing. The incidence of GI hemorrhage in these patients is unknown. To evaluate the incidence and etiology of gastrointestinal hemorrhage in patients on ECMO and to assess the safety of endoscopy in these patients. Methods: A retrospective chart review from patients who underwent ECMO at St. Boniface general hospital between December 2007 and July 2011 was performed. Patient demographics, co-morbid medical conditions, H.Pylori status, medication use (i.e anti coagulant, anti-platelet and PPI) OG/NG insertion & intra-aortic balloon pump (IABP) use as well as indication, type and duration of ECMO were obtained. GI hemorrhage was defined in the patient records and characterized as severe if one of the following was present: hemoglobin drop by >20 g/L, increased ionotropic support or transfusion of more than 4 units of pRBCs. Type of endoscopic evaluation and therapies were documented, as well as the response to these therapies. Incidence of surgical intervention and death related to GI bleeding were also obtained. Results: A total of 54 patients were included in the study. GI hemorrhage occurred in 30 (55%) of patients and occurred after, during and before ECMO administration in 11 (37%), 16 (53%) and 3 (10%) respectively. Peripheral and central cannulation for ECMO was used in 41 (76%) 13 (24%) patients respectively. Six patients had veno-venous circulation for respiratory support and 4 of them developed GI hemorrhage. Eleven (37%) had intra-aortic balloon pump in addition to ECMO. The cause of GI hemorrhage was isolated to the upper GI tract in 26 (87%) and lower GI tract in 4 (13%). Endoscopy was performed in 21(70%) patients and 7 (33%) underwent therapeutic hemostasis. Endoscopic proven causes of GI hemorrhage were: peptic ulcers or erosion (n=8), erosive esophagitis (n=4), ischemic colitis (n=4), gastric angiodysplasia (n=1), ischemic gastritis (n=1) and post sphincterotomy bleed (n=1). Three patients did not respond to endoscopic or conservative management and required surgery, one required fluoroscopic embolization, and two patients died as a result of upper GI tract hemorrhage. There were no complications related to endoscopy in patients on ECMO. Conclusions: In patients undergoing ECMO, GI hemorrhage is a common complication occurring in 55% of patients. Bleeding appears to be more common in the upper GI tract in these patients and in general is not severe. Bleeding from lower GI tract is less common and is secondary to ischemic colitis in most cases, with up to 75% patients requiring surgical intervention. Endoscopy appears to be safe in this patient population when indicated however therapeutic interventions were limited to those with upper GI tract hemorrhage.

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A83 PROSPECTIVE ASSESSMENT OF PATIENT SATISFACTION WITH ENDOSCOPY AT AN ACADEMIC PEDIATRIC CENTRE T. Ngan3, S. Forget2, D. Lévesque2, V. Morinville2, A. Sant'Anna2, E. Seidman1, T. Sigman2, N. Ahmed2 1. McGill University Health Centre, Montreal, QC, Canada; 2. Montreal Children's Hospital, Montreal, QC, Canada; 3. McGill University, Montreal, QC, Canada. Aims: To assess patient and family satisfaction among pediatric patients undergoing gastrointestinal endoscopic procedures. Methods: A questionnaire was administered to 110 patients over 3 months to assess satisfaction with endoscopy as part of a quality assurance initiative. Simultaneously, gastroenterologists and endoscopy nurses completed a separate questionnaire. Results: 92(83.6%)patients and 100% of physicians/nurses returned the questionnaires. 44.6% of patients underwent procedures with gastroenterologist administered sedation and 55.4% with general anesthesia. All respondents rated their overall experience as good, very good or excellent. Pre-endoscopy, most were satisfied with the information provided, however some patients responded that they were not adequately informed of potential risks(7.8%), sedation options(10%) and alternatives to the procedure(20.7%). 6(6.5%) patients rated the wait-time for the procedure as unacceptable while physicians rated the wait-time as unacceptable for 12(13%) patients. The day of the procedure, 13.3% of respondents rated the wait at the hospital as fair or poor. All respondents rated the physician’s technical skills, the nurses/support staff’s personal manner and the overall rating of the visit as good, very good or excellent. 96.7% stated that they would undergo repeat endoscopy by the same physician. Among patients who received gastroenterologist-administered sedation, 34.1% reported pain during the procedure. The presence of pain correlated inversely with the patient’s willingness to undergo repeat endoscopy using the same type of sedation. Conclusions: At our center, patient satisfaction with endoscopy is positive, although several issues were identified for improvement including explanations of alternatives to the procedure and sedation options. For procedures under sedation, the presence of pain may affect willingness to use the same form of sedation in the future, however, further evaluation is needed in a larger cohort.

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A84 CURRENT PRACTICE OF CELIAC-DISEASE DIAGNOSIS IN CENTRAL AND NORTHERN ALBERTA M. Saginur, C. Prosser, R. Persad, H. Huynh, J. Turner University of Alberta, Edmonton, AB, Canada. Aims: Our study objective was to determine the number of pediatric patients in our geographic catchment with positive screening anti-tissue transglutaminase testing (aTTG greater than 10U/mL); the number who were referred and biopsied for celiac disease; and the proportion of biopsies that might be avoided by the adoption of serologic diagnosis of celiac disease. Methods: We performed a retrospective record review of children up to 17 years of age tested at the University of Alberta Hospital laboratory , which performs all aTTG assays for northern and central Alberta. Anti-TTG assays from November 1, 2008 to November 30, 2010 were identified through an automated search of the laboratory's electronic records. We then identified endoscopies performed to diagnose celiac disease for the same population and timeframe at Stollery Children's Hospital, the only tertiary referral center providing pediatric gastroenterology services to this same geographic area. Two investigators independently reviewed endoscopy lists. The two datasets were then linked using patients’ unique identifying numbers. Results: During the study period, there were 400 positive aTTG screens in 355 patients. At the same time, 170 patients were biopsied for celiac disease, including 68% (116/170) positive for the disease. Of the screening aTTGs, 41% (144/355) were greater than 100U/mL. All 53 of the patients biopsied during the study period with TTGs greater than 100U/mL were biopsy-positive for celiac disease. Conclusions: In practice, children with positive celiac serology often do not undergo endoscopic biopsies to confirm their celiac disease. Future research should clarify how these patients are being managed. The current pediatric standard of care requires small-bowel biopsies in all patients to diagnose celiac disease (1); however, the observed specificity of a high anti-tissue transglutaminase level (aTTG greater than 100U/mL) has led some investigators to question the need for biopsies to diagnose all cases of celiac disease (2). Acceptance of the serologic diagnosis of celiac disease for patients with high aTTGs could avoid the indication for endoscopy in about 40% of pediatric patients. REFERENCES 1. Hill ID, Dirks MH, Liptak GS, et al. Guideline for the diagnosis and treatment of celiac disease in children: recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition. J Pediatr Gastroenterol Nutr. 2005 Jan;40(1):1-19. 2. Mubarak A, Wolters VM, Gerritsen SAM, et al. A biopsy is not always necessary to diagnose celiac disease. J Pediatr Gastroenterol Nutr. 2011;52(5):554-7.

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Cytokines and Intracellular Signals

A85 VITAMIN D MODULATES INNATE IMMUNITY IN INTESTINAL EPITHELIAL CELLS M. Yona, S. Dionne, E. Seidman IBD Research Lab, Research Istitute of McGill University Health Centre, Montreal, QC, Canada. Aims: Intestinal epithelial cells participate in innate immunity and tolerance induction, maintaining gut immune homeostasis. Defective innate immunity is implicated in IBD. Vitamin D modulates innate immunity and was shown by our team to induce NOD2 expression & defensins(Wang et al, J Biol Chem 2010). Our aim was to examine the effect of 1,25 dihydroxyvitamin D3 (1,25D) on the immune response of intestinal epithelial cells to bacterial antigens. Methods: SW480, HT-29 and Caco-2 cells were pretreated (24h) with 1,25D (100 nm) or vehicle and stimulated with PAM3CSK4 5μg/ml, LPS 500 ng/ml, flagellin 100 ng/ml, R848 5μg/ml or muramyldipeptide (MDP) 5μg/ml, ligands for TLR2, TLR4, TLR5, TLR7/8 and NOD2, respectively. Chemokines, defensin β2 and thymic stromal lymphopoietin (TSLP) levels were determined by ELISA. E-cadherin, CYP24 and LC-3 II levels were determined by Western. Results: Increased E-cadherin & CYP24 expression confirmed that all 3 lines responded to 1,25D. MDP increased SW480 chemokine (IL-8, CCL20) production, whereas Caco-2 & HT-29 cells were unresponsive. Antimicrobial peptide defensin β2 levels were very low in Caco-2 & HT-29, while SW480 secreted appreciable amounts. Subsequent experiments focused on SW480 cells. Defensin β2 was induced by LPS (46 ± 12 pg/ml),and 1,25D pretreatment increased levels 2.9-fold (p<0.01). MDP and LPS co-stimulation increased defensin β2 by 22% and 66% in vehicle and 1,25D treated cells, respectively (p<0.05). Similar results were obtained with PAM3CSK4 & flagellin. LPS-induced IL-8 increased 21% with 1,25D treatment, while IL-8 induced by MDP + LPS increased 32% (p<0.05). 1,25D decreased CCL20 induced by LPS alone and LPS with MDP by 21% and 30%, respectively (p<0.01). Flagellin induced levels of CCL20 decreased by 60% with 1,25D, while the 3-fold increased CCL20 induced by MDP + flagellin was reduced (-15%) by 1,25D. Autophagy of monocytes was shown to be induced by 1,25D via cathelicidin. We examined whether autophagy was induced in SW480 by 1,25D. Autophagy marker LC-3 II was detected in untreated SW480, but levels were not modulated by 1,25D. Epithelial cells may condition dendritic cells (DC) toward tolerance via release of TSLP . However, TSLP was not detected in any of the intestinal epithelial cell lines tested, +/- 1,25D. Conclusions: Impaired acute recruitment of neutrophils was reported in CD and low IL-8 was implicated. Our results demonstrate that 1,25D enhanced intestinal epithelial IL-8 release upon TLR and NOD2 signaling, while CCL20 production decreased. Since CCL20 selectively attracts T cells and DC, our results suggest that 1,25D modulates epithelial cell innate responses with enhanced defensin β2 and IL-8. Supported by a NSERC summer studentship award (MY) and a CIHR New Emerging Team Grant in Clinical Autoimmunity (ES).

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A86 THE NUCLEAR COREPRESSOR NCOR1 IS A NOVEL REGULATOR OF THE INFLAMMATORY RESPONSE IN INTESTINAL EPITHELIAL CELLS. S. St-Jean, C. Jones, D. Grbic, F. Gendron, F. Boudreau Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: Intestinal epithelial cells (IECs) playan important role in the homeostasis of the intestine.They are constantly exposed to a large variety of pathogens and they act as a physical barrier to foreign antigens. IECs also play an important role in the production and secretion of cytokines and chemokines essential for the inflammatory response. Recent studies have shown that the nuclear corepressor NCOR1 controls the activation of macrophages by repressing a large variety of pro-inflammatory genes in normal conditions. The aims of this study were to determine how NCOR1 could regulate pro-inflammatory genes in IECs and how this could control the intestinal inflammatory response. Methods: Interleukine-1β (IL-1β) and lipopolysaccharide (LPS) were used to mediate the inflammatory response on Caco-2/15 and HT-29 cell lines. NCOR1 expression was monitored by western blot and q-PCR. shRNA against NCOR1 were used in Caco-2/15 and HT-29 cells to identify new target genes of NCOR1 in IECs..Expression of these targets was confirmed by ELISA and q-PCR. Luciferase assays were performed in T84 cells with the minimal CXCL8 promoter containing both NFκB and AP-1 sites.Finally, colitis was induced in wild-type (WT) and NCORΔID/Villin-cre mice using dextran sodium sulfate (DSS) to determine the impact of the loss of interaction between NCOR and nuclear receptors in the intestinal epithelium. Results: NCOR1 nuclear expression was rapidly increased in both Caco-2/15 and HT-29 cell lines followingone hour of stimulation by either IL-1β or LPS.These modulations were not reflectedat the mRNA level. When NCOR1 expression was reduced using specific shRNA, an important amount of CXCL8 was detected in culture media of Caco-2/15 cells. This result was also confirmed by q-PCR. Luciferase assays using T84 cells with NCOR1 shRNA showedthat the CXCL8 promoter was highly induced in the absence of the corepressor. When WT and NCORΔID/Villin-cre mice were treated with 3% DSS in the drinking water for 7 days, NCORΔID/Villin-cre mice showed an increase in the index of disease severity when compared to the WT mice. Moreover,,NCORΔID/Villin-cre mice were less prone to recuperate following the 7 days DSS treatment as determined bysurvival andbody weightassessment during the recuperation period. Conclusions: These observationssuggest that NCOR1 could be implicated in the negative control of intestinal inflammatory response as well as during mucosal restitution following intestinal injury.

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A87 REGULATION OF INTESTINAL SMOOTH MUSCLE CELL GROWTH VIA CYTOKINE-DEPENDENT MODULATION OF PDGF-Rβ EXPRESSION D. Nair, T. Han, S. Lourenssen, M. Blennerhassett Queen's University, Kingston, ON, Canada. Aims: Intestinal inflammation causes increased wall thickness, in part through smooth muscle cell proliferation. Elsewhere, smooth muscle proliferation in vitro or in vivo is associated with modulation or loss of phenotype, but this is poorly understood in the intestine. Since our recent studies showed the appearance of the growth factor receptor PDGF-Rβ in the inflamed colon of rats, we examined the effect of pro-inflammatory cytokines on PDGF-Rβ expression and the consequences to proliferation of intestinal smooth muscle cells. Methods: Adult circular smooth muscle cells were obtained from the mid-descending rat colon by enzymatic dissociation as previously published. Cohort cultures were treated with cytokines (50 ng/mL) and evaluated by qPCR and western blotting for mRNA and protein levels of PDGF and PDGF-Rβ. Results: Freshly isolated CSMC displayed very low levels of mRNA and undetectable protein levels for PDGF-Rβ. However, by 4 days in vitro, mRNA levels increased 20-fold over initial levels and immunocytochemistry showed positive staining. Exposure of these primary cultures to TNFα or IL1β for 17 hr did not significantly change expression of mRNA for PDGF-Rβ. However, by passages 4-7, IL1β and TNFα caused robust upregulation of mRNA by 10±0.7 and 15±1 fold, respectively. In contrast, TGFβ decreased PDGF-Rβ expression by ~2-fold (n=3). Comparison of primary with later passage cultures showed that continued proliferation altered CSMC phenotype, with decreased cell size and accelerated growth. Surprisingly, this also caused the onset of spontaneous expression of PDGF-BB, as proven by western blotting and by conditioned medium-induced phosphorylation of PDGF-Rβ. Conclusions: Pro-inflammatory cytokines that increase expression of growth factor receptors may lead to enhanced smooth muscle cell proliferation in vivo. Evidence in vitro indicates that this will promote phenotypic loss that might, over time, promote the formation of intestinal strictures, as seen in chronic inflammation in IBD. In contrast, agents such as TGF or others inhibitors of PDGF-Rβ function may serve to limit CSMC growth and thus tend to support the contractile phenotype. This suggests new approaches to control of smooth muscle growth will be beneficial in IBD. Supported by the CCFC and by a fellowship (DN) from Ferring, CAG and CIHR.

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A88 ISOFORM-SELECTIVE ROLES OF PI3-K COMPLEXES IN THE FAK/SRC-MEDIATED SUPPRESSION OF ANOIKIS IN HUMAN IECS. M. Beauséjour, D. Noël, D. Jean, M. Demers, P. Vachon Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: In human IECs, the PI3-K/Akt-1 pathway is crucial for the Fak/Src-mediated promotion of cell survival and suppression of anoikis. PI3-K consists of a complex formed by a catalytic (C) and regulatory (R) subunit. Three R (p85α, β, and p55γ) and four C (p110α, β, δ and γ) isoforms are known. It is established that: i) PI3-K isoform complexes can be selectively expressed and/or activated depending on the cell type studied; and ii) these isoforms can perform distinct roles, even within the same given cell type. Herein, we analyzed the expression of PI3-K isoforms and determined their roles in the Fak/Src-mediated regulation of cell survival and anoikis suppression in human IECs. Methods: Expression of PI3-K R and C isoforms in cells of the human HIEC cell line were determined by RT-PCR and Western blot (WB). Predominant PI3-K isoform complexes were determined by immunoprecipitation (IP) of R subunits and verification of association (co-IP) of C subunits by WB. Activation of Akt-1 (S473 phosphorylation), Fak (Y397 phosphorylation) and Src (Y418 phosphorylation), as well as functional Fak/Src interactions (phosphorylation of Y576/577 of Fak, by Src), were monitored by IP and WB. The following specific kinase activity inhibitors were used: PF573228 (Fak), PP2 (Src), PIK75 (p110α) and TGX221 (p110β). Expression knockdown of R or C isoforms was performed by transfection of specific siRNAs. Overexpression of wt p85α, p85β or p55γ were carried out by lentiviral delivery. Anoikis was induced by maintaining cells in suspension. Apoptosis/anoikis was evaluated by ISEL and/or fluorometric CASP-3 activity assays. Results: 1) the predominant PI3-K complexes expressed by HIECs are p110α/p85β and p110α/p55γ; 2) both complexes are engaged by cell adhesion/Fak/Src signaling; however, the engagement of p110α/p85β is both Fak- and Src-dependent, whereas that of p110α/p55γ is Src-independent; 3) the inhibition and/or siRNA-mediated knockdown of p110α, but not that of p110β, results in Akt-1 down-activation and consequent apoptosis; 4) the knockdown of p85β or p55γ, but not that of p85α, likewise induces Akt-1 down-activation and apoptosis; and 5) the overexpression of either p55γ or p85β promotes HIEC survival, whereas only that of p55γ additionally confers a measure of anoikis resistance. Conclusions: Our results indicate that PI3-K isoforms are indeed selectively engaged in the Fak/Src-mediated promotion of human IEC survival and suppression of anoikis. However, these also suggest that although anoikis suppression concomitantly promotes cell survival, the latter does not necessarily reciprocates with regards to the former. (Supported by the CIHR).

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A89 IDENTIFICATION OF THE PEKIN DUCK INTERLEUKIN-10 RECEPTOR-2 Q. Yao1, K. Fischer2, L. Tyrrell3, K. Gutfreund1 1. Department of Medicine, University of Alberta, Edmonton, AB, Canada; 2. Medical Microbiology & Immunology, University of Alberta, Edmonton, AB, Canada; 3. Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada. Aims: The aim of this study was to identify and characterize duck IL-10R2 (duIL-10R2) and the duck IL-10 receptor complex with the long-term goal to study the role of immunomodulatory cytokines in the immunopathogenesis of acute and chronic duck hepatitis B virus (DHBV) infection. Methods: The open reading frame of duIL-10R2 was obtained by RT-PCR with primers based on chicken sequence and 5' RACE from duck splenocytes. IL-10R2 transcript levels were assessed by real-time PCR and normalized to GAPDH. Results: Sequence analyses revealed an open reading frame encoding a 343 amino acid protein. The predicted protein showed an identity of 76%, 42% and 43% with chicken, human and murine homologues, respectively. The mature duIL-10R2 protein has similar structure to chicken and mammalian species. DuIL-10R2 transcripts were widely expressed in primary and secondary immune organs, lung, liver and kidney. In freshly isolated peripheral blood mononuclear cells (PBMCs) duIL-10R2 mRNA was readily detected. During prolonged culture IL-10R2 transcripts increased in the absence of mitogens. Mitogen stimulation resulted in a marginal transient increase of duIL-10R2 transcripts followed by a decline to levels below those of control treated cells. Conclusions: DuIL-10R2 has significant homology with mammalian and chicken homologues. The identification of the duIL-10 receptor complex will allow the study of the role of the identified duIL-10 isotype proteins in receptor binding and signaling. This may also facilitate the evaluation of strategies that block IL-10 signaling to enhance T cell effector function in proof of concept immunotherapeutic studies and the identification of other class 2 cytokine receptors that share the IL-10R2 common chain in the duck model of chronic hepatitis B infection.

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A90 INCREASED EXPRESSION OF P2Y2 RECEPTOR DURING INFLAMMATORY BOWEL DISEASES IS REGULATED BY TRANSCRIPTION FACTOR C/EBPβ. É. Degagné, F. Gendron Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: Extracellular nucleotides act as danger signal molecules and are secreted by cells following injury, hypoxia or stress. They allow the neighbouring cells to respond accordingly by activating the P2Y receptor family. We previously demonstrated that P2Y2 receptor (P2Y2R) expression is increased in tissues of patients suffering from Crohn’s disease or ulcerative colitis and in a mouse model of colitis. We are now investigating transcriptional regulation of P2Y2R in the context of inflammatory bowel diseases (IBDs). C/EBPβ is a transcription factor that regulates transcription of genes involved in response to inflammation and injury as seen in IBDs. We published the promoter sequence of P2Y2R and found potential binding sites for C/EBPβ. Our hypothesis is that under conditions seen in IBDs, the transcriptional regulation of the P2Y2R is controlled by transcription factor C/EBPβ. Methods: Mice were given 4% DSS in drinking water for 7 days. Colons were extracted and paraffin-embedded. Immunofluorescence was performed using an anti-C/EBPβ Ab and expression of C/EBPβ evaluated. Cotransfections in Caco-2 cells were done using previously generated pGL4.10 luciferase expressing-vector containing the human P2Y2R promoter and the C/EBPβ-expressing vector. The interaction was determined by luciferase assays. To induce a chemical injury, Caco-2 cells were treated 6 hours with 0.5% DSS before performing luciferase assays. Chromatin immunoprecipitation (ChIP) assays were realized using Caco-2 cells mechanically injured or not for 6 hours using a pipet tip to scratch the monolayer. C/EBPβ binding to P2Y2R promoter region was determined by real-time PCR using specific primer pairs that recognize the promoter region that contains C/EBPβ potential binding sites. Results: Expression of transcription factor C/EBPβ is upregulated throughout the colonic gland of our mouse model of colitis. We established by ChIP assays that C/EBPβ can bind in vivo to the promoter region of P2Y2R under normal conditions (2.5 fold increase (FI) ratio signal/noise) and following a 6 hour mechanical injury (5.2 FI ratio signal/noise). C/EBPβ can also transactivate in vitro the promoter region of P2Y2R under normal conditions (2.5 FI over empty vectors) or following a chemical injury (10 FI over empty vectors). Conclusions: We demonstrated that C/EBPβ expression is upregulated in a mouse model of colitis and that this transcription factor regulates the expression of P2Y2R in vivo and in vitro under normal conditions and following a chemical or mechanical injury. These results provide evidence to further study the physiological role of P2Y2R in IBDs.

Epidemiology and the Burden of Illness

A91 CHANGES IN CHOLECYSTECTOMY RATE AND TECHNIQUE AND THEIR EFFECT ON ERCP UTILIZATION IN MANITOBA: A POPULATION BASED STUDY D. Moffatt, B. Yu, Y. Wei, C. Bernstein University of Manitoba, Winnipeg, MB, Canada. Aims: We aimed to evaluate the population rate of open (OCx) and laparoscopic cholecystectomy (LCx) between 1984-2009 in Manitoba, and to compare rates of cholecystectomy (Cx) between the sexes, age groups and geographic location. Secondly we aimed to evaluate if changes in LC rates affected the rate of open bile duct exploration (OBDE) and ERCP Methods: All physician-patient interactions are logged in the administrative databases of Manitoba Health (MH), the single insurer of everyone in the Province of Manitoba. All patient contacts are recorded through a unique personal health identification number; procedures are identified by tariffs billed by surgeons/endoscopists; ICD-9 codes are used for all inpatient stays until 2004 and after 2004 with ICD-10 coding. Unique physician tariff codes exist for OCx, and Cx with OBDE. Cx were coded as LCx or OCx using ICD 9 coding from 1984-2004 and afterwards using ICD 10 coding. All Cx performed in Manitoba from 1984-2009 were analyzed. Background data on the overall population of Manitoba was obtained from the MH Registry file Results: In 1984-2009, the overall annual number of Cx has ranged from 2229 to 2394 (p>0.05) and the population rate has remained unchanged 20.08/10,000 (1984) to 19.46/10,000 (2009) (p=1.0). Rates of LCx increased from 0% (1984) to >90% (1993-2009) in both males and females (Figure 1). At all time points in the study, women were more likely to undergo Cx than men with a mean rate of 29.9/10,000/year v 11.27/10,000/year (p<0.001). Cx before the age of 20 was rare but increased from 1.16 (1984) to 3.67/10,000 (2009)(p<0.05). Cx between 20-39, 40-59, 60-79, and >80 showed variable rates from 1984 to 2009 with decreases in Cx in older patient populations and increases in the 20-39 age group (Figure 2). Patient location (urban, rural south, rural mid, rural north) had no effect on Cx rates in men, but in women, rural residence resulted in a 2-3 fold increase in Cx rate, with northern rural women having the highest recorded rates of 41.96- 65.04/10,000 population. Rates of OBDE decreased with a mean of 87.2/year during 1984-1989, compared to 20.2/year during 2004-2009, (76.8% reduction) (p<0.01). Utilization of therapeutic ERCP over the same time periods increased 10-fold (1.27 - 12.71/10,000 population). Conclusions: The population rates of Cx have been stable in Manitoba from 1984-2009 despite dramatically increased utilization of LCx. The population undergoing Cx is changing, with trends towards more female and younger patients. Rural (v urban) women had a 2-3 fold increase in Cx with the highest being found among rural northern women. The decrease in OBDE is likely related to increased therapeutic ERCP utilization. (Supported by a CAG/CIHR grant).

Figure 1: Rate of LC vs. all Cx in Manitoba over time

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A92 TRENDS IN UTILIZATION OF DIAGNOSTIC AND THERAPEUTIC ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY(ERCP) IN MANITOBA: A POPULATION BASED STUDY D. Moffatt, B. Yu, Y. Wei, C. Bernstein University of Manitoba, Winnipeg, MB, Canada. Aims: It is assumed that ERCP has changed from a diagnostic modality to a therapeutic modality and that the overall number of ERCPs may be decreasing due to competing diagnostic modalities such as CT, MRI and endoscopic ultrasound. Little data exists in the literature to support these assumptions. We aimed to assess how diagnostic and therapeutic ERCP utilization has changed between 1984-2009 on a population-based level and to evaluate trends in ERCP utilization by sex, age, and geographic location within the Province of Manitoba. Methods: All outpatient and inpatient physician-patient interactions are logged in the administrative databases of Manitoba Health (MH), the single insurer of all individuals in Manitoba. All patient contacts are recorded through a unique personal health identification number; procedures are identified by tariffs billed by endoscopists; ICD-9 codes are used for all outpatient visits and inpatient stays until 2004 and after 2004 with ICD-10 coding. Physician tariff codes are divided into a diagnostic ERCP code and an add-on therapeutic code was introduced in 1987. All ERCPs performed in the province of Manitoba from 1984-2009 were analyzed. Background data on the overall population of Manitoba was obtained from the MH Registry file. Results: The number of ERCPs has doubled from 1984 to 2009 (847 to 1683). The rate of ERCPs/10,000 people has also increased from 7.7 (1984), 11.28 (1994), 12.2 (2004), 13.86/10,000 (2009) (p<0.05). The rate of diagnostic ERCP has declined from 7.28/10,000 in 1984 to 1.11/10,000 in 2009, while the rate of therapeutic ERCP has increased from 0.42/10,000 in 1984 to 12.75/10,000 in 2009 (p<0.001) (Figure 1). Women were more likely than men to undergo ERCP at all points in time. Rates in 2004-2009 for women and men for diagnostic ERCP were 1.46/10,000 v 0.98/10,000, respectively and for therapeutic ERCPs were 14.2/10,000 v 9.15/10,000 (p<0.01). Both diagnostic and therapeutic ERCP is more commonly performed in the middle aged (60-79 years) and elderly (>80 years) with rates of therapeutic ERCP of 31.53/10,000 and 62.58/10,000 respectively in 2009. Dividing the province into four geographic locations (urban, rural south, rural mid, rural north) showed no significant differences in population rates of diagnostic and therapeutic ERCP utilization. Conclusions: ERCP utilization has steadily increased over time since 1984, and the role of ERCP has changed from being a diagnostic modality to primarily a therapeutic one. Women are more likely than men to undergo ERCP and account for >60% of all cases. The middle aged and elderly are more likely to undergo ERCP than all other age groups. Patient residence had no effect on the rate of ERCP utilization at any point in the last 25 years. (Supported by a CAG/CIHR grant)

Figure1: Population rate of diagnostic and therapeutic ERCP in Manitoba

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A93 HOSPITALIZATION FOR NEPHROLITHIASIS AMONG INFLAMMATORY BOWEL DISEASE PATIENTS: A COMMON EXTRA-INTESTINAL MANIFESTATION WITH INADEQUATE PROPHYLAXIS S. Taylor2, S. Coward1, A. Frolkis1, M. Proulx1, S. Quan1, R. Panaccione1, B. Bressler2, G. Kaplan1 1. Division of Gastroenterology, Departments of Medicine and Community Health Sciences, University of Calgary, Calgary, AB, Canada; 2. Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada. Aims: Nephrolithiasis is a common extra-intestinal manifestation of the inflammatory bowel diseases (IBD). Studies have not adequately evaluated the prevalence of hospital admissions, patient characteristics and strategy of prophylaxis. We conducted a population-based study to evaluate the burden of hospitalization for nephrolithiasis in IBD patients, the characteristics associated with nephrolithiasis formation, and the use of prophylactic management to optimize urine chemistry. Methods: We used a hospital discharge abstract database to identify a population-based cohort consisting of all adults (≥ 18 years) admitted to an acute care hospital in the Calgary Health Zone from 1996 to 2009 with an ICD-9 or ICD-10 diagnostic code for IBD (ICD-9: 555.X, 556.X; ICD-10 K50.X, K51.X) and nephrolithiasis (ICD-9: 592.0; ICD-10: N20.X-N23.X). All medical charts were reviewed to confirm the diagnoses and to extract data regarding medical conditions and hospital interventions. Univariate analyses were performed to identify factors associated with nephrolithiasis formation in Crohn’s disease (CD) versus Ulcerative Colitis (UC) patients and among patients with a prior history of surgery. Results: A total of 298 kidney stone admissions were captured for 90 patients, 75 of whom had Crohn's disease and 15 ulcerative colitis, representing 2% of all admissions for IBD patients. The majority of IBD patients underwent a bowel resection (84.0% of CD, 66.7% UC) prior to a diagnosis of nephrolithiasis. A median of 6.2 (inter-quartile range 4.8-16.8) years elapsed between bowel surgery and admission to hospital with nephrolithiasis. Most patients were recurrent stone formers (68.9%), and 35.6% presented with ≥4 unique admissions for nephrolithiasis. Calcium oxalate stones were primarily identified in 79.6% of tested Crohn’s patients, for whom disease extent was predominantly ileal or ileo-colonic (87.2%). Only 20% of patients received nephrolithiasis prophylaxis prior to admission to hospital. Statistical associations of clinical factors predicting nephrolithiasis based on IBD type or surgical status were not observed. Conclusions: Hospitalization for nephrolithiasis was common, particularly among those with a prior surgical resection. In contrast, prophylaxis prior to hospitalization was underutilized in this population. Future studies should evaluate whether greater a prescription of nephrolithiasis prophylaxis following bowel resection for IBD would reduce the rate of hospitalization.

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A94 SURVEY ON AWARENESS OF EXTRAINTESTINAL IBD (SAFE) V. Huang, R. Thanabalan, R. Misra, G. Nguyen Mount Sinai Hospital Centre for Inflammatory Bowel Disease, Toronto, ON, Canada. Aims: Up to 36% of inflammatory bowel disease (IBD) patients will experience extraintestinal manifestations (dermatologic, ocular, and oral manifestations, arthritis, hepatobiliary disease, and nephrolithiasis). IBD patients are also at increased risk for several systemic complications, including thromboembolisim, cancer, and osteoporosis. Patient awareness of EIM of IBD is important in improving patient understanding of their disease and adherence with treatment plans. We hypothesize that IBD patient will have overall low awareness of extraintestinal complications related to their disease. Patients who have some knowledge most likely obtain their information from their gastroenterologist or support groups. Methods: A cross-sectional survey consisting of a questionnaire to assess IBD patients’ awareness of EIM and complications related to IBD was carried out over 6 weeks (July - August 2011). All adult (>18yrs) IBD patients attending gastroenterology clinics at a major tertiary teaching hospital with a confirmed diagnosis of IBD (CD, UC, indeterminate) were invited to participate. The questionnaire consisted of three sections: source of information, patient awareness of EIM, demographics (with an added question about history of EIM). Results: A total of 158 patients completed the questionnaire; 82 CD, 63 UC, 13 ID. 85 completed the added question about history of EIM: 40 patients (47 %) reported having or knowing of someone who had EIM. The majority of patients obtained their IBD information from their Gastroenterologists (91.8%) and the internet (82.3%). Most IBD patients felt their IBD knowledge was “very good” (39.7%) or “enough to get by” (49.7%). However, few patients were aware about important EIM such as blood clots (20.3%), kidney stones (12%), or liver disease (21.5%). Most patients were aware of risk of colon cancer (78.5%), joint involvement (71.5%), osteoporosis (55.7%), and skin involvement (51.9%). IBD diagnosis was relevant in awareness of colon cancer (UC 88.9% vs CD 69.5%, p=0.016) and kidney stones (UC 6.3% vs CD 18.3%, p = 0.034). Patients who had personal history or knew someone with the specific EIM (eye, kidney, blood clot, joint, osteoporosis) were more likely to answer relevant statements correctly. Conclusions: This survey confirms that most IBD patients rely on their Gastroenterologist for information about their disease. However, few patients are aware of important EIM such as blood clots, kidney stones, or liver disease. This may not be due to lack of Gastroenterologist initiated education, but may be related to recall bias, decreased retention of information with time, and personal experience having EIM. The next step may be to conduct a pre- and post- educational seminar survey to assess how much information patients retain after being educated about specific topics.

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A95 RATES OF SERIOUS COMPLICATIONS FROM COLONOSCOPY IN QUEBEC M. Sewitch, M. Jiang, L. Joseph, A. Barkun McGill University, Montreal, QC, Canada. Aims: Rates of serious complications reflect the quality of colonoscopy services. We aimed to provide estimates of the rates of serious complications from colonoscopy (bleeding, perforation, diverticulitis, myocardial infarction/stroke, and death) in Quebec and to characterize patients with complications on both colonoscopy indication and polypectomy status. Methods: A prospective cohort study of endoscopists and their patients scheduled for colonoscopy were recruited from seven endoscopy facilities across Montreal. Prior to colonoscopy, patients completed a brief symptom questionnaire and provided their health insurance numbers. Diagnoses and procedures associated with hospitalization in the 30 days following colonoscopy were obtained from MEDECHO. Polypectomy status was obtained from provincial physician billing records. Results: Of the 2,134 patients (mean age=61, 50% female) who underwent colonoscopy, 32 (1.50%) were hospitalized within 30 days. Two persons experienced serious colonoscopy complications (0.09%, 95% CI: [0.01-0.34%]): 1 with bleeding (0.05%, 95%CI: [0.00-0.26%]), and 1 with perforation (0.05%, 95%CI: [0.00-0.26%]). No one experienced diverticulitis, myocardial infarction/stroke or death. These findings are consistent with rates reported in the literature (0.05% for bleeding, 0.01% for perforation). Based on patient-reported rectal bleeding, both colonoscopies were diagnostic. Polypectomy was performed in both patients; for the patient with perforation, colorectal cancer was diagnosed within the 30 days of colonoscopy. Conclusions: Rates of complications from colonoscopy are relatively low in Quebec and comparable to those in the literature. The serious complications occurred in diagnostic colonoscopy.

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A96 PREDICTING ENDOSCOPY LENGTH USING CLINICAL FACTORS L. Roth1, L. McCarthy2, J. Gregor2 1. Faculty of Health Sciences, McMaster University, Hamilton, ON, ON, Canada; 2. Division of Gastroenterology, London Health Sciences Centre, London, ON, ON, Canada. Aims: Maximizing efficiency with which an endoscopy suite is run has long been an elusive goal for all involved. Confounding this problem is the unpredictable nature that goes along with diagnostic procedures that may require therapeutic intervention. The present study aims to identify factors that are associated with endoscopy times, and attempt to predict length of endoscopy. Methods: Data was collected retrospectively from all patients experiencing upper gastrointestinal bleeding (UGB) from January to November 2009, as well as a control group of outpatient upper endoscopies performed on November 29, 2009 at the London Health Sciences Centre in London, Ontario. Demographic as well as clinical and endoscopic data was collected and analyzed for a difference in endoscopy time between groups by a student’s t-test. Further analysis of both groups combined included a regression model to predict time of endoscopy adjusting for the presence of an UGB, whether any intervention was performed, age and gender. All analyses were performed using SPSS 15.0. Results: 80 cases of UGB and 26 outpatient controls had data collected. The mean length of endoscopy was 25.13 minutes in the UGB group, and 12.58 in the control group. Comparison of the mean using the student’s t-test demonstrated a p-value of < 0.001. Regression of endoscopy length using UGB, whether intervention was performed, age and gender demonstrated an R-squared of 0.347 with the model being significant at p < 0.001, with the coefficient for both UGB and intervention showing statistical significance also at the p < 0.001 level. Age and gender were not significant predictors in this model, but were included as they were postulated a priori. Conclusions: A model incorporating the presence of UGB, whether intervention was performed, age, and gender significantly predicted endoscopy length. Although further validation of the model is required, this data may help endoscopy units better accommodate patient needs by utilizing resources more efficiently.

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A97 ECONOMIC IMPACT OF DEEP REMISSION IN ADALIMUMAB-TREATED PATIENTS WITH CROHN’S DISEASE: RESULTS FROM EXTEND W. Sandborn1, J. Colombel2, E. Louis3, R. Panaccione4, M. Yang5, J. Chao5, P. Mulani5 1. UCSD, La Jolla, CA; 2. Centre Hospitalier Universitaire de Lille, Lille, France; 3. U of Liège, Liège, Belgium; 4. U of Calgary, Calgary, AB, Canada; 5. Abbott, Abbott Park, IL. Aims: To demonstrate the economic benefit of deep remission in adalimumab (ADA)-treated patients with Crohn’s disease (CD). Methods: In EXTEND, patients with moderate to severe ileocolonic CD (CDAI 220-450) received open-label ADA 160-/80-mg induction therapy at Weeks 0/2 and were randomized at Week 4 to blinded maintenance therapy with ADA 40 mg every other week (eow) or placebo through Week 52. Early deep remission was defined as observed mucosal healing and clinical remission (CDAI <150) at Week 12. The current analysis evaluated the relationship between early deep remission status and health care costs over the next 40 weeks for ADA-treated patients. Outcomes included hospitalization costs (number of hospitalizations at a fixed cost of $36,159 each1), direct non-hospitalization medical costs (calculated using fixed biweekly costs of $277, $506, and $580 for remission [CDAI <150], moderate CD [150≤CDAI<300], and severe CD [300≤CDAI<450], respectively2), and indirect costs (cost of overall CD-related work impairment [assessed using the Work Productivity and Activity Impairment Questionnaire (WPAI)] based on a fixed biweekly median salary of $1,4963). Last-observation-carried-forward imputation was used to assess CDAI and WPAI missing values. The 95% CI of each cost was evaluated using a Monte Carlo simulation based on the data. Results: A total of 64 patients randomized to ADA 40 mg eow receiving ADA at Week 12 were analyzed. The total direct costs, including hospitalization costs and non-hospitalization medical costs through Week 52 were $5,735 for patients who achieved deep remission and $11,404 for non-achievers, representing a significant incremental cost savings of $5,669 (95% CI: $3,324, $8,957). The total indirect costs were significantly less for patients who achieved deep remission than for non-achievers, with a cost savings of $4,243 (95% CI: $2,871, $5,477). With achievement of deep remission, the total cost savings over 40 weeks were $9,912 (95% CI: $7,251, $13,576) (table). Conclusions: ADA-treated patients who achieved deep remission at Week 12 had health care costs savings of about $9,900 at 1 year vs. those who did not achieve deep remission. References: 1. Cohen RD et al. Am J Gastroenterol. 2000;95:524-30. 2. Feagan BG et al. Am J Gastroenterol. 2000;95:1955-60. 3. US Bureau of Labor Statistics. http://data.bls.gov/cgi-bin/surveymost. Accessed 4/1/2010.

Health Care Costs Over 40 Weeks for Patients Who Did and Did Not Achieve Deep Remission at Week 12 Week-52 Costs (US $ 2009) Deep Remission Achievers (N=11) Deep Remission Non-Achievers (N=53) Difference

Total direct costs Direct nonhospitalization costs

Hospitalization costs

5,735

5,735 0

11,404

7,992 3,411

-5,669

-2,257 -3,411

Total indirect costs 8,958 13,201 -4,243 Total costs (direct+indirect) 14,693 24,604 -9,912

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A98

PERSPECTIVES OF PATIENTS AND HEALTHCARE PROFESSIONALS ON ULCERATIVE COLITIS: RESULTS FROM AN INTERNATIONAL SURVEY D. Solomon1, D. Holley2, M. Buch2, N. Pym3, K. Paridaens4 1. Shire Development Inc., Wayne, PA; 2. GfK Healthcare, London, United Kingdom; 3. Shire Pharmaceuticals Inc., Basingstoke, United Kingdom; 4. Shire AG, Eysins, Switzerland. Aims: An online survey of adult patients with chronic ulcerative colitis (UC) and healthcare professionals (HCPs) who care for UC patients was conducted to examine differences in their perspectives on living with and managing UC. Methods: A total of 775 patients and 475 physicians from Canada, France, Germany, Ireland, Spain, and the United Kingdom, and 50 UK nurses completed the survey. Participants were pre-identified, and randomly sampled from patient and HCP access panels or via custom “phone-to-Web” recruitment; patients and HCPs were not necessarily connected. Patient organizations and advocacy groups were not used in recruitment to avoid potential bias in patient selection. Results: Patients reported experiencing a mean of 5.5 flares/year and discussing 4.2 flares/year with their physicians. In contrast, physicians estimated that patients experienced a typical average of 3.4 flares/year. Patients’ ratings of their UC severity were consistent with their perception of their HCPs’ ratings (32%-33% mild, 53% moderate, and 14%-15% severe). However, whereas more patients rated their UC as moderate in severity (53%) rather than mild (32%), HCPs reported that more of their patients had only mild (52%) rather than moderate (34%) UC. The highest percentage of patients ranked stress (40%) as the most common cause of flares, followed by natural disease course (27%), changes from regular diet (21%), and not taking preventative therapy (13%). The majority of HCPs (51%) ranked disease course as the most common cause, followed by not taking preventive therapy (28%), stress (19%), and changes in diet (1%). Although urgency was most frequently cited by both patients (30%) and physicians (36%) as the most bothersome aspect of UC, the next most-cited aspect for patients was pain (25%) compared with stool frequency for physicians (34%). Pain was selected by only 11% of physicians as the most bothersome aspect of UC for patients. Although 55% of patients stated that UC symptoms had affected their quality of life (QoL) over the past year, physicians estimated that 35% of patients had experienced disruption of QoL. Although 72% of patients viewed their HCP as their primary source of information on UC and its treatment options, only 41% arranged regular visits to see their HCP. Conclusions: These findings reveal important differences between patients and HCPs in their perceptions of UC that may impact the patient-physician relationship and the management of disease. In particular, physicians may underestimate the importance of certain UC-related issues to patients as well as the burden of disease on patients.

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A99 NOVEL PATIENT-DERIVED QUALITY INDICATORS FOR COLONOSCOPY SERVICES M. Sewitch1, S. Brien1, C. Dubé2, A. Barkun1, R. Hilsden2, D. Armstrong3 1. McGill University Health Centre, Montreal, QC, Canada; 2. The University of Calgary, Calgary, AB, Canada; 3. McMaster University, Hamilton, ON, Canada. Aims: Measuring patient perceptions of the quality of health services is a much neglected area of research. We previously conducted focus groups that identified 20 patient-derived indicators of colonoscopy quality. Our objectives were to validate the patient-derived indicators and to compare them to those in the Global Rating Scale (GRS). Methods: A survey questionnaire was distributed in endoscopy units in Montreal and Calgary to patients aged 18 years or older, were fluent in English/French and who had just undergone colonoscopy. Participants rated each of the 20 identified indicators for their importance (low, medium, high). Three open-ended questions asked for additional aspects of colonoscopy quality that were considered important. Descriptive statistics were used to characterize the study populations and to compare our findings to the GRS indicators. Results: 828 survey questionnaires were distributed and 402 (48.6%) were returned by mail (mean age=60, 56% female). Thirteen of the 20 identified indicators were rated as highly important by at least 55% of all respondents. Thirteen items that were not included in the original 20 indicators were endorsed by 10 or more respondents in the open-ended questions. Compared to the GRS, 16 of the indicators that we identified have never before been assessed. Conclusions: Our study captured 16 completely novel dimensions of quality in colonoscopy service delivery. Patients and care providers share some but not all of the same criteria for evaluating service quality.

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Fatty Liver Disease (Alcohol-related and Non-alcoholic)

A100 CYTOCHROME P450 3A4 EXPRESSION AND DRUG METABOLISM ACTIVITY IN NON-ALCOHOLIC FATTY LIVER DISEASE S. Woolsey1, I. Gong1, S. Stein2, R. Kim2, M. Levstik2, M. Beaton2, R. Tirona1 1. Department of Physiology and Pharmacology, The University of Western Ontario, London, ON, Canada; 2. Department of Medicine LHSC, London, ON, Canada. Aims: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease affecting approximately one third of adults. For a majority of NAFLD patients, the associated metabolic syndrome necessitates drug therapy for management of diabetes, dyslipidemia and hypertension. Interestingly, while many drugs used by patients with NAFLD are eliminated from the body by hepatic drug metabolism, little is known regarding the effect of steatosis on hepatic drug metabolism and drug response. The most important drug metabolizing enzyme, influencing the pharmacokinetics of more than 50% of all drugs on the market is the enzyme cytochrome P450 (CYP) 3A4. In this study, we explored the influence of NAFLD on CYP3A4 expression and activity as well as the potential molecular mechanisms involved. Methods: The mRNA expression of CYP3A4 was compared among a bank of normal human livers (n= 15) and liver biopsy samples from patients with confirmed NAFLD (n= 13) using quantitative polymerase chain reaction (qPCR). To assess CYP3A4 activity, we compared the pharmacokinetics of a CYP3A4 metabolized drug, midazolam, in a cohort of NAFLD patients (n=10) and healthy volunteers (n=21). After oral microdose (100 ug) of midazolam, midazolam plasma concentrations were determined by liquid chromatography tandem mass spectrometry (LC-MS/MS). To investigate the mechanisms involved in altered drug metabolism, we developed an in vitro model of NAFLD using fatty acid-loaded Huh7 human hepatoma cells. Gene expression was determined by qPCR while protein content and enzyme activity assessed by LC-MS/MS. Results: qPCR analysis demonstrated that on average, CYP3A4 mRNA expression in NAFLD was 87% lower than normal livers. Plasma midazolam concentrations 3 hours post dose were 3 times higher in NAFLD patients than healthy controls, indicating lower CYP3A4 activity. In the in vitro model of NAFLD, CYP3A4 mRNA, protein expression and activity all decrease with steatosis. These steatosis-induced changes in drug metabolism were associated with alterations in the levels of transcription factors known to regulate CYP3A4 expression. Conclusions: We conclude that the activity of CYP3A4 is reduced in NAFLD due to steatosis-induced changes in gene transcription. These findings are expected to provide the basis for further studies aimed at optimizing pharmacotherapy in NAFLD.

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Fibrogenesis, Portal Hypertension, Complications of Cirrhosis

A101 LISTERIA MONOCYTOGENES INDUCED SPONTANEOUS BACTERIAL PERITONITIS IN LIVER CIRRHOSIS: CASE REPORT AND LITERATURE REVIEW M. Bukhari1, B. Lumb2 1. Department of Gastroenterology, McMaster University, Hamilton, ON, Canada; 2. Department of Gastroenterology, McMaster University, Hamilton, ON, Canada. Aims: Spontaneous bacterial peritonitis (SBP) is an acute infection of preexisting ascitic fluid without evidence for secondary source such as a gut perforation. SBP is almost always seen in the setting of liver cirrhosis. It is a potentially life threatening complication in patients with cirrhosis. When first described, its mortality exceeded 90% but it has been reduced to approximately 20% with early diagnosis and effective treatment. The diagnosis of SBP is established by the positive fluid bacterial culture and elevated ascitic fluid absolute polymorphonuclear leukocytes (PMN) count (≥250 cells/mm3). The most common organisms involve in SBP are aerobic gram negative about 65% such as E.coli and Klebsiellae. However, the reminder due to aerobic gram positive organism such as streptococcus species SBP caused by Listeria species is a very rare cause of infection. Listeria monocytogenes is gram positive anaerobic bacilli commonly infect the neonates, pregnant female, elderly and immunocompromised patients. The most common clinical manifestation is diarrheal illness. However, it can cause serious manifestation such as bacteremia and meningitis. It has been few case reports in English literature of listeria monocytogenes induced SBP. Methods: Case Report and Literature review. Results: 75 years old man with alcoholic liver cirrhosis, his MELD score is 16 and child pugh class C presented abdominal pain, increase abdominal girth and mild confusion for 10 days. Physical examination revealed: temperature 36.6 °C, blood pressure 112/79 mm Hg, heart rate 84 and O2 saturation 98%. He was conscious but disoriented to the date, no Asterixis. Ascites was present but there was no abdominal tenderness. Laboratory results showed WBC,11.1; hemoglobin,113; platelet count,114; INR,1.6; PTT, 46s; AST,43U/L; ALT,22 U/L; total bilirubin,77umol/L; and direct bilirubin,49umol/L. Albumin 22g/L;ALK,174U/L; and alfafeto protein 1567ug/L. Paracentesis with ascitic fluid analysis revealed white blood cell 700; albumin, <10g/L. Ascitic fluid culture was positive for Listeria monocytogenes after 17 hours as well as the peripheral blood culture. Intravenous albumin and ceftriaxone were administered initially. Lactulose was also given to the treatment of hepatic encephalopathy. After the microbiology result we switch him to ampicillin and gentamicin. Conclusions: Listeria monocytogenes induced SBP is being increasingly recognized in patients with liver cirrhosis. The clinical presentation is no different from other microorganisms. This is particularly important because L. monocytogenes does not respond to conventional empiric therapy with third-generation cephalosporins, and there is a high mortality rate associated with the infection.

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A102 VERSICAN EXPRESSION AND TURNOVER IN HEPATIC STELLATE CELL ACTIVATION S. Maurice1, C. Crick1, W. Kim2, C. Law1, M. Norrie1, S. Kim1, P. Winwood2 1. University of Northern British Columbia, Prince George, BC, Canada; 2. University of British Columbia, Vancouver, BC, Canada. Aims: The pathophysiologic processes of extracellular matrix deposition and turnover in liver injury are central to our understanding of liver fibrosis and the development of antifibrotic therapies. The proteoglycan versican plays a key role in fibrogenesis in other tissues by modulating fibroblast activity through several mechanisms including chemokine sequestration, cell signaling interactions and bioactive matrikines, but has not been studied in the liver. Here we report expression of versican and the proteoglycan degrading enzymes ADAMTS1 and 4 by hepatic stellate cells (HSCs) activated to a myofibroblastic phenotype in tissue culture. Methods: Hepatic stellate cells were isolated from C57B/6 mice by pronase/collagenase digestion and density gradient centrifugation (Optiprep) and activated by culture on plastic. RNA was extracted from HSCs in GITC and purified on silica spin columns (RNeasy, Qiagen). Expression of versican and ADAMTS1 and 4 in HSCs was studied at sequential time points by quantitative real time PCR normalized against the reference gene GAPDH (PrimeTime, IDT). Protein expression was determined by western blotting and immunofluorescence of activated cells visualized by confocal microscopy. End products of qPCR were confirmed by agarose gel electrophoresis at appropriate amplicon sizes. Results: Isolation of HSCs was confirmed through desmin staining and staining for smooth muscle alpha actin confirmed activation of these HSCs. Versican expression was detected in HSCs at all stages of activation in culture. Expression increased progressively from days 1 through to 7, then increased more dramatically, up to 5 fold, by days 10 and 14. Immunofluorescence microscopy confirmed versican production by activated HSCs. Western blotting of activated HSC media demonstrated secretion of both intact versican and versican proteolytic products, suggesting that versican turnover occurs during the process of activation. Expression of the known versican processing enzymes, ADAMTS1 and 4, was detected at all time points but was suppressed during early stages of HSC activation (days 2 through 7) relative to day 1 levels. Conclusions: HSCs express versican during activation in culture. Expression of the known versican processing enzymes ADAMTS1 and 4 is reduced during early activation of HSCs. Versican synthesis and turnover appear to be important components of HSC activation. Its regulated turnover may play a role in modulating normal and fibrotic remodeling in the liver. The reduction in ADAMTS expression could contribute to the deposition of a versican rich matrix in which wound proliferation and remodeling occurs.

A103 CIRCULATORY DYSFUNCTION, RENAL IMPAIRMENT AND LONG-TERM SURVIVAL AFTER LARGE-VOLUME PARACENTESIS IN PATIENTS WITH CIRRHOSIS AND ASCITES P. James, F. Wong Division of Gastroenterology, University of Toronto, Toronto, ON, Canada. Aims: To assess the prevalence of post-paracentesis circulatory dysfunction (PPCD) as well as its effects on systemic hemodynamics, renal function and survival in cirrhotic patients undergoing large-volume paracentesis (LVP). Methods: Patients with cirrhosis and ascites without baseline renal dysfunction who required LVP of greater than 5L were enrolled. Albumin replacement at the dose of 6-8gm per L of ascitic fluid drained. Systemic hemodynamics (mean arterial pressure [MAP] and heart rate [HR]), renal function (serum sodium [Na], creatinine [Cr] and urinary volume) and various neurohormones indicating the fullness of the effective arterial blood volume (plasma rennin, aldosteorne, norepinephrine and angiotensin II) were measured at baseline, and repeated at day 6 after LVP. MAP and HR were also measured immediately after LVP. Patients were followed until death, liver transplant or insertion of a transjugular intrahepatic stent shunt. The serum creatinine for the last out-patient follow-up visit was noted. PPCD was defined as a 50% increase in plasma renin at day 6 after a LVP. Results: 60 patients with a mean age of 57±9.6 years were enrolled. A mean of 6.7±0.46L of ascitic fluid was removed per patient with 60±2.4gm of albumin given. Patients were followed for a mean of 612±101 days. There was no significant difference in systemic hemodynamics (MAP 87±10.3 and 83±10.2mmHg; HR 78.5±12.8 and 74±11.7 beats per minute) or renal function (Na 133±4.2 and 133±3.9mmol/L; Cr 93±29.7 and 92±31.6µmol/L) before and after LVP when the cohort was considered as a group. 23 patients (40%) fulfilled the diagnostic criteria for PPCD. Despite this, none of the patients who developed PPCD had evidence of renal impairment after LVP. After two years of follow-up, there were no significant differences in long-term renal function (86±35.6 versus 78±17.4µmol/L after one year) or mean survival (685±176 versus 613±101 days) between the patients who developed PPCD versus those who did not. Conclusions: PPCD is a common phenomenon after LVP and does not have a significant impact on systemic hemodynamics, renal function or survival in cirrhotic patients with ascites who undergo large volume paracentesis with albumin replacement.

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A104 ASSOCIATION BETWEEN PROTON PUMP INHIBITOR USE AND SPONTANEOUS BACTERIAL PERITONITIS IN CIRRHOTIC PATIENTS WITH ASCITES M. Ratelle1, A. Beaudoin1, S. Perreault2, J. Villeneuve1, L. Tremblay1 1. Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada; 2. Faculté de Pharmacie de l'Université de Montréal, Montréal, QC, Canada. Aims: There are data showing a link between proton pump inhibitors (PPIs) use and the development of spontaneous bacterial peritonitis (SBP) in cirrhotic patients with ascites but they are controversial. The primary objective of this study was to determine if the use of PPIs in cirrhotic patients with ascites is associated with an increased risk of SBP. The secondary objective of our study was to evaluate if the indications for PPI use in this study population are appropriate. Methods: We conducted a retrospective case-control study over 6 years (June 2004 - June 2010) at to the Centre Hospitalier de l’Université de Montréal (CHUM). Fifty one (51) cirrhotic patients admitted with paracentesis-proven SBP (≥ 250 neutrophils/mm3), occurring within 7 days of hospital admission, met the inclusion criteria. These patients were matched 1 :2 (for age, Child-Pugh score’s class and year of admission) with 102 comparable cirrhotic patients with ascites who were admitted for conditions others than SBP. We excluded those who had an unreliable medication list on admission, who received antibiotics or had an upper gastrointestinal bleeding 14 days prior admission and those who had a prior episode of SBP. Also excluded were transplant patients or those taking an immunosuppressive drug for any other indication as well as HIV patients. A patient was considered a PPI user is he had taken a PPI daily for at least one week prior to admission. Results: Patients with SBP had a significantly higher rate of prehospital PPI use (60,8%) compared to cirrhotic patients with ascites admitted for another reason than SPB (42,2%, p=0,0297). There was no significant differences in demographics, diabetes, etiology and severity of liver disease or presence of diabetes between groups. On multivariate analysis, PPI use was the only factor independently associated with SBP (odds ratio (OR) 2,09, confidence interval (CI) 1,04-4,23). Sex, race, diabetes or natremia did not have significant influence on the association in the multivariate analysis. Thirty five (35%) of patients in both groups had no documented indication for PPI use in their charts. In the remaining patients, 45% of cirrhotic patients with SBP had an inappropriate indication for PPI use compared to 25% of cirrhotics without SBP. Conclusions: Cirrhotic patients with ascites have twice the risk of developing SBP if they are taking a PPI. This data reinforce the association between PPI use and SBP observed in others studies. A high percentage of cirrhotic patients were taking a PPI without any documented indication and patients with SBP were more likely to have an inappropriate indication for PPI therapy than those without SBP.

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A105 THROMBOCYTOPENIA AS A PREDICTOR OF VARICES IN PSC Y. Tse1, J. Uhanova2, N. Narula3, N. Chandok4 1. University of Toronto, Toronto, ON, Canada; 2. University of Manitoba, Winnipeg, MB, Canada; 3. McMaster University, Hamilton, ON, Canada; 4. University of Western Ontario, London, ON, Canada. Aims: In primary sclerosing cholangitis (PSC), patients with advanced disease have delayed clinical manifestations of cirrhosis compared with non-cholestatic liver diseases, and as such, the decision to perform screening endoscopy is variable. To date, limited retrospective studies suggest that platelet count negatively correlates with endoscopic features of portal hypertension, but assessment of the strength of this association requires further observational data. The primary objective is to determine the relationship between platelet count and the presence of large esophageal varices in patients with PSC. The secondary objectives were to assess the association between liver enzymes and model for end-stage liver disease (MELD) score with the risk for large esophageal varices. Methods: Consecutive patients with PSC who were seen at University Hospital, London, Canada between 2000 and 2010 were assessed. Univariate logistic regression analysis was conducted to determine which clinical variables and laboratory test results were associated with the occurrence of large varices in PSC patients. Variables significant at p<0.05 level were to be entered into the multiple regression model to determine the combination of best predictors for the large esophageal varices in this patient population. Results: The univariate analysis revealed that only platelet count was associated with the outcome. All the other variables failed to predict the occurrence of large esophageal varices. Hence, there were no other candidate variables for the multivariate modeling (Table 1). Univariate analysis revealed that platelet count ≤ 150 x 109/mL was associated with large esophageal varices, with odds ratio (OR) 5.33 (95% confidence interval (CI) 1.3-21.3, p=0.02). Statistical significance was not present for platelet count ≤ 200 x 109/mL (OR=3.0, 95% CI 0.8-12.0, p=0.12). Conclusions: Thombocytopenia is associated with large esophageal varices in PSC. No other laboratory parameters were significant predictors. Our findings may avert the need for endoscopy in some patients with PSC. Table 1

Regr. Coeffic. SE Chi-sq P value Age at endoscopy 0.049 0.03 2.61 0.11

Male 0.095 0.73 0.02 0.90 ALB -0.032 0.04 0.51 0.47

Alk. Phos -0.001 0.001 0.6 0.44 AST -0.002 0.004 0.38 0.54 ALT -0.002 0.004 0.13 0.71 BILI 0.001 0.002 0.2 0.66 INR 0.074 0.39 0.04 0.85

MELD score 0.011 0.04 0.09 0.76 Platelets -0.009 0.004 4.17 0.04

AST/Plt ratio 0.031 0.25 0.02 0.90

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A106 SPONTANEOUS BACTERIAL PERITONITIS TREATED WITH ANTIBIOTICS AND ALBUMIN - PREDICTORS OF MORTALITY AND PATTERNS OF ANTIBIOTIC RESISTANCE J. Chaulk, M. Carbonneau, H. Qamar, A. Keough, M. Ma, P. Tandon University of Alberta, Edmonton, AB, Canada. Aims: Spontaneous bacterial peritonitis (SBP) is one of the most common bacterial infections in patients with cirrhosis. A recent meta-analysis identified renal dysfunction as the main predictor of mortality in SBP (Tandon 2011). The meta-analysis was limited by albumin not being utilized as standard of care in the majority of studies. The current study evaluated 30-day mortality in patients with SBP who received both antibiotics and albumin. It also tried to identify independent predictors of mortality to more effectively risk stratify these patients on presentation. In addition, we attempted to determine local rates of SBP infections resistant to third-generation cephalosporins in order to identify whether changes in empiric antibiotic regimens were needed. Methods: We performed a search of patients with SBP between 2003 and 2010. SBP was defined as an ascitic fluid polymorphonuclear cell count > 250 cells/mm3. Patients who received antibiotics and albumin therapy were included. Variables were described using the percentage or median and interquartile range (IQR). Univariate and multivariate logistic regression analysis were used to determine independent predictors of 30-day mortality. Results: We reviewed 115 cases of SBP from the estimated 250 identified. The complete data will be available by presentation. Sixty-seven percent (77/115) of patients were male, with a median age of 52 (IQR: 47 to 59), a presenting MELD score of 20 (16 to 28), white blood cell count of 8.7 (5.4 to 14.9) and serum creatinine of 112 (77 to 171.5). Twenty-two percent (25/115) of SBP infections were nosocomial. Forty-four percent (46/104) of SBP infections with available culture data were culture positive. Of the culture positive infections, 28% (13/46) were resistant to third-generation cephalosporin therapy. Twenty-four percent (27/115) of patients died within 30 days of the infection. The peripheral white blood cell count (OR 1.13 (1.05 to 1.21), p=0.001) and MELD score (OR 1.07 (1.007 to 1.14), p=0.029) were independent predictors of 30-day mortality. Conclusions: Preliminary analysis of our data revealed a significant 30-day mortality rate of 24% associated with SBP infection, despite treatment with both antibiotics and albumin therapy. Predictors of 30-day mortality will be confirmed utilizing the complete dataset. Our rate of cephalosporin resistance in patients with SBP is 28%, which is at the low end of the 28-41% reported in the literature. With the complete dataset, predictors of third-generation cephalosporin resistance will be identified.

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Gastro Intestinal Oncology

Poster of Distinction A107 THE INTEGRIN α6 SPLICE VARIANT REGULATES COLON CANCER CELL PROLIFERATION AND WNT/β-CATENIN PATHWAY J. Groulx, N. Basora, J. Beaulieu CIHR Team in Digestive Epithelium. Département d’anatomie et de biologie cellulaire, FMSS, Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: Colon cancer is the second cause of death by cancer in Canada. Recently, we found that integrin α6β4 was upregulated in colon adenocarcinomas. Moreover, the α6 subunit exists as two distinct splice isoforms, α6A and α6B. The α6A isoform was shown to be associated with the proliferative cell population of the normal human colon and was upregulated in 80% of the colon cancers tested. The aim of this study was to analyze the role of integrin α6A in human colon cancer, more precisely its effect on cell proliferation and its mechanism of regulation. Methods: Integrin α6A expression was specifically abolished, using shRNA technology, in colon cancer cell lines (Caco-2/15, T84, SW480, SW620, DLD-1, HT29 and COLO201). Proliferation was analyzed by BrdU incorporation and the Wnt/β-catenin pathway was analyzed by luciferase assays, specific β-catenin antibodies and gene expression. Results: In all colon cancer cell lines tested, knockdown of α6A resulted in a significant decrease in proliferation and correlated with reduced active β-catenin levels. In T84 cells, depletion of α6A interfered significantly with Wnt/β-catenin pathway activity illustrated by a decrease in nuclear β-catenin levels, a reduction of responsive β-catenin/TCF4 promoter activity, increased β-catenin phosphorylation by GSK3β and a decrease in the expression levels of Wnt/β-catenin target genes such as cyclin D2, N-myc and LGR5. Moreover, luciferase assays using the β-catenin/TCF4 promoter showed that α6A knockdown prevented activation of the Wnt/β-catenin pathway by WNT3A, but did not affect activation via the pharmacological inhibition of GSK3β or by the overexpression of a mutated non-degradable form of β-catenin. Furthermore, inhibition of GSK3β resulted in the re-expression of cyclinD2 and LGR5. To determine the role of the integrin α6A subunit on colon cancer cell proliferation in vivo, control and α6A knockdown T84, SW620 and HT29 cells were injected into nude mice. Results showed that abolition of the integrin α6A subunit led to a significant reduction in tumor growth for all three colon cell lines tested. Conclusions: Our results show for the first time that integrin α6A subunit regulates the Wnt/β-catenin pathway to promote cancer cell growth. Since 80% of colon cancers display an upregulation of integrin α6A expression, targeting this integrin in colon cancers may offer new therapeutic value.

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A108 NON-DIGESTIBLE CARBOHYDRATES MODULATE TOXICITY OF CPT-11/5FLUOROURACIL CHEMOTHERAPY IN RATS WITH WARD COLON TUMOR L. Dieleman, A. Farhangfar, X. Lin, R. Valcheva, M. Gaenzle, M. Sawyer, C. Field, B. Meijer, V. Baracos University of Alberta, Edmonton, AB, Canada. Aims: Selective fermentation of dietary fibre by gastrointestinal microbiota may alter intestinal physiology and response to injury. Our aim was to assess effects of non-digestible carbohydrates (NDCHO) on the pathobiology of mucosal injury after CPT-11 chemotherapy. This toxicity is a primary limitation for colorectal cancer treatment. Gut injury is attributed to the toxic CPT-11 active metabolite (SN-38), thought to be generated by conversion of its inactive glucuronide by bacterial β-glucuronidase in the large intestine. Methods: Female Fisher rats bearing Ward colon tumor were treated with 2 cycles of CPT-11/5 fluorouracil. Animals (n=6/diet) were fed 6 different AIN-76 based diets containing 10% fibre as cellulose, inulin, oligofructose (OligoF), 1:1 inulin/oligoF (Synergy®), isomalto-oligosaccharide (IMO), type IV resistant starch (RS4). Low fibre diet with 2%cellulose was included as well. Body weight and food intake were followed. Animals were killed 2 days after the 2nd chemotherapy cycle. Evaluations included immune cell phenotypes in mesenteric lymph nodes (MLN), β-glucuronidase activity in cecum, CPT-11 metabolites, systemic and intestinal inflammatory markers, intestinal microbiota (qPCR) and microbial metabolites. Results: Variations in NDCHO across the 7 diets corresponded to significant variation in clinical and biological indices of toxicity. Animals fed RS4 or Synergy® were least ill based on the body weight, food intake, acute phase response (haptoglobin, alpha-1-acid glycoprotein), immune cell phenotype in MLN (levels of T (CD3+) and cytotoxic T (CD3+CD8+) lymphocytes, T cell inhibitory marker CD152, T cell activation marker CD71 and MHC II antigen presenting cells (OX6)). By the same criteria, animals fed IMO or 2% cellulose were the most ill. Animals fed inulin, 10% cellulose and OligoF showed intermediate values. The SN38 concentration in jejunum and cecum correlated (p<0.05) with weight loss, decreased food intake and the studied inflammatory and immune indices. Major bacterial groups in cecum were largely invarian. Unexpectedly, animals with the least toxicity had higher β-glucuronidase activity in the cecal digesta combined with increased levels of short chain fatty acids and up-regulation of butyrate transporter gene expression in colon tissue. Conclusions: In this controlled comparison of multiple NDCHOs in CPT-11-induced intestinal injury, RS4 and Synergy® mitigated toxicity compared with other fibres. The potential for clinical benefit in human colorectal cancer patients treated with CPT-11 remains to be identified. CPT-11 toxicity appears related primarily to SN38 levels, but not to bacterial β-glucuronidase activity as generally believed.

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A109 COMBINED EXTERNAL BEAM RADIOTHERAPY AND BRACHYTHERAPY IN THE NON-SURGICAL MANAGEMENT OF ESOPHAGEAL CANCER F. Donnellan1, J. Hay2, A. Weiss1 1. Vancouver General Hospital, Vancouver, BC, Canada; 2. BC Cancer Agency, Vancouver, BC, Canada. Aims: There are few data comparing non-surgical management of esophageal adenocarcinoma (EAC) and squamous cell carcinoma (SCC).Radiotherapy is an acceptable treatment and can involve external beam radiotherapy (EBRT, brachytherapy, or a combination of both.The aim of this retrospective study was to compare survival, improvement in swallowing, and complication rate following combination EBRT and brachytherapy for inoperable and unresectable EAC and SCC. Methods: Retrospective analysis of patients who underwent EBRT and brachytherapy for non-surgical management of esophageal cancer from December 2004 to November 2010.Data are expressed as mean +/- SEM.Student’s t test, Kaplan-Meier survival analysis and Fisher’s exact test were used for analysis.P value < 0.05 was considered statistically significant. Results: 92 patients received EBRT and brachytherapy. 53 had EAC and 39 had SCC. There was no difference in gender, age, disease stage,radiotherapy regimen, numbers receiving chemotherapy or dysphagia score between the groups. Median survival was longer in the SCC group (10.8 months versus 6.4 months, p = 0.008). Dysphagia was present in 45 (85%) with EAC and 35 (90%) with SCC. Complete restoration of swallowing or an improvement in dysphagia score were not different (53% versus 49%, p = 0.82; 18% versus 11%, p = 0.32, respectively). Median time to dysphagia recurrence was longer in the SCC group. However, this did not reach significance (6 months versus 9.8 months. p = 0.08). Both overall (36% versus 46%, p = 0.39) and individual complication rates including malignant stricture (13% versus 10%, p = 0.75) and fistula development (2% versus 8%, p = 0.3) were similar between EAC and SCC groups. Benign strictures were more frequent in the SCC group. However, this did not reach significance (23% versus 9%, p = 0.08).Benign strictures in the SCC group required more endoscopic dilations (3+/- 0.3 versus 1.6 +/-0.2, p = 0.01). The number of dilations for post radiotherapy malignant strictures was not different (2.3 +/- 0.5 in the SCC group versus 3 +/- 1 in the EAC, p = 0.49). Stent insertion was only required in 5 out of 7 post radiotherapy malignant strictures in the EAC group. No stents were placed in the SCC group. Conclusions: Combination EBRT and brachytherapy is associated with similar symptomatic improvement and risk in the non-surgical management of both esophageal adenocarcinoma and squamous cell carcinoma. Benign strictures are more common and subsequent endoscopic dilation more frequent post radiotherapy for squamous cell carcinoma. Early use of removable or biodegradable stents may provide a superior therapeutic option in such patients. Furthermore, the majority of patients can be managed without metal stent insertion.

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A110 INTESTINAL METAPLASIA AND THE RISK OF GASTRIC CANCER IN AN IMMIGRANT ASIAN POPULATION A. Abadir, C. Streutker, C. Brezden-Mazley, A. Grin, Y. Kim University of Toronto, Toronto, ON, Canada. Aims: The development of intestinal metaplasia (IM) has been purported as a critical first step in the pathogenesis of gastric cancer. However, the natural history of intestinal metaplasia in patients from regions of high gastric cancer incidence has not been well elucidated. We investigated the prevalence IM, dysplasia and adenocarcinoma in an urban immigrant Asian population undergoing screening gastroscopy. Methods: A retrospective review was conducted of all Asian immigrants who underwent screening gastroscopy in an academic GI practice at St. Michael’s Hospital between March 2010 and October 2011. Those with biopsy-proven IM were included in the study. Demographics, clinical data, histopathology and data on endoscopic surveillance were reviewed. Groups with stable IM versus those with dysplasia and/or carcinoma were compared by Student’s t-test or chi-squared analysis. Results: In total, 222 patients were found to have IM (55% female). Of those, 89% were of Korean descent, followed by Japanese (5%), Chinese (4%) and Vietnamese (2%). The mean duration of residency in Canada was 15 +/- 11 years. Twenty four percent had a history of smoking, 48% had a family history of gastric cancer and 52% had a history of H. pylori infection. A total of 35 patients (16%) had high-risk pathological changes - 31 with dysplasia and 4 with adenocarcinoma - while the remainder had stable IM. Of those with dysplasia, 8 patients (26%) had persistent histologic abnormalities. There was no difference in mean age between those with stable IM versus those with high-risk pathological changes (65.6 +/- 10.1 years vs. 65.9+/- 11.6 years, p = 0.88). There was no difference in mean duration of endoscopic follow-up between the two groups (4.9 +/- 3.9 years vs. 4.8 +/- 3.9 years, p = 0.86). However, those with high-risk pathological changes underwent gastroscopy more frequently than did those with stable IM (4.7 procedures vs. 3.0 procedures, p = 0.002). Patients with stable IM were more likely to be female (60% vs. 31%, p = 0.002) and more likely to have had a normal biopsy during follow-up (32% vs. 9%, p = 0.005). No significant associations were noted regarding smoking history, family history or H. pylori. Conclusions: Intestinal metaplasia identified at screening in a high risk immigrant Asian population is predominantly a stable histologic finding associated with a low rate of persistent dysplasia and adenocarcinoma. Female patients and patients who have had a normal biopsy during follow-up were more likely to have stable IM. Correlative studies are underway and, if confirmed, these findings may influence gastric cancer screening guidelines for immigrant Asian populations in Canada. Prospective studies are warranted to clarify the natural history of IM and its role in gastric carcinogenesis in these high risk populations.

A111 THE ACCURACY OF 3D RECTAL ULTRASOUND FOR PRE-OPERATIVE RECTAL CANCER STAGING. A. Arya1, C. Romagnoli2, L. Man2, N. Hussain1, A. Fenster3, B. Yan1 1. Department of Medicine, University of Western Ontario, London, ON, Canada; 2. Department of Medical Imaging, University of Western Ontario, London, ON, Canada; 3. Robarts Research Institute, London, ON, Canada. Aims: Patients with advanced rectal cancer may benefit from neoadjuvant chemoradiation therapy. The decision to pursue treatment is highly dependent on accurate tumor and lymph node staging. Three dimensional ultrasound (3DUS) imaging has the potential to provide highly accurate tumor staging capability. The purpose of this study was to determine the accuracy of 3D rectal ultrasound staging versus 2D rectal ultrasound staging using pathology as the gold standard. Methods: A rigid ultrasound probe with 3D imaging capability along with image analysis software was previously developed at the Robarts Research Institute (London, Ontario, Canada). A retrospective analysis was completed on 105 patients who underwent transrectal 3D rectal probe ultrasound for possible or confirmed rectal cancer from November 2005 to December 2009. One Radiologist (CR) interpreted all of the 3D and 2D images. The accuracy of 3D and standard 2D rigid probe ultrasound versus pathology were determined. Results: Of the initial 105 cases identified, 78 were of interest (rectal adenomas or adenocarcinomas): 34 were excluded for not having staging results or having received neoadjuvant therapy, therefore 44 cases were available for analysis. Cases receiving neoadjuvant therapy were excluded since it would alter the final pathology. Of the 44 cases, 42 had images that were accessible for 2D analysis and 34 had images that were accessible for 3D analysis. The accuracy of 3D rectal ultrasound staging versus pathology was 47.1% (16/34). In 12/18 mismatched cases the 3DUS overestimated the T-stage, and in 6 mismatched cases the T-stage was underestimated. The accuracy for 2D ultrasound staging was 66.7% (28/42). In 6/14 of the cases with inaccurate 2D staging there was an overestimate and in 8/14 cases the T-stage was underestimated. The difference in accuracies for T-staging by 3DUS and 2DUS was not statistically significant, p=0.21. Conclusions: Transrectal 3DUS cannot currently replace other rectal cancer staging modalities, including standard 2D ultrasound. Our results demonstrate a trend towards 2DUS being a more accurate staging modality, however this was not statistically significant. Future technical improvements in the probe and the imaging software may improve accuracies.

Example of a T3 tumour with 3D rigid probe rectal ultrasound.

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A112 ENDOSCOPIST SPECIALTY IS ASSOCIATED WITH COLONOSCOPY QUALITY M. Jiang1, M. Sewitch2, L. Joseph3, A. Barkun4 1. Division of Clinical Epidemiology, Research Institute of the McGill University Health Centre, Montreal, QC, Canada; 2. Department of Medicine, McGill University, Montreal, QC, Canada; 3. Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada; 4. Division of Gastroenterology, McGill University Health Centre, Montreal, QC, Canada. Aims: Endoscopist specialty has been identified as a predictor of post-colonoscopy colorectal cancers. We sought to examine the relationship between specialty and colonoscopy quality as measured by polypectomy rate. Methods: A cross-sectional study was conducted of endoscopists and their patients at 7 endoscopy clinics in Montreal. Eligible endoscopists had colonoscopy billing rights to the provincial healthcare system. Patients scheduled for colonoscopy were recruited in endoscopy waiting rooms. Eligible patients were aged 50-75 and were eligible for provincial health coverage. A patient questionnaire assessed history of large bowel conditions, symptoms, and previous colonoscopies. Patient health insurance numbers were obtained to retrieve age, sex, and polypectomy status from provincial health databases. Bayesian hierarchical logistic regression, which accounts for endoscopist-level clustering, was used to compute polypectomy rates, as well as the odds ratio for specialty, adjusting for age, sex, large bowel conditions and symptoms, and previous colonoscopy. Results: A total of 2134 patients were included (50% female, mean age=61). Forty five endoscopists participated: 38 gastroenterologists (GIs), 6 surgeons, and 1 internist. Of the all the colonoscopies, 89.3% were completed by GIs and 10.7% by the non-GIs. The overall polypectomy rate was 25.9%. The estimated polypectomy rates were 22.0% (95%CI: 28.2-34.7%) for GIs and 12.3% (95%CI: 2.1-27.4%) for non-GIs. Adjusted odds ratio for specialty was 0.41 (95%CI: 0.18, 0.91). Endoscopist-specific polypectomy rates ranged between 12.0-54.5% for GIs and 6.2-26.1% for non-GIs. Conclusions: In terms of polypectomy rate as a quality indicator, GIs performed substantially better than non-GIs. There is wide variability in polypectomy rates among endoscopists in both specialties.

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A113 SURVEYING THE SURVEILLANCE:ARE PHYSICIANS DOING TOO MUCH COLONOSCOPY? A. King Memorial University of Newfoundland, St. John's, NF, Canada. Aims: To determine whether or not Gastroenterologists and General Surgeons in St. John’s are performing both screening and surveillance colonoscopy in accordance with the guidelines proposed by the CAG in 2004. Methods: After obtaining approval from HIC, the medical charts of patients visiting the endoscopy suites at both the Health Sciences Center and St. Clare’s Mercy Hospital were reviewed. For inclusion into the study the patients must have visited the endoscopy suite between January and June of 2010 for colonoscopy. Information such as family history, quality of colonic preparation, and indication for initial colonoscopy was collected from patient’s medical records. In addition, information regarding the size, number and histology of any polyps found was recorded. When data was obtained, the interval between the patient’s initial colonoscopy and suggested repeat colonoscopy was compared to the current CAG guidelines. Age at initial screening colonoscopy was also documented and compared to that recommended by current guidelines. Results: Data from 532 screening colonoscopies performed January - June 2010 was analyzed. According to this data, physicians adhered to current guidelines 39% of the time when recommending follow-up intervals for colonoscopy. On average, patients are being followed up 24 months earlier than guidelines would suggest. In 77% of cases involving single hyperplastic polyps, follow up was incorrect. On average, patients are undergoing initial screening 11 years later than recommended age. Conclusions: On average, patients are undergoing initial CRC screening much later than is recommended but once screening is initiated, patients are being screened more frequently than guidelines recommend. This emphasizes the importance of introducing a monitored screening program for CRC to the province of Newfoundland and Labrador. Also, since only 14 of the 532 patients examined in this study had screening modalities other than colonoscopy, this raises the importance of ensuring physicians are familiar with other available screening modalities, particularly for those at average risk.

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A114 COLONIC POLYPS IN PATIENTS WITH CYSTIC FIBROSIS: A PROSPECTIVE PILOT STUDY M. Fournier1, A. Chatterjee1, S. Aaron2 1. University of Ottawa, Department of Medicine, Division of Gastroenterology, Ottawa, ON, Canada; 2. University of Ottawa, Department of Medicine, Division of Respirology, Ottawa, ON, Canada. Aims: Cystic fibrosis (CF) is an autosomal recessive disease characterized by a defect in the CF transmembrane conductance regulator (CFTR). The CFTR gene lies in the chromosome band (7q31) adjacent to the MUC3, MUC11, and MUC12 genes. These genes are believed to be involved in the pathogenesis of colon cancer. Currently, there is no data on polyp prevalence in patients with cystic fibrosis. We performed a prospective pilot study to ascertain the feasibility of conducting colonoscopy to detect the polyps in a young population with cystic fibrosis. Methods: All patients who underwent a colonoscopy were 18 years of age or greater with a confirmed genetic diagnosis of cystic fibrosis. Demographical, CF disease characteristics, and baseline gastrointestinal data were captured. When polyps were detected on colonscopy, they were excised using standard endoscopic techniques. Polyp characteristics including location, size, and histology were recorded. Results: Complete colonoscopy with terminal ileal intubation was achieved in 6 (85%) subjects. One subject was excluded due to poor bowel preparation. The mean age at the time of colonoscopy was 33 years. No subjects had a family history of colorectal cancer and there were no lung transplant recipients. All subjects were homozygotes for the delta F508 mutation. There were 5 polyps identified and excised in a total of 2 subjects. 3 polyps excised were found to be neoplastic and one was identified as an advanced adenoma. This advanced polyp was a villous adenoma with low grade dysplasia found in the cecum of a 40-year-old male. The remaining 2 neoplastic polyps were both tubular adenomas identified in the ascending colon of a 44-year-old female. Conclusions: Polyps were detected in 33% subjects undergoing colonoscopy. Of the polyps detected, 60% were neoplastic and in one case, an advanced adenoma was detected. Given the young age of study participants undergoing colonoscopy, we believe this result to be significant. Our results demonstrate evidence supporting a larger scale prospective study to evaluate this question. Currently, this study is underway at our institution. Moreover, we feel that feasibility of performing a screening colonoscopy in a young population with CF and without known risk factors for colonic polyps is demonstrated.

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A115 SMALL BOWEL ADENOCARCINOMA: A SINGLE CENTER EXPERIENCE F. Messekher1, N. Carrier2, J. Carrier3 1. Department of Medicine, Division of Gastroenterology, Université de Sherbrooke, Sherbrooke, QC, Canada; 2. Department of Medicine, Division of Gastroenterology, Université de Sherbrooke, Sherbrooke, QC, Canada; 3. Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: Small bowel adenocarcinoma is a rare cancer with limited data available to guide its diagnosis and treatment Methods: The records of 20 patients hospitalized at the Centre Hospitalier Universitaire de Sherbrooke with small bowel adenocarcinoma diagnosis between 1990 and 2010 were retrospectively reviewed for clinical and follow-up data, including epidemiologic, tumor characteristics, cancer treatment history (surgery and chemotherapy) and survival. To study exclusively primary small bowel adenocarcinoma, cases with any known history of adenocarcinoma in other organs were excluded. Tumors arising from the ampullary region were also excluded. Results: 20 patients were included in the study. The median age at diagnosis was 65 years, 60% were female. Tumors were located in the duodenum (35%), jejunum (40%), and ileum (30%). The majority (60%) of tumors were moderately differentiated while 15% were poorly differentiated. Stage 4 was the most frequently observed (64.7%). The most common presenting symptom was abdominal pain (65%) while 55% had small bowel obstruction and 55% had anemia at the time of diagnosis. The median duration of symptoms prior to diagnostic was 47 days. 15% of patients had Crohn’s disease and 10% had celiac disease. 8 patients had adenoma at the tumor sites suggesting an adenoma-carcinoma sequence (40%). The median overall survival was 33 months, with a 5-year overall survival of 40%. The median overall survival was shorter for stage 4 (24 days) than stage 1-3 (105 days) with P=0.026. Predictors of poor survival were: age (P= 0.055), tumor stage (P=0.026) and resectability (P=0.004). 8 patients received adjuvant chemotherapy. The commonly used regimen was 5FU based chemotherapy. Adjuvant therapy did not influence overall survival (P=0.079). Conclusions: Small bowel adenocarcinoma remains a rare digestive cancer. The only curative treatment is surgical resection and the role of adjuvant chemotherapy is still controversial.

A116 ENDOSCOPIC HEMOSPRAY TM IN CONTROLLING CANCER-RELATED UPPER GASTROINTESTINAL HEMORRHAGE: PRELIMIMNARY EXPERIENCE. Y. Chen, A. Barkun, S. Mayrand McGill University, Montreal, QC, Canada. Aims: HemosprayTM is an emerging endoscopic hemostatic technology that has recently been introduced in the management of benign upper GI bleeding. It is a topical hemostatic sealant for which a delivery mechanism has been adapted for endoscopic use. Given the malleable nature of the powder, its ability to cover large areas, and especially the lack of direct contact with target tissue as it is sprayed onto the lesion, its use in bleeding gastroduodenal tumors has been suggested. The aim of this case series is to describe, to our knowledge, the first four cases worldwide of bleeding upper gastrointestinal tumors treated with HemosprayTM. Methods: A retrospective chart review of four consecutive patients with cancer-related upper GI bleeding treated with HemosprayTM at the McGill University Health Centre, Montreal, Quebec, Canada. Results: Three of our four subjects presented with acute upper GI bleeding and endoscopy showing the presence of an oozing mass in the stomach or duodenum. The remaining patient bled only following diagnostic biopsies. The underlying malignancies were metastatic adenocarcinoma of the stomach, esophageal cancer, adenocarcinoma of the pancreas, and advanced metastatic non-small cell lung cancer. Immediate hemostasis was achieved in all patients with the application of HemosprayTM (dose: less than 1 capsule, i.e. 20gm in all patients). Only one case of recurrent hemorrhage was noted in the context of severe metastatic non-small cell lung cancer and disseminated intravascular coagulation. No rebleeding was observed in the remaining subjects up to 41 days following HemosprayTM use (Range: 13-41 days, Mean: 25 days). Two patients subsequently received radiation treatments; one prophylactically, while the other continued to bleed. Complications including particle embolization and intestinal obstruction were not noted. Conclusions: HemosprayTM may be a safe and effective method in managing neoplastic upper GI bleeding. Although the optimal target patient groups remain unclear because of the limited experience, this technology would probably work best in those with active bleeding based on its mechanism of action. In addition, as it does not induce healing, it is most likely best utilized as a bridge to other modalities such as radiation therapy, if bleeding recurs. Our preliminary results appear promising but more data will be needed to further support these findings and conclusions.

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A117 NMR URINE METABOLOMICS AS A NOVEL METHOD OF SCREENING FOR COLORECTAL CANCER N. Gies, H. Wang, V. Tso, R. Foshaug, R. Fedorak University of Alberta, Edmonton, AB, Canada. Aims: Colorectal cancer (CRC) is among the leading causes of death in North America. CRC can be curable if identified early and prevented if found at the adenomatous polyp stage. However, detecting CRC at the adenomatous polyp stage currently relies upon fecal occult blood testing, which has an exceedingly poor accuracy. Metabolomics is an emerging field that identifies end products of cellular metabolism, and has been shown to be highly accurate in determining the presence of CRC or polyps on a single spot urine sample. The objective of this study was to determine if the metabolomic fingerprint defining an adenomatous polyp remains constant after the polyp is removed via polypectomy or whether the metabolomics fingerprint reverts to a pre-polyp state. Methods: Two hundred and forty three participants in the Edmonton SCOPE (Stop COlorectal cancer through Prevention and Education) study were identified to have adenomatous polyps on colonoscopy. During that colonoscopy each participant had the polyps removed via polypectomy. Prior to the colonoscopy each participant had a single spot urine sample collected and the metabolomic fingerprint determined using NMR spectroscopy. Of these 243 individuals, 139 (57.2%) provided a second spot urine sample post polypectomy. A repeat metabolomic fingerprint was determined on this second sample for comparison to the first. 80 males (57.6%) and 59 females (42.4%) participated. One-dimensional nuclear magnetic resonance (NMR) spectra were acquired using an Oxford 600Hz NMR spectrometer with a Varian VNMRS two-channel console. The 1H NMR spectrum of each urine sample was analyzed using Chenomx NMRSuite v7.0 (Chenomx, Inc. Edmonton, Canada). The metabolomic fingerprint was modeled using SIMCA-P+ v12.0.1 (Umetrics, Umea, Sweden). Results: The time from the subject’s polypectomy to the second urine sample was on average 30.3 months (SD= 4.6 months; range 22.2 - 38.7). Using multivariate statistical analysis (OPLS), separation of the pre and post polypectomy groups are shown in Figure 1. The urine metabolomic fingerprint pre-polypectomy is significantly different than the urine metabolomic fingerprint post-polypectomy. Conclusions: Our results show that the post polypectomy metabolomic fingerprint moves to a completely different section of the OPLS a plot than the identical group of patients, before polypectomy. This implies that a spot urine metabolomic fingerprint can not only predict which patient has an adenomatous polyp, but can also be used to confirm adequate polypectomy and potentially be used as a determinant of recurrent adenomatous polyp growth.

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A118 PROGNOSTIC SIGNIFICANCE OF EPHRIN B2 AND MICROSATELLITE STATUS IN STAGE III COLON CANCER M. Aljawad, A. Drucker, T. Arnason, S. Yan, K. Thompson, W. Huang Dalhousie University and Queen Elizabeth II Health Sciences Centre, Halifax, NS, Canada. Aims: to evaluate the prognostic significance of EPHERIN B2in stage III colon cancer patients treated with adjuvant chemotherapy Methods: We identified all cases of resected stage III colon cancer in our district between 1996 - 2006 (cohort 1) who received adjuvant bolus 5-fluorouracil/ folinic acid or raltitrexed and from 2007 - 9 (cohort 2) with any adjuvant chemotherapy. Tissue microarrays were performed using immunohistochemistry (IHC) for EPHB2 (high=3+/2+) or (low=1+/0), and microsatellite status for MLH1and MSH2. Microsatellite stable (MSS) tumors were defined as both MLH1/ MSH2 (+/+); otherwise, they were classified with microsatellite instability (MSI). Primary and secondary outcomes were disease free survival (DFS) and overall survival (OS), respectively Results: In cohort 1, we identified 123 cases with at least 1 year follow-up and having adequate tissue. EPHB2 stained high in 78 (70%) and low in 45 (30%), and showed MSS in 107 (87%) and MSI in 16 (13%). Of the MSS subset, 16 EPHB2-low and 33 EPHB2-high had recurred or died. Of the MSI subset, 2 EPHB2-low and 3 EPHB2-high had recurred or died. DFS at 3 years was 60% for EPHB2-low and 38% for EPHB2-high (P=0.08), but no difference was observed during complete follow-up (P=0.13). Stratification of EPHB2 by microsatellite status showed no difference in DFS (P=0.09). Analysis of cohort 2 is ongoing Conclusions: EPHB2 did not significantly discriminate as a prognostic factor alone, but showed a trend towards identifying earlier relapse in tumours with MSI. This would require prospective validation in a larger cohort.

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A119 THE METABOLIC REGULATOR ERRα AND ITS SPLICE VARIANT REGULATE COLON CARCINOGENESIS V. Giroux, G. Bernatchez, T. Lassalle, J. Beaulieu, J. Carrier Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: The nuclear receptor ERRα acts principally in pair with its coactivator PGC-1α as a regulator of metabolic processes particularly in tissues subjected to high-energy demand. Besides its implication in energy metabolism and mitochondrial biogenesis, ERRα was recently associated with tumorigenesis. Increased expression of ERRα was noted in different cancerous tissues as breast, ovary and colon. Also, a new form of ERRα lacking the exon5 (ERRα Δ5) was recently identified and suggested to be a dominant negative of ERRα and interestingly to be differently expressed in normal and cancerous tissues. Since a protumorigenic role is emerging for this metabolic regulator, we investigated the role of ERRα and its spliced form ERRα Δ5 in colon carcinogenesis. Methods: shRNA-mediated silencing of ERRα and overexpression of ERRα Δ5 were performed by lentivirus infection in DLD1 and HCT116 human colon cancer cells. The interaction between both proteins was investigated as well as their respective roles in various tumorigenic processes. Results: Silencing of ERRα by shRNA reduced proliferation of DLD1 and HCT116 cells as measured by growth kinetics and growth assays in soft agar and reduced tumor formation in NUDE mice. Furthermore, FACS-scan analysis revealed that ERRα silencing delays G1-S phase transition in colon cancer cells. Differential expression of a splice variant of ERRα (ERRα Δ5) in cancer vs normal tissues would support the importance of ERRα in colorectal carcinogenesis. This is the case at least for colon tumors as cancerous samples display lower amount of ERRα Δ5 and higher amount of ERRα compared to adjacent normal tissues. Interaction between both variants has been characterized by immunoprecipitation assays, confirming the conserved dimerization potential of ERRα Δ5 variant with ERRα. Furthermore, luciferase assays revealed that ERRα Δ5 is transcriptionaly inactive and its expression inhibits the transcriptional activity of ERRα on its target genes, suggesting that this variant acts as a dominant negative for ERRα. Interestingly, the reexpression of ERRα Δ5 in colon cancer cells reduces soft agar colony formation. Conclusions: Strong ERRα expression is associated with cancerous tissues and is required for the intense proliferation of colon cancer cells. Interestingly, the poorly active splice variant ERRα Δ5 is lost in cancerous colon tissues and has antiproliferative properties when reintroduced in colon cancer cells. Since this splice variant could interact with ERRα and inhibit its activity, ERRα Δ5 reduction of expression in cancerous tissue could allow ERRα to fully promote colon cancer cell proliferation.

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A120 THE CYCLIN-DEPENDENT KINASE CDK8 IS A NOVEL TARGET OF ERK SIGNALING INVOLVED IN HUMAN COLORECTAL CANCER É. Lemieux, C. Guillaume, S. Cagnol, N. Rivard University of Sherbrooke, Sherbrooke, QC, Canada. Aims: Strong evidences exist for the critical involvement of KRAS/BRAF/MEK/ERK signaling pathway in the regulation of intestinal epithelial cell (IEC) proliferation and colorectal carcinogenesis. Gain-of-function mutations of KRAS and its downstream effector BRAF are detected in up to 60% of colorectal cancers (CRCs). Recently, we have performed a cDNA microarray analysis which identified CDK8 gene as one of the most prominently induced gene in IECs transformed by oncogenic activation of MEK1. CDK8 is a cyclin-dependent kinase (CDK) member of the mediator complex that couples transcriptional regulators to the basal transcriptional machinery, and is implicated in the transcriptional regulation of key pathways involved in cancer. The precise role of CDK8 in colorectal carcinogenesis and the link between CDK8 and the mutational status of K-RAS and B-RAF is not known. Methods: CDK8 expression was evaluated by qPCR and western blot analysis in normal IECs (IEC-6) that express an tamoxifen-inducible form of human BRAFV600E oncogene, namely IEC-BRAFV600E:ER cells. To elucidate the role of CDK8 in human CRC, CDK8 expression was down-regulated by RNAi in human CRC cell lines exhibiting BRAF (HT29, Colo205) or KRAS mutation (HCT116,SW480). Proliferation, anchorage-independent growth in soft agarose and tumor formation in nude mice were analyzed. CDK8 expression was analyzed in human CRC cells treated or not with the MEK inhibitor U0126 and in human colorectal tumor tissues in comparison to healthy adjacent tissues. Results: 1- In IEC-BRAFV600E:ER, CDK8 mRNA and protein levels were quickly induced following activation of oncogenic B-RAFV600E, in a MEK-dependent manner. 2- CDK8 silencing in IEC-BRAFV600E:ER cells markedly reduced the transforming effect of oncogenic BRAF. 3- Of note, CDK8 mRNA and protein levels were markedly enhanced in human CRC cells exhibiting activating mutations in KRAS or BRAF compared to normal IECs. Moreover, CDK8 protein levels were also enhanced in human colorectal tumor tissues in comparison to healthy adjacent tissues. 4- Treatment of CRC cell lines with U0126 significantly reduced CDK8 mRNA and protein levels, indicating that expression of CDK8 is likely dependent of MEK/ERK activity. 5- CDK8 silencing in human CRC cell lines HCT116 and HT-29 strongly attenuated their proliferation rate and their capacity to grow in soft agarose and in nude mice. Conclusions: Our data suggest that CDK8 is up-regulated by oncogenic activation of KRAS and BRAF in a MEK-dependent manner and contributes to the tumorigenic potential of this signaling in IECs. Hence, CDK8 may represent a novel potential therapeutic target for colorectal cancer treatment.

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A121 INHIBITION OF GSK3 ACTIVITY PROMOTES AUTOPHAGY IN PANCREATIC EPITHELIAL CELLS B. Marchand, M. Boucher Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: We have previously demonstrated that prolonged inhibition of GSK3 activity induces JNK-dependent cell death in human pancreatic cancer cells. Recently, it was suggested in prostate cancer cells that inhibition of GSK3 promotes both apoptosis and autophagy, the latter playing a protective role against cell death. Interestingly, inhibition of autophagy was shown to sensitize diverse cancer cells to a wide array of stress conditions. The AIM of the study was to evaluate whether GSK3 controls autophagy in pancreatic epithelial cells and determine whether inhibition of autophagy sensitizes pancreatic epithelial cells to GSK3 inhibition-induced apoptosis. Methods: Experiments were performed using human pancreatic cancer (PC) cell lines (PANC1 and MIAPaCa2) and the human pancreatic epithelial cells HPDE. GSK3 activity was inhibited by treatment with specific GSK3 inhibitors: SB216763 (20μM) or CHIR99021 (5μM). Apoptosis was measured by assessment of PARP cleavage and caspase 3 and 7 activities. Autophagy was evaluated by the detection of the membrane-bound LC3B-II isoform. Inhibition of autophagy was achieved by treatment with the autophagy inhibitor 3-methyladenine 3-MA (10mM). Results: 1- In PC cells, prolonged inhibition of GSK3 (48-72h) provoked autophagic and apoptotic responses. 2- Treatment of PC cells with the autophagy inhibitor 3-MA elicited an apoptotic response and strongly promoted GSK3 inhibition-induced apoptosis. 3- On the other hand, prolonged inhibition of GSK3 activity in HPDE promoted autophagy without inducing apoptosis. 4- 3-MA treatment did not significantly affected HPDE cell viability but rendered HPDE cells responsive to GSK3 inhibition i.e. combined treatment with GSK3 and autophagy inhibitors induced apoptosis of HPDE cells. Conclusions: Our data demonstrate for the first time that inhibition of GSK3 activity promotes autophagy in pancreatic epithelial cells and suggest that this autophagic response protects cells against GSK3 inhibition-induced apoptosis. Our results further support a central contribution of GSK3 activity in pancreatic epithelial cell viability.

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A122 CONTROL OF THE HUMAN OSTEOPONTIN PROMOTER BY THE ESTROGEN RELATED RECEPTOR ALPHA IN COLORECTAL CANCER. S. BOUDJADI1, G. Bernatchez2, J. Beaulieu1, J. Carrier2 1. Department of Anatomy and Cell Biology. Université de Sherbrooke, SHERBROOKE, QC, Canada; 2. Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: In Canada, colorectal cancer (CRC) is the second leading cause of death from cancer. The extracellular matrix glycophosphoprotein osteopontin (OPN) is over expressed in CRC and involved in almost all steps of tumour progression by regulating cell-matrix interactions and cellular signalling through binding with integrin and CD44 receptors. In rat bone, the OPN promoter is under the control of various cancer-enriched transcription factors, including the estrogen-related receptor alpha (ERRα). Our results suggest that the latter has an important role in promoting colorectal tumour growth. The goal of this study was to determine if ERRα controls the human OPN promoter in CRC. Methods: OPN levels were quantified in HT29 colorectal cells treated with XCT790, a reverse ERRα agonist, or following shRNA lentivirus-mediated silencing of ERRα. In silico analysis of a 1-kb region of the human OPN gene revealed the presence of three imperfect ERRα response elements (ERRE): S1, S2 and S3. OPN promoter control by ERRα was studied by a promoter gene reporter assay in HEK293T cells and the three potential ERRE were tested by selective mutagenesis. In vivo ERRα occupancy of the human OPN promoter was tested by the chromatin immunoprecipitation (ChIP) assay. OPN and ERRα staining was studied by immunohistochemistry on a tissue microarray of 97 resected CRC and matched non tumoral tissues Results: Loss of ERRα function or expression in HT29 cells is associated with reduced OPN gene and protein levels. Furthermore, transient overexpression of ERRα and the coactivator PGC-1α led to a significant increase in human OPN promoter activity which was abolished by treatment with XCT790 or by shRNA targeting ERRα, as well as by disruption of ERRE-S1 and ERRE-S2 elements, suggesting that human OPN is a transcriptional target of ERRα. In addition, ERRα ChIP in HT29 cells revealed occupancy of the OPN promoter in an area overlaying ERRE-S1 and ERRE-S2. In support of their role in CRC, nuclear ERRα and cytoplasmic OPN staining were stronger in tumours than in non-tumorous tissues, although no significant correlation between scores of ERRα and OPN staining was observed. Conclusions: Our results suggest that ERRα could be a direct activator of the human OPN promoter pertinent to CRC, together with other cancer-enriched transcription factors. (supported by the CIHR)

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A123 MYELOID DERIVED SUPPRESSOR CELLS EXACERBATE COLITIS-ASSOCIATED CANCER IN THE INTERLEUKIN-10 DEFICIENT MOUSE MODEL M. Bawa, K. Ng, D. McCafferty University of Calgary, Calgary, AB, Canada. Aims: The myeloid derived suppressor cell (MDSC, Gr1+CD11b+) is a protumorigenic cell type with various immunosuppressive and proangiogenic functions. MDSC recruitment is increased in many of models of inflammation and cancer. We have previously shown increased recruitment and correlation with cancer in the colon as well as in vitro immunosuppressive activity of MDSC in the interleukin-10 deficient (IL-10-/-) mouse. However, their role in vivo in this model remains unclear. We hypothesized that MDSC exacerbate colitis-associated cancer in vivo in the IL-10-/- mouse. We tested the role of MDSC in vivo by targeting them with low doses of a cytotoxic drug, gemcitabine, and adoptively transferring them into IL-10-/- mice. Methods: IL-10-/- mice at 6 weeks of age were given 5 weekly intraperitoneal injections of 60mg/Kg gemcitabine or saline control (n=6). MDSC were isolated from the bone marrow of IL-10-/- mice via percoll density gradient centrifugation. MDSC were adoptively transferred into IL-10-/- mice at 6 weeks of age via 5 weekly tail vein injections of 3.0x106 cells (n=6). All mice were sacrificed at 3 months of age and their colons were scored macroscopically for hyperplasia. Sections of rolled colons were stained with hematoxylin and eosin and scored for neoplastic changes based on epithelial dysplasia, abnormal crypt architecture and submucosal invasion. Colon sections were also stained with rat-anti-mouse Gr1 and CD11b antibodies and the number of Gr1+CD11b+ cells per unit area of mucosa were counted. Groups were statistically compared via student’s T test (P<0.05). Results: MDSC (Gr1+CD11b+) counts were significantly decreased in the colons of IL-10-/- mice treated with gemcitabine (14.3±1.3) as compared to controls (30.6±4.2). Targeting MDSC with gemcitabine also significantly decreased hyperplasia (0.3±0.5 vs 3.0±0.0) and dysplasia (2.0±0.8 vs 4.6±0.5) in the colon. Adoptive transfer of MDSC did not significantly change polyp scores (3.0±0.0 vs 2.8±0.2). Dysplasia scores were significantly increased by adoptive transfer of MDSC (4.4±0.5) as compared to saline controls (6.4±0.5). Conclusions: Our data show that targeting MDSC in vivo decreases neoplastic changes and adoptively transferring MDSC increases neoplastic changes in the IL-10-/- mouse. This indicates that MDSC exacerbate colitis-associated cancer in the IL-10-/- mouse and may be a potential therapeutic target in colitis-associated cancer.

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A124 THE ROLE OF FUSOBACTERIUM NUCLEATUM IN THE DEVELOPMENT OF COLITIS-ASSOCIATED CANCER IN THE IL-10-/- MOUSE. J. Charette1, M. Bawa1, K. Cochrane2, E. Allen-Vercoe2, D. McCafferty1 1. University of Calgary, Calgary, AB, Canada; 2. University of Guelph, Guelph, ON, Canada. Aims: Despite the many advantages of the gut microbiome, several bacterial species have been associated with colorectal cancer. Fusobacterium nucleatum (Fn) is a gram-negative, anaerobic oral pathogen that is also resident in the human gut mucosa. Recently, an invasive EAVG_002 strain has been shown to be associated with inflammatory bowel disease. The aim of this study was to determine if EAVG_002 could alter inflammation and cancer in the IL-10-/- model of colitis associated cancer. Methods: IL-10-/- mice were studied from 6 weeks of age. Mice received Fn EAVG_002 in tryptic soy broth (TSB) per rectum (n=9) or TSB vehicle alone (n=3) on Day 0. Fecal samples were collected from day -1, 0, and at intervals over the following 6 weeks and intestinal colonization by EAVG_002 confirmed by PCR. At 6 weeks post injection, animals were sacrificed and colons scored macroscopically for inflammation and mucosal hyperplasia (polyps). Total peripheral white blood cell (WBC) numbers were assessed. Colons were fixed in formalin and processed for histological analysis. Microscopic signs of inflammation and dysplasia were assessed in 7 micron Haematoxylin & Eosin stained sections. Colonization of the mucosa by EAVG_002 was determined immunohistochemically using a polyclonal rat anti-fuso primary antibody (EAV_AS3) and a goat anti-rat Alexa Fluor 488 secondary antibody. Isotype control antibodies were used to ensure specificity of staining. Results: Total WBC counts were similar between mice treated with EAVG_002 (1.4 ± 0.2 X 106/mL) and untreated controls (1.6 ± 0.1 X 106/mL). Weight gain by IL-10-/- mice from 6-12 weeks was not altered by treatment with EAVG_002. PCR results indicated that EAVG_002 colonized the colon for approximately 3 weeks post treatment period. Positive staining for EAVG_002 within the mucosa was not observed. Macroscopic inflammation in vehicle treated 12-week old IL-10-/- mice was 3.0 ± 0.0, representing erthyma, edema, diarrhea and ulceration. No significant difference in macroscopic inflammation was observed in EAVG_002 treated mice (2.7 ± 0.2). Both groups of vehicle and EAVG_002 treated mice developed mucosal hyperplasia to similar levels (4.0 ± 0.6 and 3.6 ± 0.3 respectively). Interestingly, mean dysplasia scores determined histologically were approximately 50% in EAVG_002 treated animals (3.7 ± 1.3) than observed in the controls (7.7 ± 0.3; p=0.06, Mann-Whitney U-test). Conclusions: These data suggest that Fn EAVG_002 colonization of the colon is not associated with an increase in intestinal inflammation in the IL-10-/- mouse, however a potential role in the development of dysplasia cannot be ruled out. Further studies aimed at prolonging Fn EAVG_002 colonization of the gut are warranted.

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Hepatobiliary Neoplasia

A125 SORAFENIB FOR ADVANCED HEPATOCELLULAR CARCINOMA A. Shingina1, M. Hashim1, M. Haque1, E. Yoshida1, S. Gill2, A. Weiss2 1. British Columbia Cancer Agency, Vancouver, BC, Canada; 2. University of British Columbia, Vancouver, BC, Canada. Aims: Advanced Hepatocellular Carcinoma (HCC) has a poor prognosis with a 5-year survival < 10%1. Sorafenib, a novel oral multi-kinase inhibitor, has been approved in the treatment of unresectable HCC. We have reviewed the BC experience with sorafenib to assess its effectiveness and tolerance in a “real world” clinical setting. Methods: Retrospective clinic chart review identified 83 patients referred to the British Columbia Cancer Agency (BCCA) during 2008-2010 with a diagnosis of HCC who qualified for treatment with sorafenib. Patients eligible for sorafenib included those with failed local therapies, including resection, transarterial chemboembolization(TACE) and radiofrequency ablation(RFA) as well as those with disease too extensive for the former therapeutic modalities. Results: Population characteristics: median age was 61 years, 76% male, 64% of Asian heritage, 36% Caucasian, 34% of patients were infected with Hepatitis B, 27% with Hepatitis C, 20% had alcoholic liver disease and 19% had cryptogenic liver disease . Liver function was as follows: Child Pugh (CP) A score in 75% of patients and CPB in 25%. Sorafenib Dosage: Therapy with sorafenib was initiated and continued at a reduced dosage of 400mg daily in 60% of patients. In the 40% of patients treated with standard dose sorafenib at 400mg twice daily, the dose needed to be reduced in all patients secondary to toxicity. Side effects of therapy: Seventy patients (81%) experienced the following side effects: hand-and-foot syndrome, nausea, vomiting, diarrhea, hypertension, liver toxicity, weight loss and anorexia. Forty two patients (51%) terminated sorafenib therapy secondary to side effects while 41 patients (49%) discontinued therapy due to disease progression. Results of therapy: Mean duration of therapy was six months with 44 (53%) of patients terminating therapy within the first 3 months (50% disease progression, 50% side effects). Overall mean survival was 10 months from the start of therapy. Imaging at three months was available in 62 patients (75%): four (5%) patients had regression of liver masses, 17(20%) achieved disease stabilization and 41(50%) patients showed progression of liver and metastatic lesions. Conclusions: In our review of 83 patients with unresectable HCC treated with sorafenib, we observed a high degree of significant side effects that led to discontinuation of treatment in half of the patients. Despite using a lower dosage of sorafenib in 60% of patients with advanced HCC, the observed survival was similar to that reported in the literature. This raises the possibility that patients may achieve an adequate response to sorafenib at a lower dose which may be better tolerated and with significant cost savings. Further studies with lower doses of sorafenib are needed to confirm these findings.

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A126 SERUM ALPHAFETOPROTEIN (AFP) CONCENTRATION IN SMALL (<2CM) HEPATOCELLULAR CARCINOMAS A. Leber2, M. Sherman1 1. University Health Network, Toronto, ON, Canada; 2. University of Toronto, Toronto, ON, Canada. Aims: The value of AFP as a screening tool for hepatocellular carcinoma (HCC) is controversial. Advantages of the test include its low cost, ease of use and its high specificity at values greater than 400 ng/L. However, the sensitivity of AFP in the detection of small tumors is felt to be poor. The size of the tumor at initial detection is fundamentally important as it dictates available treatment options and the possibility for cure. Our objective was to examine the AFP level of tumors detected at a size of <2cm, 2-5cm and >5cm. Methods: Patients presented at the multidisciplinary hepatoma rounds at the University Health Network (UHN) in Toronto were reviewed. Only those patients with a first presentation of HCC and those who had a pre-treatment serum AFP and radiological measurement of tumor size were included. Data pertaining to baseline characteristics, treatment modalities and prognosis at 1 year was collected through the electronic patient records. Results: A total of 540 patients were reviewed, and 258 patients were selected based on the inclusion criteria. The mean age was 62 (range 18-89) and 81% of patients were male. The most prevalent liver disease etiologies were hepatitis B, hepatitis C and alcoholic cirrhosis. The AFP value, tumor size and number, treatment modality and prognosis at 1 year are displayed in table 1. One year survival for HCC < 2cm, HCC between 2-5cm and HCC >5cm in size was 93%, 93% and 76% respectively. Conclusions: The majority of patients with small HCCs do not have significantly elevated AFP levels. AFP is not a sensitive tumor marker for small HCCs less than 2cm in size. Table 1: AFP value, tumor size and number, treatment modality and prognosis at 1 year

Measurement <2cm (n=45)

2.1cm-5cm (n=133) >5cm (n=80)

Mean AFP (ng/L) Median AFP (ng/L) Range (ng/L) 115 9 1-1135

481 19 1-18,494

22,526 146 1-733,381

% of patients with AFP >20 ng/L 31 49 64 Mean tumour size (cm) 1.6 3.5 8.4

Number of tumours 1 2 3 multiple 31 10 3 1 80 22 12 19 43 15 4 18 Treatment modalities Surgery Transplant RFA TACE Alcohol ablation

Radiation Systemic Chemotherapy No treatment Unknown 2 3 30 0 0 2

0 6 2 21 12 47 19 10

1 2 18 3 10 4 5 26 8 8 4

14 1 Alive at 1 year Yes No Unknown 37 3 5 111 9 13 52 16 12

HCC present at 1 year Yes No Unknown 15 21 6 62 48 14 41 11 12

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Hormones, Transmitters, Growth Factors

A127 PDGF PROMOTES WOUND REPAIR OF INTESTINAL SMOOTH MUSCLE IN VITRO Y. Zhao, T. Han, D. Nair, S. Lourenssen, M. Blennerhassett Queen's University, Kingston, ON, Canada. Aims: Endothelial damage triggers the migration and subsequent proliferation of vascular smooth muscle cells (VSMC) to form a neointima in vivo, due to the onset of exposure of VSMC to PDGF. Using animal models, we have shown that intestinal inflammation causes proliferation of intestinal smooth muscle cells (ISMC), which is associated with the appearance of PDGF-Rβ. The potential for PDGF to cause ISMC migration is unknown, but this response might also be a key component of ISMC proliferation, featuring in wound healing and repair. To study this, we evaluated wound healing of ISMC in vitro. Methods: Adult circular smooth muscle cells (CSMC) were obtained from the mid-descending rat colon by enzymatic dissociation and maintained to early or late passage number (passage 1-2 vs passage 8-12) in DMEM with 5% FCS. Each cell line was derived from one animal. For analysis, cohort cultures were initiated in 35 mm dishes and standardized scrape wounds (3/dish, area<15000 µm2) were created with a pipette tip. Cultures were imaged using phase contrast microscopy and analyzed to determine wound healing (% remaining open area; ImagePro 6.0). For time lapse photomicroscopy, cultures were maintained in Liebowitz L15 medium + 5% FCS. PDGF expression was evaluated by western blotting, and its action inhibited using imatinib (LC Laboratories). Results: Scrape wounding of confluent CSMC cultures resulted in rapid reduction of wound area over the next 30 hr (average rate of reduction, 2816 ± 226 µm2/hr (n=36 replicates from n=3 cell lines)). Initial (0-12 hr) and subsequent (12-30 hr) rates of reduction of wound area did not differ significantly, implying a constant process. Time lapse studies showed cell migration and further, a cell cycle time of 17.7 ± 1.1 (5) hr, suggesting that wound repair over this period was largely dependent on cell migration rather than proliferation. Given our recent finding that proliferation in vitro resulted in endogenous PDGF expression (see Nair et al, CDDW 2012), we examined the role of PDGF in wound healing. Western blotting identified the presence of PDGF-BB in P10 but not P2 cultures, suggesting a potential autocrine/paracrine role for PDGF in mediating wound repair in vitro. Analysis of scrape wounding outcomes in P10 cell lines treated with the PDGF-Rβ inhibitor imatinib (0.5 µg/mL) showed significant impairment, with wound healing reduced by 70.3 ± 0.8 % of untreated cohorts by 30 hr (n=3 cell lines; p<0.05). Conclusions: We have developed a culture model for the study of wound repair by intestinal smooth muscle cells. Receptor inhibition has shown that PDGF promotes wound closure, primarily by promoting ISMC migration. Since inflammation initiates PDGF-Rβ expression in vivo, repair of intestinal damage may involve components of both ISMC migration as well as proliferation. Supported by CCFC and NSERC.

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Poster of Distinction A128 PROTEASE-ACTIVATED RECEPTOR 2 EXERTS A TONIC ANTI-APOPTOTIC EFFECT IN HT-29 COLONIC EPITHELIAL CELLS, MEDIATED IN PART BY PROTEIN KINASE C V. Iablokov, C. Hirota, W. MacNaughton University of Calgary, Inflammation Research Network, Calgary, AB, Canada. Aims: Protease-activated receptor 2 (PAR2) is expressed on colonic epithelial cells and is activated by serine proteases. PAR2 has been shown to increase proliferation of colonic epithelial cells and inhibit apoptosis in airway cells, actions consistent with healing of tissue damage. We previously showed that PAR2 signaling does not stimulate proliferation in HT-29 cells, but delays IFN-γ/TNF-α-induced apoptosis. Here we aimed to discover the signaling pathways responsible for these observations. Methods: 1) HT-29 cells expressing PAR2 were treated with the PAR2 activating peptide 2-furoyl-LIGRL (2fLI) for up to 3 hrs in serum free media. Phosphorylation of MAP kinase family members ERK1/2, p38, and JNK as well as Akt was determined by western blot in whole cell lysates. 2) For apoptosis studies, pre-treatment with 2fLI for 1 hr in serum-free media was followed by treatment with IFN-γ (40ng/ml) and TNF-α (10ng/ml) for different times. The role of the extrinsic pathway of apoptosis was determined by western blotting for cleaved caspase-8. Dual annexin-V/PI staining followed by flow cytometry was used to detect percentages of early apoptotic cells. PAR2 knockdown with siRNA was validated by real time PCR and a decreased calcium response to 2fLI. Involvements of calcium-dependent protein kinase C (PKC) isoforms (α, β1) were investigated using the inhibitor Gö6976 (10 nM). Results: 1) 5μM 2fLI caused a transient increase in the phosphorylation of all MAP kinases as well as Akt. ERK1/2 and Akt phosphorylation was highest after 5 min but was gone after 30 min and did not return for the 3 hrs examined. On the other hand, treatment with serum-containing media (known to stimulate proliferation) induced prolonged ERK1/2 and Akt phosphorylation that was highest at 30 min and was still present after 1 hr. 2) 2fLI significantly reduced cleavage of caspase-8 in response to IFN-γ/TNF-α. Knockdown of PAR2 not only abolished the 2fLI-mediated reduction in caspase-8 cleavage and annexin-V/PI detected apoptosis, but also increased HT-29 cell’s sensitivity to apoptosis in response to IFN-γ/TNF-α. Pretreatment with Gö6976 abolished the 2fLI-mediated reduction in caspase-8 cleavage but not annexin-V/PI detected apoptosis. Conclusions: PAR2 signaling does not stimulate the prolonged MAPK and PI3K activity associated with proliferation. However, the PAR2 protein exerts a tonic anti-apoptotic effect and its activation reduces epithelial apoptosis in response to inflammatory cytokines found up-regulated in Crohn’s disease. Our findings may represent a mechanism whereby proteases facilitate colonic healing after inflammation.

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Immunobiology and Liver Transplantation

A129 IS TYPE 1 HEPATORENAL SYNDROME REVERSIBLE AFTER LIVER TRANSPLANTATION? W. Leung, E. Renner, M. Al Beshir, K. Thongthai, M. Marquez, F. Wong Division of Gastroenterology, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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Poster of Distinction A130 IMPACT OF PREGNANCY IN A MURINE MODEL OF AUTOIMMUNE HEPATITIS. S. Bourbonnais, G. Marceau, K. Béland, F. Alvarez Gastroenterology, hepatology and nutrition, Department of Pediatrics, CHU Sainte-Justine, University of Montreal,, Montreal, QC, Canada. Aims: Autoimmune hepatitis (AIH) is a chronic disease characterized by a progressive destruction of the hepatic parenchyma by the immune system. In AIH, 75% (type 1) to 90% (type 2) of cases are women. Successful control of the disease has lead to an increasing number of them becoming pregnant. During pregnancy, a spontaneous, but temporary, remission of the disease has been observed in women with AIH, often followed by post-partum relapse. Currently, this phenomenon is not fully understood. Therefore, we aim to investigate the mechanisms underlying pregnancy-related remission and relapses. Methods: A murine model of type 2 AIH by DNA xenoimmunization (CYP2D6 and humanFTCD construct) developed in our laboratory was used for the experiment. Xenoimmunization results in a lost of tolerance, with clinical and biochemical features similar to those observed in patients with type 2 AIH. Immunized C57BL/6 mice were mated 6 months post-injection, when liver inflammation is settled. Mice were sacrificed during gestation (2 weeks post-conception). Lymphocytes were then isolated from the spleen and liver to analyse the presence of regulatory T (Tregs) and B cells (B10 cells), using flow cytometry. Liver disease was evaluated from histological inflammation using Ishak modified AIH score. Serum alanine aminotransferase (ALT) was measured as marker of liver injury. Finally, titers and isotypes of antibodies (anti-CYP2D6 and anti-FTCD), and autoantibodies (anti-mouseFTCD) were monitored monthly during the experiment by ELISA. Results: Significant decreases of liver inflammation (p=0.0087) and ALT levels (p=0.0163) have been observed in mice after two thirds of gestation. Tregs were increased (p=0.0283) in the liver but not in the spleen of pregnant mice. Autoantibodies isotypes (IgG1/IGg2A) suggests a trend towards a Th2 switch during pregnancy, which needs to be confirmed by flow cytometry of spleen and liver cells. Conclusions: Pregnancy induces remission of the disease in a murine model of type 2 AIH, as seen in patients. Tregs infiltrating the liver seem to play a role in the improvement of the disease. A better understanding of the natural immunosuppression occurring during pregnancy could bring important knowledge to design new and improved therapy for both men and women suffering from AIH.

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A131 INCIDENCE, RISK FACTORS AND EVOLUTION OF NON-ANASTOMOTIC BILIARY STRICTURE FOLLOWING LIVER TRANSPLANTATION G. Huard1, S. Remillard1, J. Villeneuve1, R. Lapointe2 1. Division of Hepatology, CHUM-Hôpital St-Luc, Université de Montréal, Montréal, QC, Canada; 2. Division of Hepatobiliary Surgery, CHUM-Hôpital St-Luc, Université de Montréal, Montréal, QC, Canada. Aims: INTRODUCTION: Non-anastomotic biliary stricture (NABS) is a complication of liver transplantation (LT). NABS occurs with an incidence of 5-15% and is a major cause of morbidity and mortality. This lesion is often associated with hepatic artery compromise (HAC), prolonged cold ischemic time (CIT) and donor age. The aim of this study was to assess the incidence, the risk factors and evolution of NABS after LT in our population. Methods: METHOD: This retrospective study included all patients who underwent LT at Hôpital St-Luc between 2000 and 2010. Re-transplantations were excluded from analysis to preserve independence of data. The diagnosis of NABS was established by imaging studies demonstrating typical intra or extra-hepatic strictures. The following parameters were studied: donor and recipient’s demographics; cause of LT; LT surgical data; type of treatment and evolution of NABS. Results: RESULTS: During the study period, 561 LT were done and 34 cases of NABS occurred (incidence 6.1%). In patients with NABS, 23/34 (68%) had diffuse strictures (DS) and 11/34 (32%) had segmental strictures (SS). Biliary drainage was performed in 24/34 patients (71%) (14 with DS and 10 with SS). Treatment was effective in 6/24 cases (25%) (3 with DS and 3 with SS) and none of them needed a re-transplantation. Overall, re-transplantation was done in 23/34 pts (68%). In those who were re-transplanted, 18 had an unsuccessful biliary drainage and 5 were re-transplanted without any attempt of biliary drainage. The only predictive factor for the development of NABS identified by multi-variate analysis was the recipient age (OR 0.96; 46.3 ± 11.2 Y in NABS vs 51.6 ± 8.7 Y in controls (C); p 0.0053). Other parameters did not meet statistical significance: mean donor age (52.2 ± 11.4 Y in NABS vs 48.3 ± 16.1 Y in C), mean MELD (21 ± 5.2 in NABS vs 21 ± 5.3 in C) and preservation solution (UW solution in 76.5% of NABS vs 89.4% in C). In patients with NABS, 14/34 (41.2%) had an HAC. No significant difference was found between the subgroup of NABS with or without HAC, in terms of recipient age, MELD or CIT. When comparing the subgroup of NABS without HAC with controls, the perfusion solution was identified as a risk factor for the development of NABS (OR 0.29 for UW vs HTK). Conclusions: CONCLUSION: In our population, the incidence of NABS after LT is 6.1% and 68% of the cases of NABS underwent a re-transplantation. Biliary drainage was tried in the majority of cases, with a success rate of 25%. Recipient age was identified as a risk factor for the development of NABS. The HTK perfusion solution was a risk factor for NABS in patients without HAC.

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A132 LIVER TRANSPLANTATION FOR OVERLAP SYNDROMES OF AUTOIMMUNE LIVER DISEASES R. Bhanji, A. Mason, A. Montano-Loza University of Alberta, Edmonton, AB, Canada. Aims: The term overlap syndrome describes variant forms of autoimmune hepatitis (AIH) that present in combination with either characteristics of primary biliary cirrhosis (PBC), or primary sclerosing cholangitis (PSC). This study analyses the recurrence and other outcomes after liver transplantation in patients with overlap syndromes compared to patients transplanted for single autoimmune liver disease. Methods: We evaluated 231 adult patients who received a liver transplant due to autoimmune liver diseases; including 103 with PBC, 84 with PSC, 32 with AIH, and 12 with overlap syndrome (7 AIH-PBC, and 5 AIH-PSC). Results: There were no significant differences in patients characteristics, including age, and gender between the overlap syndrome, and the single autoimmune liver disease groups. The duration from diagnosis to liver transplantation was significantly shorter in patients with overlap syndromes than those with single autoimmune liver disease (35±11 vs. 101±11 months; P=0.009). Patients with overlap syndromes had a higher probability of recurrence than patients with a single autoimmune liver disease (5 years: 46 vs. 17%; 10 years 64 vs. 29%, P=0.008). Median time for recurrence in overlap syndrome was shorter when compared with patients with single autoimmune liver disease (61±23 vs. 183±12 months, P=0.008). Of the 7 patients with overlap syndrome AIH-PBC, 2 patients developed features of recurrent PBC, 1 of AIH, and the other of AIH-PBC overlap. Of the 5 patients with overlap syndrome AIH-PSC, 1 patient developed features of AIH, 1 PSC, and 1 overlap AIH-PSC. There were no differences in the frequency of graft loss and survival between patients with overlap syndromes and patients with either single autoimmune liver disease. Median graft-survival for overlap syndrome was 135±13 months, and 195±21 months in patients single autoimmune liver disease (P=0.5), and median patient-survival for overlap syndrome was 136±13 months, and 256±41 months in patients single autoimmune liver disease (P=0.6). Conclusions: Patients with liver transplantation due to overlap syndrome-end stage liver disease may have disease recurrence as a single or combined autoimmune liver disease. In addition, these patients had an earlier onset and a higher rate of recurrence when compared to their counter parts (those individuals receiving liver transplantation for single autoimmune liver diseases, such as AIH, PBC or PSC). Despite this our study showed the overlap syndrome patients have similar survival post-liver transplant compared to individuals with single autoimmune liver diseases.

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Immunology and Inflammatory Bowel Disease

A133 TIME TRENDS IN PREVALENCE AND INCIDENCE OF INFLAMMATORY BOWEL DISEASE IN ALBERTA: A POPULATION-BASED STUDY. A. Rezaie, R. Panaccione, R. Fedorak, E. Cheng, L. Dieleman, S. Ghosh, H. Barkema, G. Kaplan Alberta IBD Consortium, Calgary & Edmonton, AB, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A134 THE UTILITY OF TPMT ENZYME TESTING IN INFLAMMATORY BOWEL DISEASE L. Chisick, C. Oleschuk, C. Bernstein University of Manitoba, Winnipeg, MB, Canada. Aims: We aimed to assess the levels of red blood cell thiopurine methyl transferase levels (TPMT) in subjects with IBD and to determine how these levels impacted on thiopurine dosing and leukopenia over the first 6 months of therapy. Methods: A retrospective chart review was done on all adult IBD patients (n=423, 88.2% Caucasian) who had TPMT levels checked by 11 participating gastroenterologists in Manitoba, Canada 2008-2010. Descriptive data, WBC count, dose and reason for discontinuation were analyzed for the first 6 months of therapy. Patients receiving ≥2.0 mg/kg of azathioprine or ≥1.0 mg/kg of 6-mercaptopurine were considered to be “substantially” dosed. TPMT activity was analyzed by methylation of 6-thioguanine that was quantified by HLPC-fluorescence. Normal levels were >35 nmole/g Hb/h, intermediate levels were >11 but ≤35 nmole/g Hb/h and low levels were ≤10 nmole/g Hb/h. Results: The mean age was 42±15.6 yrs and 52% were female. The mean TPMT level was 59.9 (±16.5) nmol/gHb/h (ulcerative colitis, UC: 58.3±16.1, Crohn’s disease, CD: 61.9±16.9 nmol/gHb/h). The majority (n=373, 88.2%) of patients were Caucasian. 8.3% had intermediate levels and 93.4% had normal levels. Only 1 subject had a low level. A total of 216 patients had sufficient data to be included for full analysis (TPMT levels were checked in 186 in whom thiopurine therapy was not initiated). Patients with intermediate TPMT levels were generally started at lower doses than patients with normal TPMT levels (1.0 ±0.6 mg/kg vs 1.8 ±0.5 mg/kg). Of the subjects with normal TPMT levels, 158 completed 1 month of therapy (42 (19%) did not complete 1 month) and 100 completed at least 6 months. Intolerance was the most common reason for discontinuation within 1 month-occurring in 28 (15%) of patients. Only 74 (37.8%) were initially dosed with ≥2.0 mg/kg of AZA (36.2% of UC subjects and 48.1% of CD subjects). Each month ~5% of subjects were leukopenic with a mean overall AZA dose of 1.9(±0.6) mg/kg and a mean WBC=3.7(±0.7) X109/L in those subjects. Of 16 patients with intermediate TPMT levels, 11 completed 6 months of therapy and overall 5 became leukopenic at some time. Conclusions: Our TPMT enzyme levels (in terms of distribution of normal, intermediate and low) corroborate the initial genotype reports in a mostly Caucasian population. We have also shown that 5% of thiopurine users with normal TPMT enzyme levels become leukopenic monthly and hence vigilance with monthly blood count monitoring must be maintained for at least 6 months. If thiopurines are to maintain a place in the therapeutic armamentarium of IBD patients, clinicians measuring TPMT levels should consider more substantial dosing initially to help facilitate more rapid pharmacologic effects. Finally, by 6 months as many as half of subjects may no longer be using the drug either due to intolerance or lack of efficacy.

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A135 ROLE OF RAC2 IN INFLAMMATORY BOWEL DISEASE (IBD) R. Fattouh1, C. Guo1, G. Lam1, M. Gareau1, P. Sherman2, A. Muise2, J. Brumell1 1. Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada; 2. Division of Gastroenterology, Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada. Aims: The etiology of IBD remains largely uncertain. It is clear that in addition to environmental influences genetic factors also contribute to susceptibility. Recent studies have identified a number of susceptibility genes and many of these genes code for proteins known to play critical roles in the intestinal immune response. We previously identified several single nucleotide polymorphisms (SNPs) in the RAC2 gene that are associated with increased susceptibility to IBD. Rac2 is a leukocyte specific GTPase that is thought to be an integral mediator of various macrophage and neutrophil functions. How alterations in the RAC2 gene impact the intestinal immune response in vivo and influence the development of IBD are unknown. Thus, the central aim of this project is to examine the extent to which a defective Rac2 protein may compromise immune responses in the intestine and promote disease. Methods: The consequences of a defective Rac2 protein on intestinal immunity was investigated in i) untreated Rac2 knockout (KO) mice (at various ages; 1-6 months) to determine if, and to what degree, disease develops as a consequence of gene disruption alone, and ii) in mice subjected to chemically-induced (dextran sulfate sodium; DSS) and infection-based (Citrobacter rodentium) models of colitis. Various clinically relevant and immune related parameters were evaluated including weight loss, clinical score, crypt hyperplasia, and tissue inflammation. Results: Untreated Rac2 KO mice did not display any overt signs of disease and there was little evidence of colitis by histopathological analysis, up to 6 months of age. In contrast, Rac2 KO mice subjected to DSS treatment lost more weight and displayed more severe symptoms (dehydration and rectal bleeding) than DSS-treated WT controls. Colon shortening was also more pronounced in DSS-treated Rac2 KOs. Similarly, Rac2 KO mice infected with C. rodentium also showed worsened clinical symptoms compared to infected WT mice. Quantification of C. rodentium staining in colon sections revealed significantly more C. rodentium in the colon of Rac2 infected mice compared to infected controls at day 11. Crypt hyperplasia was comparably increased in Rac2- and WT-infected mice at day 11. Interestingly, while hyperplasia was mostly resolved in WT-infected mice by day 22, hyperplasia was further elevated in infected Rac2 KOs. In addition, we observed marked leukocyte infiltration in the colons of Rac2 KO- but not WT-infected mice at day 22. Conclusions: Collectively, our findings demonstrate that Rac2 KO mice develop more severe disease when subjected to models of colitis, and further illustrate the importance of innate immune defects in the pathogenesis of IBD.

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A136 TARGETED DEFICIENCY IN SRC HOMOLOGY 2-CONTAINING INOSITOL-5-PHOSPHATASE (SHIP) REDUCES SEVERITY OF EXPERIMENTAL COLITIS C. Waterhouse, B. Atkinson, X. Cai, S. Lee, P. Kubes University of Calgary, Calgary, AB, Canada. Aims: Neutrophils play an important role in mucosal defense, but contribute directly to tissue damage during intestinal inflammation. SHIP plays an important role in limiting phosphoinositol-3-kinase (PI3K) activation, and may therefore regulate immune cell activation during colitis. SHIP deficiency was recently shown to cause experimental granulomatous ileitis. In order to dissect cell-specific roles for SHIP, we examined the course of colitis in mice with a neutrophil-targeted SHIP deficiency. Methods: SHIP (flox/flox) mice were interbred with congenic mice expressing Cre-recombinase under the control of the granulocyte elastase promoter. Resulting Cre+ (with targeted deletion of SHIP) and Cre- (control) mice were given 2% dextran-sulfate sodium (DSS) colitis for 5 days with subsequent recovery over the following 9 days (total 14 days). Mice were harvested at day 7 and 14 for assessment of colitis. Results: : Cre+ mice showed a trend to decreased weight loss during the course of DSS colitis as well as decreased diarrhea (Stool dry:total weight 26.0 (Cre+) vs 21.0% (Cre-) on day 7; 33.4 vs 29.5% on day 14). Colonic myeloperoxidase assay showed diminished neutrophil infiltration during DSS colitis in Cre + compared to Cre - (Day 7: 4.1 vs 7.6 U/mg, p < 0.01; Day 14: 4.0 vs 2.7 U/mg, p < 0.05). Histological scores in Cre+ mice were significantly lower than in the Cre- group (Day 14: 7.6 vs 12.4; p < 0.001). Interestingly, in spite of the diminished levels of inflammation seen in the colon by MPO assay and histological analysis, granulomata were noted in approximately 80% of the Cre+ mice at day 14, primarily in lymphoid follicles, with no granulomata noted in the Cre- group. Conclusions: Targeted neutrophil deletion of SHIP reduces neutrophil recruitment and histological damage in experimental colitis, but with the subsequent development of granulomata in the intestinal tract. This highlights a critical, cell specific role for SHIP in mediating intestinal disease.

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A137 PERIANAL DISEASE IN ULCERATIVE COLITIS: IS IT REALLY CROHN’S DISEASE? D. Li, M. Waterman, J. Stempak, M. Silverberg Zane Cohen Centre for Digestive Diseases, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada. Aims: Ulcerative colitis (UC) and Crohn’s disease (CD) are inflammatory bowel diseases (IBD) each with unique and overlapping characteristics. Cases with features of both CD and UC are labelled as inflammatory bowel unclassified (IBDU). Perianal disease (PAD) is classically associated with CD, however it has been reported in 5-25% cases of UC. This case series reviews clinical features and outcomes of patients with UC and PAD, and examines the impact of PAD on IBD classification. Methods: Patients initially diagnosed with UC who had a perianal abscess or fistula were identified from the IBD Genetics Database at Mount Sinai Hospital in Toronto. Results: Of 449 patients initially diagnosed with UC, 40 (8.9%) had PAD with fistulae in 24 (60%) and abscess in 17 (42.5%). 3 of these patients had PAD prior to IBD diagnosis, while the rest developed PAD after diagnosis with an average latency of 8.6 years. 9 patients (22.5%) had a first degree relative with IBD. The majority were ex-smokers (42.5%) or non-smokers (42.5%) with only 7.5% active smokers. At diagnosis, left-sided colitis (E2)(37.5%) and extensive disease (E3)(27.5%) were more frequent than proctitis (E1)(15%). For their IBD treatment overall, 47.5% required azathioprine/6-MP with efficacy in only 31.6%. 16 patients were treated with anti-TNF agents, and the majority had a good response (87.5%). As for type of IBD, 21 (52.5%) had a change in diagnosis. 66.7% were re-classified from UC to CD and 33.3% to IBDU. The main reasons for change in diagnosis were endoscopic appearance (38.1%) and clinical behaviour defined by appearance of perianal disease, penetrating complications, or small bowel involvement (47.6%). On T-test analysis, there were no significant differences in any baseline or clinical features between those with and without a change in diagnosis. Conclusions: Among UC patients with PAD, the majority did not have other features classically associated with CD such as small bowel disease or intra-abdominal abscess. Anti-TNF treatment was effective in the majority of cases. About half of the UC patients with PAD had a change in diagnosis, which suggests that development of PAD in itself does not necessarily warrant reclassification of IBD.

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A138 THE RELATIONSHIP OF GASTROINTESTINAL SYMPTOMS AND MENSES IN WOMEN WITH IBD M. Bernstein, L. Graff, L. Targownik, K. Downing, P. Rawsthorne, C. Bernstein, L. Avery University of Manitoba, Winnipeg, MB, Canada. Aims: Many women with Crohn’s disease (CD) and ulcerative colitis (UC) report changes in their gastrointestinal (GI) symptoms with menses, however, the nature of these changes has not been well documented and may reflect normative menses alterations. We aimed to determine the relationship between GI symptoms and menses. Methods: Women aged 18-65 in the University of Manitoba IBD Research Registry, a population-based database were invited to participate, with the aim of including those who had current or recent active menstrual cycles. Healthy women presenting for routine care (contraception prescription or routine examination) to outpatient gynecological clinics at the largest hospital in the province were consecutively recruited to serve as controls. Exclusions were those with gynecological conditions with a significant pain component (e.g. endometriosis), dysfunctional uterine bleeding, gynecological malignancy, or chronic GI disease. Participants completed a survey assessing patterns of menses, age at first menses, and GI and general symptoms in the 5 days prior to the onset of menses and during menses. Results: 47% with IBD responded; of those 38% (n=238) met inclusion criteria with ongoing menses and CD (n=151) or UC (n=87). The non-IBD controls (n=156) were significantly younger than women with CD or UC (mean 32.3 yrs vs 38.6 or 39.3 yrs, p<0.0001). The mean age of menarche was similar in all 3 groups (mean 12.7-12.9 yrs) as was the proportion with regular menses in each group (68-75%). However, women with UC had significantly shorter menses than controls (5.0 vs 5.7 days, p=0.03). Women with CD were more likely than those with UC to report worsening of GI symptoms in the premenstrual phase (46% vs 24%, p=0.0007), but no significant differences were found in reporting of symptom worsening during menses (47% vs 39%). A larger proportion of those with CD than UC or controls observed increased diarrhea both premenstrually (46% vs 26% or 24%, p=0.0006) and during menses (60% vs 43% or 28%, p<0.006). Fatigue during menses was more common in CD than UC (56% vs 40%, p=0.009) but no different than controls (49%). Healthy women were more likely to report painful menses (52.6%) than those with IBD (CD 42.4%, p=0.037; UC 33.3%, p=0.002). There were no significant differences among the groups for any of the other 10 symptoms queried either before or during menses. Conclusions: Healthy women are more likely to report painful menses than women with IBD, but other GI symptoms and mood are similar. Women with CD are more likely to have a worsening of GI symptoms premenstrually than those with UC, and they more commonly experience an increase in diarrhea, both prior to and during menses. The timing of menses should be taken into consideration when evaluating GI symptoms in patients with IBD.

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A139 BASELINE C-REACTIVE PROTEIN IS ASSOCIATED WITH DISEASE PROGRESSION IN PATIENTS WITH CROHN’S DISEASE J. Colombel1, W. Sandborn2, M. Castillo3, B. Huang3, Q. Zhou3, R. Thakkar3 1. Centre Hospitalier Univ de Lille, Lille, France; 2. University of California, San Diego, La Jolla, CA; 3. Abbott Laboratories, Abbott Park, IL. Aims: Elevated C-reactive protein (CRP), a marker of inflammation, is known to correlate with Crohn’s disease (CD) activity1,2 and to be a predictor of disease relapse in CD.3,4 However, in patients with moderate or severe CD it is not known whether CRP is associated with disease progression. Methods: This post hoc analysis evaluated the association of baseline (BL) CRP and change in CDAI over time in patients with moderate (CDAI>220 to ≤300) to severe (CDAI>300) CD who were randomized to the placebo group in the CHARM trial5 (N=238). Patients received open-label adalimumab (ADA) induction (week 0: 80mg; week 2: 40mg) followed by blinded weekly placebo treatment from weeks 4-56, with switch to open-label ADA allowed after week 12 for disease flare. This analysis grouped patients by CD severity and BL CRP (severe, high: CDAI>300, CRP≥10mg/L; severe, low: CDAI>300, CRP<10mg/L; moderate, high: CDAI≤300, CRP≥10mg/L; moderate, low: CDAI≤300, CRP<10mg/L). Mean CDAI scores at each visit from weeks 4-56 were calculated for each subgroup, using last observation carried forward (after week 4) to handle dropouts or switch to ADA. Results: Mean CDAI decreased from BL in all subgroups after ADA induction (Week 4, Table). By week 56, the mean CDAI in all subgroups had increased compared with week 4, and was greater in patients who had higher CRP versus lower CRP at BL (244 vs 223, 306 vs 260, for moderate and severe groups, respectively). In patients with moderate CD and high CRP, week 12 and week 56 CDAI approached that of patients with severe CD and low CRP, despite BL differences in CDAI of over 90 points (week 12: 235 vs 243; week 56: 244 vs 260). Conclusions: This post hoc analysis of disease activity and CRP demonstrates that an elevated BL CRP in patients with moderate or severe CD is associated with higher disease scores after one year. Disease activity over time in patients with moderate CD and higher CRP behaved similarly to that of patients with severe CD and lower CRP. References: 1. Solem C. Inflamm Bowel Dis. 2005; 11:707. 2. Henriksen M. Gut. 2008; 57:1518. 3. Bitton A. Gut. 2008; 57:1386. 4. Consigny Y. Inflamm Bowel Dis. 2006; 12:551. 5. Colombel JF. Gastroenterology. 2007; 132:52. Table. Mean CDAI Over Time

Severe (CDAI >300) Moderate (CDAI ≤300)

CRP <10mg/L N=60

CRP ≥10mg/L N=87

CRP <10mg/L N=70

CRP ≥10mg/L N=44

BL CRP, mg/L, median (range) 2.5 (0.2-9.7) 33.6 (10.1-287.0) 4.2 (0.2-9.9) 31.4 (10.1-104.0) BL CDAI, mean (SD) 348 (46) 370 (49) 259 (24) 254 (32)

Wk 4 CDAI, mean (SD) 243 (85) 242 (96) 162 (68) 174 (70) Wk 12 CDAI, mean (SD) 243 (102) 286 (109) 190 (85) 235 (120) Wk 56 CDAI, mean (SD) 260 (95) 306 (114) 223 (91) 244 (116)

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A140 COST-PER-RESPONDER ANALYSIS OF INFLIXIMAB COMPARED TO ADALIMUMAB AMONG INDIVIDUALS WITH MODERATE TO SEVERE ULCERATIVE COLITIS B. Feagan4, C. Gunnarsson2, P. Mallow2, J. Rizzo3, J. Lofland1 1. Janssen Scientific Affairs, Horsham, PA; 2. S2 Statistical Solutions, Inc, Cincinnati, OH; 3. Stonybrook University Medical Center, New York, NY; 4. Robarts Research Institute, London, ON, Canada. Aims: In North America, the prevalence of ulcerative colitis (UC) ranges from 37 to 238 patients per 100,000 adults. There is little evidence on the cost effectiveness of alternative biologic treatments for UC, yet the increasing budgetary impact of biologic treatment has intensified the need to determine the relative therapeutic value vs. the cost of biologic agents. The purpose of this study was to compare the cost effectiveness of adalimumab (ADA) vs. infliximab (IFX) for the treatment of UC. Methods: A cost-effectiveness model was developed for the clinical endpoint of clinical remission. The models are calculated for 8, 52, and 54 weeks of treatment. ADA was administered at an initial dose of 160 mg, 80 mg at week 2, and 40 mg every other week until week 50 for the 52 week follow up and week 52 for the 54 week follow-up. IFX was administered at 5 mg/kg based on a patient weight of 80 kg at week 0, 2, 6, and then every 8 weeks until week 46. Data on medication dosing, efficacy, and time periods were obtained from the literature.1,2 Medication Costs are based on current Wholesale Acquisition Pricing (WAC). For IFX, treatment costs include infusion costs in addition to cost of drug. Results: Cost per clinical remission was lower for IFX than ADA at week 8 ($37,885 vs $69, 619), week 52 ($132, 667 vs $270, 772) and week 54 week ($132, 667 vs $280, 109). Conclusions: IFX is more cost effective than ADA in the treatment of UC. Further studies are needed to prospectively compare the effectiveness of these treatments. References: 1. Rutgeerts P, Sandborn J, Feagan BG, et al. Infliximab for induction and maintenance therapy for ulcerative colitis. N Engl J Med. 2005;353:2462-2476. 2. Sandborn WJ, Van Assche G, Reinisch W, et al. Induction and Maintenance of Clinical Remission by Adalimumab in Patients with Moderate-to-Severe Ulcerative Colitis. Poster presented at 6th Congress of ECCO, February 24 - 26, 2011, Dublin, Ireland.

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A141 NOD2 EXPRESSION IN DENDRITIC CELL SUBSETS: INSIGHT INTO REGULATION OF INTESTINAL HOMEOSTASIS K. Geddes, D. Philpott University of Toronto, Toronto, ON, Canada. Aims: Mutations in Nod2 are associated with a heightened risk for developing Crohn's disease. Nod2 is a pattern recognition receptor that recognizes bacterial peptidoglycan and initiates expression of cytokines that regulate inflammatory responses. The mechanisms of how Nod2 variants contribute to disease progression is not clear but is likely to involve regulation of intestinal homeostasis. Therefore to gain insight into the mechanism by which Nod2 might regulate intestinal homeostasis we investigated the expression of Nod2 in intestinal cells. Methods: Cell-type specific expression of Nod2 was analyzed using a green fluorescent protein (GFP) reporter mouse that expresses GFP under control of the Nod2 promoter. Cells from these mice were isolated from various organs and tissues (spleen, mesenteric lymph node (MLN), intestinal lamina propria and intraepithelial cells from ileum, cecum and colon) and the level of GFP expressed in T cells, B cells, dendritic cells (DC), monocytes, neutrophils and epithelial cells was analyzed by flow cytometry. Results: Nod2-GFP expression was detected in almost every cell type in every tissue examined. CD8 T cells expressed the lowest, almost non-detectable level of GFP. CD4 T cells, B cells, intestinal epithelial cells all expressed intermediate levels of GFP whereas monocytes, neutrophils, and dendritic cells expressed higher levels of GFP. Interestingly, there was a discreet population of cells expressing very high levels of GFP in all organs. These cells were predominantly MHC class II expressing dendritic cells and in the cecum and colon these cells were mostly CD103 positive dendritic cells. Conclusions: Analysis of Nod2-GFP expression in tissues revealed that in the cecum and colon CD103 positive DCs express very high levels of Nod2. This is particularly intriguing considering the fact that the CD103 DC is a cell type that is known to regulate intestinal homeostasis. This implies that Nod2 plays a critical function in regulating CD103 DC function and therefore targeting Nod2 in these cells may represent a new approach for developing therapies to treat inflammatory bowel disease.

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A142 INDUCTION AND MAINTENANCE ADALIMUMAB THERAPY FOR THE TREATMENT OF MODERATE TO SEVERE CROHN'S DISEASE IN CHILDREN J. Hyams1, A. Griffiths2, J. Markowitz3, R. Baldassano4, W. Faubion, Jr.5, R. Colletti6, M. Dubinsky7, J. Kierkus8, Y. Wang9, B. Huang9, B. Bittle9, M. Marshall9, A. Lazar10 1. CT Children’s Med Center, Hartford, CT; 2. Hosp for Sick Children, Toronto, ON, Canada; 3. Cohen Children's Med Center of NY, New Hyde Park, NY; 4. Children’s Hospital of Philadelphia, Philadelphia, PA; 5. Mayo Clinic, Rochester, MN; 6. U of VT, Burlington, VT; 7. Cedars Sinai Med Center, Los Angeles, CA; 8. Children’s Memorial Health Inst, Warsaw, Poland; 9. Abbott, Abbott Park, IL; 10. Abbott, Ludwigshafen, Germany. Aims: Compare efficacy and safety of 2 adalimumab (ADA) regimens in pediatric patients with moderate to severe Crohn’s disease (CD). Methods: Patients (6-17 yrs) had CD (PCDAI>30 at baseline + endoscopic/radiologic confirmation) for ≥12 weeks (wks), despite concurrent oral corticosteroids and/or immunosuppressants. Prior infliximab (IFX), discontinued for loss of response or intolerance, was allowed. Patients received open-label ADA induction per baseline body weight (BW): 160/80mg at Wk0/2 for BW ≥40kg or 80/40mg at Wk0/2 for BW<40kg. patients were stratified per Wk4 clinical response (PCDAI decrease ≥15 points from baseline) and prior IFX exposure and randomized 1:1 to 48 wks of double-blind ADA maintenance therapy at 2 dosages: high-dose=40mg every other Wk (eow) if Wk4 BW≥40kg or 20mg eow if Wk4 BW<40kg; low-dose=20mg eow if Wk4 BW≥40kg or 10mg eow if Wk4 BW<40kg. Weekly therapy (blinded) for flare/non-response was allowed after Wk12. Primary endpoint was Wk26 clinical remission (PCDAI≤10). Results: 192 patients received ADA induction (56% men, 89% white, 64% ≥13 years old, 64% ≥40kg, 44% prior IFX use, median PCDAI=40.0 at baseline). 87% and 80% of randomized patients with 80mg/40mg and 160mg/80mg induction doses, respectively, were Wk4 responders. 188 patients were randomized (low-dose: 95; high-dose, 93); 124 completed the study (low-dose: 58; high-dose, 66). A higher % of high-dose patients achieved clinical remission or response at Wk26 vs. low-dose patients. Remission and response rates at Wk26 were greatest for IFX-naïve patients, especially Wk4 responders (Table). The safety profile was comparable to that in adults with CD. Conclusions: ADA was safe and effective for inducing and maintaining remission in pediatric CD. IFX-naïve patients receiving high-dose ADA achieved the greatest efficacy, especially those who responded to ADA induction. IFX-experienced pts also benefitted from ADA.

Table. Clinical remission/response at Wk26 in randomized patients, non-responder imputation. Prior IFX Wk4 Response ADA Low-dose, % (n/N) ADA High-dose, % (n/N) P valuea,b,c

Clinical Remission Overall 28 (27/95) 39 (36/93) 0.075

Yes Yes No

20 (8/41) 22 (7/32) 11 (1/9)

17 (7/42) 19 (6/32) 10 (1/10)

0.736 0.756

—

No

__________

Yes No

__________

35 (19/54) 38 (18/48) 17 (1/6)

_______________

57 (29/51) 63 (27/43)

25 (2/8) _______________

0.026* 0.016*

— ____________

Clinical Response Overall 48 (46/95) 59 (55/93) 0.073

Yes Yes No

29 (12/41) 31 (10/32) 22 (2/9)

48 (20/42) 56 (18/32) 20 (2/10)

0.086 0.044*

—

No

Yes No

63 (34/54) 67 (32/48) 33 (2/6)

69 (35/51) 74 (32/43)

38 (3/8)

0.541 0.419

— aCochran-Mantel-Haenszel test adjusted for prior IFX use and Wk4 response status for overall. bChi-square test (or Fisher's exact test for small cell counts) within each category of prior IFX use or Wk4 response. cIf blank, test not performed due to small sample size.

*Statistically significant at an α=5% level.

A143 THE EFFECT OF PREOPERATIVE INFLIXIMAB THERAPY IN CROHN’S PATIENTS ON POST-OPERATIVE COMPLICATIONS: A META-ANALYSIS G. Rosenfeld1, H. Qian2, B. Bressler1 1. University of British Columbia, Vancouver, BC, Canada; 2. St. Paul's Hospital, Vancouver, BC, Canada. Aims: The impact of preoperative infliximab on post-operative complicatons in patients with Crohn's disease is controversial. We conducted a systematic review and meta-analysis of studies comparing rates of post-operative complications among Crohn’s Disease patients treated with Infliximab therapy versus alternative therapies. Methods: We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and searched 4 electronic databases along with major conference abstract databases (from inception of database until October, 2011) for all English-language articles and abstracts that evaluated post-operative complications among Crohn’s disease patients. We applied meta-analysis with random effects model to calculate the overall odds ratio and its 95% confidence interval for total major complications as well as several secondary outcomes. Results: Data were extracted from seven studies including 1213 patients among whom 446 complications were identified. The most common complications were wound infections, anastomotic leak and sepsis. Although not statistically significant, the results of this meta-analysis show a trend toward an increased major complication rate amongst patients treated with Infliximab (Odds Ratio = 1.58 [95% Confidence Interval: 0.93 - 2.67]; p = 0.09). When minor complication rates (Odds Ratio = 1.38 [C.I.: 0.70 - 2.73]; p = 0.36), reoperation (Odds Ratio = 1.74 [C.I.: 0.69 - 4.36]; p = 0.24) and 30 day mortality (Odds Ratio = 5.13 [C.I.: 0.61 - 42.86]; p = 0.18) were considered, there was not a significant difference between the Infliximab treated group and the control group. Conclusions: The available literature suggests that use of Infliximab during the perioperative period is associated with a trend toward higher rates of major post-operative complications. A similar, but smaller trend was found for minor complications, reoperation and 30 day mortality rates suggesting that clinicians should at least consider the discontinuation of infliximab prior to surgery for their Crohn’s Disease patients.

*Major complications were defined as sepsis, anastomotic leak, peritonitis, local fistula or abscess, wound infection, wound failure, stoma complications, bowel perforation severe anemia and hemorrhage

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A144 INVARIANT NATURAL KILLER T CELL FUNCTION IN INTESTINAL INFLAMMATION T. Selvanantham, S. Girardin, D. Philpott, T. Mallevaey University of Toronto, Toronto, ON, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A145 CROHN’S DISEASE ASSOCIATED NOD2 VARIANTS SHOW DIFFERENTIAL ACTIVATION OF NF-KB IN RESPONSE TO AUTO-SIGNALING AND MURAMYL DIPEPTIDE J. Van Limbergen2, F. Soares3, R. Russell4, S. Girardin3, A. Griffiths2, D. Philpott1 1. Department of Immunology, University of Toronto, Toronto, ON, Canada; 2. Hospital for Sick Children, Toronto, ON, Canada; 3. Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; 4. Yorkhill Hospital, Glasgow, United Kingdom. Aims: Single nucleotide polymorphisms (SNPs) located of the NOD2/CARD15 gene (nucleotide-binding oligomerization domain containing 2/caspase recruitment domain family, member 15) are associated with increased susceptibility to Crohn’s disease (CD). These SNPs are thought to disrupt the sensing of bacterial muramyl dipeptide (MDP) at the C-terminus of the NOD2 protein. The precise contribution of each of these SNPs (SNP5, 8, 12 and 13) to NF-kB activation by means of NOD2-auto-signaling and stimulation with MDP has not been investigated at low levels of NOD2 expression. Data regarding the linkage disequilibrium (LD) between these CD-associated SNPs are scarce. Methods: NOD2 variant constructs (rs2066842 (SNP5), rs2066844 (SNP8), rs2066845 (SNP12) and rs2066847 (SNP13), SNP5+8, SNP5+12 and SNP5+13) were created by site-directed mutagenesis of a pCMV plasmid containing wild-type N-terminal FLAG-NOD2. NF-kB luciferase assays were performed on HEK293 cells following transient transfection (20hr) with wildtype (WT) and NOD2 variant constructs, titrating NOD2 from 1-100ng/well. The NF-kB luciferase response of NOD2 (1ng)-transfected HEK293 cells to MDP (10microgram/well) was measured. 2-way ANOVA and unpaired t-tests were used. By means of Haploview-analysis of sequencing data of the exons and exon-intron boundaries in 24 paediatric Caucasian Crohn’s disease patients, we assessed the LD between SNP5 and SNP8, 12 and 13. Results: 2-way ANOVA demonstrated an effect of NOD2 genotype and concentration on auto-signaling at low levels of expression (p<0.0001). This was due to the significant difference of auto-activation between WT and SNP5, SNP8 and SNP12 (p<0.001). At low levels of NOD2 expression (1-2ng), the presence of SNP5 modified the auto-activating potential of SNP12 (p<0.01). Based on these titration experiments, a low NOD2 transfection of 1ng/well was chosen for the MDP-stimulation experiment. MDP stimulation led to a significant increase of NF-kB luciferase activity in WT and all NOD2 variant constructs, except SNP13 and SNP5+13 (p<0.0001). Haplotype analysis of 11 NOD2 SNPs, identified through direct sequencing in 24 children with CD, showed that LD between SNP5 and the other CD-associated variants is low (r-squared <0.1), in spite of close physical proximity (D’ 1.0). Conclusions: Our combined genetic and functional analyses demonstrate that the association of SNP5 with Crohn’s disease is unlikely due to LD with other SNPs. At low levels of NOD2 expression, NOD2 variant constructs differ from WT in their auto-signaling and MDP-stimulated activation of NF-kB.

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A146 PHARMACOKINETIC PROFILES FOR ORAL AND SUBCUTANEOUS METHOTREXATE IN PATIENTS WITH CROHN’S DISEASE: A FOLLOW-UP A. Wilson, V. Patel, N. Chande, J. Gregor, R. Kim, T. Ponich, G. Dresser, R. Tirona, U. Schwarz University of Western Ontario, London, ON, Canada. Aims: Methotrexate (MTX) is an effective treatment in the induction and maintenance of remission in Crohn’s disease. Despite effective treatment with oral dosing in other disease populations, it is administered subcutaneously to individuals with Crohn’s disease due to concerns over drug absorption. The aim of this study was to compare the pharmacokinetic profiles (PK) of oral (PO) and subcutaneous (SC) MTX in patients with stable Crohn’s disease to determine the bioequivalence of these two dosing regimens. Preliminary data revealed comparable Pk profiles for PO and SC MTX in three patients with stable Crohn’s disease; however, we have targeted a larger sample size to better assess for the inter-individual variability in the bioavailability of MTX. Methods: Eight patients with stable Crohn’s disease met the inclusion criteria for enrollment. Each patient participated in two Pk studies: PO MTX and SC MTX that occurred over the course of 2 separate study days separated by one week’s duration. During each study day, patients received either a PO or an SC dose of MTX followed by plasma collection at 10 pre-specified time-points over a 24-hour time period. MTX plasma levels were then obtained using a sensitive mass spectrometer. Pk analysis was carried out to ultimately determine bioequivalence with area under the curve (AUC) ratio representing relative bioavailability and Cmax ratio representing the rate of bioavailability. Results: The mean Pk parameters for the 8 patients were obtained. The mean maximum concentrations were 706ng/ml (PO) and 873ng/ml(SC). The times to maximum concentration were 1.4hrs(PO) and 0.60hrs(SC). The mean half-life was 2.7 hours(PO) and 3.1 hours(SC). This is consistent with values quoted in the literature. The mean AUC ratio (PO/SC) and the mean Cmax ratio were 0.86 and 0.81 respectively. This correlates with a relative PO bioavailability of 86% in comparison to SC MTX which is the established standard. There were no adverse events. Conclusions: This study reaffirms what was shown previously in 3 stable Crohn’s patients in 2011: the Pk profiles of PO and SC MTX are comparable. The mean relative bioavailability (AUC ratio) and the mean rate of bioavailability (Cmax) in these 8 patients meet the established criteria set forth by the FDA for bioequivalence. This would suggest that PO MTX is an option for treating patients with Crohn’s disease. This larger sample size allowed us to better compensate for any inter-individual variability in the bioavailability of MTX.

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A147 DOES A PHYSICIAN GLOBAL ASSESSMENT OR BLOOD TEST PREDICT MUCOSAL HEALING IN INFLAMMATORY BOWEL DISEASE? M. Brahmania, C. Bernstein University of Manitoba, Winnipeg, MB, Canada. Aims: The assessment of mucosal healing requires a colonoscopy. With limited endoscopic resources and procedure risks we aimed to determine how well a physician global assessment (PGA) or serum markers correlate with endoscopic mucosal healing. We present our data on the first 148 subjects analyzed. Methods: We retrospectively reviewed colonoscopy reports of patients with either ulcerative colitis (UC, n=92) or Crohn’s disease (CD, n=56) of a single gastroenterology practice. Inclusion criteria included having a PGA and assessing whether the disease was in remission based on number of bowel movements, abdominal pain, presence of blood with defecation, and objective weight loss. Having bloodwork within one month of undergoing colonoscopy was also a requirement. Bloodwork included serum Hg, albumin, ferritin, platelets and C-reactive protein. In the case of CRP there were insufficient data (n=24) to include in our analysis. Endoscopic disease activity was based on a scoring system which was categorized as: 1)Remission: complete mucosal healing (could include ‘footprints” of past disease such as pseudopolyps or white scars). 2)Mild disease: vascular blush or loss of vascular pattern, minimal exudates or friability. 3)Moderate disease: friability, granularity, scattered erosions and ulcers. 4)Severe disease: contiguous or deep ulcers and frank bleeding. The last 3 categories were grouped as active for this analysis. Results: There were 26 CD and 49 UC in endoscopic remission. Table shows sensitivity (SN) and specificity (SP) for variables in relation to endoscopic scores. Conclusions: Abnormal lab tests are specific for active endoscopic disease, however, when endoscopy is abnormal these lab tests may be normal. Normal lab tests are commonly present in those with negative endoscopy, however, reflects low specificity. Hence, while these blood tests help in defining the health state of a person with IBD they are not adequate surrogate markers for endoscopy. If we are using mucosal healing as the primary endpoint routine blood testing would be sufficient to predict a healed mucosa while PGA may be useful in UC. Two key issues are whether complete mucosal healing needs be the therapeutic goal and further whether the finding of incomplete mucosal healing would necessarily lead to a ‘step up’ in therapy in the majority of patients. We are expanding our cohort to ensure the robustness of the results.

Hemoglobin

(Crohn's Disease)

Platelets (Crohn's Disease)

Albumin (Cohn's Disease)

Ferritin (Crohn's Disease)

PGA (Crohn's Disease)

Hemoglobin (Ulcerative Colitis)

Platelets (Ulcerative

Colitis)

Albumin (Ulcerative

Colitis)

Ferritin (Ulcerative

Colitis)

PGA (Ulcerative

Colitis)

Sensitivity * 0 13 8 0 83 13 4 0 15 54

Specificity * 76 94 100 100 71 100 95 100 95 96

Sensitivity ** 76 94 100 100 71 100 95 100 95 96

Specificity ** 0 13 8 0 83 13 4 0 15 54

*Assessing relationship of abnormal tests with active endoscopic disease **Assessing relationship of normal tests with negative endoscopy Data expressed as percentages

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A148 THE MANITOBA IBD COHORT STUDY: PARTICIPANTS’ VIEWS OF THE CAUSES OF THEIR ILLNESS ON THE ILLNESS PERCEPTION QUESTIONNAIRE R. Carr, J. Walker, L. Graff, J. Ediger, L. Lix, P. Rawsthorne, L. Rogala, N. Miller, L. Targownik, C. Bernstein University of Manitoba, Winnipeg, MB, Canada. Aims: A person’s perception of their illness has important implications for the course of the illness. For example, illness perceptions have been found to affect outcomes such as distress, coping, and functional disability. It may also underscore areas of importance for patient education. This study looked at participants’ beliefs about the causes of their inflammatory bowel disease (IBD) in the Manitoba IBD Cohort Study. The Cohort Study is a longitudinal, population-based study of multiple determinants of health outcomes in those diagnosed with IBD within 7 years at enrollment (mean disease duration=4 years). Methods: Participants filled out the IPQ-R, a widely used, validated measure that assessed understanding of their illness across several dimensions, at 12 months (n = 327) and 42 months (n = 298) into the study. The IPQ-R is divided into five components and this study focused on the “causes” component of the IPQ-R measure. Participants were asked to rate how strongly they felt that each of 18 potential causes was a cause in the development of their IBD. Each cause was rated on a 5 point-Likert scale (ranging from strongly agree to strongly disagree). Results: See Table for the top 5 variables considered by subjects as causes of their IBD. The correlations between month 12 and month 42 are relatively high (ranging from r = 0.36 to r = 0.65), though they may have been moderated by the measure’s restricted range. No significant differences were found between those with Crohn’s disease and those with ulcerative colitis or between those with active disease and those with inactive disease. Conclusions: Stress was the variable that most participants associated as potentially causal of their IBD. There was remarkable consistency in terms of subjects’ perceptions of factors causing their disease at 12 and 42 months into the study. Hence, further disease duration did not change their perceptions. While there is no evidence to date that stress causes IBD, there is emerging evidence that perceived stress increases the likelihood of a disease flare. This finding also should encourage clinicians to address stress with their IBD patients as they consider it to be germane to their disease. Research is continuing to evaluate the pathophysiologic role of stress in IBD. The top 5 potential causes on the IPQ-R as rated by respondents at month 12

% of participants agreeing it was a cause Mean rating (scale= 1-5) Stress/worry 70% 3.74

Diet/eating habits 46% 3.15 Heredity 38% 2.98

Germ or virus 30% 2.87 Altered immunity 28% 2.88

A149 SURGICAL RATES IN CROHN’S DISEASE PATIENTS TREATED WITH ANTI-TNF THERAPY ARE RELATED TO DISEASE PHENOTYPES G. Moran1, G. Kaplan1, H. Yang1, C. Seow1, S. Devlin1, L. Dieleman2, R. Fedorak2, S. Ghosh1, R. Panaccione1 1. Alberta IBD Consortium, Calgary, AB, Canada; 2. Alberta IBD Consortium, Edmonton, AB, Canada. Aims: Published data provide conflicting evidence on the effect of biological therapy on surgical rates in Crohn’s disease (CD). The objective of our study is to describe the incidence of post-biologic surgery in CD and identify related prognostic risk factors. Methods: A cohort of CD patients (n=104) who were prescribed a biologic (infliximab or adalimumab) between 1st July 2000 and 29th June 2011 were identified. The primary outcome was CD-related surgery following biologic therapy. The primary exposure of interest was disease behavior at onset of first biologic as per the Montreal classification: inflammatory (B1); fibrostenotic (B2); or penetrating disease (B3). The following secondary factors were collected from chart review: age at diagnosis; sex; time from diagnosis to onset of first biologic; and surgical history before onset of a biologic. The rate of surgery following the start of the first biologic with 95% confidence intervals (CI) were calculated assuming a Poisson distribution. Kaplan-Meier (KM) survival curves of post-biologic surgery, stratified by disease behavior (B1, B2, and B3) at onset of biologics, were compared using the log rank test. Cox proportional regression model evaluated the effect of disease behavior (B1 referent versus B2 and B3) at biologic onset on the risk of surgery after biologic-onset after adjusting for confounders. Risk estimates were presented as hazard rate ratios (HR) with 95% CI. Results: Following onset of biologics, 26.0% of CD patients underwent surgery (0.09 per person-year; 95% CI 0.06-0.13). KM survival curves showed a significant (p=0.002) increase in surgical rates over time for B2 (mean time to surgery=1.6±0.17 years; figure 1) and B3 (mean time to surgery=1.4±0.08 years) as compared to B1 (mean time to surgery=7.3±0.48 years). B2 (HR=10.7; 95% CI: 3.3 - 37.5; p=0.0001) and B3 (HR=4.2; 95% CI: 1.2 - 15.4; p=0.027) disease behavior at onset of the first biologic showed a significantly increased risk for surgery as compared to B1 after adjusting for age at the onset of biologic (HR=1.0; 95% CI: 0.97 - 1.03), pre-biologic surgical status (HR=0.48; 95% CI: 0.18 - 1.3), time from diagnosis to onset of biologic (HR=0.97; 95% CI: 0.91 - 1.03), and pre-biologic perianal disease (HR=1.9; 95% CI: 0.75 - 5.1). Conclusions: Fibrostenotic and penetrating CD behavior at the start of therapy with biologics were significant predictors of surgery. Treating CD at the inflammatory state (B1) rather than at a complicated disease behavior state (B2-B3) may improve disease outcomes in CD.

Figure 1. KM curves indicating the cumulative risk of surgery following onset of first biologic.

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A150 INDUCTION AND MAINTENANCE OF CLINICAL REMISSION BY ADALIMUMAB IN PATIENTS WITH MODERATE-TO-SEVERE ULCERATIVE COLITIS W. Sandborn1, G. Van Assche2, W. Reinisch3, J. Colombel4, G. D'Haens5, D. Wolf6, M. Kron7, M. Tighe8, A. Lazar7, R. Thakkar8 1. UCSD, La Jolla, CA; 2. Univ Hospital of Gasthuisberg, Leuven, Belgium; 3. Medical Univ of Vienna, Vienna, Austria; 4. Centre Hospitalier Univ de Lille, Lille, France; 5. Imelga GI Clinical Research Center, Bonheiden, Belgium; 6. Atlanta Gastroenterology Assoc, Atlanta, GA; 7. Abbott, Ludgwigshafen, Germany; 8. Abbott, Abbott Park, IL. Aims: Assess efficacy and safety of adalimumab (ADA) for induction and maintenance of clinical remission in patients (pts) with moderate-to-severe ulcerative colitis (UC). Methods: Adults with UC (Mayo score: 6-12 points; endoscopy subscore: 2-3 points despite concurrent oral corticosteroids/immunosuppressants) were randomized 1:1 to placebo (PBO) or ADA (160/80 mg at Week 0/2; 40 mg every other week [eow] from Week 4). Pts with prior anti-TNF therapy were allowed. Co-primary endpoints were % of pts with clinical remission at (1) Week 8 and (2) Week 52. At/after Week 8 corticosteroid tapering was permitted. Pts demonstrating inadequate response based on protocol-specified partial Mayo score criteria could switch to open-label (OL) 40 mg eow at Week 12 and subsequently to 40 mg weekly. The ITT population was analyzed using nonresponder imputation for missing data. Results: 248 of 494 ITT pts received ADA. Significantly more ADA-treated pts achieved clinical remission, clinical response, and mucosal healing at Week 8, Week 52, and both Week 8 and 52 vs. PBO (Table). Among corticosteroid-treated pts at baseline, significantly more ADA-treated pts discontinued corticosteroids before Week 52 and achieved clinical remission at Week 52 vs. PBO (13.3% vs. 5.7%, P=0.035). In pts with prior anti-TNF therapy, significantly more ADA-treated pts achieved clinical remission at Week 52, clinical response at Week 52, and sustained clinical response at both Week 8 and 52 vs. PBO. No deaths, tuberculosis or lymphomas were reported. Incidences of serious and infectious AEs were similar between PBO and ADA groups. Conclusions: ADA was efficacious in inducing and maintaining clinical remission in pts with moderate-to-severe UC who did not adequately respond to conventional therapy with oral corticosteroids/immunosuppressants. The safety profile in UC was consistent with the known safety profile of ADA.

Table. Clinical Remission and Major Secondary Endpoints at Week 8 and 52a Week 8 Week 52 Week 8 and 52

Placebo (N=246)

ADA (N=248) P valueb Placebo

(N=246) ADA

(N=248) P

valueb Placebo (N=246)

ADA (N=248) P valueb

Clinical remissionc, n (%) 23 (9.3) 41 (16.5) 0.02 21 (8.5) 42 (17.3) <0.01 10 (4.1) 21 (8.5) <0.05

Clinical responsed, n (%) 85 (34.6) 125 (50.4) <0.001 45 (18.3) 75 (30.2) <0.01 30 (12.2) 59 (23.8) <0.001 All Patients

Mucosal healinge, n (%) 78 (31.7) 102 (41.1) 0.03 38 (15.4) 62 (25.0) <0.01 26 (10.6) 46 (18.5) 0.01

Clinical remissionc, n (%) 16 (11.0) 32 (21.3) 0.02 18 (12.4) 33 (22.0) 0.03 9 (6.2) 16 (10.7) 0.17

Patients with No Prior Anti-TNF Clinical

responsed, n (%) 56 (38.6) 89 (59.3) <0.001 35 (24.1) 55 (36.7) 0.02 24 (16.6) 44 (29.3) <0.01

Clinical remissionc, n (%) 7 (6.9) 9 (9.2) 0.56 3 (3.0) 10 (10.2) 0.04 1 (1.0) 5 (5.1) 0.12

Patients with Prior Anti-TNF Clinical

responsed, n (%) 29 (28.7) 36 (36.7) 0.23 10 (9.9) 20 (20.4) 0.04 6 (5.9) 15 (15.3) 0.03

aIntent-to-treat (ITT) population; non-responder imputation (NRI). bP values to compare treatment groups were based on Cochran-Mantel-Haenszel test (for all patients) or chi-square test (for patients with/without prior anti-TNF, respectively). cMayo score ≤2 with no individual subscore >1.

dDecrease from baseline in Mayo score ≥3 points and ≥30%, rectal bleeding subscore 0 or 1 or decrease from baseline ≥1 point. eEndoscopy subscore ≤1. Abbreviations: ADA = adalimumab; TNF = tumor necrosis factor.

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A151 5-AMINOSALICYLIC ACID INHIBITS BIOFILM FORMATION BY ADHERENT INVASIVE E COLI S. Skulsky, J. Beatty, H. Ceri, A. Buret, K. Rioux University of Calgary, Calgary, AB, Canada. Aims: Adherent invasive strains of E. coli (AIEC) are implicated in the pathogenesis of IBD, particularly the early lesions of ileal Crohn’s Disease (CD) as occurs in the post-operative setting. 5-aminosalicylic acid (5ASA) is a mainstay of IBD therapy, and an accepted indication in CD is for prevention of post-operative recurrence. Delayed or targeted release formulations of 5ASA are delivered to the distal GI tract where bacteria are most abundant. We hypothesized that some of the therapeutic action of 5ASA is mediated through its effects on gut bacteria. In support of this, our lab has previously reported that 5ASA inhibits AIEC adherence and invasion of epithelial monolayers. AIEC adherence correlates with the ability to form biofilms, and bacterial biofilms likely contribute to the perpetuation of pathogenic bacteria in the intestinal tract. Therefore, the aim of this study was to determine the impact of 5ASA on biofilm formation by AIEC. Methods: Basal levels of monospecies biofilm formation in AIEC (strain: LF82) and non-pathogenic E. coli (strain: K-12) were determined using the Calgary Biofilm Device (MBEC™ , Innovotech, Edmonton) after 24 hours incubation. Inocula of both strains were subsequently prepared with doses of 5ASA relevant to luminal concentrations attainable in humans (10-100 mM); these inocula were also prepared on the MBEC ™ device and biofilm formation was measured via XTT and Crystal Violet (CV) assays. Biofilms were further characterized with confocal microscopy (CLSM) and SEM. Significant differences in biofilm formation between treatment and control conditions were assessed via a one-way ANOVA and a Tukey’s post test. Results: 5ASA reduced in vitro biofilm formation in both LF82 and K-12 strains in a dose-dependent manner, with concentrations of 80mM and 100mM 5ASA producing statistically significant reductions biofilms. In both strains, inocula exposed to 80mM 5ASA formed biofilms that were ≈50% of control values. Additionally, LF82 biofilms were slightly more persistent than K-12 biofilms when treated with 80mM 5ASA. Statistical significance was accepted at p<0.05. Conclusions: 5ASA reduces the ability of AIEC and non-pathogenic E. coli to form biofilms in vitro. Our findings suggest that effects of 5ASA on bacterial biofilms in the gut may underlie some of its clinical effects in IBD. Improved understanding of the effects of 5ASA on biofilm formation and polymicrobial interactions within the gut may provide clues on how best to use these medications in IBD. For example, our data suggest that 5ASA medications may have greatest benefit in the subset of IBD patients that harbour adherent-invasive strains of E. coli.

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A152 DYSPLASIA AND COLORECTAL CANCER IN A IBD AND PCS POPULATION M. Auclair, R. Lahaie Hopital St-Luc, CHUM, Montréal, QC, Canada. Aims: Introduction: Inflammatory bowel disease (IBD) is associated with an incresed rate of colorectal cancer (CRC), particularly when associated with primary sclerosing cholangitis (PSC). In the recent years, many studies showed that the risk of CRC was lower than previously thought. Hypothesis: The rate of dysplasia and colorectal cancer should be low in our IBD population. Goal: Analyse our IBD and PSC population followed regularly with surveillance colonoscopy and find predictors of CRC. Methods: We conducted a retrospective study, reviewing all the IBD patients who had a surveillance endoscopy in 2008 or 2009 and all the patients known with IBD plus PCS who had surveillance endoscopy from 2006 to 2010. Results: 173 patients were analyzed; 120 ulcerative colitis (UC), 50 crohn disease (CD) and 3 indeterminate colitis (IC). Twenty eight patients had PSC plus IBD (9 orthotopic liver transplantation (OLT)). Disease duration was in average 18 years. Four colorectal cancer were found. CRC affected 3 patients with PSC plus UC (3 pancolitis, 2 OLT) and 1 patient with IC (pancolitis). Disease duration was 4, 21, 24 ans 25 years. Two of them died from the neoplasia at the age of 34 and 36. Both had PSC. They had colonoscopy in the past showing dysplasia: one patient had a DALM and the other had low grade and indeterminate dysplasia. At 20 years of disease, the risk of CRC was 5,1% for all IBD patients, but 28,5% for PCS patients. Low grade dysplasia (LGD) was found in 14 patients (4 PSC); since the end of the study, one of them had a colectomy but no dysplasia was found on the specimen, 9 patients had follow up endoscopy without dysplasia and 4 did not have other endoscopy yet. Overall, five patients had DALM; 1 with PSC found at colectomy done for LGD. Conclusions: The rate of CRC in our IBD population is low, but becomes high and aggressive in our PSC population. The main risk factors found are PCS, pancolitis and OLT. Eventhough our study was small, a more accurate screening aimed specificaly for this population with a supplemetary tool like chromoendoscopy should be considered.

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A153 CHANGE IN CROHN'S DISEASE PHENOTYPE FROM DIAGNOSIS TO YEAR TWO: HOW IS INITIAL PHENOTYPE DETERMINED? J. Ryan, C. Bernstein University of Manitoba IBD Clinical and Research Centre, Winnipeg, MB, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A154 ADMISSIONS AND SURGERIES FOR CROHNS DISEASE (CD) AND ULCERATIVE COLITIS (UC) IN HALIFAX 2001-2010. D. Leddin, L. Federico, G. Leddin DALHOUSIE UNIVERSITY, Halifax, NS, Canada. Aims: Nova Scotia has a high incidence and prevalence of CD and UC. We wished to determine whether changes in practice have been reflected in a change in hospital care over the decade 2001-2010. Since admission to hospital may not necessarily indicate improved care we used the number of ileal resections in patients with CD, the number of colectomies in patients with UC, and the number of in-hospital days of both, as secondary markers of change in care. Methods: The Halifax health district encompasses about half the population of Nova Scotia, approximately 500,000 people. About 20% of IBD patients followed in Halifax are from other districts. There are three hospitals in Halifax where patients with IBD may be admitted. Discharge diagnosis, surgical procedures, and length of stay in hospital procedures from these hospitals have been captured on a database since 2001. The database was searched using standard ICD codes for discharge diagnosis, surgical procedures if performed, and number of inpatient days. Results: Results are shown in Table 1 Conclusions: Overall in the decade from 2001-2010 the number of patients admitted with a diagnosis of CD dropped by one fifth. Ileal resections, and total hospital days for CD have fallen by a lesser amount. In patients with UC, although both admissions and bed occupancy have dropped, there has been no change in the number of colectomies. However between 2001-2005 the trend was towards an increase in admissions, surgeries and inpatient days for both CD and UC. This worsening trend reversed between 2005 and 2010. The improvement in these parameters correlated with the significant utilization of anti-TNF therapy, which increased ten fold from 2006 to 2010 but was not commonly in use from 2001-2005. The improvement in IBD outcomes is likely due to multiple factors including changes in physician and nursing care, earlier use of immunosuppressants, and the increased utilization of anti TNF therapy. The reasons behind the lack of change in the numbers of colectomies need to be examined as nearly two thirds of patients admitted with UC proceed to surgery.

2001 2005 2010 %Change CD Admissions 151 164 121 -20

Ileal resections 73 82 54 -7 Inpatient days 1441 1522 1200 -8

UC Admissions 59 88 52 -12 Colectomy 33 44 33 0 Inpatient days 972 972 521 -14

Number of individuals admitted, resection, total inpatient days and percent change from 2001-2010 for CD and UC.

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A155 IDENTIFICATION OF SUBGROUPS OF ADALIMUMAB-TREATED PATIENTS WITH CROHN’S DISEASE WHO EXPERIENCE HIGH RATES OF DEEP REMISSION W. Sandborn1, J. Colombel2, E. Louis3, R. Panaccione4, M. Yang5, J. Chao5, P. Mulani5 1. UCSD, La Jolla, CA; 2. Centre Hospitalier Universitaire de Lille, Lille, France; 3. U of Liège, Liège, Belgium; 4. U of Calgary, Calgary, AB, Canada; 5. Abbott, Abbott Park, IL. Aims: Adalimumab (ADA) is efficacious in inducing and maintain deep remission, defined as clinical remission (CDAI <150) and mucosal healing (absence of mucosal ulceration), in EXTEND. We identified patient subgroups (hyper-responders) for whom ADA treatment provided a high probability of achieving deep remission. Methods: EXTEND was a randomized, placebo-controlled study of patients with moderate to severe ileocolonic Crohn’s disease (CDAI 220-450). Patients received open-label ADA 160-/80-mg induction therapy at Weeks 0/2 and were randomized at Week 4 to maintenance therapy with ADA 40 mg every other week or placebo. Hyper-responders were identified through a novel method that generated an incremental benefit index score (IBIS) for each patient. IBIS was generated as the differences in predicted values of deep remission rates through the regression models from ADA and placebo arms. The association between IBIS and the probability of achieving deep remission and the 95% confidence intervals were evaluated using non-parametric methods. Hyper-responders among patients using ADA were identified as patients with an IBIS threshold of more than a certain value, which corresponded to a ≥34% probability of achieving deep remission at Week 12. This rate is double the average deep remission rate (17%) of all ADA-treated patients in EXTEND. Validation of the IBIS model based on Week-52 deep remission data was conducted using ROC curves and C statistics. Results: Deep remission hyper-responders at Week 12 (N=7) were identified as patients with an IBIS threshold ≥0.32, which corresponds to a 34% probability of achieving deep remission. The hyper-responders tended to be younger and with shorter disease duration than non-hyper-responders (N=57); hyper-responders were also more likely to have greater baseline IBDQ scores and to be naïve to anti-TNF therapy (table). ROC curves indicated excellent predictive value of IBIS with a C statistic of 0.92. Conclusions: Using the novel method of IBIS, we were able to identify a subgroup of the EXTEND population who were deep remission hyper-responders at Week 12 if treated with ADA maintenance therapy. These patients tended to be younger with shorter disease duration, greater IBDQ scores, and no history of anti-TNF therapy.

Week-12 Hyper-Responders Receiving Adalimumab Treatment Characteristic IBIS ≥0.32 (N=7) IBIS <0.32 (N=57) P-Value

Mean disease duration, yrs 3 11 <0.0001 Mean age, yrs 25 39 0.002

Prior anti-TNF therapy use, % of patients 14 51 0.07 Mean baseline IBDQ score 125 108 0.09

Deep remission rate, % of patients 71 11 <0.001 Other variables (eg, prior steroid use, prior IMM use, and baseline CRP) also contributed to the composition of IBIS

scores, though only those with p <0.1 were presented in the table.

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A156 ASSOCIATION OF BASELINE C-REACTIVE PROTEIN WITH MAINTENANCE OF REMISSION IN PATIENTS WITH MODERATE TO SEVERE CROHN’S DISEASE TREATED WITH ADALIMUMAB W. Sandborn1, J. Colombel2, A. Robinson3, P. Pollack3, Q. Zhou3, R. Thakkar3 1. University of California, San Diego, La Jolla, CA; 2. Centre Hospitalier Universitaire de Lille, Lille, France; 3. Abbott Laboratories, Abbott Park, IL. Aims: In the pivotal randomized placebo-controlled adalimumab (ADA) maintenance trial (CHARM1), patients with elevated baseline C-reactive protien (CRP) who achieved clinical response after induction dosing attained numerically higher rates of clinical remission with weekly vs every other week (eow) ADA dosing. This effect was greater than the overall difference in clinical remission between weekly and eow dose groups. To determine if this difference was also seen in patients who achieved clinical remission after induction dosing, we examined the effect of baseline CRP concentrations on the maintenance of remission with weekly vs eow dosing of ADA in this subset of patients. Methods: In CHARM, all patients received 4-week induction with open-label ADA (80mg at week 0, 40mg at week 2). At week 4, all patients were randomized to receive double-blind maintenance ADA (40mg weekly or eow) or placebo for 52 weeks. In this analysis, clinical remission (CDAI<150) at weeks 26 and 56 by baseline CRP (high: ≥10mg/L, or low: <10mg/L) was determined for patients who achieved remission at week 4 and were randomized to placebo, eow, or weekly ADA treatment groups, using non-responder imputation. Results: 101 patients with high baseline CRP (placebo, 34; eow, 39; weekly, 28) and 114 with low baseline CRP (placebo, 39; eow, 42; weekly, 33) were included in the analysis. Baseline median CRP for each subgroup is shown in the Table. Remission rates for high CRP patients randomized to weekly dosing were approximately 50% higher than for patients in the eow group (weeks 26 and 56; Table). By contrast, ADA-treated patients with low baseline CRP had consistent rates of remission at both timepoints, regardless of dose group. The incidence of adverse events was similar among the subgroups. Conclusions: Weekly ADA dosing was associated with higher remission rates compared with eow dosing in patients with elevated baseline CRP, although a substantial proportion of these patients also maintained remission with eow dosing. Patients with elevated baseline CRP may be better candidates for escalation from eow to weekly dosing for loss of remission than those with low baseline CRP. Reference: Colombel JF. Gastroenterology. 2007; 132:52.

Table. Percent of Patients in Clinical Remission, by Baseline CRP Category CRP ≥10mg/L CRP <10mg/L

Placebo N=34

ADA 40mg eow

N=39

ADA 40mg weekly N=28

Placebo N=39

ADA 40mg eow

N=42

ADA 40mg weekly N=33

Baseline CRP, mg/L, median (range)

37 (10-287) 32 (12-162) 29 (10-350) 4.1 (0.2-

9.9) 4.4 (0.4-9.8) 2.5 (0.4-9.7)

Remission at Wk 26, % 29.4 51.3 78.6 30.8 47.6 42.4 Remission at Wk 56, % 11.8 41.0 64.3 17.9 42.9 42.4

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Poster of Distinction A157 IDENTIFICATION OF AN INNATE TH17 RESPONSE TO INTESTINAL BACTERIAL PATHOGENS S. Rubino1, K. Geddes1, J. Magalhaes1, C. Streutker2, D. Philpott1, S. Girardin1 1. university of toronto, toronto, ON, Canada; 2. St-Michael's Hospital, toronto, ON, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A158 CROHN'S DISEASE DIAGNOSIS FOLLOWING CLOSTRIDIUM PARAPUTRIFICUM BACTEREMIA: A CASE FOR INTESTINAL BARRIER DYSFUNCTION A. Cheung, T. Murdoch, J. Tinmouth University of Toronto, Toronto, ON, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

A159 PNEUMATOSIS INTESTINALIS AFTER COLONOSCOPY IN A CROHN'S DISEASE PATIENT WITH MUCOSAL HEALING Y. Fu, E. Kim, B. Bressler University of British Columbia, Vancouver, BC, Canada. Aims: We present the first case of pneumatosis intestinalis after colonoscopy in a Crohn’s disease patient with endoscopic mucosal healing. Methods: Case presentation and review of literature. Results: CASE A 22 year-old man with fistulizing Crohn’s disease (CD) and previous ileocecal resection presented with severe abdominal pain after colonoscopy. He had complete endoscopic mucosal healing while being treated with adalimumab and azathioprine. However, extensive pnematosis intestinalis (PI) and retroperitoneal air were found on abdominal CT. He was clinically stable. He responded well to conservative therapy with bowel rest and broad-spectrum antibiotics. LITERATURE REVIEW PI is defined as the presence of gas within the wall of the gastrointestinal tract. PI in adults is often asymptomatic and rarely life-threatening. Morbidity and mortality of PI reflect the underlying pathology. CT and abdominal radiograph are the most frequently used modalities for PI diagnosis. PI has been infrequently describes in patients with IBD, more commonly in CD. PI in CD patients was associated with corticosteroid usage and increased disease severity. Colonoscopy has been reported to cause PI. Currently, PI only been documented in CD patients with active disease. Aside from surgical intervention, conservative management including oxygen therapy, antibiotics and elemental diet have been studied. Inhaled and hyperbaric oxygen may facilitate the washout of pneumocyst gas. Metronidazole has been used to treat primary PI. Elemental diet may decrease hydrogen production from colonic bacteria. Conclusions: We present the first case of pneumatosis intestinalis after colonoscopy in a Crohn’s disease patient with endoscopic mucosal healing. The radiological findings in our relatively asymptomatic patient were likely due to biopsies and/or small mucosal defects at the ileocolonic anastamosis. Conservative management was sufficient for our patient. Endoscopic investigation for assessment of mucosal healing in IBD is gaining increasing interest. However, the risks of multiple colonoscopies should be carefully evaluated. LEARNING POINTS 1) Pneumatosis intestinalis can occur in Crohn’s disease patient with endoscopic mucosal healing. 2) The overall clinical status of patients with pneumatosis intestinalis should direct the treatment plan. 3) In clinically stable patients, conservative management with oxygen therapy, antibiotics and/or elemental diet may be sufficient.

Abdominal CT showing pneumatosis of the distal ascending and proximal transverse colon, large retroperitoneal air and small intraperitoneal air.

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A160 EFFECT OF NOD1 AND NOD2 STIMULATION ON THE MODULATION OF T CELL FUNCTION G. Zanello1, K. Forster1, A. Goethel1, M. Amoozgar1, D. Philpott2, K. Croitoru3 1. University of Toronto, Department of Medicine, Toronto, ON, Canada; 2. University of Toronto, Department of Immunology, Toronto, ON, Canada; 3. Mount Sinai Hospital, Division of Gastroenterology, Toronto, ON, Canada. Aims: In inflammatory bowel diseases (IBDs), T cells produce inflammatory cytokines and this response is thought to result from the effect of environmental or microbial activation of the local immune response in a genetically predisposed host. Mutations in the nucleotide-binding oligomerization domain containing 2 gene (NOD2) are linked to susceptibility to Crohn’s disease (CD). The exact mechanism by which NOD2 mutations contribute to the development of CD is unknown. Recently, it has been shown that Nod2 protein is expressed and functionally active in human T cells. We hypothesize that expression and activation of Nod1 and Nod2 receptors in T cells are critical for the direct modulation of T cell responses to commensal flora in maintaining intestinal homeostasis. Methods: T cells were isolated from spleens of C57BL/6 mice and sorted by flow cytometry. Nod1 and Nod2 mRNA levels were assessed by conventional PCR in naïve (CD3+CD4+CD45RBhi) and effector or regulatory (CD3+CD4+CD45RBlo) T cells. Nod1 and Nod2 protein expressions were assessed by western blot in total CD3+CD4+ T cells untreated or treated with iE-DAP (Nod1 ligand), MDP (Nod2 ligand) or inflammatory cytokines (TNFα and IFNγ) either in presence or absence of monoclonal anti-CD3 antibody. IKBα phosphorylation was assessed by western blot in total CD3+CD4+ T cells untreated or treated with iE-DAP, MDP or PMA and ionomycin. Results: Our data show that murine CD4+ T cells including both naïve and activated T cells isolated from spleen express Nod1 and Nod2 at the mRNA level. Western blot analysis demonstrated that Nod1 expression is detectable in untreated T cells and was increased after treatment with Nod ligands or TNFα plus IFNγ. In contrast, Nod2 expression is only detectable in T cells treated with Nod ligands or inflammatory cytokines. Stimulation of T cell receptor with anti-CD3 monoclonal antibody induced the higher expression of Nod1 and Nod2. Furthermore, T cell stimulation with Nod ligands increased IKBα phosphorylation. Conclusions: These results indicate that Nod receptors are modulated by Nod1 and Nod2 agonists and inflammatory cytokines. In addition, Nod receptor stimulation in T cells could lead to NF-kB activation and possibly cytokine secretion. Therefore Nod stimulation in T cells could have important role in the modulation of activated T cells. These findings may define the mechanism by which NOD2 mutations alter homeostasis and contribute to the pathogenesis of IBD. These results could lead to new strategies for immune modulation of mucosal inflammation. Funded by CCFC and CAG/CIHR/CCFC fellowship (KF).

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Intestinal Disorders

Poster of Distinction A161 ALTERED INTESTINAL EPITHELIAL HOMEOSTASIS IN MICE WITH A TARGET MUTATION IN THE GENE ENCODING VASOACTIVE INTESTINAL PEPTIDE (VIP) X. Wu, V. Conlin, A. Buchan, K. Jacobson University of British Columbia, Vancouver, BC, Canada. Aims: VIP is a neuropeptide known to modulate intestinal epithelial barrier integrity and mucosal immune function during colitis. However, the mechanisms responsible for the biological activities of VIP on intestinal homeostasis and epithelial cell crypt development under physiology condition remain unclear. The aim of the present study was to examine the role of VIP on intestinal homeostasis, including epithelial cell proliferation, migration, apoptosis and differentiation under physiology condition. Methods: Eight-week- old C57BL/6 wild type and VIP-/- mice were used. BrdU (5’-bromo-2’deoxyruidine) was injected i.p. into mice for 2 h and 72 h, respectively. Colonic cross sections and swiss roll sections were used to evaluate colonocyte proliferation and migration. Ki-67 immunostaining and the TUNEL assay were used to evaluate epithelial cell proliferation and apoptosis respectively. Differentiation of intestinal epithelial cells into goblet cells was examined by staining for acidic, neutral and Muc2 mucins using Alcin blue (AB), Periodic-acid Schiff (PAS), and anti-Muc2 stains, respectively. TFF3 expression was assessed by immunoreactivity and real-time PCR, respectively. VIP treatment was performed by i.p. injection to wild type and VIP-/- mice from day 1 to day 10. Results: VIP-/- mice have significantly reduced colonic crypt height compared to wild type mice (147.2 ± 2.8 µm vs. 168.5 ± 2.6 µm, n=6, p<0.001). In addition, VIP-/- mice had reduced rates of proliferation (BrdU positive cells: 3.7 ± 0.2/crypt vs. 5.4 ± 2.2/crypt, n=4, p<0.01) and migration compared to wild type mice. The percentage of PAS-positive goblet cells was also significantly decreased in the colon of VIP-/- mice (18.22 ± 1.48 vs. 26.58 ± 2.23, respectively, n=6, p<0.05). Moreover, TFF3 expression in goblet cells in VIP-/- mice was significantly decreased at both transcript level (42% decrease, p<0.05) and translational level compared to wild type mice (3.6 ± 0.4/crypt vs. 7.2 ± 0.3/crypt, p<0.001). Treatment with exogenous VIP to VIP-/- mice significantly increased the expression of TFF3 (1.6 fold increase, p<0.01) and the number of Ki-67 positive cells (6.4 ± 0.6/crypt vs. 3.0 ± 0.7/crypt, n=5, p<0.05) compared to untreated mice, but had no impact on crypt height. Conclusions: These data provide new sights into the function of VIP establishing its role in regulating colonic crypt development and epithelial cell function and in maintaining intestinal epithelial homeostasis under physiological conditions in vivo. Supported by CCFC (Canada)

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A162 THE EFFECT OF DIETARY OILS ON CITROBACTER RODENTIUM INDUCED COLITIS K. Jacobson1, A. Hekmatdoost2, X. Wu1 1. University of British Columbia, Vancouver, BC, Canada; 2. , Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran. Aims: Increasing evidence suggests that high dietary intake of n-3 fatty acids attenuates inflammation in chemically induced colitis, but data evaluating the effect of dietary oils on bacterial-induced colitis is lacking. The aim of this study was to determine the effect of fish oil, canola oil, and safflower oil on Citrobacter rodentium- induced colitis. Methods: Female 6-8 week-old C57BL/6 mice were fed 20% energy fish oil (FO), canola oil (CO), or safflower oil (SO) varying only in fat composition for three weeks before and 10 days after Citrobacter rodentium inoculation. The distal colon was assessed for histological damage score and bacterial count. Macrophage and neutrophil recruitment in response to C. rodentium infection was evaluated by immunohistochemistry analysis. Intestinal epithelial cell proliferation was evaluated by Ki-67 immunoreactivity and levels of IL6, IL-10 and IL-17 mRNA expression were assessed by real-time PCR. Results: Uninfected mice fed FO had the highest 20:5n-3 and 22:6n-3 in their colon phosphatidylcholine (PC) and phosphatidylethanolamine (PE) followed by CO and SO groups. In contrast, 18:2n-6 and 20:4n-6 were highest in the colon PC and PE of the SO group followed by CO and FO groups. While bacterial counts were similar between groups after infection, the FO group was the least susceptible to C. rodentium-induced colitis; histological damage score was lowest in the FO group (2.6 ± 0.8) followed by canola oil (5.0 ± 1.1), safflower oil (6.6 ±0.8), and chow diet group (10.6 ± 0.6). Moreover, the FO group demonstrated a significantly reduced inflammatory cell infiltration (0.6 ± 0.4/crypt) and epithelial cell proliferation (19.4 ± 1.0/crypt) in contrast to all other groups. Cytokines measurement indicated that the FO group had the highest anti-inflammatory IL10 mRNA expression compared to all other groups. In addition, the FO group had the highest IL6 and IL-17A expression compared to all other groups. Conclusions: Our results indicate that in Citrobacter rodentium-induced colitis, the intake of fish oil was associated with a modulating effect on the host mucosal immune response in the absence of an effect on initial bacterial colonization. Supported by CCFC (Canada).

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A163 FACTORS AFFECTING COMPLIANCE TO A GLUTEN-FREE DIET IN CHILDREN WITH CELIAC DISEASE K. MacCullouch, M. Rashid Department of Pediatrics, Dalhousie University, Halifax, NS, Canada. Aims: The only treatment for celiac disease is strict, life-long adherence to a gluten-free (GF) diet. The GF diet is complex, costly and socially restrictive. Cross contamination is a major problem as wheat is ubiquitous in the western diet. Poorly treated celiac disease can lead to complications including nutritional deficiencies like anemia and osteoporosis, development of other auto-immune disorders and malignancy. Identification of factors that affect compliance would help in developing strategies to improve patient’s adherence to the GF diet. The aim of the study was to investigate compliance with the GF diet in children with celiac disease and to identify factors that inhibit or improve compliance. Methods: All patients (<18 yrs) with biopsy-confirmed celiac disease followed at the Division of Gastroenterology, IWK Health Centre, the tertiary care pediatric institution of Canadian Maritime provinces, were surveyed with a mailed questionnaire. It included items to assess demographics, time since diagnosis, geographic location, family size, affected family members and factors affecting eating at restaurants, school/daycare, travel and social life. Factors were scored from 1-10 for how often they were problematic (10=always, 1=never). Parents of patients <13 yrs were advised to complete the survey along with the child, adolescents >13 yrs were asked to complete it themselves. Results: Of the 253 study subjects, 126 (50%) completed the survey. The median age of participants was 12 yrs (range 2-18), 70% were female. Median time since diagnosis was 3 yrs. Forty percent of surveys were completed independently by adolescents, the remainder by parents. Overall, patients reported excellent compliance at home and at school. Compliance was slightly lower at social events (e.g. sleepovers, restaurants). Availability of GF foods was by far the most significant overall barrier to compliance especially at school (median 9/10) and in restaurants (median 8/10). While at home, cost and labeling were also substantial obstacles. The GF diet positively affected the health of the patients (median 9/10) but negatively affected family finances, social life, and ability to travel. Improving variety and taste of products and support by family members and Canadian Celiac Association were factors identified as improving compliance. Factors that would make it easier to eat GF included better availability, education for schools and restaurants, lower cost and better government support. Conclusions: Availability, cost and product labeling are major barriers to compliance with the GF diet. The GF diet can adversely affect the social life including ability to travel. Better awareness, improved labeling and income support are required to improve the lives of children and families with celiac disease.

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A164 HIGH INCIDENCE OF PEDIATRIC INFLAMMATORY BOWEL DISEASE IN THE CANADIAN MARITIME REGION M. Rashid, A. Otley, G. Mahdi Division of Gastroenterology, Department of Pediatrics, Dalhousie University, Halifax, NS, Canada. Aims: Inflammatory bowel disease (IBD) in children has been reported from around the world with varying epidemiological results. The IWK Health Center in Halifax, Nova Scotia is the only tertiary care, university-affiliated pediatric hospital providing care to the children of the three Canadian Maritime provinces of Nova Scotia, New Brunswick and Prince Edward Island. It is the only facility offering services in pediatric gastroenterology thus providing a unique opportunity to capture data prospectively on all new cases of IBD in children of this region. The aim of the study is to investigate the incidence of IBD in children in the Maritime provinces. Methods: All patients 0-16 yrs of age diagnosed with IBD Crohn’s disease (CD) and ulcerative colitis (UC) at IWK Health Center from 2006-2010 were studied. The diagnosis of IBD was based on clinical, biochemical, radiological and endoscopic findings. Population figures for each province were obtained from the Canadian Socio-economic Information Management System (CANSIM) database of Statistics Canada. Data is expressed as mean per 100,000 pediatric population. Results: The population of the Maritimes has remained stable over the last five years, mean total population1.83 million and pediatric (0-16 yrs) population 0.33 million. Total cases diagnosed with IBD were 174 (CD101, UC73). Mean age at diagnosis was 11.4(±3.3) years, range 1-16, and 60% were males. The mean cumulative incidence per 100,000 for all three provinces is shown in the Table below. In the last five years, the incidence of all IBD has almost doubled and that of UC up 2.8 times. In 2010, the incidence of IBD in children in Nova Scotia was 15.4 (CD7.4, UC8.0) one of the highest reported from anywhere and in New Brunswick 13.7 (CD8.4, UC5.3). The mean age at diagnosis of IBD has decreased from 12.12 years in 2006 to 10.64 years in 2010. While the mean age at diagnosis has remained stable for ulcerative colitis, it has decreased significantly for Crohn’s disease, from 12.76 to 10.39 years. Conclusions: Overall incidence of IBD in children in the Maritimes has almost doubled over the last five years, the cause remaining unclear. Incidence of Crohn’s disease has fluctuated but that of ulcerative colitis has tripled. Children with Crohn’s disease are presenting at a younger age (mean 10.39 yrs). Nova Scotia has the highest reported rate of pediatric IBD yet reported. This offers an opportunity to study the genetic and environmental factors that may play a role in the etiology of this disorder. Incidence of IBD per 100,000 children for all three Maritime provinces

Year 2006 2007 2008 2009 2010 All IBD 7.3 11.7 9.7 10.4 13.7

Crohn's disease 5.0 8.4 4.9 5.2 7.2 Ulcerative colitis 2.3 3.3 4.8 5.2 6.5

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A165 FACTORS ASSOCIATED WITH POSITIVE OUTCOMES IN CAPSULE ENDOSCOPY FOR THE INDICATION OF OBSCURE GASTROINTESTINAL BLEEDING N. Shahidi, G. Ou, S. Svarta, J. Tong, R. Kwok, K. Donaldson, J. Frenette, E. Lam, R. Enns Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, BC, Canada. Aims: Capsule endoscopy (CE) allows for early detection of pathological causes of obscure gastrointestinal bleeding (OGIB), thereby improving patient outcomes. Identifying predictors of positive pathology on CE has the ability to improve resource utilization and alter current investigational algorithms. Therefore, we sought out to identify clinical factors associated with positive findings on CE in individuals suffering from OGIB. Methods: Capsule endoscopies between December 2001 and April 2011 at St. Paul’s Hospital in Vancouver were analyzed. A positive finding was defined as definitive pathology believed to be the source of bleeding (i.e. ulceration/mitotic lesion/visible blood). Interim analysis was carried out after approximately 600 CEs were analyzed. Univariable and multivariable logistic regression analyses (Odds ratios, 95% confidence intervals) were utilized to determine the correlation of demographic and clinical parameters with positive findings on CE. Results: 69.4% of CEs were for the evaluation of OGIB. 5.1% were deemed incomplete and thus excluded from analysis. Of the remaining cases, 47% presented with overt bleeding, 29.8% demonstrated fecal occult blood positivity, and 23.2% presented solely with anemia. The median age was 62.7 years (range 15-93), and 51.6% were men. Definitively positive findings on CE were seen in 41.1% of cases. During univariable analysis, age (OR 1.02, 95%CI 1.00-1.02), increasing transfusion requirements (OR 1.37, 95%CI 1.16-1.61), number of esophagogastroduodenoscopies (OR 1.27, 95%CI 1.06-1.52), number of total upper endoscopies (OR 1.17, 95%CI 1.04-1.32), occult blood positivity (OR 1.93, 95%CI 1.12-3.33) and overt bleeding (OR 1.72, 95%CI 1.04-2.86) were significantly associated with positive findings on CE (all p < 0.02). However, following multivariable analysis, only increasing transfusion requirements remained significant (OR 1.25, 95%CI 1.03-1.53; p = 0.02). Conclusions: While a modest CE positivity rate across OGIB cases was seen, the interim analysis only identified increasing transfusion requirements as a significant factor associated with positive outcomes. The low number of positive predictors limits our ability to utilize demographic and clinical factors as a tool to improve efficiency in selecting patients for CE.

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A166 SCREENING FOR CELIAC DISEASE: WHAT IS THE SIGNIFICANCE OF SEROLOGIC TESTS POSITIVE FOR TISSUE TRANSGLUTAMINASE BUT NEGATIVE FOR ENDOMYSIAL ANTIBODIES A. Benzaglam, D. Duerksen

University of Manitoba, Winnipeg, MB, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A167 NCE-DAILY VERSUS TWICE-DAILY MESALAZINE (PENTASA®) FOR ACTIVE ULCERATIVE COLITIS: EFFICACY RESULTS FROM MOTUS, A MULTICENTRE, CONTROLLED, RANDOMISED, INVESTIGATOR-BLINDED STUDY B. Flourié1, A. Masclee2, O. Dewit3 1. Lyon Sud Hospital, Lyon, France; 2. Maastricht University Medical Center, Maastricht, Netherlands; 3. Saint Luc, Brussels, Belgium. Aims: In ulcerative colitis (UC), compliance with 5ASA is poor with a significantly increased risk of recurrence (5-fold) in non-compliant patients (pts) (Kane, Am J Med 2003). Data show that less frequent dosing may positively impact compliance. PODIUM demonstrated non-inferiority, and superiority (p=0.02), of once-daily (OD) vs twice-daily (BID) Pentasa for the maintenance of remission in UC (Dignass, CGH 2009). The objective of MOTUS was to show non-inferiority of OD Pentasa 2g sachet prolonged release granules (new concentrated formulation) vs standard BID dosing for the induction of remission in active UC. Methods: Pts with active mild-to-moderate UC were randomised to Pentasa 4g/d: 2x 2g OD or 1x 2g BID. All pts also received Pentasa enema (1g/d) for 4 wks. Primary endpoint: clinical and endoscopic remission at wk 8 (UC-DAI score ≤1). Secondary endpoints: clinical remission at wks 4, 8, 12 (normal stool frequency, no bloody stools, no active disease by physician’s global assessment); mucosal healing at wk 8 (UC-DAI endoscopic mucosal appearance score ≤1). Statistical data are from intent-to-treat (ITT) and per-protocol (PP) analyses. Results: 206 pts enrolled (OD n=102; BID n=104). Primary endpoint met (Table): 5ASA 4g OD was non-inferior to BID, the lower limit of the two-sided 95% CI of the difference in remission rate was -3%, within the pre-specified non-inferiority margin of -15%. Secondary endpoints for OD vs BID: clinical remission at wks 4, 8, 12: 39.8% vs 27.6% (p=0.07), 45.1% vs 40.8% (p=0.53), 92.4% vs 79.4% (p=0.13); mucosal healing at wk 8 by UC-DAI sub-score ≤1: 87.5% vs 71.1% (p=0.007). Conclusions: MOTUS showed non-inferiority of Pentasa® 4g OD vs BID in pts with active UC. The primary endpoint was met in all analysis groups. All secondary endpoints were also non-inferior for OD vs BID, with mucosal healing being significantly better with OD. The data are consistent with PODIUM (maintenance 5ASA), these studies show that OD treatment with Pentasa is at least as effective as BID dosing, allowing treatment to be personalised to pt preference.

Primary Endpoint 5ASA OD N (%) 5 ASA BID N (%) Difference % [95% CI] Non-inferiority* ITT 52/101 (52.1) 42/101 (41.8) 10.4 [-3.4; 24.1] NI PP 48/79 (61.0) 37/77 (48.3) 12.8 [-2.7; 28.2] NI

*Cochran-Mantel-Haenszel for non-inferiority OD vs BID; NI=non-inferior

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A168 CAPSULE ENDOSCOPY AND SMALL INTESTINE ULCERATION:WHAT EXACTLY DOES IT MEAN? I. Hemmati1, S. Svarta1, G. Ou2, R. Enns2 1. Depratment of Medicine, University of British Columbia, Vancouver, BC, Canada; 2. Division of Gastroenterology, University of British Columbia, Vancouver, BC, Canada. Aims: Small bowel capsule endoscopy (CE) is the gold standard for non invasively assessing the small intestinal mucosa. Not infrequently, however, findings such as ulceration is noted where the differential diagnosis may be wide and the findings non-specific. In this study we review our experience in patients with small bowel ulceration on their CE in an effort to better determine the etiology and management strategies. Methods: Of 1050 total capsules performed between 10/01-04/11, 111 patients (mean follow up 39 months) were deteremined to have single or multiple small bowel ulceration. Only those patients with the specific finding of small bowel ulceration were selected for further analysis. Their history, findings and outcomes in regards to these ulcerations were then assessed. Results: 111 patients (61 male, 52 +/- 19 years old) subsequently found to have small bowel ulceration on CE were determined to have been referred for the following indications: obscure gastrointestinal bleeding (58 %), abdominal pain (12%), iron deficiency anemia (11%), abnormal radiological findings (4.5%), diarrhea (4.5%), inflammatory bowel disease (IBD) (1%), and “other” indications (9%). Of the 111 patients with ulcerative disease noted on capsule study, 66 (59%) were thought to be related to IBD, 10 (9 %) related to NSAIDs, 3 (3%) celiac disease, 5 (4%) ischemic, 4 (4%) vascular lesions and 3 (3%) were related to malignant lesions. Peptic ulcer disease in distal duodenum was found in 3 (3%) of cases. In 17 (15%) of the cases there was no specific diagnosis made based on the capsule findings and follow up. Ancillary findings included active bleeding (14%), angiodysplasias (9%), strictures (5%) and diverticula (2%). Capsule retention occurred in 2 cases and was managed by surgery. Follow up (mean 39 months) was performed to ensure long term accuracy of diagnosis. Conclusions: In our patient population undergoing CE the most common cause of small bowel ulceration was IBD followed by NSAIDs use. When small bowel ulceration is seen and the etiology is unclear, a careful history can elucidate the most likely etiology and subsequently guide further management. A significant portion of these patients (15%) seem to do well despite these ulcerations and have no specific diagnosis.

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A169 DO PROTON PUMP INHIBITORS INCREASE THE RISK OF SMALL INTESTINAL BACTERIAL OVERGROWTH IN PATIENTS WITH PRIMARY BILIARY CIRRHOSIS? C. Letendre, S. Sidani, M. Bouin, C. Vincent Department of Gastroenterology and Hepatology, CHUM Research Center, Montréal, QC, Canada. Aims: The prevalence of small intestinal bacterial overgrowth (SIBO) is high in patients with primary biliary cirrhosis (PBC) . Proton pump inhibitors (PPIs) may increase SIBO as observed in patients with gastroesophageal reflux disease . Also, patients with PBC often complain of multiple upper gastrointestinal symptoms that lead to a high number of PPI prescriptions. We hypothesize that the use of PPIs is a risk factor for developing SIBO. Our goal was to demonstrate that SIBO is more frequent in patients with PBC treated with PPI. Methods: Prospective study from 2005 to 2011, at Saint-Luc Hospital, CHUM Research Center, Montreal, Qc, Canada. Subjects with a diagnosis of PBC (clinical, biological +/- histological) that underwent evaluation of SIBO by lactulose hydrogen breath test (LHBT) were included. Data concerning PBC, comorbidities, and medication was collected. The patients were divided into 2 groups based on whether or not they were using PPI at the time of the LHBT and were compared. Results: Results: 89 patients were included (93% women, mean age 60±10). Among them, 45% (n=40) were treated with a PPI. The group treated with PPIs and the one without were similar for sex, BMI (26,4 vs 25; NS) and Child score (5,8 vs 5,5; NS), but different for age (63 vs 57; p=0,004). The prevalence of SIBO was similar in both groups (n=14 (35%) vs n=14 (29%); NS). Conclusions: We observed a high prevalence of SIBO in patients with PBC. However PPIs do not seem to be responsible for it; the liver disease itself could cause SIBO.

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A170 DETRIMENTAL METABOLIC EFFECTS OF INDOMETHACIN ON THE HUMAN INTESTINE AT MID-GESTATION N. Perron1, É. Tremblay1, C. Babakissa2, E. Ferretti3, E. Levy4, E. Seidman5, D. Ménard1, J. Beaulieu1 1. Équipe IRSC sur l’épithélium digestif, Départment d’anatomie et biologie cellulaire, Université de Sherbrooke, Sherbrooke, QC, Canada; 2. Équipe IRSC sur l’épithélium digestif, Département de pédiatrie, Université de Sherbrooke, Sherbrooke, QC, Canada; 3. Équipe IRSC sur l’épithélium digestif, Département de pédiatrie, CHEO, Ottawa, ON, Canada; 4. Équipe IRSC sur l’épithélium digestif, Département de nutrition, CHU Sainte-Justine, Université de Montréal, Montréal, QC, Canada; 5. Équipe IRSC sur l’épithélium digestif, Département de gastro-entérologie, Centre de santé de l’Université McGill, Montréal, QC, Canada. Aims: Indomethacin (INDO) is an non-steroidal anti-inflammatory drug used for the treatment of patent ductus arteriosus in preterm infants and also as a tocolytic agent in pregnant women. The use of INDO in preterm infants is associated with an increased risk of developing necrotizing enterocolitis, a disease characterized by intestinal mucosal lesions that can lead to perforation of the intestinal wall. The goal of our study was to determine the impact of INDO on the gene expression profiles of the developing human small and large intestines at mid-gestation under conditions of serum-free organ culture. Methods: We used Illumina microarrays to identify gene expression profiles in the human fetal intestinal explants (ileum and colon, n=3) cultured for 48 hours in the presence of 1µM INDO. Differentially expressed genes were analyzed with Ingenuity Pathway Analysis software to identify biological functions and canonical pathways modulated by INDO. Results: Our results show that INDO induced major metabolic effects in each intestinal segment. In the ileum, IPA analysis revealed that INDO negatively modulated important biological functions such as “nucleic acid metabolism”, “DNA replication, recombination and repair”, “cell cycle” and “energy production”. We also found that “HIF1α signalling”, an important regulator of glucose metabolism and angiogenesis, was also affected by INDO in the ileum. At the gene level, we observed a down-regulated expression of several chemokines, namely CXCL5 and IL8, denoting the anti-inflammatory properties of INDO. INDO was also found to induce major metabolic effects on the colonic mucosa. Indeed, we observed that the expression of genes involved in “purine and pyrimidine metabolism”, “amino acid metabolism”, “cell cycle control of chromosomal replication”, “glycolysis/gluconeogenesis” and “mismatch repair” was highly down-regulated in the colon. Conclusions: In conclusion, our study demonstrated that INDO modulates several different metabolic pathways in the developing human intestine. Furthermore, our results evidenced that INDO has detrimental metabolic impacts on the immature intestinal mucosa and emphasize the need for a better understanding of the molecular mechanism of NSAIDs in premature infants. (Support by CIHR)

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A171 DIVERTICULAR DISEASE-ASSOCIATED SEGMENTAL COLITIS: A 14 YEAR FOLLOW UP V. Huang, F. Habal University Health Network, University of Toronto, Toronto, ON, Canada. Aims: Diverticular Disease-Associated Segmental Colitis is a variant of chronic colitis which is limited to the rectal area, which is associated with diverticular disease. Histologically it can be differentiated from idiopathic colitis with limited inflammation to the segment and sparing the rest of the colon. There is no long term data on the natural history of this entity. Methods: This is a prospective fourteen year follow up on 14 patients who presented with recurrent abdominal pain, with bloody mucousy diarrhoea. Patients were referred either from the emergency room of a teaching hospital or from private offices. Investigation included haematological and biochemical parameters, stool cultures including C. difficile toxin. Colonoscopy with multiple biopsies was performed on all patients at admission and repeated at one year and every three years or earlier. Patients who had acute diverticulitis with CT scan finding of abscess or stricture were excluded. Patients who were diagnosed with acute colitis were excluded. All patients were started on Mesalamine and some received intermittent courses of topical 5ASA therapy. Results: There were 9 males and 5 females with a mean age of 53.2±14.5. The mean duration of symptoms was 34.8± 27 weeks. All patients fit the criteria for Diverticular Disease-Associated Segmental Colitis. Endoscopically the mucosa revealed patchy hyperaemic changes without any evidence of ulceration. This involvement was restricted to the segment with diverticular involvement. Histologically the biopsies showed moderate on chronic colitis with moderate gland distortion, mucin loss and lymphoid hyperplasia. The biopsies proximal and distal to the involved areas were reported to be normal. Five patients stopped their medications and relapsed within six weeks, and were restarted on Mesalamine. The mean follow was 10.4 ± 4.2 years .All patients were treated with Mesalamine at a dose of 1220±600mg. Three patients underwent resection for persistence of symptoms and remained asymptomatic. Three patients had intermittent flare ups of symptoms. One patients developed severe diverticulitis and perforated. He subsequently died. Conclusions: Diverticular Disease-Associated Segmental Colitis may respond to 5-aminosalicylate with improvement in symptoms. These patients are at the risk of developing diverticulitis and recurrence in symptoms. Although Mesalamine appears to control the symptoms flare-ups are not uncommon. A proper placebo controlled study is needed to ascertain the natural history of this entity.

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A172 CLINICAL SPECTRUM OF DIARRHEA POST RENAL/PANCREAS TRANSPLANTATION. B. Salh, A. Astenehe, P. Keown, J. Shapiro Vancouver General Hospital, Vancouver, BC, Canada. Aims: The anti-rejection drug mycophenolate (Cellcept/Myfortic) is a well-recognized cause of diarrhea following transplantation, and this problem usually responds to a reduction in its dose. Here we report on a case series exemplifying our experience with management of diarrhea post combined renal/pancreatic transplantation, where there was often significant accompanying fat malabsorption. Methods: 9 patients were identified from the solid organ transplant registry at Vancouver General Hospital, and included individuals who had had severe diarrhea that had not responded to the usual work-up and management for infectious causes. In some cases, patients required weekly intravenous fluid replacement therapy at their local hospitals, due to unmanageable fluid losses. Results: In some patients the diarrhea had started either after a prolonged, or recurrent courses of antibiotic therapy. In 2 cases there was a complete response to discontinuation of MMF. Intestinal histology was either normal or non-diagnostic in the remainder, with typical changes of MMF toxicity in only 2. Radiology was negative for any obvious inflammatory or mass lesion. Several cases had fat malabsorption of greater than 50gm/day. In 1 case there was a complete response to antibiotic therapy with metronidazole given for SIBO. In 3 cases there was a complete or partial response to pancreatic enzyme therapy. In some, antidiarrheal treatment provided partial symptom control. In the severest case no interventions have been successful and the patient has been unresponsive even to octreotide, and requires TPN. No graft loss has yet been noted in any of these patients. Conclusions: Post-transplantation diarrhea is a common problem and responds usually to minor changes in drug therapy when infectious causes have been excluded. However, in a subset of cases with severe diarrhea, we have found significant fat malabsorption, which may be refractory to pancreatic enzyme treatment. Further investigation into the elucidation of its cause is warranted.

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A173 BROADENING THE DIFFERENTIAL FOR DIARRHEA- EOSINOPHILIC COLITIS A. Dinani, A. Dhillon, S. Ganguli McMaster University, Hamilton, ON, Canada. Aims: A 65-year-old Caucasian woman presented with a 3-month history of non-bloody watery diarrhea, 6-8 times/daily usually proceeded by abdominal pain. She denied any urgency, fever or chills. Her symptoms were not associated with food. She denied sick contacts and no recent travel history. She had lost 35 lbs but otherwise denied any alarm symptoms or extra intestinal manifestations. Normally she has 1-2 formed bowel movements daily with infrequent constipation. Her medical history included T2DM, HTN and a cholecystectomy. She denied a family history of IBD, autoimmune diseases or atopy. On reviewing her medications, we noted that she was started on Metformin and sitagliptin for her T2DM approximately 6 months ago. Her physical examination was unremarkable. Methods: On initial investigations her WBC was 13.7 x10 9/L, eosinophils of 0.1x 109/L, electrolytes and liver enzymes were normal. Her glucose was 8.0 mmol/L, TSH was 0.23 mU/L, TTG was not elevated and normal quantitative immunoglobulin levels. Her stool was negative for fecal leukocytes, ova and parasites, C. difficile toxin, adenovirus and rotavirus. Stopping her Metformin improved her symptoms transiently. Colonoscopy revealed diverticulosis. Biopsies from the sigmoid, transverse and ascending colon showed chronic and active colitis with eosinophilia, no definite crypt distortion or abscesses. A diagnosis of eosinophilic colitis was made. She was started on Prednisone 40mg daily and her symptoms improved dramatically. She now has 2 bowel movements daily. She is scheduled for an EGD to rule out eosinophilic gastroenteritis and a consultation with an allergy specialist. Results: EC is a rare disease entity within eosinophilic gastrointestinal disorders (EDIDs). EC has a bimodal distribution affecting both neonates and adults and is not gender specific. The etiology is largely unknown, but thought to be related to food allergies or hypersensitivity reaction given its correlation with other atopic disorders and response to corticosteroids. The clinical presentation is highly variable ranging from abdominal pain, nausea and vomiting, diarrhea, obstruction, weight loss, malabsorption, protein losing enteropathy and ascites depending on the depth of inflammatory response. Diagnosis of EC is that of exclusion. Presence of eosinophils and other causes of peripheral eosinophilia need to be ruled out, which include intestinal parasites, malignancies, Crohns disease, polyarteritis nodosa and hypereosinophilic syndrome. There are no consensus guidelines on threshold of eosinophils that need to be present on high power field like eosinophilic esophagitis. Initial treatment includes elimination diet and removal of allergen, followed by corticosteroids and immunomodulating therapy for maintenance. Conclusions: EC should always be included in one’s differential in a patient with long standing diarrhea.

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A174 AMEBIASIS? AN UNUSUAL GI PRESENTATION M. Dulai, E. Kim, A. Ramji University of British Columbia, Vancouver, BC, Canada. Aims: Rectal bleeding can be a challenging clinical encounter to manage, as the differential can be broad, ranging from entities such as hemorrhoids or diverticulosis to malignant lesions. Moreover, infectious and inflammatory etiologies must also be taken into account in the appropriate clinical context. We present a case of a 78 year old male with prostate cancer and previous radiation and hormonal treatment. The patient presented with a 6 month history of rectal bleeding attributed to a background diagnosis of hemorrhoids. Methods: This was a case report, and all information was collected from chart review. Results: A rectal mass was revealed on anoscopy and subsequent colonoscopy revealed two discrete, flat appearing ulcerated lesions, the largest of which spanned 4-5 cm in length and approximately 5-6 cm in width. An additional smaller ulcerated lesion spanning only a few centimeters was also found at 15cm from the anal verge, with the rest of the colon including the terminal ileum being normal. The lesions were felt to be atypical for malignancy in that they were flat and the intervening mucosa was normal. Subsequent pathology revealed protozoan parasites consistent with Entamoeba histolytica. Conclusions: Amebiasis is a worldwide illness however developing countries have significantly higher prevalence rates because of poorer socioeconomic conditions and sanitation levels. The spectrum of clinical presentation can vary from the asymptomatic carrier to amoebic dysentery with fulminant necrotizing colitis with bleeding and perforation. Amebiasis is becoming more recognized as a pathological cause of rectal bleeding in developed nations, with diagnosis being made largely by clinical suspicion and pathological confirmation. Our patient’s history of radiation therapy may have facilitated invasive amebiasis, though there is no consistent literature to support this. We will review an interesting case of rectal bleeding attributed to this entity and review the literature available on intestinal amebiasis.

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A175 CECAL DIVERTICULUM PRESENTING AS POSSIBLE CROHN'S DISEASE IN AN ADOLESCENT MALE J. Silverman, D. Boctor, C. Ortiz-Neira, L. McKenzie University of Calgary, Calgary, AB, Canada. Withdrawn at author’s request

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A176 THE EFFECT OF CHEWING GUM ON SMALL BOWEL TRANSIT TIME: A PROSPECTIVE RANDOMIZED TRIAL S. Svarta, G. Ou, R. Enns St.Paul's Hospital, Vancouver, BC, Canada. Aims: We wanted to examine (a): if chewing gum shortens small bowel transit time (SBTT) and therefore also cecal entry. Secondarily, we want to see (b): If chewing gum has an effect on gastric transit time (GTT Methods: We did a prospective, randomized, single-blinded controlled trial. 90 patients have so far been randomized into two groups. We calculated our sample size based on previous capsules done in our institution (the goal is n=122). Subjects were divided into two groups: Group A (n=46) chewed chewing gum and group B (n=44) did not. All patients received 2 L of Golytely as bowel preparation prior to the capsule. Group A chewed one piece of gum every 2 h for for approximately 20-30 minutes. One blinded gastroenterologist examined all studies. The number of CE that reached the cecum within 8-h, gastric transit time (GTT) and small bowel transit time (SBTT) were calculated. Results: Our calculation of sample size was n=122. So far we have done 90 capsules (F=50, M=40), mean age 58 (min: 22, max: 85). The preliminary results are shown in Table 1. Cecal completion rate was higher in the chewing gum group compared to the control group (93% versus 91% respectively), but these findings were not significant. There was no significant difference in the two groups in GTT (p=0.52), in SBTT (p=0.83) or in cecal completion rate. Conclusions: So far our findings suggest that chewing gum does not significantly reduce GTT, SBTT or cecal completion rate. We do not expect these finding to change even when reaching our full sample size Table 1

Group Mean Median Min Max St.Dev Chewing Gum 00:35:59 00:18:16 0:02:32 2:51:55 0:40:21

GTT Control 0:30:37 0:16:58 0:03:30 3:43:44 0:37:53

Chewing Gum 3:40:48 3:43:16 0:29:41 7:01:07 1:29:06 SBTT

Control 3:36:39 3:53:37 0:18:20 6:31:23 1:13:03

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A177 PROBABLE OVER-REPRESENTATION OF ASIAN PATIENTS WITH ISCHEMIC COLITIS C. Evaschesen1, B. Mangat2, E. Yoshida2, B. Salh2 1. Gastroenterology Division University of Alberta, Edmonton, AB, Canada; 2. Gastroenterology Division University of British Columbia, Vancouver, BC, Canada. Aims: Ischemic colitis is the most common form of intestinal ischemia. Prior studies have characterized this patient population with regards to presenting symptoms, co-morbidities, location of ischemia, surgical operations, and mortality. Our aim was to identify the racial background of patients with colonic ischemia at a Canadian tertiary care centre and determine if there were any disparities in its incidence in various populations. Methods: All confirmed biopsy cases of ischemic colitis from 2006 were examined. Patients with IBD, infective colitis, rectal prolapse, NSAID use, and diverticulosis were excluded. 20 cases were available for review and electronic records were searched to characterize this population. Results: Of the 20 cases of ischemic colitis six were Chinese, one was Vietnamese, and one was Korean. Of the remaining cases 11 were Caucasian and one was Fijian. Thus Asian patients comprised 40% (8/20) of this ischemic population. The 2006 Stats Canada demographics for the referring catchment area showed that the Asian population was 21.1%. Comparing these two groups with Fischer’s exact test demonstrated a P value of 0.0597. The average age of the study group was 73.5 years (range 42 to 89). Hypertension (50%, 10/20) and coronary artery disease (45%, 9/20) were the most common co-morbidities. As in prior studies the most common presenting features were frank rectal bleeding (70%, 14/20) and abdominal pain (65%, 13/20). The majority of patients (80%, 16/20) had non-isolated right colon ischemia. The average length of stay was 10.85 days (range 1 to 84) and the overall mortality was 10% (2/20). Conclusions: There was an almost significant higher incidence of ischemic colitis in Asian populations, despite our major limiting factor of the small sample size. Interestingly there were no South Asians with ischemic colitis identified during that year, even though this population has a very high incidence of cardiovascular disease. No definitive conclusions regarding the incidence of ischemic colitis in Asian populations could be made, but this pilot study needs to be repeated with an increased sample size incorporating other centres.

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A178 ELAFIN THERAPY ATTENUATES FUNCTIONAL AND MORPHOLOGICAL CHANGES INDUCED BY GLIADIN EXPOSURE IN GLUTEN-SENSITIVE MOUSE MODELS M. Wiepjes1, J. Jury1, X. Huang1, J. Gratadoux2, L. Bermudez-Humaran2, N. Vergnolle3, P. Langella2, E. Verdu1 1. McMaster University, Hamilton, ON, Canada; 2. INRA, Jouy-en-Josas, France; 3. INSERM, Toulouse, France.

NOT PUBLISHED AT AUTHORS REQUEST

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A179 SUPPRESSION OF CHRONIC GLUTEN-INDUCED ENTEROPATHY BY A POLYMERIC BINDER IN HCD4-DQ8 TRANSGENIC MICE H. Galipeau1, M. Pinier2, G. Fuhrmann4, N. Rivard5, J. Murray3, C. David3, J. Leroux4, E. Verdu1 1. McMaster University, Hamilton, ON, Canada; 2. University of Montreal, Montreal, QC, Canada; 3. Mayo Clinic, Rochester, MN; 4. ETH Zürich, Zurich, Switzerland; 5. Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: Celiac disease (CD) is a chronic immune-mediated enteropathy, triggered by the ingestion of gluten in susceptible individuals. When HCD4-DQ8 mice are sensitized with gluten they develop acute gut dysfunction and mild intraepithelial lymphocytosis. This is prevented by oral treatment with the polymeric gluten binder (P(HEMA-co-SS). Here, we investigate the chronic effects of gluten sensitization and challenge in HCD4-DQ8 mice as well as the efficacy and toxicity of (P(HEMA-co-SS) upon prolonged administration to gluten-sensitive mice. Methods: Male and female HCD4-DQ8 transgenic mice were mucosally sensitized with gluten plus cholera toxin once a week for three weeks. Following sensitization, mice were gavaged with or without P(HEMA-co-SS; 4 mg), followed by challenge with a mixture of wheat starch, BSA, and gluten (2 mg each) twice a day, three times a week, for three weeks. Non-sensitized mice on a gluten-free diet were used as controls. Enteropathy was evaluated by intraepithelial lymphocyte (IEL) counts and villus/crypt ratios. Anti-gliadin IgA antibodies (AGA) in intestinal washes were determined as a marker of gluten sensitization. To assess P(HEMA-co-SS) toxicity, weight loss, blood glucose levels, and cellular parameters in blood samples were analyzed. Results: Chronic gluten administration to HCD4-DQ8 mice caused a significant decrease in villus/crypt ratios in females (6.1 to 2.3) and males (5.7 to 2.86), and increased IEL counts compared to controls. Gluten-induced enteropathy was prevented by treatment with P(HEMA-co-SS), with villus/crypt ratios increasing to 4.6 and 5.2 in females and males, respectively. No AGAs were detected in intestinal washes of control mice or gluten-sensitized mice treated with P(HEMA-co-SS). However, AGAs were detected in 3 of 5 gluten-sensitized females and 2 of 5 gluten-sensitized males. No signs of toxicity were observed with prolonged P(HEMA-co-SS) treatment. There was a similar weight gain in all groups and no differences in biochemical and cellular parameters were observed between groups. Conclusions: This is the first report of development of chronic gluten-induced enteropathy characterized by significant reduction in villus/crypt ratios, and development of AGA in HCD4-DQ8 mice. Previous studies using acute gluten-sensitization protocols have only demonstrated mild gluten-induced functional and innate immune changes in mice. Treatment with the polymeric gluten-binder (P(HEMA-co-SS) prevented the development of enteropathy and AGAs in gluten-sensitized mice. This supports the potential therapeutic value of this novel mode of treatment for patients with CD and other gluten-induced disorders.

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A180 BMP SIGNALING IN COLONIC MYOFIBROBROBLASTS IMPACT ON THE SUBEPITHELIAL MICROENVIRONNEMENT PROMPTING EPITHELIAL DYSPLASIA J. Allaire1, S. Roy1, K. Kaestner2, F. Boudreau1, N. Perreault1 1. Université de Sherbrooke, Sherbrooke, QC, Canada; 2. University of Penn Genetics, Philadelphia, PA. Aims: In the last decade, the epithelial molecular genetic sequence leading to colorectal cancer (CRC) has been under intense scrutiny. Progress in this field has demonstrated that alterations in the microenvironment can promote tumorigenesis. These changes can both influence cellular processes in the stroma and in the epithelium. However, the functional relevance of colonic subepithelial myofibrobroblasts (CSEMFs) as an initiator of changes in the microenvironment, leading to CRC, has never been experimentally proven in vivo, due to the lack of appropriate tools. BMPs are multifunctional growth factors belonging to the TGF-β superfamily which can activate a signaling cascade within epithelial and mesenchymal cells. Recently, the BMP signaling pathway has been shown to play key crucial roles in gut morphogenesis, cell fate, adult homeostasis and tumorigenesis. However, these studies did not allow to specifically dissect the direct role played by stomal BMP signaling on the surrounding microenvironment and its subsequent impact on colonic epithelial homeostasis. We propose to address the molecular relevance of the BMP signaling within the CSEMFs on mucosal integrity and its impact on stromal/epithelial microenvironment. Methods: With use of the Cre/loxP system, we generated a mouse with abrogation of BMP signaling exclusively in the CSEMFs. H&E, Alcian blue and Masson Trichrome staining were used to evaluate histology and cellular functions. PCNA immunostaining and TUNEL assay were used to visualize proliferation and apoptosis respectively. Results: Morphological analysis of the CSEMFs-specific BmpR1a-null mice demonstrated sporadic dysplastic regions in the distal colon of 3 month-old mice compared to controls. These dysplastic regions were more frequent and extensive in 9 month-old mice. Alcian Blue staining revealed a significant decrease in goblets cells in colonic dysplastic region of 3 and 9 month-old mutant mice compare to controls. Masson Trichrome staining demonstrated an increased in collagen fibrils production in dysplastic regions of older mutant mice. An increase of 1,7-fold in number of proliferative cells and an increase of 1,5-fold in number of apoptotic cells in dysplastic regions was observed in mutant mice. With aging, CSEMFs-specific BmpR1a-null mice developed an average of 17 polyps in their middle colon where none were found in controls. These polyps were an average of 1.65 mm in size. Conclusions: Our results have highlighted an important role played by CSEMFs dependent BMP signaling in colonic epithelial homeostasis. Further experiments will confirm the involvement of mesenchymal BMP signaling in the maintenance of stromal microenvironment and also during the various steps of cancer.

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A181 AQUAPORIN 3 EXPRESSION AND LOCALIZATION IS ALTERED EARLY IN THE DEXTRAN SODIUM SULFATE MODEL OF INTESTINAL INFLAMMATION. M. Peplowski, V. Iablokov, M. Dicay, W. MacNaughton University of Calgary, Calgary, AB, Canada. Aims: Altered absorption and secretion of water, ultimately resulting in diarrhea, is a key characteristic of inflammatory bowel diseases (IBD). Although aquaporins (AQP) are known to be involved in water movement, the role of AQP3 in the barrier dysfunction that characterizes IBD remains unknown. We hypothesized that AQP3 expression and localization were altered in IBD. Methods: C57Bl/6 mice, 6 - 8 weeks of age, were administered 2.5% dextran sodium sulfate (DSS) in drinking water for up to 7 days to induce colonic inflammation. Colon lengths and myeloperoxidase (MPO) activity were quantified to verify establishment of disease. Real-time RT-PCR was used to assess AQP3 mRNA expression, whereas immunofluorescence was performed on formalin-fixed paraffin-embedded colonic tissue using E-cadherin as a marker for epithelial cell membranes. In addition, human biopsy samples obtained from the Intestinal Inflammation Tissue Bank were used to assess AQP3 mRNA expression. Results: In DSS-treated mice, no changes in MPO activity or colon length were observed at 3 days. However, there were significant increases in MPO activity and significantly decreased colon lengths at 7 and 14 days of DSS treatment, compared to water-treated controls. AQP3 mRNA obtained from mucosal scrapings revealed unaltered expression levels at 3, 7 and 14 days. However, immunofluorescence studies revealed overall downregulated expression of AQP3 in 3 day DSS-treated tissues, with diminished basolateral membrane staining in epithelial cells lining colonic crypts. These changes were no longer evident at 7 days, where epithelial cells that were present expressed similar levels of AQP3 compared to controls. However, there was an increase in AQP3 positive, E-cadherin negative cells in regions lacking normal crypt architecture. At 14 days, AQP3 staining was similar to that seen in control mice. Real-time RT-PCR analysis of human biopsy samples revealed no significant differences in AQP3 mRNA expression between healthy control, active and quiescent ulcerative colitis biopsy samples. Samples from Crohn’s disease patients appear to show downregulated AQP3 expression, although this did not reach significance. Conclusions: The data suggest that alterations in AQP3 expression and localization represent early events that occur in colonic inflammation.

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Nutrition, Obesity and Aging

A182 DIETARY POLYUNSATURATED FATTY ACIDS MODULATE THE INTESTINAL MICROBIOTA AND IMPAIR INTESTINAL IMMUNITY D. Gibson, R. Ethendhar, K. Brown, E. Molcan UBC Okanagan, Kelowna, BC, Canada. Aims: Microflora components play a crucial role in development of both local and systemic immunity, and lie at the interface of the internal and external environment in the gastrointestinal mucosa. The lumen of the intestine is exposed to dietary antigens, and recent evidence has shown that dietary choices alter the ecology of the microbiota. Specific groups of microbes can alter intestinal immune responses and are an important factor in conferring susceptibility to enteric disease. Polyunsaturated fatty acid (PUFA) dietary consumption has increased in the past few decades and omega-6 PUFA rich diets have been linked to increased colitis risk in humans while omega-3 PUFA has been suggested to decrease risk. The effects of either omega-6 or omega-3 PUFA consumption on the ecology of the intestinal gut microbiota and the consequences for host immune responses are unclear. We examined the effect of PUFA rich diets on the microbial community structure of the intestinal microbiota and the consequences on host intestinal immunity. Methods: Mice were fed isocaloric high lipid diets (20% wt/wt) with corn oil, fish oil (18% wt/wt of corn oil + 2% wt/wt of fish oil), canola oil or low fat (5% wt/wt corn oil) for 5 weeks and infected with Citrobacter rodentium. qPCR was used to study the ecology of the gut microbiota prior to infection and infected mice were examined for morbidity and colonic tissues were examined for intestinal inflammatory responses. Results: We found that PUFA rich diets modulate the ecology of the intestinal microbiota where the Bacteroidetes / Firmicutes ratio was decreased. Diets supplemented with fish oil induced high levels of Lactobacillus and Bifidobacterium species and low levels of Enterobacteraceae and Segmented Filamentous Bacteria. In general, PUFA rich diets when compared to the low fat diet, intestinal immunity was impaired. Miced fed diets supplemented with fish oil had increased oxidative responses and severely impaired immune responses during C. rodentium infection where all mice fed fish oil supplemented diets succumbed to infection. Conclusions: Our study reveals that PUFA rich diets alter specific microbes and impairs intestinal immunity. Specifically, fish oil supplemented diets, while increasing some beneficial microbes but not others and decreasing invasive microbes, results in a severely impaired immune response that mice succumb to C. rodentium infection. This has significant implications when considering recommendation’s for dietary fish oil supplementation and the many food items including infant formula, that are supplemented with omega-3 potentially impairing immune responses necessary for infection associated inflammation.

A183 TRANSIENT ELASTOMETRY AS A MEASURING TOOL FOR LIVER COMPLICATION IN TOTAL PARENTERAL NUTRITION M. Dumas-Campagna1, L. D'Aoust3, M. Lemoyne3, C. Vincent2 1. University of Montreal, Montreal, QC, Canada; 2. Service of Hepatology, Departement of Medecine, Hôpital St-Luc du CHUM, Montreal, QC, Canada; 3. Service of Gastroenterology, Departement of Medecine, Hôpital St-Luc du CHUM, Montreal, QC, Canada. Aims: Intrahepatic cholestasis is a possible complication of long-term total parenteral nutrition (TPN), which can progress to fibrosis and up to now, no noninvasive diagnostic modality evaluate this complication and consequently transient elastometry is being studied here. Methods: Transient elastometry was performed on long-term TPN patients during their follow-up at Hôpital St-Luc du CHUM (Centre hospitalier de l'Université de Montréal). Liver function tests were obtained in parallel. Twenty-three patients were classified according to their transient elastometry results, based on Corpechot et al.1. A fibrosis score of ≥F2 is considered clinically significant. Cholestasis is defined as an alkaline phosphatase measure superior to normal. Results: A total of 23 patients get a transient elastometry evaluation. Reliable transient elastometry values were obtained for 22 patients. Average transient elastometry value is 8,21 KPa +/- 3,49 (3,4-34,8 KPa). Fibrosis grades obtained are: F0-F1 for 14, F2 for 4, F3 for 1 and F4 for 3 patients respectively. There is a significant fibrosis (≥F2) in 8 patients (36%). Transient elastometry results are higher in patients with biochemical cholestasis, the averages being respectively of 12,5 and 4,63 KPa (p=0,05) for cholestatic and non-cholestatic subjects. Patients with significant fibrosis have a higher alkaline phosphatase value, for an average of 168 U/L compared to 96 U/L (p=0,045). Furthermore, there is a significant difference between alkaline phosphatase values in function of fibrosis stages (p<0.0001). Conclusions: Obtaining transient elastometry measures is possible in patients on TPN and is related to the presence of biochemical cholestasis. To determine whether an elevated transient elastometry value is a result of cholestasis or liver fibrosis, a liver biopsy would be necessary. Nevertheless, biochemical cholestasis translation into transient elastometry values suggests that the phenomenon is significant. This is the first study that suggests, by a noninvasive method, a high probability of developing liver fibrosis in patients undergoing parenteral nutrition. In this perspective, could it be suggested an omegaven based diet to this population of patients? 1.Corpechot C, Naggar AL, Poujol-Robert A, et al. Assessment of biliary fibrosis by transient elastography in patients with PBC and PSC. Hepatology 2006; 43:1118-24.

1. Corpechot C, Naggar AL, Poujol-Robert A, et al. Assessment of biliary fibrosis by transient elastography in patients with PBC and PSC. Hepatology 2006; 43:1118-24.

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A184 MALNUTRITION IN CANADIAN HOSPITALS: PRELIMINARY RESULTS FROM THE CANADIAN MALNUTRITION TASK FORCE (CMTF) K. Jeejeebhoy2, J. Allard1, M. Laporte3, L. Gramlich4, D. Duerksen5, H. Payette6, P. Bernier7, H. Keller8 1. University Health Network, Toronto, ON, Canada; 2. St. Michael’s Hospital, Toronto, ON, Canada; 3. Réseau de santé Vitalité Health Network, Bathurst, NB, Canada; 4. Department of Nutrition, University of Alberta, Edmonton, AB, Canada; 5. University of Manitoba, Winnipeg, MB, Canada; 6. University of Sherbrooke, Sherbrooke, QC, Canada; 7. McGill University, Montreal, QC, Canada; 8. University of Guelph, Guelph, ON, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A185 PHYSICIAN PERCEPTIONS REGARDING THE IDENTIFICATION AND MANAGEMENT OF MALNUTRITION IN CANADIAN HOSPITALS D. Duerksen1, H. Keller2, J. Allard3, P. Bernier4, L. Gramlich5, K. Jeejeebhoy6, M. Laporte7, H. Payette8 1. University of Manitoba, Winnipeg, MB, Canada; 2. University of Guelph, Guelph, ON, Canada; 3. University of Toronto, Toronto, ON, Canada; 4. Jewish General Hospital, Montreal, QC, Canada; 5. Alberta Health Services North, Edmonton, AB, Canada; 6. St Michael's Hospital, Toronto, ON, Canada; 7. Reseau de Sante Vitalite Health Network, Moncton, NB, Canada; 8. University of Sherbrooke, Quebec City, QC, Canada. Aims: Although malnutrition is common in hospitalized patients this is not always identified or managed appropriately. The purpose of this study was to describe the nutrition practice of physicians to identify ways that management of malnourished patients can be optimized. Methods: Attending physicians working at hospitals participating in the multicenter Canadian Malnutrition Task Force (CMTF) study were given a survey regarding nutrition practice in hospitalized patients. This 48 question survey was adapted from a previous questionnaire 1 that had been developed based on ESPEN standards of nutritional practice. Results: To date, 95/316 (30.1%) physician surveys have been completed. Physician characteristics are: 80% male; mean 10.5 yrs since graduation; 72% academic; 48.5% internal medicine 48.4% surgery. Nutrition assessment(NA) on ward was practiced > 50% of time: on admission (24.3%), during hospitalization(34.8%), at discharge(30%). Over 80% of physicians felt that NA should be evaluated on admission, during hospitalization, and discharge. Resources available to physicians included: nutrition team(54.7%), protocol for malnutrition detection(37.9%), tube feeding protocol(63.2%), education for medical staff(35.8%). Over 90% of respondents wanted access to these resources. Physicians felt using dietitians more extensively would be helpful(80.1%). On a scale of 1-10 physicians’ self-reported knowledge of the treatment of malnourished patients was 5.61 but the perception of the relevance was 7.38. Conclusions: NA is frequently neglected in Canadian hospitals. Physicians feel that nutrition care is important and relevant but their self reported knowledge of nutrition is insufficient. Strategies need to be developed to enhance use of dietitians, improve the nutrition knowledge and awareness of physicians, and integrate this into the nutrition management of hospitalized patients.

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A186 WHAT DO PATIENTS SAY ABOUT NUTRITION CARE IN CANADIAN HOSPITALS? L. Gramlich4, H. Keller1, K. Jeejeebhoy2, D. Duerksen3, M. Laporte5, H. Payette6, P. Bernier7, J. Allard8 1. University of Guelph, Guelph, ON, Canada; 2. University of Toronto, Toronto, ON, Canada; 3. University of Manitoba, Winnipeg, MB, Canada; 4. University of Alberta, Edmonton, AB, Canada; 5. University of Moncton, Moncton, NB, Canada; 6. University of Sherbrooke, Sherbrooke, QC, Canada; 7. McGill, Montreal, QC, Canada; 8. University of Toronto, Toronto, ON, Canada. Aims: Poor food intake is common in acute care hospitals and can lead to insufficient energy and nutrients to support recovery. Food is the primary way in which patients are nourished and quality food and foodservice are needed. Methods: As part of the Nutrition Care in Canadian Hospitals study conducted by the Canadian Malnutrition Task Force, surveys were administered to 220 medical or surgical patients from four hospitals (2 academic/tertiary care, 2 community hospital; 3 with own kitchen) to determine their satisfaction with their nutrition care experience. The survey was based on prior work (Naithiani et al., 2009) and included items on sensory perception as well as barriers to food consumption. Surveys were completed when discharge was ordered Results: Response rate was 93% (n=204); the average age of respondents was 63 years and 44% were female. Three-quarters (76%) of respondents were satisfied with the taste and temperature (72%) and almost all (87%) with appearance of food. Most considered portions sizesappropriate (71% ). Over half were disturbed (smells, noise, activity; 57%) and 60% were interrupted at least once during their meal, while 34% missed a meal due to medical procedures. Difficulties were reported with:poor position for eating (30%) cutting food (21%), reaching meals (19%) and opening packages (35%). Over two-thirds(69%) complained of poor appetite during admission. Other common reasons for not eating were: sickness (52%), pain (42%), tiredness (42%), being worried (28%) or depressed (20%). Conclusions: Patient perception of food quality was high. Many reasons were given for not eating food including being unwell. Meal disturbances and assistance with meals needs to be improved. Protected mealtimes with adequate supports to facilitate eating are needed in acute care hospitals in Canada.

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A187 EFFECTIVENESS OF AN EDUCATIONAL INTERVENTION TARGETING MEDICAL STUDENTS’ NUTRITION KNOWLEDGE AND SKILLS F. Peerani, B. Dicken, L. Bistritz University of Alberta, Edmonton, AB, Canada. Aims: Since the lack of nutritional education in the medical undergraduate curriculum is a common theme throughout Canadian medical schools, a portion of the undergraduate GI block at the University of Alberta was dedicated to improving the nutritional knowledge of medical students in innovative ways. Two specific modifications implemented in the curriculum were: 1) a knowledge translation assignment utilizing evidence-based medicine to address a nutrition-based question from a fictional patient and 2) dietician-led small group case based teaching sessions. Methods: We implemented these curricular changes during the undergraduate GI block at the University of Alberta between August 31, 2010 and October 9, 2010. Medical students completed pre- and post-test surveys of their self efficacy regarding their nutritional knowledge, attitudes and skills. The survey consisted of 25 questions of which 15 served to assess confidence in the domains of nutritional knowledge and nutritional assessment skills both before and after the GI block. The remaining 10 questions assessed satisfaction with the nutrition portion of the GI block. Statistical analysis in the form of paired t-tests compared the responses between pre- and post-test surveys for the group using a p-value of 0.05. Qualitative survey data was also collected and coded for dominant themes. Results: Of the 223 students provided with the survey, 68 matched pre- and post-test surveys were completed (30% response rate), while 58 unmatched pre-test surveys and 134 unmatched post-test surveys were also collected. When comparing the paired pre- and post-test questions, all pairs showed statistically significant improvement except for students’ personal adherence to Canada’s Food Guide. After completing the course, students felt their knowledge of clinical nutrition had increased (mean 3.18 on a 4 point scale), and felt more confident applying nutrition principles to a clinical encounter (mean 3.05), taking a nutrition history (mean 3.12), and counseling a patient about his/her diet (mean 3.14). Perceived strengths of the curriculum included access to skilled nutritional educators such as dieticians, the use of small groups and case-based teaching whereas perceived weaknesses included content-dense lectures, a deficiency of pediatric nutrition, timing of the nutrition block, and the lack of opportunity to apply practical skills to standardized patients. Conclusions: This study was successful in engaging medical students in a topic that has been underemphasized in the curriculum to date and will provide them with more confidence and expertise to counsel their patients about nutrition in the future. Qualitative data from this survey will also serve to modify the curriculum of future GI blocks at the University of Alberta.

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A188 INTESTINAL MICROFLORA IS ALTERED IN PATIENTS WITH NON-ALCOHOLIC FATTY LIVER DISEASE COMPARED TO HEALTHY CONTROLS M. Mouzaki1, B. Arendt1, E. Comelli2, D. Krause3, A. Wong2, J. Bonengel1, J. Allard1 1. University Health Network, Toronto, ON, Canada; 2. University of Toronto, Toronto, ON, Canada; 3. University of Manitoba, Winnipeg, MB, Canada. Aims: The primary aim was to compare the intestinal microbiota (IM) composition of patients with non-alcoholic fatty liver disease (NAFLD) to that of healthy controls. Secondary aim was to compare the Bifidobacteria counts in the stool of patients with NAFLD to that of controls. Methods: Pilot, cross-sectional study performed at a single institution. Data from 16 adult patients with biopsy proven NAFLD (5 simple steatosis [SS], 11 non-alcoholic steatohepatitis [NASH]) and 8 healthy controls were collected. Patients with liver disease secondary to other etiologies, those for whom liver biopsy was contraindicated and those having used antibiotics, pro- or prebiotics and/or antioxidants in the preceding 6 months were excluded. One stool sample was collected from each participant. Stools were homogenized and DNA was extracted (Omega, BioTek kit; Norcross, GA). A global IM analysis was done via 16S rRNA pyrosequencing, performing a discriminate analysis at the phylum level; quantitative polymerase chain reaction (qPCR) was performed to measure total bacterial and Bifidobacteria counts. Unpaired t-tests or Fisher’s exact test were used to compare the two groups and Pearson correlation coefficients were calculated, using SAS Enterprise Guide 4.2. Results: Pyrosequencing showed that Bacteroidetes, Firmicutes, and Proteobacteria were highly correlated with SS and NASH. Verrucomicrobia, Actinobacteria and Cyanobacteria primarily drove the IM composition of controls. The total number of cells in fecal samples by qPCR were not different between the groups There were large variations in the Bifidobacteria counts between study subjects, but NAFLD patients still had lower Bifidobacteria numbers compared to controls (mean±SD: 7.29±2.32 vs. 8.80±0.40 log cells / g feces; p=0.022). There was no difference for age or gender distribution between the two groups, but patients with NAFLD had significantly higher BMI (31.2±4.0 vs. 24.7±3.4 kg/m2; p=0.001). However, the number of Bifidobacteria was not correlated with BMI (r=-0.078; p=0.722). Conclusions: The IM of patients with NAFLD is different compared to that of controls at the phylum level. In addition, patients appear to have lower numbers of Bifidobacteria in their stool, previously associated with altered intestinal permeability. Larger studies are needed to look into specific differences between the IM of patients with SS, NASH and healthy controls. Should our results be replicated in larger studies, the use of pre- or probiotics for the management of NAFLD could be studied.

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A189 RELATIONSHIP BETWEEN DIETARY IRON INTAKE AND SERUM FERRITIN CONCENTRATION IN C282Y HFE HOMOZYGOTES. P. Adams9, V. Gordeuk1, L. Lovato2, M. Vitolins2, G. McLaren3, R. Acton4, J. Barton5, C. McLaren3, E. Harris6, M. Speechley9, J. Eckfeldt7, S. Diaz1, P. Sholinsky8 1. Howard University, Washington, DC; 2. Wake Forest University, Winston-Salem, NC; 3. University of California, Irvine, CA; 4. University of Alabama, Birmingham, AL; 5. Southern Iron Disorders Center, Birmingham, AL; 6. Kaiser Permanente, Portland, OR; 7. University of Minnesota, Minneapolis, MN; 8. National Institute of Health, Bethesda, MD; 9. University of Western Ontario, London, ON, Canada. Aims: HFE C282Y homozygotes have an increased risk for developing increased iron stores and related toxicity. It is controversial whether dietary iron restrictions should be recommended to such individuals. Methods: Serum ferritin concentration was measured and a dietary iron questionnaire completed as part of the evaluation of 219 HFE C282Y homozygotes who were identified through screening of primary care patients at five centers in the US and Canada.To quantify dietary iron content and alcohol consumption, participants filled out the University of Hawaii Multi-Ethnic Dietary Questionnaire. The test-retest reliability of this questionnaire has been validated. The questionnaire asks about average eating habits over the past year. The questionnaire was analyzed at the University of Hawaii and the results of the analysis provided estimates for average daily total dietary iron as well as the amount of dietary iron derived from meat, fish and poultry. An estimate for supplemental iron intake was also provided. We classified the iron derived from meat, fish and poultry as heme iron and the difference between total dietary iron and dietary heme iron as non-heme iron. Results: No significant relationships were found of serum ferritin concentration with dietary heme iron or non-heme iron content, or of serum ferritin concentration with supplemental iron. Conclusions: These results do not support recommending dietary iron restrictions for HFE C282Y homozygotes in North America.

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A190 THE REGUALTION OF P2X7 RECEPTOR EXPRESSION IN RESPONSE TO GLUCOSE LEVEL VARIATION M. Bilodeau, J. Bourzac, F. Gendron sherbrooke university, sherbrooke, QC, Canada. Aims: Background. The regulation of glucose homeostasis is essential to physiological processes. There is some evidence for the implication of P2X7 receptor in pancreatic beta cell functions and survival. We reported that activation of the ATP-gated ion channel P2X7 regulates glucose transporter-2 (GLUT2) internalization in intestinal epithelial cells (IEC). This modulating effect leads to a reduction in the transport of glucose by IEC. Glucose is the main energy source required for normal cell function, but recent evidence suggests that glucose could act as an extracellular signaling molecule. In this study, we investigated whether the variation in glucose levels influenced the transcription of P2X7 and identified potential transcription factors (TF) that could regulate P2X7 expression in IEC. Methods: Methods. We used the IEC-6 and Caco-2 cell line models. Cells were serum-starved for 24h and depleted of glucose for 3h prior to glucose re-introduction. Glucose concentrations range from 0 g/l up to 8 g/l. We analyzed the impact of glucose variation levels on P2X7 expression by quantitative real-time PCR and on TF expression using Western blots. We identified potential TF, first, by in silico analysis and used a combination of luciferase and chromatin immunoprecipitation assays to validate the identified TF. Results: Results. Following glucose privation to mimic the situation between meal intake, we have shown that the re-introduction of glucose stimulated P2X7 gene transcription in a concentration-dependent manner. We have identified C/EBPb as one potential TF regulating P2X7 transcription by interacting with the minimal receptor promoter region spanning a region located between -400 bp upstream to the transcription initiation site (+1) up to position +4. The direct interaction of C/EBPb with the promoter was confirmed by chromatin immunoprecipitation. Having established that C/EBPb regulates P2X7 gene expression, we determined whether glucose level variation affected C/EBPb expression. We showed by Western blots that addition of glucose increases C/EBPb expression. The expression of nuclear C/EBPb is increased 5 min after the addition of glucose and decreases with time until three hours where it goes up again. A similar pattern of expression was observed for P2X7 mRNA expression. Conclusions: Conclusion. These results suggest a possible pathway that starts with glucose sensing and the induction of an intracellular pathway, that is not yet identified, that could regulate P2X7 transcription and expression. Our data support a role for C/EBPb in this signaling cascade. We are now looking for the possible signaling events linking sugar sensing and P2X7 expression. These could involve the glucose-transporter SGLT1 or member of the sweet taste receptors of the T1R family.

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Poster Session 2 Sunday, February 26, 17h00-18h30 Clinical Practice

A191 IDENTIFICATION OF FACTORS ASSOCIATED WITH SEDATION TOLERANCE DURING COLONOSCOPY: PRELIMINARY RESULTS A. Shingina, S. Svarta, G. Ou, R. Kwok, J. Tong, K. Donaldson, J. Frenette, E. Lam, R. Enns Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, BC, Canada. Aims: Colonoscopy is the preferred test for colorectal cancer screening. Current recommendations involve the use of benzodiazepines with opiates to achieve sufficient sedation rates. The factors previously reported to be associated with increased sedation requirements include present use of opiates/benzodiazepines, alcohol abuse, pre-procedural anxiety and a previous difficult procedure. Methods: A retrospective chart review is underway on 2000 patients who underwent an outpatient colonoscopy at St. Paul’s Hospital from 2009 to 2010 in order to develop a predictive tool for identifying patients who will require increased doses of sedatives. Results: A preliminary analysis of 850 patients (mean age 57±12, 55% male) was performed. 93% of patients required sedation with more than 2 mg of intravenous midazolam and 66% with more than 50 mcg of intravenous fentanyl. Univariate analysis using logistic regression model identified the following variables linked to higher midazolam doses: younger age (p=0.000, 95%CI=-0.036-0.022), difficult procedure as reported by endoscopist (p=0.000, 95%CI=0.377-0.849), history of difficult endoscopy requiring increased sedation (p=0.000, 95%CI=0.303-0.931), current uses of benzodiazepines (p=0.013, 95%CI:0.048-0.411) and opioids (p=0.007, 95%CI:0.066-0.431). Univariate analysis of fentanyl dosage revealed similar variables: younger age (p=0.000, 95%CI:-0.672-0.631), difficult procedure (p=0.000, 95%CI:7.6-17.9) and previous requirement of high sedative doses (p=0.000, 95%CI:6.74-20.55), as well as current uses of antidepressants (p=0.000, 95%CI:3.13-10.48) and benzodiazepines (p=0.000, 95%CI:2.37-10.28). Multivariate regression analysis identified younger age, difficult procedure and previous high sedation dose requirement as variables impacting higher fentanyl doses in colonoscopy. Midazolam dosing was also affected by age and difficulty of procedure, but not by the current uses of opioids and benzodiazepines in the multivariate analysis. Conclusions: Pre-procedural planning is the key in conducting successful, efficient colonoscopy. Logistic regression analysis of almost 1000 patients who underwent out-patient colonoscopy revealed the following factors associated with increased sedation requirement: younger age, difficult endoscopy and requirement for high sedation rates in past procedures. These patients are more likely to need a longer recovery periods post-endoscopy, which could result in additional time and personnel requirements. The final data would be used to create a predictive model, which would take into account all individual variables that were shown to be previously significant and whose efficacy would be tested in a multivariate regression model.

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A192 DOES CAP-ASSISTED COLONOSCOPY DECREASE COLONOSCOPE INSERTION TIME? A RANDOMIZED CONTROLLED CLINICAL TRIAL R. Berger, M. Curley, E. MacIntosh, P. Newcombe, E. MacDonald, S. Gruchy, D. MacIntosh Dalhousie University, Halifax, NS, Canada. Aims: Colonoscopy is an essential procedure for the diagnosis and prevention of colorectal cancer. Withdrawal time and adenoma detection rate (ADR) have been identified as two key quality indicators in the performance of screening colonoscopy. In addition, patient comfort and satisfaction are important outcome measures in colonoscopy performance. Colonoscopy assisted by the attachment of a transparent cap on the end of the colonoscope has been investigated for its potential in decreasing insertion time, improving patient comfort and increasing polyp detection rate. We planned a randomized controlled trial to determine if cap-assisted colonoscopy (CAC) reduced insertion time to cecum compared to standard colonoscopy (SC). Methods: Patients aged 18 and older who were able to give consent presenting for outpatient colonoscopy were invited to participate in the study. Patients with previous colonic resection, a known stricture or obstructing colon lesion were excluded. Study subjects were randomized in blocks of 10 in a blinded fashion to CAC or SC using consecutively numbered sealed opaque envelopes. In the CAC group, a 15.7mm transparent cap (D-201-15004, Olympus Medical Systems) fixed to the tip of the colonoscope. The primary outcome was time to cecal intubation measured by stopwatch. Secondary outcome measures included cecal intubation rate, colonoscope withdrawal time and polyp detection rate. The sample size (200 in each arm) was calculated to detect a difference in insertion time of 3.5 minutes with a beta error 0.8 and alpha 0.05. The Research Ethics Board of the Capital District Health Authority approved the study protocol. Results: One hundred and ninety-two patients were enrolled in the study (92 CAC group and 100 SC group). Unfortunately, the study was prematurely discontinued when the manufacturer was no longer able to supply the device. Eleven endoscopists, with 2 performing 55% of the cases, performed the colonoscopies in this study. Ninety-nine cases (51.6%) were diagnostic, the remaining were screening or surveillance cases. Mean insertion times were 8.96 minutes in the CAC group and 9.53 minutes in the SC group (p=0.481). The cecal intubation rate did not differ between the two groups (89.1% CAC, 94.0% SC; p=0.233). Mean withdrawal time was 9.27 minutes in the CAC group and 9.60 minutes in the SC group (p=0.633). Polyp detection rates were similar in both groups (46.7% CAC, 42.0% SC; p=0.131). Conclusions: No difference in mean insertion time between the study groups was demonstrated. There were no statistically significant differences in secondary outcome measures. Although this study is clearly underpowered, our results suggest that use of CAC may not improve the performance of routine colonoscopy.

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A193 SURVEY ON THE PRACTICE OF AFTER-HOURS/EMERGENCY ENDOSCOPY IN CANADA K. Muthiah1, R. Enns2, D. Armstrong2, A. Noble2, J. Gray2, P. Sinclair2, P. Colacino2, H. Singh2 1. University of Manitoba, Winnipeg, MB, Canada; 2. CAG clinical affairs committee, Toronto, ON, Canada. Aims: Several guidelines recommend appropriate staffing for emergency endoscopy as essential but do not define the appropriate level of staffing. We conducted a survey to determine the staffing and practice patterns for after-hours endoscopy in Canada Methods: A link to a web based survey was sent by electronic mail to all the clinician members of CAG in Feb 2011. A reminder was sent 4 weeks later. A-priori we planned to assess regional variations across Canada, and differences among pediatric and adult gastroenterologists (GIs) and between those practicing at university vs community hospitals. Results: Out of 422 potential respondents, 168 (39.8%) responded. All (n=17) of the pediatric GIs practiced at university hospitals; 70% performed after-hours endoscopy in ORs, with an anesthetist (65%), with access to propofol (94%) but did not have a trained endoscopy nurse available every day of the week (only 12% did) and only 12% were highly satisfied (score of 8 or more on a 10 point Likert scale) with the current arrangements for after hours endoscopy. Of the 135 adult GIs, 61% performed after hours endoscopy in the endoscopy suite, 62% had a trained endoscopy nurse available every day of the week, 38% had access to propofol, and 7% had an anesthetist present for after hours endoscopy. Twelve percent of the respondents reprocessed the endoscopes themselves or with the help of a resident. 4% of the adult GIs had out of hospital patients come directly to their endoscopy suite and 53% were highly satisfied. The adult endoscopists practicing at community hospitals were less likely to perform after hour endoscopy in a critical care unit or ER, have endoscopes reprocessed by a resident or endoscopist, but were more likely to have an anesthetist present (21% vs. 5%). Regional differences were noted with more involvement of anesthetist (13%) and availability of propofol (50%) in Ontario, more frequent reprocessing of endoscopes in the central reprocessing units in BC (78%) and, almost universal availability of a trained endoscopy nurse (96%) for after hours endoscopy and with concomitant higher endoscopist satisfaction (84% highly satisfied) in Alberta. Conclusions: More than one third of surveyed endoscopy units across the country do not have a trained endoscopy nurse to assist for after hours endoscopy—the time period when sicker patients present and need endoscopic interventions often. There are significant regional differences in practice of after hour endoscopy. In absence of data on effect of different levels of staffing on patient outcomes, there needs to be consensus based standards on minimum level of appropriate staffing for after hours endoscopy so as to ensure all patients have appropriate access to care, irrespective of where they receive their care.

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A194 ESOPHAGEAL STENTS EFFECTIVELY MANAGE LARGE GASTRIC LEAKS FOLLOWING BARIATRIC SURGERY M. Pinchbeck, D. Birch, S. Karmali, C. Wong University of Alberta, Edmonton, AB, Canada. Aims: Gastric leaks are a serious complication of bariatric surgery. Management has traditionally consisted of surgical repair, which is technically difficult and frequently fails. Endoscopically placed removable self-expanding esophageal stents are safe and effective in the management of post-esophagectomy anastomotic leaks, but their use in treating gastric leaks is not well described. The noninvasive nature, technical ease and relative low cost of stenting are advantageous. The objective of the current study is to determine the safety and efficacy of endoscopic stenting for the treatment of gastric leaks following bariatric surgery. Methods: Patients at a single center who underwent esophageal stenting for treatment of a gastric leak following bariatric surgery from January 2010 - October 2011 were included in this case series. Data on clinical presentation, stent type and duration, healing rates and stent-associated complications was obtained through retrospective chart review. Results: Among 4 patients identified for study inclusion, the mean age was 52 years (range 30 - 62), 1/4 (25%) was male, 2/4 (50%) had BMI < 35, all had laparoscopic sleeve gastrectomies, 1/4 (25%) had surgery in Canada, and 3/4 were medical tourists who had surgery in Mexico. Leaks were diagnosed a mean of 9.5 days (range 6 - 12) post-op. The most common presenting symptoms were abdominal pain and fever. The estimated size of the gastric defects ranged from 5 - 20 mm. 1 patient had 6 laparotomies for washout and 2 unsuccessful attempts at surgical closure of the leak prior to stenting. The mean number of post-op days at stenting was 56 (range 20 - 67). All stents were centered at the defect with fluoroscopic guidance. Two of four initial stents were fully covered self-expanding metal esophageal stents, and the remaining two were self-expanding plastic silicone esophageal stents. All stents were 18 mm in diameter and ranged in length from 12.3 - 15.3 cm. Initial stents were removed after a mean of 35 days (range 9 - 91). Complete healing had been achieved in 3/4 patients at initial stent removal. 1 patient required 2 subsequent stents to achieve complete healing. Five of six stents migrated, 3 to the extent that the defect was uncovered. Two of three metal stents were complicated by mucosal ulceration and tissue hyperplasia at the stent ends. All stents were removed endoscopically without complication. Conclusions: Endoscopically placed esophageal stents are safe and effective treatment for gastric leaks post-bariatric surgery. The most frequent complication observed in this study was stent migration. Metal stents may be more likely to result in mucosal damage than plastic stents. Three of four patients in this series were medical tourists, suggesting that higher than acceptable complication rates may be present in this population.

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A195 COMPARISON OF TRIPLE THERAPY, QUADRUPLE THERAPY AND SEQUENTIAL THERAPY FOR THE ERADICATION OF HELICOBACTER PYLORI INFECTION M. Pinchbeck, S. Veldhuyzen van Zanten University of Alberta, Edmonton, AB, Canada. Aims: Helicobacter pylori infection can cause ulcer disease, MALT lymphoma and gastric cancer. The current recommended initial therapy for H. pylori consists of a proton pump inhibitor, clarithromycin and amoxicillin (PPI-CA) or metronidazole (PPI-CM). However, this standard triple therapy eradicates H. pylori in less than 80% of cases, and is even less effective in populations with high rates of clarithromycin-resistant bacteria. Alternative treatment regimens include quadruple therapy with bismuth, tetracycline, metronidazole and PPI, and sequential therapy with PPI and amoxicillin for 5 days, followed by PPI-CM for an additional 5 days. The objective of the present study was to determine the efficacy of the triple, quadruple and sequential therapy regimens for the eradication of H. pylori in the Edmonton area. Methods: Patients diagnosed with H. pylori infection on histology or urea breath test were eligible for this retrospective cohort study. Patients who did not comply with therapy or have post-treatment testing for H. pylori eradication were excluded. Data was collected on treatment regimens used and eradication testing. The efficacy of triple, quadruple and sequential therapy was calculated. Results: 141 patients were eligible for study inclusion. 60 (43%) were male, and the mean age was 52.5 ± 13.8 years. 8 patients (5.7%) did not comply with treatment and were excluded. Of the 133 patients who received treatment, 92 (69.2%), 13 (9.8%), and 24 (18.0%) received PPI-CA, PPI-CM, and sequential therapy as first line treatment, respectively. Second, third, and fourth courses of therapy were required in 42/133 (31.6%), 13/133 (9.8%), and 3/133 (2.3%) patients, respectively. 32/33 (97.0%) patients received quadruple therapy for failure of other treatment. Post-treatment eradication testing followed 163/191 (85.3%) courses of therapy. First-line therapy with PPI-CA achieved eradication in only 43/78 (55.1%) cases. Eradication was achieved with first-line sequential therapy in 18/20 (90%) cases. 2nd-line quadruple therapy eradicated H. pylori in 16/21 (76.2%) cases. Conclusions: The efficacy of standard triple therapy for H. pylori was unacceptably low and worse than previously reported. Sequential therapy was superior to triple therapy for first-line treatment. Quadruple therapy was the most effective second-line therapy.

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A196 NURSE PRACTITIONER COLONOSCOPY IN A COLON CANCER SCREENING PROGRAM: A NOVEL AND HIGHLY SUCCESSFUL TRAINING AND CREDENTIALING PROGRAM IN CANADA M. Harriot, G. Sandha, E. Semlacher, C. Wong, R. Fedorak University of Alberta, Edmonton, AB, Canada. Aims: Population-based colon cancer screening in both high risk and average risk individuals has been accepted as a public health measure across Canada. Within the current clinical structure, the demand for screening colonoscopy cannot be met by physician providers alone. Nurse Practitioner Colonoscopists (NPCs) are accepted alternate providers of colonoscopy within colon cancer screening programs in the UK, however similar programs do not exist in North America. We describe the first NPC training program initiated and the first successfully trained candidate in Canada. Methods: NPC Training: (1) Cognitive training was achieved using colonoscopy-specific instructional modules undertaken online through the University of Hull, UK NPC 2 yr training program; (2) Technical training was achieved using progressive development skills for colonoscopy acquired over 2 yrs under direct apprenticeship mentoring by gastroenterologists at the University of Alberta Hospital. Quality assessment of colonoscopy training was determined using modified global rating scales. Results: As a prerequisite, a Master’s of Nursing and Nurse Practitioner certification in Gastroenterology was obtained. Cognitive training was carried out between Sept 2009 and Sept 2011 and included 3 colonoscopy modules. Technical training was initiated Jan 2010, extended through to Dec 2011, and included 225 supervised colonoscopies. Assistance was required to achieve cecal intubation in 18 of the first 50 colonoscopies (36%) but only 4 of the last 50 (8%). Cecal intubation rate is 92%. Polyp detection rate is 39%. Minor adverse events included 1 pt with post-polypectomy bleeding. There were no perforations or serious adverse events. At the end of training, a Postgraduate Certificate in Colonoscopy was awarded through the University of Hull and credentialing from the University of Alberta Hospital. Conclusions: A successful training curriculum and credentialing process for an NPC has been implemented at the University of Alberta. Colonoscopy quality assessments for the NPC are similar to those seen with gastroenterologists. NPCs represent an excellent solution to colonoscopy manpower issues in colon cancer screening programs.

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A197 SEVERE EPSTEIN BARR VIRUS INFECTION IN A PATIENT WITH CROHN’S DISEASE ON AZATHIOPRINE. A CASE REPORT AND LITERATURE REVIEW. M. O'Byrne, W. Afif McGill University, Montreal, QC, Canada. Aims: Epstein Barr Virus (EBV) infection is generally a self limited or asymptomatic infection in immunocompetent patients. In immunocompromised patients, EBV infection has a more hazardous course. We present a case of a young female with Crohn’s disease on azathioprine, who developed septic shock secondary to an EBV infection. Methods: A medical chart review and a subsequent literature review of an EBV infection complicating immunosuppressive treatment was performed Results: A 19 year old female with a four year history of colonic Crohn’s disease, who had been treated with azathioprine over the last two years and was in clinical remission, presented with a two week history of fever, night sweats, myalgias, and fatigue. On admission the patient was tachycardic and laboratory investigations revealed leukopenia. The initial work-up of her febrile symptoms, including bacterial and fungal cultures, chest X-ray and CT abdomen did not reveal a source of her symptoms. Five days post-admission to hospital, the patient continued to be febrile and developed pancytopenia, worsening tachycardia and hypotension, despite aggressive fluid resuscitation. She was transferred to the intensive care unit for hemodynamic support for septic shock. Although her initial Monospot test was negative her EBV PCR revealed a viral load of approximately 7000 copies/ml and an EBV IgM was postive. Subsequent testing revealed an EBV viral titre of 2.8 x 10*6 copies/ml. Bone marrow biopsy revealed non-caseating granulomas. She had clinical criteria consistent with a possible diagnosis of hemophagocytic syndrome. The patient received supportive management and intravenous corticosteroids and was weaned off hemodynamic support. She was eventually discharged from hospital 2 weeks post admission. She is presently in clinical remission on only 5-ASA enemas and her EBV viral titre is non-detectable. Conclusions: Primary EBV infection, leading to septic shock and hemophagocytosis, is a rare but serious complication of immunosuppressive treatment in patients with IBD.

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A198 IMPACT OF A MANAGEMENT AUDIT TO IMPROVE STRATEGY OF CARE OF UPPER GASTROINTESTINAL HEMORRHAGE FROM PEPTIC ULCER BEFORE AND AFTER THE ESTABLISHMENT OF GUIDELINES. E. Sculo, A. Fichet, M. David, F. Rostain, M. Bardou, C. Michiels Hepatogastroenterology, CHU Dijon, University of Burgundy, Dijon, France. Aims: Upper gastrointestinal bleeding (UGIB) represents a substantial clinical and economic burden. The aim was to improve, and assess, quality of care of patients with UGIB from peptic ulcer by using an audit before and after the establishment of guidelines. Methods: The methodology use to build the audit was that recommended by the French High Health Authority. A standardized scale was developed from guideline after a bibliographic review. We first performed an audit of practice based on the review of medical records of the last 34 patients hospitalized in the intensive care unit (ICU) of University hospital of Dijon during the year 2007, for UGIB from peptic ulcer. This audit assessed both management by the physician and facilities made available by the hospital. We then built a plan to improve both points. This plan included: writing and dissemination of guidelines, computerized prescription of resuscitation care and drug therapy, and education and training of physicians and nurses. This improvement plan included the presence of a trained nurse to assist for out of hours endoscopies. A second audit of practice was performed in 2011 by reviewing medical records for the last 30 patients hospitalized in our ICU for UGIB using the same methodology. Results: Most of the quality criterions were improved between 2007 and 2011. Concerning preendoscopy management, appropriate fluid resuscitation (76.7% vs. 100%; p<0.01), blood transfusion (26.0% vs. 100%; p=0.02), preendoscopic PPI bolus (16.7% vs.73.3% (p<0.0001)), preendoscopic PPI IV therapy (8.3% vs. 93%; p<0.0001), endoscopy performed within 24 hours (82.4% vs. 100%; p<0.0001), appropriate endoscopic treatment of only lesions at high recurrence risk (respectively 79.4% vs. 100%; p<0.001/ 78.0% vs 88.0%; NS), Helicobacter pylori screening (32.3% vs. 100%; p<0.00001). This better enforcement of the references showed a non significant trend toward improved outcomes: thirty days mortality has fall from 14.6% to 6.7%, and embolisation rate from 8.8% to 3.3%. The recurrence rate after a first endoscopic treatment was similar (10% vs. 8.8%). Baseline patients and endoscopic lesion characteristics did not differ between 2007 and 2011. Conclusions: This study show that an audit methodology improved the quality ofcare and the prognosis of upper gastrointestinal hemorrhage from peptic ulcer in our hepatogastroenterology unit at Dijon university hospital.

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A199 UTILITY OF A DEDICATED WEEKEND ENDOSCOPY CLINIC IN REDUCING URGENT ENDOSCOPIES AND THE BURDEN OF INPATIENT CARE G. Sekhon, J. Gregor, N. Chande, P. Adams Department of Medicine, University of Western Ontario, London, ON, Canada. Aims: Pilot study to determine the utility of a dedicated after-hours weekend endoscopy clinic in expediting patient care at two tertiary care hospitals in London, Ontario. Methods: Prospective study of patients requiring endoscopic assessment. A Sunday morning endoscopy clinic was run for 11 weeks between January and March 2011. Patients assessed in the clinic included any patients referred through the emergency department or Gastroenterology clinics whose admission could be avoided by having endoscopy results, as well as admitted inpatients awaiting endoscopy where inpatient length of stay could be shortened or other interventions could be facilitated by having early endoscopy. Data collected included age, sex, comorbid diagnoses, reception of blood transfusions, reason for admission and diagnosis, reason for endoscopy and endoscopic diagnosis, number of admissions avoided, number of inpatient days avoided, number of interventions or assessments (such as anticoagulation, cardiac investigations, or oncologic assessments), and number of out of hours urgent endoscopies performed. ASA classification was determined for each patient. Results: 51 patients were assessed in the clinic (26 males, 25 females). 37 patients were inpatients (36 patients on wards, 1 patient in Cardiac Care Unit). 5 patients were in the Emergency Department on the day of the procedure. 9 patients were seen as outpatients, referred via the Emergency Department or Gastroenterology Clinics, whose admissions were avoided. The average age was 62 +/- 21 years with the average ASA score of 2.3 +/- 0.9. There were 36 esophagogastroduodenoscopies (EGD's) and 25 colonoscopies performed. The most common reasons for endoscopic assessment included gastrointestinal bleeding, anemia and abdominal pain. The most common EGD finding was peptic ulcer disease (8 patients) and normal (7 patients) while the most common finding of colonoscopies was normal (9 patients). There were on average 1.1 +/- 0.7 admissions avoided per weekend. 2.0 +/- 1.5 inpatient days were avoided per weekend and 1.1 +/- 1.0 interventions were facilitated per weekend. The number of out of hours urgent endoscopies performed on weekends during the study period was 26 (2.4 +/- 2.5 per weekend), whereas in the 11 weeks after the study period, this number rose to 44 (4.0 +/- 3.9 per weekend). Conclusions: A dedicated weekend endoscopy clinic successfully serves to reduce the number of inpatient admissions, inpatient length of stay and also serves to reduce the number of out of hours urgent endoscopies needed. This has implications on the structure of provision of endoscopy services in expediting patient care and in reducing the burden of inpatient admissions in a busy health-care system.

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A200 HEMOSPRAY APPLICATION FOR COLONIC POST-POLYPECTOMY BLEEDING: CASE REPORT SOULELLIS CA, BARKUN AN, CARPENTIER S DIVISION OF GASTROENTEROLOGY MONTREAL GENERAL HOSPITAL MONTREAL, QUEBEC, CANADA C. Soulellis, A. Barkun, S. Carpentier Montreal General Hospital, McGill University Health Center, Montreal, QC, Canada. Aims: Lower gastrointestinal (GI) bleeding comprises 20% of all acute GI bleeds. Endoscopy remains a cornerstone of diagnosis and therapy in lower bleeds, especially for treatable lesions such as angiodysplasia, dieulafoy lesions, and post-polypectomy bleeding. Traditionally, therapeutic modalities have been divided into thermal applications, injection, and mechanical devices such as clips. Recently, topical hemostatic sealant that adheres to blood and tissue (known as Hemospray™) has been introduced as a novel therapeutic device. Recent pilot study results demonstrate both efficacy and safety of this powder in upper GI tract bleeding. Our center reports the first two worldwide cases of Hemospray™ application in the colon for post-polypectomy bleeding. Methods: This is a retrospective chart review of the first two cases of Hemospray™ use in the lower gastrointestinal tract at the Montreal General Hospital. Results: Our first patient, a 79 year old man with an unprovoked deep venous thrombosis, underwent a colonoscopy as part of a workup to exclude malignancy. A sessile 3 cm cecal polyp was seen and removed piecemeal. The patient was reanticoagulated and did well until 48 hours later, when he developed blood per rectum and hemodynamic instability. A repeat colonoscopy was performed, demonstrating a large clot with underlying oozing from the polypectomy base. Approximately 20 grams of Hemospray™ was applied to coat the site after clot removal and hemostasis was achieved with no further complications. The second patient was a 56 year old man who underwent a screening colonoscopy. A sessile 1 cm sigmoid polyp was removed by snare cautery. There was no evidence of immediate bleeding, but the patient returned to the Emergency Room, hemodynamically stable, with fresh blood per rectum 8 hours later. A repeat colonoscopy was performed the next day and the polypectomy site was found to be actively bleeding. Both mechanical and thermal therapies were applied with no success. A 20 gram application of Hemospray™ was attempted as a last resort - hemostasis was achieved and the patient was discharged home within 48 hours. Neither patient experienced any side effects of the therapy or recurrent bleed by the followup duration of 72 hours. Conclusions: At the time of writing, Hemospray™ has been studied in one prospective human trial on upper GI bleeding, demonstrating a favourable efficacy and side effect profile. We present the first two worldwide cases of colonic Hemospray™ application, suggesting this novel therapy is feasible, safe, and effective for post-polypectomy bleeding. More studies are required to better determine the role of Hemospray™ in colonic, and other, GI applications.

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A201 SCOPEGUIDE-ASSISTED COLONOSCOPY VS. CONVENTIONAL COLONOSCOPY FOR IMPROVED ENDOSCOPIC PERFORMANCE AND ENHANCED PATIENT EXPERIENCE C. Teshima, S. Zepeda-Gomez, G. Sandha Division of Gastroenterology, University of Alberta, Edmonton, AB, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A202 ABNORMALITIES OF HEPATIC BIOCHEMISTRY IN PEDIATRIC INFLAMMATORY BOWEL DISEASE PATIENTS. A. Foster, A. Glesby, R. Schreiber, K. Jacobson, O. Guttman British Columbia Children's Hospital, Vancouver, BC, Canada. Aims: When abnormalities of hepatic biochemistry are seen in inflammatory bowel disease (IBD) patients, their clinical significance is often unclear. This study aimed to evaluate the incidence of abnormal hepatic biochemistry and chronic liver disease in a large database of pediatric IBD patients. Methods: A retrospective chart review was performed of all IBD patients diagnosed at BC Children’s Hospital between January 2005 and December 2010. Data collected included: age, gender, IBD subtype, disease location, medications, liver disease diagnosis, liver biochemistry and time from IBD diagnosis to abnormal liver biochemistry. Results: The total patient population consisted of 415 patients, of whom 266 patients (64%) had Crohn Disease, 104 patients (25%) had Ulcerative Colitis, and 45 patients (11%) had Indeterminate IBD. 197 patients (47%) were found to have elevations in either AST, ALT or GGT. At the time of first elevated liver biochemistry, 60 patients (30%) were receiving azathioprine, 12 patients (6%) were on infliximab, 8 patients (4%) were on methotrexate, 5 patients (2.5%) were on 6-mercaptopurine and 1 patient (0.5%) was on adalimumab. Nine patients had chronic liver disease (7 with primary sclerosing cholangitis, 1 with autoimmune sclerosing cholangitis and 1 with autoimmune hepatitis). Of these, all had abnormalities in liver biochemistry prior to, or within two months of their IBD diagnosis. Diagnosis of chronic liver disease was made in 5 of the 9 patients prior to their IBD diagnosis. Conclusions: Elevated liver biochemistry was found in almost half of our pediatric patients with IBD. This is a higher rate than previously described in earlier series. Use of potentially hepatotoxic medications may be a contributing factor in these biochemical abnormalities.

A203 MYCOBACTERIUM COLOMBIENSE INFECTION DIAGNOSED AT COLONOSCOPY IN A PATIENT TREATED WITH INFLIXIMAB S. Carpentier1, J. McNabb-Baltar2, A. Bitton3 1. McGill University, Montreal, QC, Canada; 2. McGill University, Montreal, QC, Canada; 3. McGill University, Montreal, QC, Canada. Aims: To describe the pathology, endoscopic appearance, and clinical course of a patient found to have colonic Mycobacterium colombiense infection Methods: Clinical case discussion and literature review Results: We report the case of a 70 year-old, initially asymptomatic woman with a longstanding history of ulcerative colitis (UC) treated with infliximab. On routine surveillance colonoscopy, several areas of whitish mucosal nodularity were noted. Biopsies of these lesions showed numerous macrophages expanding the lamina propria, with the presence of acid fast bacilli confirmed by Ziehl-Neelsen stain. Cultures of these specimens revealed Mycobacterium colombiense, and further work-up of this patient demonstrated disseminated infection with positive stool, urine, and blood cultures. On diagnosis of disseminated mycobacterial infection, the patient’s scheduled infliximab was held, and antibiotic treatment with a combination of clarithromycin, rifabutin, and ethambutol was begun. One day following initiation of treatment, the patient developed malaise, shaking chills, night sweats, nausea, and upper abdominal pain. Upon evaluation, the patient was diagnosed with immune reconstitution inflammatory syndrome (IRIS). Antibiotics were continued, and high dose prednisone therapy was initiated with rapid resolution of symptoms. Conclusions: To our knowledge and following review of existing literature, this case represents the first description of Mycobacterium colombiense infection in the gastrointestinal tract. We observe Mycobacterium colombiense to be similar in endoscopic appearance to other members of the Mycobacterium avium complex. We further present a clinical course complicated by IRIS following cessation of infliximab and initiation of anti-mycobacterial therapy. This phenomenon has been previously described in association with other mycobacterial species. (i.e M. tuberculosis) Given that the genomic sequence of M. colombiense has only recently been characterized, there is much to be learned about the pathogenesis and clinical manifestations of this novel mycobacterial strain.

Area of whitish mucosal nodularity in rectum. Biopsy confirmed presence of M. colombiense.

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A204 AN AUDIT OF QUALITY INDICATORS IN COLONOSCOPY REPORTS USING AN ELECTRONIC REPORTING SYSTEM WITH MANDATORY DATA FIELDS. DONALD MACINTOSH MD MSC FRCPC, ELLEN MACDONALD, AND STEVEN GRUCHY MD MSC FRCPC, DIVISION OF GASTROENTEROLOGY, DALHOUSIE UNIVERSITY, HALIFAX, NS. D. MacIntosh, E. MacDonald, S. Gruchy Dalhousie University, Halifax, NS, Canada. Aims: Audits of the quality of colonoscopy reports at our institution have previously demonstrated frequent deficiencies of essential information such as documentation of cecal intubation and withdrawal time1. In January 2011, an Electronic Reporting System (ERS) was introduced in the Capital District Health Authority in Halifax. All endoscopists have been using the Clinical Outcomes Research Initiative (CORI) template to generate endoscopy reports. Before changing to an ERS, a number of modifications were made to the original version of CORI making several additional reporting fields mandatory. These mandatory fields require completion before endoscopy reports can be signed off. Methods: We performed a quality audit of 200 randomly selected colonoscopy reports. Quality indicators such as procedure indication, documentation of consent, bowel preparation used, quality of bowel preparation, cecal landmark documentation, reason for incomplete examination, withdrawal time, procedure tolerability, polyp detection and retrieval as well as documentation of planned follow up were extracted into standardized work sheets. The results were compiled and analyzed using SPSS. Results: All mandatory data fields such as documentation of consent, quality of bowel preparation, cecal landmark documentation, withdrawal time, polyp detection, and procedure tolerability were completed 100% of the time. Non-mandatory reporting fields continued to be underreported including type of bowel preparation used (56%), retrieval of resected polyps (14%), and follow-up plan (16%). Conclusions: All mandatory data fields such as documentation of consent, quality of bowel preparation, cecal landmark documentation, withdrawal time, polyp detection, and procedure tolerability were completed 100% of the time. Non-mandatory reporting fields continued to be underreported including type of bowel preparation used (56%), retrieval of resected polyps (14%), and follow-up plan (16%). 1Berger R, Gruchy S, Crawford K and MacIntosh D. Quality Indicators in Colonoscopy: Experience at a Canadian Academic Centre Before and After an Educational Intervention. Can J Gastroenterol 2009; 23 Suppl A: 94A.

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A205 AN ANALYSIS OF REPORTING ACCURACY OF ENDOSCOPIC DATABASES T. Rahman, L. Win, P. Moayyedi, D. Armstrong, K. Khan McMaster University, Hamilton, ON, Canada. Aims: Computerized reporting systems that generate standardized endoscopy reports are available to all centres. Most endoscopy quality research uses prompted data entered into specified fields but this data can be manually changed in the proofing stage of report generation potentially compromising accuracy of reporting. At our centre, data are entered and the report finalised using endoPRO (Pentax Medical Company, Montvale NJ) before it is electronically sent to our electronic health record (Meditech, Westwood, MA). We aim to compare our endoscopy database fields (endoPRO) to the final report and determine the effect of editing in capturing data related to colonoscopic procedures. Methods: In a retrospective analysis, we compared data retrieved from endoPRO to the final colonoscopy reports from Hamilton Health Sciences(HHS). The data included demographics, indications for procedures, bowel prep quality, findings, extent of exam, and recommendations. Colonoscopy reports retrieved from Meditech were manually compared to endoPRO fields with discrepancies, changes or missing information pertaining to key quality indicators for colonoscopies recorded. Results: In total, 1843 colonoscopy procedures were done at HHS from January to March 2010, and reports for 592 colonoscopies, randomly selected, were analyzed for this study. Findings include: Indication - 34 cases (5.7%) had missing indications fields when compared to the report; Assistants present during colonoscopy - 94 cases (15.9%) had discrepancy between the assistant fields when compared to the report; Extent of colonoscopy and verification technique- all data was unchanged; Quality of bowel preparation - 35 cases (5.9%) where data disagreed within the report. (Prep quality is prompted twice in the structured report); Findings & impressions - 38 cases (6.4%) described findings on the final colonoscopy report that were not captured by endoPRO retrieved data. This included polyps, inflammation, diverticulosis and haemorrhoids. Conclusions: Our study shows that some variability exists between data found in patients' final colonoscopy reports and data retrieved from the endoscopy databases. Most concerning is that in 6.4% of reports, findings are not captured in the retrieved data. Structured endoscopy reporting and the use of databases facilitate quality assurance but editing of procedure reports after structured data entry compromises accuracy of the data in key quality measures. Informing physicians how to properly enter fields, modifying the software interface to reduce need for comments, and recording changes affecting the data fields are solutions worth exploring to mitigate the discrepancies identified in this study. Inaccurate or incomplete data recording will compromise the enhancements in quality assurance that would accrue otherwise from regular audit processes.

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A206 RABEPRAZOLE INDUCED ACUTE INTERSTITIAL NEPHRITIS A. Merali, F. Tse Department of Gastroenterology- McMaster University, Hamilton, ON, Canada. Aims: Proton pump inhibitors are commonly prescribed medications in Canada. Although well tolerated, there have been case reports and case series reporting acute interstitial nephritis (AIN) and acute renal failure caused (ARF) by these medications. We report only the fourth documented case of rabeprazole induced AIN. Methods: A 53 year old female with a baseline creatinine of 72umol/L and no history of underlying renal disease presented with a two week history of fatigue, chills, frontal headaches, new onset hypertension and acute renal failure. Her urinalysis showed trace blood, 1+ protein and the presence of eosinophils. Serum creatinine was 471umol/L at admission. Renal biopsy demonstrated marked interstitial infiltrates, interstitial edema, tubulitis, severe tubular damage and tubular casts in keeping with acute tubulo-interstitial nephritis. A significant number of eosinophils were noted suggestive of an allergic drug reaction A medication review revealed that 12 weeks prior to presentation the patient had been started on Rabeprazole for reflux symptoms. A clinical and pathological diagnosis of acute interstitial nephritis secondary to Rabeprazole was made. The medication was stopped and a short course of prednisone was given. Serial serum creatinine measurements demonstrated rapidly improving renal function. The reaction was submitted to the Canada Vigilance Program for adverse drug reporting. A literature review was conducted to examine the prevelance and presentation of proton pump induced AIN Results: A recent systematic review found 64 reported cases of PPI-associated interstitial nephritis with 58 being classified as either certain, probable or possible using the WHO classification. There have been 3 reported cases of rabeprazole induced AIN and one case reported to the Adverse drug database in Canada. Presentation of nephritis occurs on average 13 weeks after starting PPI therapy but can range from 2-52 weeks. The presentation of PPI induced AIN is non specific. Common presenting symptoms include fatigue (44%), fever (39%), nausea and vomiting(30%) and malaise (23%). The most common urine analysis abnormalities are pyuria (60-70%), hematuria(50%), protienuria (60%) and eosinophiluria (60%). The classic triad of fever, rash and eosinophila is rare and has only been reported in one case. Renal recovery is excellent following withdrawal of the medication and the majority of patients recovery renal function to baseline within 10 months time. Conclusions: Proton pump inhibitor induced AIN is a rare idiosyncratic reaction that is difficult to predict. A review of the literature suggests that this is a class effect but that the prevalence is low and should not prevent clinicians from prescribing the medication.

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A207 DOCUMENTATION OF DISCLOSURE OF POTENTIAL SIDE EFFECTS OF STEROID THERAPY PRIOR TO INITIATION IN HOSPITALIZED PATIENTS Z. Karim1, S. Alkhowaiter1, E. Yoshida2 1. UBC, dept of Gastroenterology, Vancouver, BC, Canada; 2. Vancouver General Hospital, dept of Gastroenterology, Vancouver, BC, Canada. Aims: To examine documentation of disclosure of potential side effects of steroid therapy prior to initiation in hospitalized patients. Methods: A retrospective chart review was performed at both Vancouver General hospital (VGH) and St. Paul’s hospital (SPH), two tertiary care hospitals in Vancouver, BC. We included charts from patients admitted to the GI service with the diagnosis of “inflammatory bowel disease,” or “ulcerative colitis,” or “crohn’s disease.” We excluded patients who were on steroids at time of admission. Charts were reviewed from September 1st to October 31st, 2010 at both sites. Fourteen patients at SPH and 22 patients at VGH were included. Results: A total of 36 patients were included in the study. Thirteen patients had crohn’s disease and 23 patients with ulcerative colitis. Eight patients were started on oral steroids and 28 patients on IV steroids. At VGH, we found 2 out of 22 patient charts reviewed had documentation of discussion with patients about the side effects of steroid therapy. In both of these patients, the risks of avascular necrosis and osteoporosis were documented. The cosmetic, mood, and infectious risks were only documented in a single case. At SPH, none of the fourteen charts had any such documentation prior to starting the patients on steroids. Conclusions: Gastroenterologists are at risk of being sued for not disclosing the risks of steroid therapy when starting these drugs in patients with inflammatory bowel disease (IBD). There have been multiple lawsuits against Canadian Gastroenterologists from patients who have claimed they were not adequately informed of these side effects. A number of these lawsuits have resulted in awards in the order of $1 million or more. The major factor in finding liability against the physician in most of these cases was a failure to demonstrate through documentation that the patient was adequately informed of the potential side effects of therapy. We found inadequate documentation of discussion of side effects of steroid therapy prior to initiation in patients hospitalized under the GI service, with only 2 out of 36 patients (5.5%) with such documentation. These findings and the history of successful litigation brought against gastroenterologists highlights that the informed consent process, documentation, and close monitoring of patients are critical to avoid potential litigation associated with steroid use.

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A208 DOCETAXEL-RELATED DRUG INDUCED COLITIS R. Martin, C. Struthers, M. Curley Dalhousie University, HALIFAX, NS, Canada. Aims: Drug-related diarrhea and colitis have been described in several chemotherapy regimens. There have been several case reports describing docetaxel-related colitis. Methods: We present a case of colitis in a 58-year-old woman receiving docetaxel after a modified radical left mastectomy for high-grade multifocal breast cancer. We include the history, clinical course, colonoscopy results and pathological examination of this case. Results: Our patient was diagnosed with a T2, N1 high grade, multifocal ductal carcinoma of the right breast. It was determined to be a ER, PR, HER-2/Neu positive cancer. There was no evidence of metastatic disease. She under went modified radical mastectomy. She was subsequently treated with 5-FU, epirubicin and cyclophosphomide for three cycles. This was followed by three cycles of docetaxel, and finally four cycles of trastuzumab and regional radiation therapy. She developed loose stools, arthalgias and myalgias after beginning the first cycle of docetaxel. A colonoscopy was performed and pancolitis was found. Viral and bacterial infections were ruled out. Histologically the findings were suspicious for drug-induced colitis. There were no changes made in her chemotherapy. Follow-up sigmoidoscopy and biopsy revealed significant endoscopic healing and moderate microscopic healing while remaining on the trastuzumab. Conclusions: This case illustrates a potential side effect of doxetacel. The demonstrated healing, both microscopically and macroscopically, are suggestive that the offending agent in this patient’s colitis is docetaxel and not trastuzumab. There have only been 10 other case series/reports in publications that have suggested this association with docetaxel. We have collected excellent endoscopic and histologic photographic documentation

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A209 THE ACCURACY OF CT SCAN FINDINGS IN THE SETTING OF ACUTE DIVERTICULITIS; IS A FOLLOW UP COLONOSCOPY NEEDED? N. Chan, J. Brown, B. Bressler University of British Columbia, Vancouver, BC, Canada. Aims: Current practice dictates that patients who have been diagnosed clinically and radiologically with acute diverticulitis are to undergo follow up colonoscopy after their attack has resolved. The rationale is that acute diverticulitis on CT scan may mimic other conditions, of most concern, colon cancer. However, as CT technology has advanced, it may now be able to more accurately delineate acute diverticulitis from underlying malignancy and thus remove the need for follow up colonoscopy. This study aimed to determine whether or not patients with acute diverticulitis diagnosed on CT scan will require follow up colonoscopy to rule out malignancy. Methods: A retrospective chart review of all patients at St. Paul’s Hospital, Vancouver, BC, Canada who were diagnosed with acute diverticulitis on CT scan from December 2005 to December 2010 was performed. Patients with previous history of diverticulitis or colon cancer were excluded. Once patients were identified, their colonoscopy reports were reviewed for findings and the subsequent findings were compared to the results of the CT scans. Results: Three hundred and one patients had clinical and radiological presentation of acute diverticulitis. One hundread and sixy eight had a follow up colonoscopy. The average age of those who had a colonoscopy was 57 years old, and ninety-four were male. The average length of time from the CT scan to colonoscopy was 3 months and 3 days. Six patients (3.5%) had colonic malignancies identified on their follow up colonoscopies. Of those 6 patients with cancer 5 of them were found to have the cancer at the site of the diverticulitis identified on CT scan. Conclusions: Despite the improvements in CT scan technology with regards to image resolution, follow up colonoscopy is still necessary to rule out colonic malignancy in cases of acute diverticulitis.

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A210 ECTOPIC GASTRIC MUCOSA IN THE RECTUM: A POTENTIAL CAUSE OF IBS-LIKE SYMPTOMS A. Kadhim University of Ottawa, Ottawa, ON, Canada. Aims: Ectopic gastric mucosa in the rectum is a very rare entity. In fact, there are about 48 published cases world-wide. There are no current guidelines regarding medical treatment, surveillance, and endoscopic resection. Methods: We report a rare case of 36 years old female who presented with bloating, abdominal pain that was relieved with defecation, and frequent changes in her stool pattern. The patient’s blood work showed iron deficiency anemia and subsequently had an upper endoscopy to look for Celiac disease which was negative. Results: The patient underwent a colonoscopy which identified rectal areas that looked flat, erythematous, and sessile. The pathology report of the rectal lesion confirmed that the biopsy was gastric mucosa with features mild chronic inflammation, negative for H. Pylori, and negative for Celiac disease and dysplasia. The patient with placed on a trial of PPI therapy and showed moderate response. Conclusions: This case reports three important findings; first ectopic gastric mucosa is a rare entity that should be investigated in patients undergoing endoscopy. Second, patients with history of irritable bowel syndrome-like symptoms undergoing endoscopic investigation need to be considered for the possibility of ectopic gastric mucosa. Third, clear guidelines regarding treatment and surveillance need to be established.

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A211 THE SAFETY AND EFFICACY OF GASTRIC FUNDAL VARICEAL GLUING M. Mosli, B. Aljudaibi, P. Marotta UWO-LHSC, London, ON, Canada. Aims: We report on our prospectively collected case series of patients referred for the management of GV to examine the safety and efficacy of endoscopic gastric fundal variceal gluing using periodic injections of cyoacronate in preventing GV rebleeding and preventing subsequent hospitalizations. Methods: Twenty-eight patients with documented GV secondary to portal hypertension were treated with GV glue injection; the average follow up was 29 months. The rate of success in eradicating GV endoscopically was evaluated and the rate of rebleeding was calculated. Results: 89 sessions of cyoacronate injections were carried out for 28 patients (average 3.2 sessions/patient), a total of 120 injections were applied (average 4.3/patient, 1.3/session). 75% of patients were free of rebleeding once 3 sessions of glue injection were completed. 4 patients (14%) had GV rebleeding while being scheduled for additional future sessions. 9 (32%) patients had successful eradication of GV, 4 of which were documented by endoscopic ultrasound (EUS) and 5 by direct endoscopic assessment. 15 patients had documented residual GV by either EUS (12, 80%) or direct endoscopic assessment (3, 20%). One patient had recurrence of GV bleeding after documented eradication and one patient failed to respond to gluing and subsequently went on to have a systemic shunt procedure (TIPS). Two patients needed gluing done after failing TIPS. No acute (specifically, no bleeding, fever, endoscopy related complications or glue embolic phenomena) or long-term complications of this procedure were reported in any of these cases during the time of follow-up. Conclusions: Cyoacrylate injection of Gastric Varices is a safe and successful therapeutic intervention. The rate/risk of bleeding from GV is low after adequate numbers of sessions (3) have been performed. We suggest that a minimum of 3 endoscopic sessions be completed before evaluating for complete eradication. This treatment will reduce bleeding, rebleeding and likely costs and potential mortality associated with GV bleeding.

Epidemiology and the Burden of Illness

A212 COMPARING THE INCIDENCE OF PERFORATED AND NON-PERFORATED APPENDICITIS: A VALIDATION AND TEMPORAL TREND STUDY H. Kareemi, S. Coward, M. Proulx, D. Tanyingoh, S. Quan, A. Frolkis, E. Dixon, R. Myers, A. MacLean, S. Brar, G. Kaplan Universit of Calgary, Calgary, AB, Canada. Aims: Studies using administrative databases have described a difference in the rates of perforated and non-perforated appendicitis; however, the validity of diagnostic codes stratified by type of appendicitis is not known. We compared pathologically proven appendicitis cases to an administrative database and determined the incidence rates of perforated versus non-perforated appendicitis. Methods: A hospital discharge abstract database identified patients admitted with appendicitis (n=15,458) from 2000-2008 using: 1) ICD-9-CM or ICD-10-CA diagnostic code for non-perforated (ICD-9: 540.9; ICD-10: K35.1, K35.9) or perforated appendicitis (ICD-9: 540.0, 540.1; ICD-10: K35.0); and 2) a procedural code for appendectomy (ICD-9: 47.0; CCI: 1.NV.89.LA, 1.NV.89.DA). Sensitivity (Se), Specificity (Sp), Positive Predictive Value (PPV) and Negative Predictive Value (NPV) with 95% confidence intervals (CI) were calculated by comparing administrative codes to pathology reports. Incidence rates for pathology proven perforated and non-perforated appendicitis cases were calculated. Temporal trend analyses were assessed using a generalized linear model that assumed a Poisson distribution. Results: Se, Sp, PPV, and NPV of appendicitis codes were 94.4% [93.9-94.9%], 64.3% [63.1-65.5%], 81.3% [80.5-82.0%], and 87.5% [86.5-88.5%], respectively. For perforated appendicitis Se, Sp, PPV, and NPV were 91.4% [89.9-92.8%], 75.9% [75.0-76.9%], 42.1% [40.4-43.8%], and 97.9% [97.5-98.2%], respectively. The incidence rates of pathology proven appendicitis varied from 80.7 to 106.3 per 100,000 person-years in 2000 and 2008, respectively (Figure 1). Incidence rates of non-perforated appendicitis significantly increased by 3.9% per year (95% CI: 2.2%, 5.6%). In contrast, incidence rates for perforated appendicitis were stable at 0.7% per year (95% CI: -3.2%, 4.7%). Conclusions: Codes in administrative databases accurately identify appendicitis patients, but cannot discriminate between perforated and non-perforated appendicitis. A pathology proven appendicitis cohort suggests that the incidence of non-perforated appendicitis is increasing, whereas perforated appendicitis is stable.

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A213 NATIONAL DIFFERENCES IN PERCEPTIONS OF ULCERATIVE COLITIS: AN INTERNATIONAL SURVEY OF PATIENTS AND HEALTHCARE PROFESSIONALS D. Solomon1, D. Holley2, M. Buch2, N. Pym3, K. Paridaens4 1. Shire Development Inc., Wayne, PA; 2. GfK Healthcare, London, United Kingdom; 3. Shire Pharmaceuticals Inc., Basingstoke, United Kingdom; 4. Shire AG, Eysins, Switzerland. Aims: To evaluate differences among countries in perceptions of ulcerative colitis (UC), an international survey was conducted in patients with chronic UC and healthcare professionals (HCPs) who treat UC patients. Methods: Participants in Canada, France, Germany, Ireland, Spain, and the United Kingdom were recruited through patient and HCP access panels, or through custom “phone-to-Web” recruitment. Patients and HCPs did not have to be directly linked. Patient organizations and advocacy groups were not used for recruitment. A total of 775 patients and 475 physicians participated in the survey. Results: Patients reported experiencing a mean number of flares ranging from 2.5 (Ireland) to 8.0 (France) in the last 12 months. Ireland had the highest percentage of patients who rated their UC as severe (36%) compared with other countries (4%-23%). Conversely, Spain had the fewest patients who rated their UC as severe (4%) and the most patients who rated their UC as mild (45%). Consistent with patient self-reporting, Spanish physicians reported the lowest proportion of severe UC cases (9%) and the highest proportion of mild cases (63%) among countries. There were national differences in patient definitions of remission, with significantly more Spanish patients stating that remission meant experiencing no symptoms (65%; P <0.05), compared with a range of 26% (Ireland) to 52% (France) in other countries. Across all countries, patients (45%-69%) were more likely than physicians (28%-45%) to report that UC negatively affected patients’ quality of life (QoL), with the greatest discrepancy observed in France (69% and 34%, respectively). Spain had the highest percentage of patients who reported being fully adherent with 5-aminosalicylic acid (5-ASA) treatment (91%) compared with other countries (50%-73%). However, Spanish patients were also most likely to be “not very” or “not at all” satisfied with 5-ASA treatment (42%) compared with patients from other countries (2%-27%). Irish patients were significantly less likely than patients from other countries to arrange regular visits to see their HCP (14%; P <0.05) and were significantly more likely to often keep information from their physician (12%; P <0.05). Conclusions: These findings show significant national differences in patients’ perceptions of, and attitudes toward, UC. Spanish patients had the highest expectations for control of UC and the highest treatment adherence rates, and Irish patients were least likely to regularly visit and be open with their HCP.

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A214 “THE EPIDEMIOLOGY OF COLORECTAL CANCER IN THE KINGDOM OF SAUDI ARABIA; A RETROSPECTIVE ANALYSIS OF DATA FROM THE NATIONAL SAUDI CANCER REGISTRY (SCR) FROM 2001-2006” M. Mosli, M. Alahwal KAAU, JEDDAH, Saudi Arabia. Aims: Colorectal cancer (CRC) has become one of the commonest malignancies and major health concerns worldwide. Its incidence has decreased dramatically worldwide over the past decade due to implemented screening programs, but there is an observed variation in the age of diagnosis between different parts of the world. The aim of this study is to characterize the epidemiology of CRC in the Saudi population and to examine the average age of Saudi patients at the time of diagnosis and compare it to other countries. Methods: We performed a retrospective analysis of data provided by the national Saudi Cancer Registry (SCR), which recorded all cases of CRC amongst Saudi citizens in all provinces between 2001 and 2006. Results: A total of 4201 cases of CRC were registered in the national SCR between 2001 and 2006 with a noticeable increase in incidence rates. The mean age of patients at the time of diagnosis was calculated to be 58 with the majority of patients being older than age 45 (77%). There was a slight predominance of newly diagnosed cases in males (54%). The left side of the colon harbored most cases of CRC (68%) with the most common location being the rectum (28%) followed by the sigmoid colon (19%). A total of 977 (23%) patients presented with localized disease and 1018 (24%) patients had distant metastasis at the time of diagnosis, the rest of the patients had various degrees of regional extension or an unknown stage. Patients younger than age 45 did not show more advanced disease at the time of diagnosis compared to others. The most common pathological variant reported was adenocarcinoma (73%) with grade 2 (moderately differentiated) being the most common grade among all variants (61%). Conclusions: There is a significant increase in the incidence of CRC amongst Saudis with a lower average age at the time of diagnosis compared to other countries. Further research is needed to identify the cause of these observations but this may be a reason to implement more strict guidelines for colon cancer screening and to consider starting them a younger age.

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A215 CONSULTING DR GOOGLE: INFORMATION USE BY OUTPATIENTS UNDERGOING ELECTIVE COLONOSCOPY J. Silvester, J. Walker, L. Graff, D. Duerksen University of Manitoba, Winnipeg, MB, Canada. Aims: 1. To determine common and preferred sources of medical health information among patients undergoing diagnostic colonoscopy. 2. To determine how use of internet health information influences the behaviour of individuals with undiagnosed gastrointestinal symptoms. Methods: Consecutive adults presenting for elective outpatient diagnostic colonoscopy at a tertiary care hospital between July and September 2011 were invited to complete a brief survey prior to their procedure. Those with language difficulties or undergoing concurrent upper endoscopy or interval endoscopy for a previously diagnosed condition (e.g., polyps) were ineligible. The survey contained items pertaining to sources of health information, experiences using online health information, internet use characteristics and demographic questions. Results: 195 patients were screened; 90% of the 123 eligible completed the questionnaire. Most (58%) procedures were for colon cancer screening, with the remainder for symptoms. The majority of respondents (76%) were internet users; however, only 40% used the internet to research their possible medical condition. The most common sources of information were doctors (80%) and family and friends (50%). Over 90% of internet users started with a Google search and most (55%) spent < 30 minutes, with only 5% searching for > 2 hours. Nevertheless, 55% were motivated to see their doctor as a result of their internet search, 39% asked for a referral and 23% requested a diagnostic test. Most internet users never or rarely assess the quality of the information they view. Those who used the internet reported being less confused (39%), more worried (40%), more empowered (38%) and more interested in their own health (55%) following their online information search. Of those who did not use the internet to research their condition, 37% did not feel any need, and 22% relied on other sources (e.g., family doctor, family) or did not think to use the internet. A further 9% did not have internet access while 9% reported that they do not trust health information on the internet. Conclusions: Although the internet widely available, most patients undergoing colonoscopy learn about their possible medical condition from their physicians, family or friends. The significant minority who use the internet for health questions rate the experience positively. However, they typically only briefly research their health questions and do not evaluate the quality of information presented, yet they act upon the information by increasing their use of health care resources. Physician-guided internet use identifying reputable websites may be a useful way to enhance patient knowledge and education, and requires further investigation.

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A216 USE OF INTERNET RESOURCES BY PATIENTS AWAITING GASTROENTEROLOGY CONSULTATION A. Teriaky, V. Tangri, N. Chande The University of Western Ontario and London Health Sciences Centre, London, ON, Canada. Aims: The purpose of this study is to better comprehend the medical information on the internet sought by outpatients awaiting gastroenterology consultation and whether wait times affect internet use. Methods: A cross-sectional survey of 87 gastroenterology outpatients awaiting consultation was performed at a tertiary care centre. Results: Fifty-two (60%) patients sought the internet for medical information. The mean age of patients using the internet was 41 years compared to those not using the internet which was 60 years (p<0.0001). The internet was used by 71% of females and 47% of males (p<0.05). The web was sought by 33% with less than secondary school, 59% with secondary school, 66% with a college or undergraduate degree, and 100% with a postgraduate degree (p=0.14). The mean consultation wait time for patients that used the internet was 158 days and 147 days for patients that did not use the internet (p=0.60). Websites searched were medical websites in 71%, through search engines in 63%, institutional and society websites in 19%, blogs in 6%, and pharmaceutical websites in 6%. Medical information sought on the internet was symptoms and diagnosis in 85%, treatment in 62%, disease causes in 62%, coping in 27%, and prognosis in 19%. The reason for internet use was wait times in 36% and at the recommendation of a physician in 10%. Patients that used the internet believed they had an underlying disease in 87% while patients not using the internet felt so in 46% (p=0.0001). Conclusions: Younger patients and females were more likely to use the internet. Wait times did not affect internet use. The internet is a powerful patient resource, but further physician guidance is required to assist patients in identifying reliable resources.

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Poster of Distinction A217 THE INCIDENCE OF PRIMARY BILIARY CIRRHOSIS: A SYSTEMATIC REVIEW AND META-ANALYSIS M. Mathivanan, F. Ladak, M. Antón, G. Kaplan, R. Myers Liver Unit, Division of Gastroenterology and Hepatology, Department of Medicine, University of Calgary, Calgary, AB, Canada. Aims: Studies examining the epidemiology of primary biliary cirrhosis (PBC) are important for quantifying the burden of disease and may enhance our understanding of its pathogenesis. Our objective was to conduct a systematic review of incidence studies in PBC and to investigate possible geographic variations and temporal trends in the epidemiology of this condition. Methods: A systematic literature search of MEDLINE (1948-2011) and EMBASE (1980-2011) was conducted to identify population-based studies describing the incidence of PBC. Two independent reviewers confirmed study eligibility and extracted relevant data. The overall incidence rate (IR) of PBC was summarized and heterogeneity was assessed using the Q statistic. Stratified analyses and meta-regression were performed to explore heterogeneity between studies potentially due to the region of study (North America vs. Europe) and period of data collection (1970s, 1980s, and 1990s/2000s). Results: The literature search retrieved 4431 potentially eligible citations; 14 population-based studies met the inclusion criteria. These studies included data on 1,576 patients with PBC collected between 1971 and 2002. According to a random-effects model, the pooled IR of PBC was 1.7 (95% confidence interval [CI] 1.2-2.2) per 100,000 person-years. Significant heterogeneity was observed between studies (P<0.0005). Studies from North America (n=2) reported a higher incidence of PBC (2.9 [95% CI 2.5-3.4] per 100,000 person-years) than those from Europe (n=12; IR 1.5 [95% CI 1.0-2.0] per 100,000 person-years), however this difference was not statistically significant (P=0.14). Temporal trend analyses suggested a possible increase in the incidence of PBC. The incidence of PBC (per 100,000 person-years) in studies that collected data predominantly from the 1970s (n=4), 1980s (n=5), and 1990s/2000s (n=5) were 0.9 (95% CI 0.3-1.5), 1.2 (95% CI 0.7-1.7; P=0.70), and 2.6 (95% CI 1.9-3.4; P=0.004), respectively. Conclusions: The incidence of PBC appears to be increasing and may be higher in North America than Europe. Additional studies that examine genetic and environmental influences on the epidemiology of PBC are necessary to further our understanding of the pathogenesis of this condition.

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A218 UTILITY OF QUANTIFYING INTERNET SEARCH VOLUME FOR THE SURVEILLANCE OF COMMON LIVER DISORDERS A. Shaheen, G. Kaplan, R. Myers Liver Unit, Division of Gastroenterology and Hepatology, University of Calgary, Calgary, AB, Canada. Aims: Patients frequently use Internet search engines (e.g. Google) as a source of medical information. Although these websites may be useful for the surveillance of some conditions (e.g. influenza), the relationship between Internet search volume and liver-related morbidity has not been described. The objectives of our study were to describe the correlation between Internet search activity and hospitalizations due to selected liver disorders. Methods: We used Google Insights for Search to generate monthly volumes of Internet search activity (January 2004 to December 2007) for specific phrases related to three common hepatic conditions (acetaminophen overdose, variceal hemorrhage, and cirrhosis) in the United States. To define disease burden, we calculated monthly admission volumes for these conditions during the same interval using the Nationwide Inpatient Sample database, a sample which is representative of ~90% of admissions in the United States. The correlations between monthly Internet search volume and hospitalizations were calculated overall and according to the health insurance status of hospitalized patients (private vs. non-private) as a proxy for socioeconomic status (SES). Results: The correlations between Internet search volume and hospital admissions varied between conditions. For acetaminophen overdose, significant correlations were observed for the search terms ‘Tylenol’ (r=0.47, P<0.001); ‘Tylenol overdose’ (r=0.35, P=0.02); and ‘Tylenol liver failure’ (r=0.28, P=0.05). More technical searches including the term ‘acetaminophen’ were not correlated with admissions. There was a significant correlation between ‘Tylenol’ and private hospitalizations (r=0.44, P=0.002), yet ‘Tylenol overdose’ and ‘Tylenol liver failure’ were associated with non-private admissions (r= 0.31, P=0.03; and r=0.32, P=0.02, respectively). For liver-related hospitalizations among patients with cirrhosis, the search terms ‘cirrhosis’ and ‘liver failure’ were not associated with admissions. However, the term ‘liver disease’ was associated with cirrhosis admissions (r=0.38, P=0.008), with higher correlations observed for patients with private compared to non-private insurance (r= 0.43 vs. 0.27, respectively). Finally, no search terms (including ‘varices’, ‘variceal bleeding’, ‘cirrhosis + bleeding’, and ‘gastrointestinal bleeding’) were associated with the number of hospitalizations for variceal hemorrhage. Conclusions: The correlations between Internet search activity and hospital admissions vary among liver disorders, and are modest at best. Refinements in search strategies, including the use of less technical (e.g. non-medical) search terms will be necessary before this approach can be recommended for the surveillance of liver disorders.

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A219 THE IMPACT OF POPULATION BASED SCREENING STUDIES ON HEMOCHROMATOSIS SCREENING PRACTICES N. Chandok, M. Speechley, P. Ainsworth, S. Chakrabarti, P. Adams University of Western Ontario, London, ON, Canada. Aims: To determine if community population screening studies for hemochromatosis influenced HFE genetic screening practices in non-study populations. Methods: An audit of all genetic testing for HFE mutations at London Health Sciences Center, London, Ontario, Canada from 1997-2010 was performed. The frequency of genetic testing and the frequency of C282Y homozygous cases identified during the years of the London Red Cross (1998-1999) and HEIRS (2000-2005) screening studies were compared with the corresponding frequencies in the specified years outside of this range (1997-1998 and 2006-2010). Results: An increase in HFE gene mutation testing is seen during the London Red Cross study, and the frequency of testing rose further during the HEIRS study. Genetic screening activity continued to increase in the years following publication of the HEIRS study. The proportion of patients with homozygosity for C282Y mutation remained relatively constant despite fluctuations in numbers of persons screened per annum. Conclusions: The rise in HFE gene testing among non-study populations during the HH studies could be explained by the Hawthorne Effect, a phenomenon referring to the improvement or modification of behavior by a population as a consequence of it being studied. In this case, we postulate that primary care physicians at our center performed more HFE gene tests for their patients as a consequence of being influenced by knowledge of the screening studies. Despite a general increase in testing during and following completion of the studies, the total number of hemochromatosis cases (C282Y homozygotes) diagnosed per annum remained relatively constant.

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Esophagus, Gastric and Duodenal Ulcer Disorders

A220 LACK OF EFFICACY OF TOPICAL MITOMYCIN-C APPLICATION IN REFRACTORY ESOPHAGEAL STRICTURES AFTER SURGICAL REPAIR OF ESOPHAGEAL ATRESIA L. Chapuy, M. Pomerleau, P. Perreault, C. Faure Division of pediatric gastroenterology, Sainte-Justine Hospital, Department of pediatrics, Université de Montréal, Montreal, QC, Canada. Aims: There are only a few limited studies on esophageal strictures of various origins (caustic, peptic, postsurgical) that have suggested a role of mitomycin-C, an antifibrotic agent, in preventing secondary restricturing. The aim of this study was to specifically evaluate the efficacy of topical application of mitomycin-C in refractory anastomotic strictures occurring after surgical repair of esophageal atresia (EA). Methods: We retrospectively reviewed the medical records of 12 patients suffering from esophageal stricture after surgery for EA (type C, n=8; type A, n=4), who underwent esophageal dilation and concomitant topical application of mitomycin-C (median age 12 months, range 2 months - 15 years). All patients received 1 or 2 applications of mitomycin-C except one who received 6 applications. Mitomycin-C was applied after the 1st dilation (n=2 patients), 2nd dilation (n=3), 3rd dilation (n=2), 4th dilation (n=4) and the 5th (n=1). The endpoints of the study were (i) the need for subsequent dilation following the first application of mitomycin-C and (ii) the resolution of dysphagia. Results: With a median follow-up after the first application of mitomycin-C of 34 months (range 3 - 134), only 2 out of the 12 patients did not need subsequent dilation. For the remaining 10 patients, 1 to 7 subsequent dilations were performed. 6 of 10 patients finally experienced an improvement of their symptoms, after repeated dilations (median number of total dilations was 5, range 3 to 11). 4 of 10 patients remained with dysphagia. No dysplasia related to mitomycin-C was demonstrated. One patient presented with a tracheoesophageal fistula at 10 months, after 6 dilations (2 with mitomycin-C). Conclusions: In the setting of anastomotic esophageal strictures after surgery for EA, local application of mitomycin-C does not prevent restricturing nor improve dysphagia.

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A221 GASTROESOPHAGEAL REFLUX DISEASE AFTER ERADICATION OF HELICOBACTER PYLORI IN PATIENTS WITH DUODENAL ULCER: A META-ANALYSIS. M. Yaghoobi McGill University Health Centre, Montreal, QC, Canada. Aims: Most studies suggested that eradication of H. pylori (Hp) does not significantly increase the risk of gastroesophageal reflux disease (GERD). In this study the incidence of GERD after Hp eradication in patients with duodenal ulcers. Methods: A comprehensive English literature search was performed using PubMed from 1983 to October 2011, major gastrointestinal journals and congress abstracts. One hundred and fifty five potential articles were reviewed. Only prospective cohort studies comparing the prevalence of erosive esophagitis (confirmed by endoscopy) in patients with duodenal ulcer (free from erosive esophagitis at baseline) with eradicated versus persisted Hp infection after treatment were included. Endoscopy was required at baseline and end of follow up. Quality of studies was assessed by Jadad score. Meta-analysis of pooled odds ratio (fixed model) was performed using Review Manager 5.1. Results: Five studies were included (n= 1754 eradicated vs. n=303 controls). Average incidence of new diagnosis of GERD was significantly higher in patients with eradicated than in those with persisted Hp infection [11.2% versus 5.6%, respectively, OR=2.31 (CI; 1.38-3.89), P=0.001]. Test of heterogeneity was not significant for the analysis (Chi2=3.85, p=0.43, I2=0%). Conclusions: In this study, Hp eradication significantly increased new diagnosis of GERD in patients with duodenal ulcer. Although eradicating Hp in might not increase GERD in general population, it seems that in those with duodenal ulcer it may increase the risk by 2-3 fold and therefore patients should be informed before eradication therapy is administered.

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A222 THE INTRODUCTION OF PRE-ENDOSCOPY HIGH-DOSE INTRAVENOUS PROTON PUMP INHIBITION IN THE MANAGEMENT OF PATIENTS WITH ACUTE UPPER GASTROINTESTINAL BLEEDING - A BUDGET IMPACT ANALYSIS Y. Lu1, A. Barkun1, V. Teich2, I. Gralnek3, M. Bardou4, V. Adam1 1. Divisions of Gastroenterology and Clinical Epidemiology McGill University Health Center, Montreal, QC, Canada; 2. MedInsight, Rio de Janeiro, Brazil; 3. Department of Gastroenterology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel; 4. INSERM CIC-P 803 CHU de Dijon et Bourgogne, Dijon, France. Aims: To quantify the budget impact of using high dose intravenous proton pump inhibiton (HDIVPPI) before upper endoscopy (EGD) in ambulatory patients presenting with acute, overt upper gastrointestinal bleeding (UGIB) in different clinical scenarios Methods: A decision tree compared pre-endoscopy HDIVPPI to none in a model that emulates contemporary standards of practice. Patients were stratified by clinical likelihood of rebleeding (high/low), time to EGD, method of endoscopic hemostasis(epinephrine injection/other),and early discharge for clean-base ulcers (frequent/rare). Probabilities (including downstaging of high-risk endoscopic stigmata by HDIVPPI) and lengths of stay originated from the literature and bleeding registries. Hospital and additional pharmacological costs came from the Nationwide Inpatient Sample and Red Book (2008 $US). Expert consensus was sought when needed. The cost of Esomeprazole was the PPI cost used in the base-case with an assumed class effect for efficacy/effectiveness. One-way deterministic sensitivity analyses were performed on all variables across wide pre-set ranges. Model time horizon was 30 days, adopting a third-party payer perspective. Results: Model assumptions included 96 probabilities and 11 costs. In the base-case, average costs were $9,139 for the pre-endoscopy HDIVPPI strategy and $9,029 for the arm without (average incremental cost $110 per patient). This increment rose slightly amongst patients with a high clinical likelihood of rebleeding ($117/pt) or when using only hemostatic methods other than epinephrine injection ($128/pt). It dropped, as did overall mean costs in both strategies, amongst patients undergoing epinephrine injection ($95/pt) or a late EGD ($37/pt). All mean costs were lowest, and this time favoring the HDIVPPI approach, when clean-base ulcer patients were discharged early ($8,263 for HDIVPPI versus $8,282 for none, -$19/pt). In sensitivity analyses, variables with the greatest impact were the per diem cost of hospital stay complicated by rebleeding, and the elapsed times to early or late EGD; overall per patient incremental costs varied from $16-$174. Conclusions: The introduction of HDIVPPI prior to endoscopy in a US managed care setting amongst acute UGIB patients in most scenarios raise modestly mean patient costs. This approach, however, becomes cheaper than no PPI administration pre-EGD when selected patients bleeding from clean-base ulcers are discharged home from the emergency room.

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A223 GASTROESOPHAGEAL REFLUX IN PRE- AND POST-LUNG TRANSPLANTATION Y. Nasser1, M. Thakrar2, D. Helmersen2, M. Storr3, C. Andrews1 1. Division of Gastroenterology, University of Calgary, Calgary, AB, Canada; 2. Division of Respirology, University of Calgary, Calgary, AB, Canada; 3. Division of Gastroenterology, Ludwig Maximilians University, Munich, Germany. Aims: Gastroesophageal reflux (GER) and subsequent aspiration events are hypothesized to be contributors to chronic allograft dysfunction in lung transplant recipients. There are limited data on changes in GER or esophageal motility post-transplantation. We hypothesized that patients who had undergone lung transplantation would be predisposed to increased GER. Methods: Prospective comparative series of 19 pre-transplant patients (47% female) and 13 post-transplant patients (23% female) being evaluated for GER. All patients were on regular acid suppression therapy. After informed consent, patients filled out a detailed GER symptom questionnaire. Thereafter, both groups underwent esophageal manometry and 24hour pH monitoring. Results: Mean age was similar between groups (Pre: 55yrs, 95% CI: 49-60; Post: 53yrs, 95% CI: 47-58. p= 0.65) . Cause of lung disease was also similar between groups (interstitial lung disease: 9/19 (47%) patients pre, 4/13 (31%) post. COPD: 7/19 (37%) patients pre, 4/13 (31%) post). No differences in esophageal manometry, including baseline lower esophageal sphincter (LES) pressures (Pre-transplantation: 12.5 mmHg, 95% CI: 9.5-16.0. Post transplant: 9.0, 95% CI: 5.0-12.9. p=0.13) and percent LES relaxation (Pre-transplant: 76%, 95% CI: 63-88. Post transplant: 70%, 95% CI: 58-83, p=0.28) were observed between the two groups. Patients post-lung transplantation had a significantly increased total time spent in reflux over the 24 hour study period, as well as a significantly increased number of reflux episodes over five minutes (Table). There was a trend towards an increase in the DeMeester score in patients post-lung transplantation. Conclusions: This hypothesis-generating study suggests that post-lung transplant patients have more prolonged reflux episodes and increased total time spent in reflux compared to pre-transplant candidates, via a mechanism independent of altered esophageal motility. As patient numbers accrue, a case-control analysis is anticipated to better elucidate variables which may predict predisposition to reflux post-lung transplantation.

Total time in reflux (%) Episodes >5 minutes DeMeester composite score Pre-transplantation 1.1 (95% CI: 0.3-2.0) 0.8 (95% CI: 0.2-1.4) 4.1 (95% CI: 1.8-6.5) Post-transplantation 8.0 (95% CI: 1.7-17.6) 2.9 (95% CI: -1.1-4.7) 27.6 (95% CI: -3.6-58.8)

P value 0.037 0.033 0.051

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A224 EFFICACY OF SWALLOWED TOPICAL CORTICOSTEROIDS IN EOSINOPHILIC ESOPHAGITIS J. Brar, R. Persad, S. Sankarlingam, S. Carr, H. Huynh university of alberta, edmonton, AB, Canada. Aims: To examine the efficacy and safety of swallowed aerosolised corticosteroids Fluticasone (FS) and Oral viscous Budesonide (OVB) in the treatment of EE. Methods: A retrospective chart review of patients aged 1- 18 years who were diagnosed of EE between Jan 2005-Dec 2009. EE was defined as having a peak eosinophil count (PEC) of >15 per high power field (hpf) on microscopy. Data on demographics, presenting symptoms, endoscopic appearance, esophageal histology and treatment were collected. Primary outcome assessed was complete histological remission and secondary outcome was symptomatic resolution. Non-parametric Wilcoxon-Matched Pair Test was used to analyze differences between pre-treatment and post-treatment data. Our standard initial treatment was swallowed FS 500 mcg twice a day. Second line treatment was OVB at a dose of 500 mcg twice a day, used in those having difficulty swallowing aerosolized FS. Results: 43 patients met our diagnostic criteria, comprised of Caucasians(91%),South Asians(7%)and EastAsian(2%). Presenting symptoms included dysphagia(80%),choking(58%), food impaction(46%), vomiting(44%),abdominal&chest pain(35%)and failure to thrive(14%).Food allergy to peanuts(32%), eggs(16%),dairy(11%)and fish(9%)was noted.Asthma(39%), rhinitis(58%) and environmental allergies(46%)were the common associated co-morbidities.39patients were treated with FS and 4 with OVB.Significant improvement was noted with dysphagia (49%,P<0.0001),choking(21%,P = 0.0002),food impaction(11%, P = 0.0004),abdominal/chestpain,vomiting (14%,P = 0.0014)and complete resolution of failure to thrive(P = 0.02) post corticosteroid treatment.Endoscopy demonstrated presence of ring, furrow, exudates,and vascular permeability in both proximal (P) and distal(D) esophagus. Corticosteroid treatment significantly reduced the number of rings(P = 0.0033),furrows (P < 0.0001)and exudates (P<0.0001). Improvement in vascular pattern (P<0.001),histological appearance and reduced PEC (P<0.0001) was seen in both P and D esophagus.Complete histological Remission was better in proximal (52.5%) versus distal esophagus (40%).Corticosteroids significantly reduced both basal cell hyperplasia (P=0.0003 & 0.0011) and intraepithelial eosinophils(P = 0.0003 & P = 0.0030)in both P and D esophagus. Only few patients reported side effects such as esophageal candidiasis (4%) and mood changes(2%). Conclusions: Steroid treatment is effective and safe in the pediatric population and induced remission in about40% of our patients.Response was better in proximal than distal esophagus.

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A225 GLUTEN-FREE DIET DOES NOT APPEAR TO INDUCE SYMPTOMS AND ENDOSCOPIC REMISSION OF EOSINOPHILIC ESOPHAGITIS IN CHILDREN WITH COEXISTING CELIAC DISEASE H. Huynh, J. Abraham, R. Persad, J. Turner Division of GI and Nutrition, Department of Pediatrics,University of Alberta, edmonton, AB, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A226 THE ASSOCIATION BETWEEN CELIAC DISEASE AND EOSINOPHILIC ESOPHAGITIS IN CHILDREN AND ADULTS M. Stewart1, E. Shaffer2, S. Urbanski3, P. Beck2, M. Storr4 1. Division of Gastroenterology, Dalhousie University, Halifax, NS, Canada; 2. Division of Gastroenterology, University of Calgary, Calgary, AB, Canada; 3. Department of Pathology, University of Calgary, Calgary, AB, Canada; 4. Division of Gastroenterology, University of Munich, Munich, Germany. Aims: An association between eosinophilic esophagitis (EoE) and celiac disease (CD) has been suggested in the pediatric literature. This population-based study therefore sought to clarify this association and determine if it extended to adults. Methods: All patients in a large Canadian city with a histologically confirmed diagnosis of EoE or CD were identified using a searchable pathology database between January 1, 2004 and December 31, 2008 for both the adult and pediatric populations. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were calculated to quantify the association between EoE and CD. Results: Over the five-year study EoE was diagnosed in 421 patients and CD was diagnosed in 763 patients. Among the EoE cohort, 83 (20%) cases were diagnosed in pediatric aged patients and within the CD cohort 245 (32%) cases were diagnosed in pediatric aged patients. The age- and gender-adjusted incidence of EoE in the pediatric subpopulation ranged from 3.7 to 6.9 cases per 100,000 population. The age- and gender-adjusted incidence of CD in the pediatric population ranged from 9.5 to 22.7 cases per 100,000 population. The concomitant diagnosis of both EoE and CD was made in three patients, all of whom were pediatric males. The SIR for EoE within the pediatric CD cohort was 48.4 (95% CI = 9.73, 141.41) with a SIR for CD within the paediatric EoE cohort of 75.05 (95% CI = 15.08, 219.28). Conclusions: This population-based study confirms the association between EoE and CD. However, this association appears to be limited to pediatrics. The risk of each condition is increased 50 to 75-fold in pediatric patients diagnosed with the alternative condition. Thus, the concomitant diagnosis of these conditions should be considered in pediatric patients and routine biopsies of both sites should be obtained.

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A227 EARLY ADENOCARCINOMA AND HIGH-GRADE DYSPLASIA AMONG ADULT PATIENTS LESS THAN 55 YEARS OF AGE P. James1, M. Cirocco2, G. Kandel2, P. Kortan2, G. May2, N. Marcon2 1. Division of Gastroenterology, University of Toronto, Torono, ON, Canada; 2. Division of Gastroenterology, St. Michael's Hospital, University of Toronto, Torono, ON, Canada. Aims: To describe the experience of a single endoscopic tertiary care centre with an interest in Barrett’s esophagus (BE) in managing patients less than 55 years of age diagnosed with esophageal adenocarcinoma (EAC) or high-grade dysplasia (HGD) and determine if any factors can be found which predict these conditions. Methods: All patients under 55 years of age with a diagnosis of Barrett’s Esophagus at St. Michael’s Hospital since September 2004 were analyzed. Data on age, sex, risk factors for EAC, symptoms, medications, upper gastrointestinal endoscopy findings, histology, treatment and outcomes were collected. Results: Of the 68 patients who met the inclusion criteria, 29 (43%) had HGD or EAC. 16 (24%) patients with HGD or EAC were under 50 years of age. Among the patients with HGD and EAC, the average age was 48 years (standard deviation [SD] 4.8, range 38-54) and 25 (86%) were men. Three patients had a body mass index of greater than 30. All were diagnosed with GERD for greater than 5 years and were on proton-pump inhibitors. On endoscopy, the average Barrett’s length was 4.2cm (SD 2.7). Nodular lesions were appreciated on 13 (45%), hiatus hernia on 4 (17%), esophagitis in 2, and Helicobacter Pylori in none of the patients. Endoscopic mucosal resection was performed in 22 (76%), radiofrequency ablation in 3 and photodynamic therapy in one of these patients. 19 (66%) had complete response to endoscopic therapy, while only 3 had worsening dysplasia and went to esophagectomy. Conclusions: Persons with GERD less than 55 years of age are at risk of HGD and EAC. Early detection and treatment of HGD and EAC in these patients is effective. Age alone should not be used and chronic GERD may be helpful to determine BE screening eligibility. This data can be compared to GERD patients less than 55 years of age without Barrett’s, EA or HGD to establish factors which predict these conditions.

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A228 IMPACT OF HELICOBACTER PYLORI INFECTION AND MICROSCOPIC DUODENAL HISTOPATHOLOGICAL CHANGES ON CLINICAL SYMPTOMS OF PATIENTS WITH FUNCTIONAL DYSPEPSIA M. Ostovaneh, S. Mirbagheri, N. Khajavirad, N. Rakhshani, S. Eshagh Hoseini, V. Hoseini, Y. Farrokhi-Khajeh-Pasha Tehran University of medical sciences, Tehran, Islamic Republic of Iran. Aims: Functional dyspepsia (FD) is the most prevalent form of dyspepsia that points to a substantial economic health care system burden. Despite large amount of studies, pathophysiology and treatment of FD is still matter of controversy. Even though, prevalence of helicobacter pylori(H.pylori) has been found to be higher in FD than normal population but its impact in producing symptoms in these patients has not been clearly recognized and there is no consensus to eradicate H.pylori infection in FD patients or not. The aim of this study is to evaluate the microscopic histopathological changes in duodenal tissue and its relationship with severity of symptoms in FD patients while taking the effect of H.pylori infection into account. Methods: Several gastric and duodenal biopsy specimens were obtained in 217 FD patients without history of H.pylori eradication and were then evaluated for histopathological changes and H.pylori colonization. Urease Breath Test was additionally used to detect H.pylori infection. Severity of symptoms was assessed by Leeds Dyspepsia Questionnaire (LDQ) and its relationship to histopathological changes and helicobacter pylori infection status was assessed. Results: Prevalence of microscopic duodenitis was significantly higher in H.pylori infected than non-infected patients (82.2% vs 33.8%, P<0.001), as well as Severity of microscopic duodenitis which was also higher in presence of H.pylori infection(P<0.001). Severity of dyspepsia symptoms was not higher in H.pylori infected than non-infected patients (p:0.15). But in presence of H.pylori infection, Microscopic duodenitis significantly worsened the LDQ symptom severity score (p<0.001). We performed ordinal logistic regression analysis to evaluate independent effect of gender, H.pylori infection, microscopic duodenitis and gastritis on LDQ score. Accordingly, we found that presence of severe microscopic duodenitis increased the odds of experiencing severe symptoms to 2.22 times greater than having normal duodenal mucosa, given that other variables in the model were held constant (p:0.043). Females also had a odds ratio of 1.95 for experiencing severe dyspepsia symptoms when compared to males with a p value reaching toward significance (P:0.089). Conclusions: Microscopic duodenitis in H.pylori infected patients may play a major role in producing and aggravating symptoms in FD patients. It should be considered that microscopic duodenitis is sometimes the only noticeable finding in these patients and may be a determinant factor to decide about to treat H.pylori infection in FD or not.

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A229 PREVALENCE OF BARRETT’S ESOPHAGUS IN ADULT PATIENTS OPERATED FOR AN ESOPHAGEAL ATRESIA DURING CHILDHOOD : AN ENDOSCOPIC AND HISTOPATHOLOGIC STUDY S. Grand'Maison1, T. Terzic2, S. Maynard1, V. Huynh-Trudeau1, G. Soucy2, M. Bouin1 1. Gastroenterology unit, Hôpital Saint-Luc du CHUM, CRCHUM, Montréal, QC, Canada; 2. Pathology unit, Hôpital Saint-Luc du CHUM, CRCHUM, Montréal, QC, Canada. Aims: Adult patients operated of an esophageal atresia (EA) during childhood have a high prevalence of gastroesophageal reflux disease (GERD). GERD can result in Barrett’esophagus (BE) which is a known precursor of esophageal adenocarcinoma. With the hypothesis that adult patients operated for an EA during childhood have more risk to develop BE, the objective of this study was to evaluate the prevalence of BE in this population. Methods: All patients followed at the EA clinic at the Saint-Luc Hospital of CHUM were eligible for this study. Patients included in the study had an upper endoscopy where was noted the presence of visible surgical anastomosis, peptic esophagitis, hiatal hernia, esophageal diverticula or endoscopic suspicion of BE. Biopsies were made when an endoscopic suspicion of BE was present. These biopsies were reviewed by specialized pathologists. Results: 32 patients were included in our study and the endoscopic findings were : surgical anastomosis 87,5% (n=28), peptic esophagitis 12,5% (n=4) (all of Los Angeles score A), hiatal hernia 62,5% (n=20) and esophageal diverticula 12,5% (n=4). An endoscopic suspicion of BE was present in 50% of the patients (n=16). All of them had biopsy which showed BE in 31% of the cases (n=5) and a peptic esophagitis also in 31% of the cases (n=5). Conclusions: Prevalence of BE in adult patients operated of EA during childhood is 15% and 31% if an endoscopic suspicion of BE is present. Considering that the oesophageal adenocarcinoma risk could be higher for these patients than in general population, we conclude that these results could justify a detection program for this specific population.

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A230 DIFFERENTIATING VARICEAL FROM NON-VARICEAL BLEEDING USING PRE-ENDOSCOPIC CLINICAL CHARACTERISTICS L. Targownik1, M. Dhruve2, E. Inegbu1 1. University of Manitoba, Winnipeg, MB, Canada; 2. University of British Columbia, Vancouver, BC, Canada. Aims: Variceal bleeding is a common complication occurring in aptietns with cirrhosis, though they are also at risk for non-variceal bleeding. The prevalence of non-variceal bleeding in patients with cirrhosis is unclear. Distinguishing variceal from non-variceal bleeding prior to endoscopy may be useful for deciding on the use of octreotide and the timing of endoscopy. The presenting characteristics which may allow differentiation between non-variceal and variceal bleeding in patients with cirrhosis have not been previously described. Methods: We reviewed the patient records of all subjects admitted to a tertiary care hospital in Winnipeg, Manitoba in April 2007 to Mar 2010 with cirrhosis who had evidence of acute upper gastrointestinal bleeding (hematemesis or melena) who underwent endoscopy within 24 hours of presentation. We reviewed the patient record for demographics, presenting symptoms, initial bloodwork, and vital signs, and severity of underlying liver disease. The endoscopic record was reviewed to determine if the patient had variceal or non-variceal bleeding. Subjects were considered to have variceal bleeding if esophageal or gastric varices were present, signs of acute bleeding or recent bleeding (fibrin clot) were detected, and no other culprit lesions were detected. All other subjects were considered to have non-variceal bleeding. Chi-Square testing and T-testing was performed to assess for presenting characteristics which differed between the two groups Results: We identified a total of 65 patients who met entry criteria, of whom 23 (35%) were found to have non-variceal bleeding. Nine of the patients with variceal bleeding had evidence of non-variceal bleeding. 9 (39%) of the non-variceal patients had non-bleeding EVs. Subjects with variceal bleeding had a significantly lower platelet count than those with non-variceal bleeding (164 vs. 101, p<0.001), but there were no other significant differences between the two groups. Conclusions: Approximately one-third of patients with cirrhosis who present with upper gastrointestinal bleeding have a non-variceal source. There is no reliable way of distinguishing variceal from non-variceal bleeding prior to endoscopy based on clinical characteristics. Therefore, all persons with cirrhosis who present with evidence of upper gastrointestinal bleeding should be managed as if variceal source is present, with provision of octreotide and rapid access to endoscopy.

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A231 EOSINOPHILIC ESOPHAGITIS AND SWALLOWING -INDUCED ATRIAL TACHYCARDIA: A CASE REPORT AND REVIEW OF THE LITERATURE. M. Al Beshir, K. Ho, L. Harris, H. El-Zimaity, L. Liu University of Toronto, Toronto, ON, Canada. Aims: The incidence of eosinophilic esophagitis (EoE) has increased over the last decade. This increase may be related to previously un-recognized cases. It usually affects young males and presents with dysphagia. The aim of this report is to describe a case of eosinophilic esophagitis presented with swallowing induced atrial tachycardia and perform review of the literature. Methods: We report an otherwise healthy man whose dysphagia related atrial tachyarrhythmia resolved after the treatment of his underlying EoE. We performed literature search using Medline and PubMed database, we conducted a comprehensive search of English language literature encompassing the period from 1948 to September 2011. We searched for the key words “eosinophilic esophagitis”, “dysphagia”,“ swallowing”, “arrhythmia” or “ atrial tachycardia”. Results: This report describes a 54-year-old man whose dysphagia-induced atrial tachyarrhythmia associated with syncope, resolved after successful treatment of EoE. He complained of palpitations and syncope whenever he experience dysphagia even with minimal esophageal discomfort. A 24-hr telemetry result demonstrated episodes of irregular wide complex tachycardia. Echocardiogram, cardiac MRI and coronary angiography were normal. An electrophysiologic study confirmed the arrhythmia as atrial in origin and was followed by ablation for an inducible typical atrioventricular nodal reentrant tachycardia (AVNRT). Post ablation, he experienced no further AVNRT, however, he continued to have palpitations with frequent episodes of atrial tachycardia at rapid rate associated with dysphagia. Upper GI endoscopy revealed features consistent with EoE that was confirmed with histology. Oral fluticasone was initiated. Within 72 hours, his dysphagia improved as well as his atrial tachycardia. At 6 weeks of therapy, his palpitations had resolved and the repeat 24-hr Holter study demonstrated no further episodes of atrial tachycardia. Review of the literature identified approximately 50 cases of swallowing-induced atrial tachyarrhythmia; however, all reported cases described a normal underlying esophageal structure. Conclusions: As far as we know, this is the first formal documentation of a unique symptomatic atrial tachycardia in a patient with dysphasia secondary to EoE. This report raises the awareness of the importance to fully evaluate and treat underlying dysphagia to minimize potentially unneeded invasive cardiac intervention in patients with atrial tachyarrhythmia.

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A232 THE PREVALENCE OF CANDIDA GLABRATA, AN AZOLE-RESISTANT YEAST, IN AN ENDOSCOPY POPULATION: A 30-MONTH REVIEW A. Wilson, T. Ponich University of Western Ontario, London, ON, Canada. Aims: Candida species are the most common cause of fungal infections. Although Candida albicans remains the most common cause of fungal esophagitis at many institutions, non-albicans species are increasingly associated with esophageal candidiasis. In particular, Candida glabrata has been a more frequently recognized pathogen in the development of fungal esophagitis. There is a growing body of evidence that suggests a large proportion of these isolates are azole-resistant. Furthermore, a large amount of variability in the prevalence of this disease exists in the limited data available. The prevalence in south western Ontario is unknown. The objective of this study was to determine the incidence of Candida glabrata esophagitis at London Health Sciences Centre in an adult gastroenterology population. Methods: Adult gastroenterology patient charts were identified based on billing codes for esophageal biopsies and brushings taken from January 1, 2009 to July 30, 2011. The microbiologic results of each chart were reviewed. Any charts identified as having a positive fungal culture were further reviewed for the presence or absence of any risk factors that would predispose that patient to esophageal candidiasis. Results: 1701 charts were identified as meeting the inclusion criteria. Fifty five patients were recognized as having endoscopic findings consistent with Candida esophagitis. However, the true prevalence of Candida esophagitis based on microbiologic culture was 2.2% (n= 37). Candida albicans was implicated in the vast majority of infections (73%). Candida glabrata was the next most prevalent (24.3%), followed by Candida tropicalis (2.7%). Sixteen men and 14 women were affected. There were 7 cases where patients had a mixed infection. Of the Candida glabrata cohort, all patients had a history of type 2 diabetes and of the Candida albicans cohort, 62% of patients had at least one risk factor predisposing them to candidiasis. Conclusions: Candida glabrata-associated esophagitis makes up not an insubstantial portion of the candidal esophageal infections seen at LHSC. Empirical treatment of Candida infections with fluconazole based on endoscopic appearance alone would not be effective for fluconazole-resistant Candida glabrata. This study highlights the need to take esophageal brushings and await culture results rather than proceeding with empiric treatment.

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A233 RECURRENT MICROPERFORATION CAUSING PNEUMOMEDIASTINUM IN A PATIENT WITH EOSINOPHILIC ESOPHAGITIS C. Struthers, M. Curley Dalhousie University, Halifax, NS, Canada. Aims: Esophageal perforation in patients with eosiniphilic esophagitis has been reported with food impaction, dilatation as well as simple passage of the endoscope. Perforation in the absence of significant mechanical trauma has rarely been described. Methods: We describe a case of recurrent pneumomediastinum secondary to spontaneous esophageal microperforation in a young man who was eventually diagnosed with eosinophilic esophagitis. Results: A 20-year-old man with 1-year history of intermittent dysphagia presented to hospital with acute onset of retrosternal chest pain associated with nausea, vomiting and diarrhea. He was sent home on oral antiemetics. Four days later, he returned with ongoing persistent dysphagia. A CT scan showed extensive subcutaneous emphysema, pneumomediastinum and a small right pneumothorax but no extravasation of oral contrast. He was admitted to hospital with a diagnosis of esophageal microperforation. After six days of conservative management with intravenous fluids and antiemetics he was discharged home on a soft diet. One-month follow-up chest radiograph was normal. He returned 2 months later with identical symptoms. A chest radiograph showed subcutaneous emphysema and a possible tiny pneumomediastinum. A gastrograffin swallow could not identify esophageal perforation. He was discharged home after three days. Gastroscopy, performed 2 months later, showed LA Class B esophagitis at the gastroesophageal junction but was otherwise normal. Oral proton pump inhibitor was started. Repeat gastroscopy, two months later, showed persistent esophagitis and the remainder of the esophagus had a diffusely granular appearance with spots of white exudate. Biopsies showed active esophagitis with marked eosinophilic infiltrate, consistent with eosinophilic esophagitis. Swallowed fluticasone was added and at 1-year follow-up, there has been complete resolution of dysphagia with no further perforations. Conclusions: It is well established that patients with eosinophilic esophagitis are at risk of perforation during endoscopy, especially if dilatation or removal of food bolus are attempted. This rare case presents a patient with two radiographically-documented spontaneous microperforations. A history of dysphagia in a young person should prompt early gastroscopy. Morphologic features of eosinophilic esophagitis are not always present which underscores the importance of empiric biopsies throughout the esophagus. Had the diagnosis of eosinophilic esophagitis been confirmed earlier, the second perforation may have been avoided.

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A234 COMPLICATIONS OF TRANS-ESOPHAGEAL ECHOCARDIOGRAPHY: A CASE OF LATE PRESENTING ESOPHAGEAL STRICTURE. J. Ryan, A. Ilnyckyj University of Manitoba, Winnipeg, MB, Canada. Aims: Dysphagia following intra-operative trans-esophageal echocardiography (TEE) is a common complaint and correlated with increased complications such as aspiration pneumonia, ICU admission and need for tracheostomy (1). There is a paucity of data regarding complications of this technology in the gastrointestinal literature. We report a case of a 69 year old female presenting with severe dysphagia following TEE use in cardiac surgery. Methods: The patient had no previous history of GERD or swallowing problems. Following uncomplicated cardiac bypass surgery with TEE she immediately complained of odynaphagia and dysphagia for solids. The symptoms were noted but felt to be within the range of normal for the post-operative state. She was discharged on day 12 tolerating liquids. Her symptoms persisted and she presented to the Emergency room 6 days later. She could no longer tolerate liquids and could not swallow oral medications. Upper endoscopy demonstrated an esophageal ulcer, rectangular in shape with sharp demarcation suggestive of contact injury at 33 cm. There was an associated pin point stricture below the ulcer edge. (Photos attached). The patient required a 23 day admission during which time she received IV PPI and 4 progressive dilatations. She was discharged tolerating solids and medications. She was seen in the community at week 6 and swallowing was preserved. Results: Table 1. Conclusions: TEE is now a standard imaging modality in cardiac surgery and its use is increasing. Dysphagia post-TEE is common while bleeding and perforation are rare (Table 1). TEE complication rates have not been published in the GI literature thus our case is important to increase awareness of the potential for esophageal injury. Furthermore, our case illustrates an unusual and severe case of stricture as the cause for dysphagia. Table 1. Reported incidence of esophageal complications associated with intraoperative TEE.

COMPLICATION INCIDENCE Dysphagia (subjective) 72:200 (2)

Dysphagia (barium cineradiography) 23:404 (1) Bleeding 2:7,200(3)

Perforation 1:7,200(3) References 1. Hogue CW, Lappas GD, Creswell LL, Ferguson TB, Sample M, Pugh D, Balfe D, Cox JL, and Lapas DG. Swallowing dysfunction after cardiac operations. The Journal of Thoracic and Cardiovascular Surgery. 1995;(2)110:517-522. 2. Chin JH, Lee EH, Choi DK, and Choi IC. A modification of the trans-esophageal echocardiography protocal can reduce post-operative dysphagia following cardiac surgery. Journal of International Medical Research. 2011;39:96-104. 3. Kallmeyer IJ, Collard CD, Fox JA, Body SC, and Shernan SK. The safety of intraoperative transesophageal echocardiography: a case series of 7200 cardiac surgical patients. Anaethesia and Analgesia. 2001;92:1126-30

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A235 EVALUATION OF NOVEL GI-SPARING NSAIDS IN MODELS OF COMPROMISED MUCOSAL DEFENCE R. Blackler1, G. McKnight1, M. Bolla2, E. Ongini2, J. Wallace1 1. Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada; 2. NicOx Ltd., Nice, France. Aims: Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used drugs, due to their ability to alleviate pain and inflammation. As the populations of developed countries age, the prevalence of age-related diseases, such as osteoarthritis, will increase substantially, likely increasing the use of NSAIDs. However, NSAID use is considerably hindered by their ability to cause clinically significant gastrointestinal (GI) damage and bleeding. Moreover, the risk of adverse GI events from chronic NSAID use is significantly increased in patients with co-morbidities (Laine, 2006). These facts emphasize the need for novel drug evaluation in models of compromised mucosal defence. Two novel NSAIDs, ATB-346 and NCX-429 (hydrogen sulfide- and nitric oxide-releasing naproxen derivatives, respectively) were evaluated for their ability to induce GI damage in rat models of obesity, arthritis, and advanced age. Methods: Co-morbid rats (Zucker obese, Freund’s adjuvant arthritis, or aged (19 months)) and healthy controls were treated orally twice-daily with vehicle, an anti-inflammatory dose of naproxen (10 mg/kg), or equimolar (and equi-effective) doses of ATB-346 (14.5 mg/kg) or NCX-429 (14.88 mg/kg) for 4 days. Three hours after the final administration, the stomach and small intestine were blindly evaluated for hemorrhagic damage. Samples of gastric tissue were collected for prostaglandin E2 measurement. Whole blood thromboxane B2 synthesis was measured as an index of systemic COX-1 activity. Results: ATB-346 and NCX-429 were as effective at suppressing prostaglandin (>85%) and thromboxane (>95%) synthesis, as the equimolar dose of naproxen. In healthy rats, none of the test drugs induced significant GI damage at the doses tested. In obese rats, naproxen caused a 40-fold increase in intestinal damage over healthy controls, whereas ATB-346 did not elicit any intestinal damage. In arthritic rats, naproxen caused ~10-times as much gastric and intestinal damage as in healthy controls. ATB-346 did not elicit detectable damage in the stomach or intestine of arthritic rats. In aged rats, naproxen caused extensive gastric damage (damage score of 19 ± 4.2), whereas ATB-346 (1.7 ± 0.7) and NCX-429 (2.0 ± 1.1) caused no significant damage. None of the drugs elicited intestinal damage in aged rats. Conclusions: Rats with clinically relevant co-morbidities exhibit a substantial increase in susceptibility to naproxen-induced GI injury. Despite this, both naproxen derivatives (ATB-346 and NCX-429) were well tolerated in the GI tract, producing negligible damage despite comparable anti-inflammatory effects to naproxen. This may be related to their ability to release gastro-protective mediators (hydrogen sulfide and nitric oxide, respectively).

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A236 ROLE OF EPITHELIAL PTEN ON GASTRIC ARCHITECTURE, PROLIFERATION AND CELL SPECIFICATION IN THE MOUSE F. Maloum, M. Langlois, N. Perreault, S. Roy university of Sherbrooke, Sherbrooke, QC, Canada. Aims: The phosphatase and tensin homolog (PTEN), a negative regulator of the phosphatidylinositol 3-kinase/ AKT pathway, is one of the most frequently mutated/deleted gene in various human cancers. PTEN has also been shown to regulate numerous cellular processes such as genomic stability, stem cell renewal, senescence and cell differentiation. However, the potential effects of Pten on gastric organogenesis and homeostasis have not yet been explored. The aim of our study is to investigate the role of epithelial Pten in the maintenance and specification of gastric epithelium. Methods: Using the Cre/loxP system, we have generated a mouse model with a deletion of Pten exclusively in the foregut endoderm. Glandular architecture was assessed with H&E staining. Analysis of cell proliferation was performed by immunofluorescence with a PCNA antibody. Gastric cell type patterns from control and mutant mice were analyzed by antibody- specific immunostaining, alcian blue and Periodic Acid Schiff stainings. Results: PtenΔGEC mice are viable and have no severe abnormality in gastric organogenesis. Loss of Pten in the stomach epithelium was confirmed by IHC and, as expected, leads to an increase of p-Akt in the mutant gastric glands. Histological analysis by H&E staining demonstrates a disorganized glandular architecture associated with cystic regions in the corpus from 4 months of age. The PtenΔGEC mice display a delocalization and upregulation in epithelial proliferation associated to an increase of the glands length. Analysis of the different cell lineages shows an increase in the mucus cell population. Furthermore, chromogranin A immunostaining shows an increase in the number of enteroendocrine cells in Pten mutant mice. Analysis of parietal cells reveals a significant decrease in this cell population in PtenΔGEC mice. Surprisingly, zymogenic cells are absent from the glandular epithelium in mutant mice, whereas GSII positive cells, specific for neck cells, are increased and delocalized to the basal region, suggesting a possible impairment of their maturation. With aging, loss of Pten leads to an increasing inflammatory process demonstrated by the expression of myeloperoxidase positive cells in the cystic regions and the mesenchyme. Conclusions: Altogether, our results indicate that Pten in the gastric epithelium impacts on gastric gland architecture negatively regulates the proliferation and plays an important role in the regulation of the cytodifferentiation and maturation of gastric cells.

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Immunology and Inflammatory Bowel Disease

A237 COMPLETE MUCOSAL HEALING AND STEROID-FREE MUCOSAL HEALING WITH INFLIXIMAB, AZATHIOPRINE, OR INFLIXIMAB+AZATHIOPRINE: UC SUCCESS SUBANALYSIS R. Panaccione1, S. Ghosh1, S. Middleton2, J. Márquez3, I. Khalif4, L. Flint5, H. van Hoogstraten5, H. Zheng5, S. Danese6, P. Rutgeerts7 1. U Calgary, Alberta, AB, Canada; 2. U Cambridge, Cambridge, United Kingdom; 3. Clínica Las Américas, Medellín, Colombia; 4. State Scientific Centre of Coloproctology, Moscow, Russian Federation; 5. Merck Research Laboratories, Kenilworth, NJ; 6. Istituto Clinico Humanitas, Milan, Italy; 7. U Leuven, Leuven, Belgium. Aims: To assess the best treatment strategy in patients with moderate to severe ulcerative colitis (UC) failing steroids. Methods: This 16-week, double-blind, controlled trial included 239 patients with moderate to severe UC (baseline total Mayo score 6-12). All had failed corticosteroids and were biologic and azathioprine (AZA)/6-MP naïve or had stopped AZA ≥3 months prior. Patients were randomized to: AZA 2.5 mg/kg+placebo; infliximab (IFX) 5 mg/kg+placebo; or IFX 5 mg/kg+AZA 2.5 mg/kg. Nonresponders at week 8 (partial Mayo score reduction <1) in AZA group were eligible for IFX 5 mg/kg at weeks 8, 10, and 14. Primary endpoint was steroid-free remission at week 16 (total Mayo score ≤2 without steroids and no individual subscore >1). Major secondary endpoints were response at week 8 (decrease in partial Mayo score ≥1) and response at week 16 (decrease in total Mayo score ≥3 and ≥30% reduction from baseline total Mayo score). Primary comparison was IFX+AZA vs AZA. To control for multiplicity, secondary comparisons of IFX vs AZA and IFX+AZA vs IFX were conducted in sequence if prior test achieved statistical significance at 0.05 level. Other secondary endpoints included mucosal healing (MH; Mayo endoscopy subscore 0 or 1) at week 16. Subanalyses included impact of treatment on complete (Mayo endoscopy subscore 0) and steroid-free MH (Mayo endoscopy subscore 0 or 1) at week 16. Results: Data from 231 patients were analyzed. Primary endpoint was achieved, with a significantly greater percentage of patients in steroid-free remission at week 16 in IFX+AZA arm vs AZA arm (percentages were similar in IFX and AZA arms, and differences were not statistically significant) (table). Greater percentages of patients receiving IFX-based strategies achieved MH and steroid-free MH. Safety was similar across all arms. Conclusions: IFX+AZA was superior to AZA monotherapy for achieving steroid-free remission and response at week 16. Patients Achieving Each Clinical Outcome at Week 16 by Treatment Arm

Outcomes IFX+AZA (n=78) IFX (n=77) AZA (n=76) Clinical endpoints, week 16 (% of patients)

Steroid-free remission 40a,c 22 24 Response 77a 69b 50

MH (Mayo 0 or 1) 63a 55b 37 Subanalyses, week 16 (% of patients)

Steroid-free MH (Mayo 0 or 1) 56a 52b 36 Complete MH (Mayo 0) 30a,c 12 13

aP<0.05 IFX+AZA vs AZA. bNominal P<0.05 IFX vs AZA. cNominal P<0.05 IFX+AZA vs IFX.

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A238 ADALIMUMAB IMPROVES HEALTH-RELATED QUALITY OF LIFE FOR 52 WEEKS IN PATIENTS WITH ULCERATIVE COLITIS W. Sandborn1, G. Van Assche2, R. Thakkar3, A. Lazar4, M. Kron4, M. Yang3, J. Chao3, P. Mulani3 1. U of California, La Jolla, CA; 2. Univ. Hospital Gasthuisberg, Leuven, Belgium; 3. Abbott, Abbott Park, IL; 4. Abbott GmbH & Co, Ludwigshafen, Germany. Aims: To investigate the effects of adalimumab (ADA) maintenance therapy on health-related quality of life (HRQOL) through 52 weeks (wks) in patients (pts) with ulcerative colitis (UC). Methods: 494 pts with moderate to severe UC (Mayo score, 6-12 points; endoscopic subscore, 2-3 points; anti-tumor necrosis factor [anti-TNF]-naïve and anti-TNF-experienced [40.3%]) who had failed conventional therapy were enrolled in a 52-wk, randomized, double-blind, placebo-controlled maintenance trial. ADA-treated pts received induction therapy (160/80 mg at Wks 0/2) and 40-mg every-other-week (eow) maintenance therapy. Pts with inadequate response could switch to open-label eow therapy after Wk 12 and subsequently to weekly therapy. HRQOL was measured by the Inflammatory Bowel Disease Questionnaire (IBDQ). The intent-to-treat population was analyzed. IBDQ response rates were compared between the treatment groups using the Cochran-Mantel-Haenszel test stratified for prior anti-TNF use whereas the chi-square test was used in anti-TNF-naïve pts. Non-responder imputation was used for response variables. For change of IBDQ scores, the ANCOVA model with treatment and prior anti-TNF status as factors and baseline value as covariate was used. Missing values were imputed through last observation carried forward (LOCF). Results: Significantly more ADA-treated pts were IBDQ responders (increase in IBDQ score ≥16 points from baseline) throughout Wks 8, 32, and 52 compared with placebo. Mean changes from baseline IBDQ scores were consistently greater for ADA- vs. placebo-treated pts (table). In anti-TNF-naïve pts, the improvements from baseline for IBDQ were 34±38 and 22±37 at Wk 8 (p=0.002), 33±43 and 24±43 at Wk 32 (p=0.03), and 33±44 and 23±42 at Wk 52 (p=0.02) for ADA and placebo, respectively. The IBDQ responder rates were 68% and 52% at Wk 8 (p=0.004), 42% and 27% at Wk 32 (p=0.006), 32% and 21% at Wk 52 (p=0.040) for ADA and placebo, respectively, among anti-TNF-naïve pts. Conclusions: For pts with moderate to severe UC who failed conventional therapy, ADA was more effective than placebo for inducing and maintaining improvements in HRQOL, as measured by IBDQ through 52 wks.

A239 PYRAMID REGISTRY: AN OBSERVATIONAL STUDY OF ADALIMUMAB IN CROHN’S DISEASE: RESULTS AT YEAR 3 G. D'Haens1, W. Reinisch2, J. Satsangi3, E. Loftus4, R. Panaccione5, D. Tokimoto6, Y. Wang6, K. Lomax6 1. Academic Medical Centre, Amsterdam, The Netherlands, and Imelda GI Clinical Research Center, Bonheiden, Belgium; 2. Medical University of Vienna, Vienna, Austria; 3. Western General Hospital, Edinburgh, United Kingdom; 4. Mayo Clinic, Rochester, MN; 5. University of Calgary, Calgary, AB, Canada; 6. Abbott Laboratories, Abbott Park, IL. Aims: Adalimumab, a fully human anti-tumor necrosis factor (TNF) monoclonal antibody, is approved as treatment for Crohn’s disease (CD) and has been shown to induce and maintain remission in CD patients. Our objective was to assess the long-term safety of adalimumab as prescribed according to local product labels in PYRAMID, an ongoing observational CD registry in 24 countries, now at Year 3. Methods: PYRAMID has a planned 6-year study duration for each enrolled patient. Study visits are scheduled every 3 months through Year 1, then every 6 months thereafter. Safety data is collected including all serious adverse events (SAEs) and adverse events of special interest (AEIs), including serious infections, intestinal obstructions, malignancies, and demyelinating diseases. Results: Of the 5080 enrolled patients, 3866 (76.1%) were ongoing as of December 1, 2010 (mean age, 38 years; 57% female; 96% white) with a cumulative adalimumab exposure of 9249 patient years including exposure from prior adalimumab trials. 24% of patients have discontinued from the registry, most frequently due to lack of efficacy or occurrence of an AE. 51% of patients had been previously treated with biologics, 36% were treated with concomitant immunosuppressants at enrollment, and 30% with concomitant corticosteroids at enrollment. 20% of patients experienced at least 1 treatment-emergent SAE, the most frequent being worsening of CD (5.9%) and small intestinal obstruction (1.4%). AEIs are listed in the table. Conclusions: At the 3-year timepoint, there were no new clinical concerns regarding incidence of SAEs, or AEIs; no new safety signals were observed. These findings are in line with the results from earlier timepoints of PYRAMID. a Patient years (PYs) reflect exposure in the registry only and do not include exposure from previous studies. b TB, 5 events; esophageal candidiasis, 3 events; Pneumocystis jiroveci pneumonia, 1 event.

Year 2 Year 3

Patient Years (PY)a 4310.1 8174.7

Median exposure (days) 287 599

Adverse Event of Special Interest _____________________________________________________________

Events (E/100 PY) ________________

Events (E/100 PY)________________

Serious treatment-emergent opportunistic infection including TB 4 (<0.1) 9 (0.1)b

Intestinal obstruction/stricture 150 (3.5) 283 (3.5)

Malignancies 19 (0.4) 48 (0.6)

Lymphoma 1 (<0.1) 3 (<0.1)

Immune reaction including lupus/lupus-like syndrome 2 (<0.1) 8 (<0.1)

CNS demyelinating disorders 0 1 (<0.1)

AE leading to permanent discontinuation of adalimumab 169 (3.9) 266 (3.3)

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A240 ADALIMUMAB THERAPY REDUCES HOSPITALIZATION AND COLECTOMY RATES IN PATIENTS WITH ULCERATIVE COLITIS: DATA FROM CONTROLLED TRIALS B. Feagan1, W. Sandborn2, M. Yang3, K. Lomax3, A. Lazar3, R. Thakkar3, P. Mulani3, J. Chao3 1. Robarts Research Institute, University of Western Ontario, London, ON, Canada; 2. University of California, San Diego, La Jolla, CA; 3. Abbott Laboratories, Abbott Park, IL. Aims: The efficacy and safety of adalimumab (ADA) for the induction and maintenance of clinical remission in patients with moderate to severe ulcerative colitis (UC) was demonstrated in 2 double-blind, placebo-controlled trials (M06-826 and M06-827). Methods: We assessed the effect of ADA on the risk reduction of all-cause and UC-related hospitalization and colectomy in these 2 trials. Patients in the 160-/80-mg induction (N=223) and placebo (N=222) arms of M06-826 and patients in the ADA (N=248) and placebo (N=246) arms of M06-827 were combined into a single dataset (N=939). Hospitalization (all-cause and UC-related) and colectomy events were based on serious adverse event reports reviewed by 2 gastroenterologists who were blinded to the treatment groups. The risk of hospitalization was compared between the treatment arms using person-year (PY)-based incidence rates (IRs). Z-scores with confidence intervals were used to determine the statistical difference between treatment groups.1 The number of hospitalizations was compared with Poisson regression with time offset. Results: The table summarizes the hospitalization and colectomy IRs. A 33% reduction in the percentage of patients hospitalized for any reason and a 35% reduction in the number of all-cause hospitalizations were observed with ADA treatment vs. placebo (p<0.05 for both comparisons). When UC-related hospitalizations were compared, the reductions for hospitalization rate (45%) and number of hospitalizations (48%) were both statistically significant. Rates of colectomy were numerically lower in the ADA group compared with the placebo group, representing a 22% reduction. Conclusions: ADA-treated patients had a significantly lower risk for UC-related and all cause hospitalization compared with placebo-treated patients. In addition, a numerically lower colectomy rate in patients receiving ADA therapy vs. placebo was observed. These data support a favorable benefit/risk profile of ADA in UC. Reference: 1. Miettinen O. Am J Epidemiol. 1976;103:226-35.

Hospitalization and Colectomy IRs in M06-826 and M06-827 Trials ADA Placebo Risk Ratio (Placebo/ADA) P-Value n/TAR IR (n/100-PYs) n/TAR IR (n/100-PYs) RR [95% CI]

Patients hospitalized, % All-cause 67/378 18 57/214 27 1.5 [1.1, 2.2] 0.022

UC-related 45/389 12 47/215 22 1.9 [1.3, 2.8] 0.002 Hospitalizations

All-cause 82/401 20 70/224 31 1.5 [1.1, 2.1] 0.0095 UC-related 53/401 13 57/224 25 1.9 [1.3, 2.8] 0.0006 Colectomy 14/399 3.5 10/223 4.5 1.3 [0.6, 2.9] 0.554

RR, relative risk; TAR, time at risk in PYs.

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A241 VITAMIN D MODULATES CYTOKINE RESPONSES INDUCED BY TLR LIGANDS IN PBMC AND MONOCYTE-DERIVED DENDRITIC CELLS IN CROHN’S DISEASE S. Dionne, M. Yona, D. Levesque, E. Seidman Research Institute, McGill University Health Centre, Montreal, QC, Canada. Aims: Vitamin D modulates innate & adaptive immunity, and was demonstrated by our group (Wang et al J Biol Chem 2010) to induce NOD2, the most common susceptibility gene for Crohn's disease (CD). AIM: To examine the effect of 1,25D (50 nM) on the immune response to bacterial antigens in CD. Methods: PBMC from 61 CD patients were stimulated with PAM3CSK4, LPS, flagellin, R848 and muramyldipeptide (MDP), ligands for TLR2, TLR4, TLR5, TLR7/8 and NOD2, respectively. Monocyte-derived dendritic cells (Mo-DC) were prepared from CD14+ cells and stimulated with LPS, R848 and MDP. Results: TLR ligands induced PBMC TNFα, IL-12/IL-23p40 & IL-10. IL-23 was induced by LPS + R848. Combining LPS + R848 increased levels 1.9 - 7.5 fold vs LPS alone, especially IL-23. 1,25D decreased IL-12/IL-23p40 & IL-23 levels induced by TLR ligands (-44 to -78%, p<0.01); IL-10 decreased -4 to -44%; TNFα was 0 to -52% lower. 1,25D decreased IL-10, but less than IL-12/IL-23p40. The IL-10 to IL-12/IL-23p40 ratio increased with 1,25D (1.5 - 3.8x, p<0.05). MDP alone induced low IL-10 & IL-12/IL-23p40, but synergized with LPS & LPS+R848 to induce cytokine(p<0.01). Cytokines increased 2.2-6.6 fold with MDP + LPS. MDP alone or with LPS decreased IL-12/IL-23p40 levels, but the other cytokines were increased. When combined with LPS+R848, cytokines levels decreased (-26 to -49%, p<0.05) but to a lesser extend than without MDP. The anti-inflammatory effects of 1,25D were then examined in Mo-DC. Single TLR triggering resulted in very low cytokine levels. LPS+R848 induced high levels of IL-23 & TNFα (8300,4250 pg/ml). Moderate amounts of IL-10 and IL-23 were produced (280 & 583 pg/ml, respectively). In addition, IL-12p70 was released (79 pg/ml). Addition of MDP significantly increased all cytokines (>1.5 fold, p<0.05) except for TNFα. Cytokines levels induced by LPS+R848 were decreased by 54 - 91 % by 1.25D (p<0.01). When MDP was also present, the decrease was more moderate (17% for IL-10, 46% for TNFα 88%). IL12p70 was similarly decreased (91% and 88%). IL-23 levels were not decreased in the presence of MDP. Conclusions: 1,25D decreased TLR-induced inflammatory cytokines TNFα, IL-12/23p40 & IL-23 in PBMC from CD. 1,25D lowered the pro-inflammatory profile (increased IL-10 to IL-12/IL-23p40 ratio). 1,25D decreased Mo-DC TLR-induced cytokines, particularly IL-12p70. NOD2 signaling by MDP combined with TLR stimulation resulted in preservation of IL-23 & IL-10 compared to TNFα & IL-12. APC production of IL-12p70 & IL-23 promotes Th1 and Th17 cells, respectively. Our results suggest that 1,25D decreased inflammatory cytokines & inhibits the IL-12/23 inflammation pathway and may help to restore the aberrant inflammatory response in CD. Supported by a CIHR Team Grant in Clinical Autoimmunity.

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A242 SURGICAL RATES HAVE DECREASED FOR EMERGENT CROHN'S DISEASE RESECTIONS WHILE INCREASING FOR ELECTIVE RESECTIONS: A POPULATION-BASED TIME TREND STUDY L. Meddings1, R. Panaccione1, H. Yang1, K. Rioux1, A. MacLean2, D. Buie2, A. Frolkis1, G. Moran1, S. Ghosh1, G. Kaplan1 1. Division of Gastroenterology, University of Calgary, Calgary, AB, Canada; 2. Department of Surgery, University of Calgary, Calgary, AB, Canada. Aims: The rates of bowel resection for Crohn’s disease (CD) have remained stable in some studies while others have demonstrated decreased surgical rates. However, prior studies have not evaluated whether surgical rates have differed by setting of surgery. We studied whether surgical resection rates for CD differed by emergent versus elective operations. Methods: Population-based surveillance was conducted between January 1, 1997 and December 31, 2010 to identify all adults (≥ 18 years) living in the Calgary Health Zone with a discharge abstract code for CD and an intestinal resection (n=1551). The yearly incidence of CD surgery was calculated by dividing the annual total number of surgical resections by the annual population size for the Calgary Health Zone. The annual percent change (APC) from 1997 to 2010 was calculated using a generalized linear model adjusted for age that assumed a Poisson distribution. Joinpoint regression was used to explore whether each temporal trend would be better modeled with multiple log-linear segments. Effect modifications were tested for age and setting of surgery (i.e. elective versus emergent). Results: The incidence rates of surgery for CD were 16.3 to 11.0 per 100,000 person-years in 1997 and 2010, respectively. During this time period the APC significantly decreased by -2% per year (95% CI: -1%, -4%). Effect modification was observed between emergent and elective surgery (p<0.01), but not age. The APC among emergent resections decreased linearly by -7% (95% CI: -8%, -5%; p<0.0001). In contrast, the APC marginally increased among elective operations (3%; 95% CI: 1%, 5%; p=0.003). Joinpoint analyses did not reveal statistical significant inflections points. Conclusions: While emergent operations for CD steadily declined, from 1997 to 2010, elective operations marginally increased. These findings suggest that advances in the medical management of CD have reduced overall surgical rates and shifted surgical management from the emergent to the elective setting.

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A243 PI3KP110δ DEFICIENT CLASSICALLY ACTIVATED MACROPHAGES EXACERBATE INFLAMMATION DURING DSS-INDUCED COLITIS L. Sly1, S. Weisser1, H. Brugger1, N. Voglmaier1, N. Nico van Rooijen2 1. Department of Pediatrics, Division of Gastroenterology, BC Children’s Hospital, Child & Family Research Institute, and University of British Columbia, Vancouver, BC, Canada; 2. Department of Molecular Cell Biology, Vrije Universiteit Amsterdam, Amsterdam, Netherlands. Aims: Inflammatory bowel disease (IBD), encompassing Crohn’s Disease and ulcerative colitis, is a chronic disorder characterized by intestinal inflammation and ulceration. IBD is caused, in part, by an inappropriate immune response to commensal microorganisms in the gut. Macrophages contribute to intestinal inflammation in IBD but can display distinct inflammatory and anti-inflammatory activation profiles. Classically activated macrophages (CAMs), activated by IFNγ produce robust pro-inflammatory responses to microbial products. In contrast, alternatively activated macrophages (AAMs), activated by IL-4/13, have reduced inflammatory responses to microbial ligands. We have reported that AAMs are protective during DSS-induced colitis and that generation of AAMs requires the activity of the p110δ catalytic subunit of phosphatidylinositol 3-kinase (PI3K). Intriguingly, PI3Kp110δ deficient mice develop spontaneous colonic inflammation that correlates with increased macrophage production of pro-inflammatory cytokines but a causal role for macrophages in intestinal inflammation has not been demonstrated. In addition, PI3Kp110δ deficient mice have a lack of giant cells in their lymph nodes and spleens consistent with a defect in their ability to produce AAMs. Based on this, we hypothesized that increased numbers of CAMs and a defect in AAM generation disrupt intestinal homeostasis and exacerbate mucosal immune responses in these mice. Methods: To address this hypothesis, we compared PI3Kp110δ deficient mice to their wild type counterparts during DSS-induced intestinal inflammation. To determine whether increased disease severity was CAM-mediated, we used clodronate-containing liposomes versus control, to deplete macrophages during disease. Results: We found that PI3Kp110δ deficient mice had increased disease activity indices, which includes measures of weight loss, stool consistency, and rectal bleeding. PI3Kp110δ deficient mice also had increased histological damage relative to their wild type littermates, which included increased crypt loss and immune cell infiltration. Consistent with our hypothesis, PI3Kp110δ deficient mice had increased numbers of CAMs and few AAMs in their inflamed colons relative to wild type mice. CAM depletion in PI3Kp110δ deficient mice resulted in decreased disease activity indices and histological damage. Conclusions: These findings identify PI3Kp110δ as a key regulator of macrophage polarization in vivo, an important regulator of intestinal homeostasis, and a possible target for manipulation to treat IBD.

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A244 ONE THIRD OF PATIENTS TREATED WITH ADALIMUMAB AND INFLIXIMAB FOR CROHN’S DISEASE OR ULCERATIVE COLITIS PERMANENTLY DOSE-ESCALATE DUE TO LOSS OF RESPONSE D. Fedorak, P. Osatiuk, K. Wong, K. Kroeker, L. Dieleman, R. Fedorak University of Alberta, Edmonton, AB, Canada. Aims: To assess in patients with a stable, IFX-induced or ADA-induced corticosteroid-free response, the proportion of patients that lost response and required dose escalation and the proportion of those in who dose de-escalation was attempted. Methods: Through a hand searched chart review, patients were eligible to be included in the cohort for this study if they had: (1) responded to IFX (5mg/kg) induction dosing given at wks 0, 2, and 6 or ADA induction dosing of 160mg, 80 mg and, (2) advanced onto scheduled maintenance treatment every 8 weeks with IFX or every 2 wks with ADA and, (3) achieved a stable corticosteroid-free clinical benefit for at least 6 months and, (4) lost response to the anti-TNF therapy and, (5) had sufficient follow-up that allowed assessment of ongoing wellness and/or disease relapse with escalated therapy. Results: 363 patients with IBD were included in this study. 187/287 (65%) of IFX-treated patients remained in remission on 5mg/kg every 8 wks and did not dose escalate; while 100/287 (35%) required dose escalation to 5mg/kg every 4 wks. In contrast, 55/76 (72%) of ADA-treated patients remained in remission on 40mg every other wk; while 21/76 (28%) dose escalated to 40mg weekly. The median time to dose escalation was 17.7 mo (range 2.7 to 81.2mo) for IFX and 16.9 mo (range 1.4 to 92.6 mo) for ADA. De-escalation of dose was uncommon; 7 IFX patients and zero ADA patients de-escalated to the original doses. These results were similar for CD and UC. Conclusions: Approximately one third of patients with IBD treated with an anti-TNF agent lost response and required dose escalation in order to regain response. Following dose escalation only very few patients were de-escalated to the original dose.

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A245 ELEVATED C-REACTIVE PROTEIN IN ANTI-TNF-NAÏVE PATIENTS IS ASSOCIATED WITH HIGHER REMISSION RATES W. Sandborn1, J. Colombel2, M. Castillo3, Q. Zhou3, R. Thakkar3 1. University of California, San Diego, La Jolla, CA; 2. Centre Hospitalier Univ de Lille, Lille, France; 3. Abbott Laboratories, Abbott Park, IL. Aims: The CHARM trial1 demonstrated that adalimumab (ADA) was effective for the maintenance of remission in patients with moderate to severe Crohn’s disease (CD), and that remission rates are influenced by a patient’s baseline C-reactive protein (CRP) concentration and prior anti-TNF experience.1 Patients who were either anti-TNF-naïve or had an elevated baseline CRP achieved higher rates of remission than the general study population. In this post hoc analysis we examined whether patients who were anti-TNF-naïve and had an elevated CRP at baseline could achieve higher remission rates than those previously reported. Methods: Data from CHARM, a 56-week, randomized, placebo-controlled trial of ADA maintenance therapy, were analyzed. All patients received open-label ADA during a 4-week induction period, and were then randomized to ADA (40mg weekly or every other week [eow]) or placebo for a 52-week double-blind period. In this analysis, clinical remission at week 56 was determined for randomized responders (patients who had a decrease in CDAI≥70 at week 4 compared with baseline) who were naïve to prior anti-TNF treatment, by baseline CRP subgroups (high: ≥10mg/L, vs. low: <10mg/L), using non-responder imputation. Remission rates for patients treated with weekly or eow ADA were compared with rates for placebo-treated patients, using Fisher’s exact test. Results: ADA treatment (weekly or eow) resulted in statistically significantly greater rates of clinical remission at week 56 compared with placebo treatment in each CRP subgroup of anti-TNF-naïve patients (Table). The percentage of patients in clinical remission was greater in the high CRP subgroup for both weekly and eow ADA treatment. Conclusions: In the CHARM trial, anti-TNF-naïve patients with baseline CRP≥10mg/L experienced greater rates of clinical remission, regardless of ADA dose frequency, compared with patients with baseline CRP<10mg/L. Reference: 1. Colombel JF, et al. Gastroenterology. 2007;132:52-65.

Table. Clinical Remission at Week 56 in Anti-TNF-Naïve Patients in CHARM Placebo ADA 40mg eow ADA 40mg weekly n/N (%) n/N (%) P valuea n/N (%) P valuea

Baseline CRP <10mg/L 6/46 (13) 17/49 (35) 0.017 18/43 (42) 0.004 Baseline CRP ≥10mg/L 6/43 (14) 19/36 (53) <0.001 23/43 (53) <0.001

a P value versus placebo, from Fisher’s exact test.

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A246 THE SAFETY AND EFFICACY OF ANTI-TUMOR NECROSIS FACTOR-ALPHA THERAPY FOR INFLAMMATORY BOWEL DISEASE IN PATIENTS POST-LIVER TRANSPLANTATION: A CASE SERIES A. Sandhu1, T. AlAmeel2, C. Dale1, M. Levstik1, N. Chande1 1. London Health Sciences Centre, London, ON, Canada; 2. University of Alberta, Edmonton, AB, Canada. Aims: To investigate the safety and efficacy of anti-tumor necrosis factor-alpha (anti-TNF) therapy for refractory inflammatory bowel disease (IBD) in the post-liver transplantation population. Methods: The liver transplant database at London Health Sciences Centre was searched to identify adult patients with IBD post-transplantation. These patients were subsequently reviewed to identify those who had received anti-TNF therapy. Results: Seven patients (6 male, 1 female) were identified, aged 26-65. All patients had orthotopic liver transplants. Five required transplantation due to primary sclerosing cholangitis, one due to autoimmune hepatitis, and one due to biliary atresia. With respect to their IBD, six patients definitively suffered from Crohn’s disease (CD). Of these, two were initially suspected to have ulcerative colitis (UC), however following colectomy, both patients developed active ileitis and were deemed to have CD. The remaining seventh patient had pancolitis on colonoscopy with granulomas on biopsies and was diagnosed with indeterminate colitis. Four patients were diagnosed with IBD prior to transplantation and three after transplantation. Of the seven patients, all were treated with infliximab 5mg/kg every 8 weeks after undergoing induction at weeks 0, 2, and 6. The duration of infliximab therapy ranged from three months to five years at the time of data collection. Six patients treated with infliximab experienced significant improvement of their IBD symptoms post-transplantation, with improved abdominal pain, and decreased frequency and increased consistency of bowel movements. The one remaining patient, originally diagnosed with UC post-transplantation, lost response after 16 months of infliximab therapy. He ultimately required a colectomy and ileo-anal pouch procedure but experienced continued symptoms one year post-operatively and active ileitis was discovered. He was then started on adalimumab due to these unremitting symptoms. His adalimumab dose was 40mg subcutaneously every week, increased from every other week, but he did not have sustained improvements of his IBD. No patients experienced significant side effects from anti-TNF therapy, despite being on multiple anti-rejection immunosuppressive medications. As such, there were no infections, demyelinating disease, malignancy or induction of auto-immunity in these patients. Conclusions: Based on this case series, anti-TNF therapy appears to be safe and effective for treating refractory IBD in patients post-liver transplantation. These patients respond to anti-TNF therapy similarly to those who have not been previously transplanted. To date, this is the largest case series on this rarely documented population.

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A247 POOLED ANALYSIS OF LONG-TERM MMX®,A MESALAMINE SAFETY D. Solomon1, K. Paridaens2, M. Palmen3, K. Barrett3, P. Streck1 1. Shire Development Inc., Wayne, PA; 2. Shire AG, Eysins, Switzerland; 3. Shire Pharmaceuticals Inc., Basingstoke, United Kingdom. Aims: Ulcerative colitis (UC) is a chronic inflammatory disease with relapsing-remitting symptoms that often affect patients for their entire lives. As UC patients may require lifelong treatment, the long-term safety of UC therapy is very important. To evaluate the long-term safety of MMX mesalamine in the treatment of UC, safety data from 3 clinical trials were pooled and analyzed. Methods: In a phase 3 trial, patients in clinical and endoscopic remission (modified UC Disease Activity Index score ≤1, rectal bleeding and stool frequency scores of 0, no mucosal friability, and a ≥1-point reduction from baseline in sigmoidoscopy score) were randomized to 2.4 g/day MMX mesalamine administered either once daily (QD) or as 1.2 g twice daily (BID) for 12 months. In a second phase 3 trial, patients in endoscopic remission (endoscopy score ≤1 and a combined symptom score ≤1 for stool frequency and rectal bleeding) were randomized to either 2.4 g MMX mesalamine QD plus placebo BID, or 0.8 g delayed-release mesalamine BID (1.6 g/day total) plus placebo QD for 6 months. In a phase 4 trial, patients with quiescent UC (no rectal bleeding and 0-1 bowel movements/day more than normal) received 2.4 g MMX mesalamine QD for 12 months. Results: In total, 1,083 patients were enrolled or randomized to MMX mesalamine treatment across the 3 studies. Of these, 1,082 received ≥1 dose of MMX mesalamine for a mean treatment duration of 40.7 weeks. Among patients who received ≥1 dose of MMX mesalamine, 451 (41.7%) reported ≥1 adverse events (AEs) with 237 (21.9%) experiencing only mild AEs, 176 (16.3%) experiencing AEs with a maximum severity of moderate, and 38 (3.5%) experiencing severe AEs. Serious AEs were reported by 33 (3.0%) patients and 122 (11.3%) patients experienced AEs that were possibly related to study treatment. A total of 43 (4.0%) patients experienced AEs that led to withdrawal from their respective studies. The most frequently reported AEs (excluding UC) were headache (2.9%) and nasopharyngitis (2.8%). Among treatment-related AEs, the most common (excluding UC) were abdominal pain, abdominal distension, upper abdominal pain, diarrhea, dyspepsia, and increased alanine aminotransferase (0.6%-0.9%). Overall, the majority (58.3%) of patients who received MMX mesalamine did not experience any AEs and >90% of patients who reported AEs experienced ones that were mild to moderate in severity. The majority of reported AEs were considered to be unrelated to MMX mesalamine treatment. Conclusions: These findings indicate that long-term treatment of UC patients with MMX mesalamine is generally safe and well tolerated. AMMX® and MMX Multi Matrix System® are registered trademarks of Cosmo Technologies Ltd., Ireland.

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A248 ADHERENCE TO MONTHLY THIOPURINE BLOOD WORK MONITORING DECLINES OVER TIME IN ADULT PATIENTS WITH INFLAMMATORY BOWEL DISEASE J. Wong, R. Fedorak, K. Wong, K. Kroeker University of Alberta, Edmonton, AB, Canada. Aims: Patient adherence is medical therapy is usually studied in the context of medication use. Thiopurines, such as azathioprine (AZA) and 6-mercaptopurine (6-MP), are frequently used to maintain remission in inflammatory bowel disease (IBD) patients. However, due to the adverse effects of thiopurines, namely leukopenia and elevated liver enzymes, monthly blood work monitoring is recommended to patients on thiopurines. The aim of this study is to determine the adherence of patients on thiopurines to monthly blood test monitoring and to determine if this changes over time on thiopurines. Methods: A patient search was conducted in a university gastroenterology patient database to identify IBD patients currently on thiopurines. Charts were reviewed for demographic information, diagnosis and blood test frequency and results, which include white blood cell (WBC) and liver enzymes. Data was recorded on a spreadsheet. For the purpose of this study, only blood tests measured over 20 days apart were counted as monthly blood tests. In addition, only blood test results between 2005 and 2011 were considered. Blood work was grouped based upon the time period from initiating thiopurine therapy to standardize the results. Data was subsequently categorized into groups by number of venipunctures per year and analyzed using Microsoft Excel 2007 and SPSS 14.0. Results: The initial patient search identified 348 IBD patients on thiopurines. 165 patients were included in this study. Reasons for exclusion include: did not live in the local area and so could not confirm if all blood tests were available (163); patients were in clinical trials (4); and incomplete patient records (16). Mean age was 36.5±1.1 years, 48% were male, and 76% had Crohn’s disease. The average blood tests per year (mean±SE) for the first year of thiopurine treatment was higher than patients on thiopurines for greater than one year (7.7±0.32 v. 5.3±0.17, p=5.47x10-11). Conclusions: IBD patients on thiopurines had blood tests less frequently than the recommended monthly monitoring. Adherence to blood work monitoring was significantly higher in the first year of thiopurine treatment compared to subsequent years. Table 1. Frequency of venipuncture per year varies by duration of thiopurine use (Data reported as number and % of patients in that year of thiopurine use; Chi-squared, p=0.000015)

# Venipuncture in that Year Year of Thiopurine Treatment 0 1-3 4-6 7-9 10-12

1 (n=78) 0 4 (5.1%) 23 (39.5%) 28 (35.9%) 23 (29.5%) 2 (n=59) 0 15 (25.4%) 24 (40.7%) 9 (15.3%) 11 (18.6%) 3 (n=55) 0 14 (25.5%) 21 (38.2%) 13 (23.6%) 7 (12.7%) 4 (n=54) 0 17 (31.5%) 21 (38.9%) 10 (18.5%) 6 (11.1%) 5 (n=50) 1 (2.0%) 14 (28.0%) 23 (46.0%) 8 (16.0%) 4 (8.0%)

6+ (n=65) 2 (3.1%) 20 (23.3%) 31 (27.7%) 11 (16.9%) 1 (1.5%)

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A249 AN AUDIT OF ADALIMUMAB ESCALATION STRATEGIES AND THEIR EFFECTIVENESS IN PATIENTS WITH CROHN’S DISEASE FLARES AT A CANADIAN ACADEMIC CENTER. J. McCurdy, B. Currie, K. Phalen-Kelly, D. MacIntosh, S. Gruchy Dalhousie University, Halifax, NS, Canada. Aims: Chrohn’s disease flares in individuals treated with the tumor necrosis factor alpha (TNF) neutralizing antibody, adalimumab, are common and challenging to treat. Medical options include: switching to an alternate biologic agent or escalating adalimumab therapy by dose increase, reducing the drug interval or re-induction followed by a return to maintenance doses. Currently no studies have determined the optimal strategy. The current study assessed the frequency of each therapeutic strategy for adalimumab and their effectiveness in the treatment of individuals with crohn’s disease flares. Methods: A retrospective chart review analyzed one hundred and two consecutive patients with crohn’s disease treated with adalimumab from a nurse practitioner database. All primary responders who developed clinical flares requiring an escalation of adalimumab therapy were included in the analysis. The frequency of each strategy utilized was examined along with their clinical effectiveness. Endpoints included hospitalizations and surgeries within six months and rates of clinical remission at greater than two months determined by the clinicians global assessment. Results: Twenty-four of one hundred and two patients initially treated with adalimumab required drug escalation. Fifty-four percent were male and had a mean disease duration of 15 years. Disease location involved, the small bowel, colon, or both in 29, 21 and 50% respectively. Perianal disease occurred in 54%. Re-induction, dose increase or decreasing the drug interval was used in 29, 8 and 63% of individuals respectively. Combined, 67% of patients achieved a clinical response and 46% were in remission. 25% required hospitalization while 16% required surgery. Sub group analysis revealed remission rates of 50 and 40%, hospitalization rates of 28 and 26% and surgical rates of 14 and 13% respectively for re-induction and drug interval reduction strategies. Conclusions: The results of this study demonstrate the effectiveness of adalimumab escalation strategies for achieving clinical remission in individuals with crohn’s disease flares. Although the various escalation strategies yielded similar clinical outcomes including remission rates, surgeries and hospitalizations, the study was not powered to detect individual differences. Further studies using a prospective approach and validated crohn’s disease activity indexes are required to determine the optimal therapeutic approach.

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A250 AZATHIOPRINE COMPLIANCE AND ADVERSE EVENTS IN A COHORT OF PATIENTS WITH INFLAMMATORY BOWEL DISEASE I. Soo, S. Randhawa, R. Fedorak university of alberta, edmonton, AB, Canada. Aims: Leukopenia and hepatoxicity are recognized adverse effects of therapy with azathioprine occuring in approximately 5% of patients with inflammatory bowel disease (IBD). Conventional clinical wisdom dictates serial monitoring of white blood cell count (WBC) and abnormal LFTs as a means of identifying patients at risk of these complications. Nevertheless, evidence to support serial monitoring is lacking and the adherence rate of patients relative to the venipuncture needed to acquire this testing remains unknown. The objective of this study is, in patients with IBD treated with azationprine: (1) to characterize patient compliance with serial venipuncture for monitoring azathioprine-associated adverse events and to (2) determine the incidence of leucopenia and abnormal LFTs. Methods: A retrospective chart review of patients with IBD initiated on azathioprine between 2007 to 2011 was conducted. All patients on azathioprine were supplied with written and verbal instructions to obtain venipuncture for serial monitoring of azathioprine-associated adverse events. Results: 05 patients (65 Crohn’s, 38 ulcerative colitis, 2 indeterminate) were entered into the study. Mean age 36.7 ± 14.2 yr. 57 male; 48 female. 60.0 ± 41.0% patients completed the weekly venipuncture requested by the protocol during the first month of azathioprine therapy. After the first month of therapy only 57.5 ±28.4% of patients were adherent to the monthly venipuncture protocol. There was no significant difference in adherence between patients started on therapy in hospital compared to an outpatient. Ten (9.5%) patients experienced a WBC ≤ 3.0. Six had a singular episode while two had two, one had three and one had four episodes of leucopenia. All patients had the low WBC within one year of either azathioprine initiation or therapeutic modification including two with 5-ASA therapy initiation and one with an escalation of azathioprine dosage. Patients with low WBC did not develop any clinical sequella as a consequence. The weekly (median 100%, IQR 50-100%) and monthly compliance (median 88.5%, IQR 56.5-100%) rates were excellent in the group of patients found to have low WBC. Six (5.7%) patients experienced abnormal LFTs. All episodes occurred within one year of azathioprine initiation or therapy modification. No significant illness occurred from the abnormal LFTs. Weekly (median 100%, IQR 62.5=100%) and monthly (69.2%, IQR 45.8-89.2%) bloodwork compliance was above average compared to the entire IBD cohort. Conclusions: Compliance with serial venipuncture to monitor leucopenia and abnormal LFTS associated with azathioprine therapy in patients with IBD is generally poor. Leucopenia and/or abnormal LFTs are generally detected within one year of azathioprine therapy being initiated or modified and patients remain clinically well during these events.

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A251 THE C/EBPβ TRANSCRIPTION FACTOR REGULATES INTESTINAL INFLAMMATION. C. Asselin, N. Turgeon, M. Blais Département d'anatomie et biologie cellulaire, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: The C/EBPβ transcription factor regulates the intestinal epithelial cell (IEC) inflammatory response, and controls the differentiation of immune cells, including macrophages and granulocytes. Hypothesis: C/EBPβ is an important regulator of intestinal inflammation in vivo. Methods: Colitis was induced in control, C/EBPβ global or intestinal-specific knockout mice by adding 3.5% DSS to the drinking water. Proximal and distal colons were harvested after 6 days. Severity of colitis was assessed by the Disease Activity Index (DAI), with parameters including body weight, stool consistency, fecal blood loss and colon length, and by histological criteria. The presence of inflammatory cells was determined by immunofluorescence with antibodies against the immune cell marker CD4. Inflammatory gene expression was assessed by semi-quantitative RT-PCR analysis, with total distal colon RNAs. Results: C/EBPβ-deficient mice did not display apparent signs of intestinal inflammation at the basal level. However, C/EBPβ knockout mice were more sensitive to DSS treatment, as determined by DAI and histological criteria. C/EBPβ -/- mice showed decreased recovery and increased mortality after the end of DSS treatment. Increased recruitment of CD4+ immune cells was observed. Aggravated C/EBPβ-deficient mice colitis symptoms correlated with increased expression of inflammatory genes, such as Il6, Il17, Ifnγ, Il12b, Il22, Tnfα, Icos and Cxcl1. Finally, IEC-specific C/EBPβ-deficient mice showed increased inflammatory manifestations. Conclusions: C/EBPβ regulates intestinal inflammation by affecting both the resolution and the duration of the inflammatory response. In addition, IEC-specific C/EBPβ may contribute to the intensity of colitis manifestations. Supported by CCFC.

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A252 EFFICACY AND SAFETY OF ADALIMUMAB IN MODERATE COMPARED WITH SEVERE CROHN'S DISEASE: POOLED DATA FROM THE CHARM AND EXTEND TRIALS J. Colombel1, W. Sandborn2, M. Castillo3, Q. Zhou3, R. Thakkar3 1. Centre Hospitalier Universitaire de Lille, Lille, France; 2. University of California San Diego, La Jolla, CA; 3. Abbott Laboratories, Abbott Park, IL. Aims: The efficacy of adalimumab (ADA) in Crohn’s disease (CD) by disease duration has been explored,1 but efficacy and safety of ADA by disease severity have not been investigated. The CHARM2 and EXTEND3 trials assessed ADA treatment for the maintenance of remission in patients with moderate to severe CD. Results from CHARM and EXTEND in patients with moderate versus severe CD were pooled to assess efficacy and safety by disease severity. Methods: This analysis of pooled data was performed to assess clinical response and clinical remission at week 56 (CHARM) or 52 (EXTEND) in patients with moderate (CDAI≤300) or severe (CDAI>300) CD, treated with blinded ADA every other week (eow) or placebo. In both trials, patients received open-label ADA induction (CHARM: 80mg at week 0, 40mg at week 2; EXTEND: 160mg at week 0, 80mg at week 2), followed by blinded treatment (ADA 40mg eow or weekly, or placebo in CHARM, 40mg eow or placebo in EXTEND) from weeks 4 to the end of the trial (week 56 in CHARM, week 52 in EXTEND). Data from the ADA 40mg eow arm of CHARM was pooled with data from EXTEND; safety and efficacy (proportion of patients in clinical remission, defined as CDAI<150, or clinical response, defined as at least a 70 point decrease in CDAI [CR70]) at week 56/52 were assessed for patients who achieved CR70 at week 4, separated by baseline disease severity (moderate or severe). Results: A total of 438 patients were included in the pooled analysis: 187 with moderate CD (placebo: 92; ADA: 95) and 251 with severe CD (placebo: 126; ADA: 125). For both moderate and severe CD groups, a statistically significantly greater proportion of patients treated with ADA 40mg eow achieved clinical response and clinical remission at week 56/52 compared with placebo treated patients (Table). The safety profiles in the moderate and severe CD subgroups were similar. Conclusions: The analysis of the pooled data from CHARM and EXTEND suggests that ADA 40mg eow is safe and effective for the treatment of either moderate or severe CD. References: 1. Schreiber S. Gastroenterology. 2007; 132:A-147. 2. Colombel JF. Gastroenterology. 2007; 132:52. 3. Rutgeerts P. Gastroenterology. 2009; 136:A-116.

Table. Clinical Response (CR70) and Clinical Remission at Week 56/52, by Baseline CDAI: Pooled Data from CHARM and EXTEND

CDAI ≤300 CDAI >300 Placebo ADA 40mg eow P value* Placebo ADA 40mg eow P value*

CR70 (%) 16 44 <0.001 14 44 <0.001 Clinical remission (%) 14 40 <0.001 7 34 <0.001

*ADA vs placebo.

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A253 FREQUENT INSUFFICIENT VITAMIN D LEVELS OCCUR IN BOTH IBD PATIENTS AND CONTROLS WHILE IBD FAMILIES, BUT NOT CONTROL FAMILIES ARE REPLETE A. Grunbaum1, C. Holcroft1, D. Heilpern1, S. Gladman1, B. Burstein2, E. MacNamara1, P. Gordon1, A. Szilagyi1 1. Jewish General Hospital, Dept Medicine, Gastroenterology, Montreal, QC, Canada; 2. Jefferson Medical College, Philadelphia, PA. Aims: Previously, vitamin D insufficiency in IBD was suggested to increase risk of disease activity.We hypothesize that vitD insufficiency may be more prevalent in IBD families thus increasing IBD risk both dietetically in addition to genetics. Methods: We undertook a prospective observational study of vit D in patients (PTS, CD and UC, 90% remission), 1o family compared to matched healthy controls (CT) and 1o families (not matched to PTS families), (Jan 2008-May 1,2010, Ethics approved). A diet questionnaire was completed(including Vit D, Ca, dairy foods and supplemnets of Vit D and Ca) and blood tests were drawn (CBC, biochemistry,Ca, and serum Vit D 25 (OH) [RIA kit])[replete ≥75nmol/l, insufficient 50-74nmol/l, deficient <50nmol/l] noting seasons [Oct-April, May-Sept]. Patients Vit D levels were compared: CD vs UC; PTS to CT and IBD family units [PTS + 1o family] andCT family units [CT + 1o family]. Statistical analysis was carried out using t-tests and regression with log Vit D, α was set at 0.05. Results: 55 PTS [34 CD, 21 UC], 48 CT, and 1o degree families were recruited (N206). Family unit analysis showed a modest vit D correlation within families (PTS and family r2=0.24; CT and family r2=0.29; NS) . Demography: PTS: 62% male, µ age 41.5, 95% Caucasian, 51% Jewish; CT: 79% male, µ age 39.6, 79% Caucasian, 42% Jewish. BMI (PTS) was 24.6 [range 18.8-34.4], (CT) 25.7 [18.8-64.1]. PTS µ duration was 5.7, [0.1-47] yrs. Site of CD: 58% small bowel 42% colon alone and UC: 81% pancolitis.Of all PTS, 15% were on steroids, 42% Aza, 11% on biologics and 27% post-surgery (93%CD). Total Vit D intake was 784 ± 720 IU[PTS] and 917 ± 1028 [CT] (NS). Overall Vit D 25 (OH) nmol/L, (PTS vs CT NS): PTS: 71.2 ± 32.8, Family: 82.3 ± 34.2, CT: 68.3 ± 26.2 and Family: 69.9 ± 27.6.CD and UC PTS had similar values.53% PTS and 63% CT had Vit D <75 nmol/L , 31% PTS and 23% CT were < 50nmol/L (all NS). When PTS and Family Vit D levels were paired, the difference from 0 (p = 0.016). Levels of Vit D were significantly (p< 0.05) influenced in univariate analysis by season (sunny mo.: µ= 76.1±30, sunny- mo; µ=64.8±28.7nmol/L, p=0.046), vacation 1mo prior to test (only 8 subjects in PTS and CT), Jewish ethnicity, total and dietary intake of calcium. In multivariable regression for Vit D including PTS and CT, vacation 1mo prior to test (p=0.002), total calcium intake (p=0.02) and season (p=0.098) remained in the model. Conclusions: Prevalence of vitD insufficiency is high in PTS and CT. Contrary to expectations, family members of IBD patients have higher Vit D levels and are more often replete than patients. The explanation for this is not readily apparent.

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A254 ASSESSING THE PERFORMANCE OF INTERFERON-GAMMA RELEASE ASSAYS IN INFLAMMATORY BOWEL DISEASE: A SYSTEMATIC REVIEW AND META-ANALYSIS N. Shahidi1, Y. Fu1, H. Qian2, B. Bressler1 1. Department of Medicine, Division of Gastroenterology, University of British Columbia, Vancouver, BC, Canada; 2. Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, BC, Canada. Aims: Current guidelines mandate screening for latent tuberculosis infection (LTBI) prior to commencing anti-tumor necrosis factor (anti-TNF) therapy. However, many patients are already taking immunosuppressive therapy (IST), which can affect current diagnostic tests, such as the tuberculin skin test (TST). Due to the recent introduction of the interferon-gamma release assays (IGRA), we sought out to assess their ability to detect LTBI in patients with inflammatory bowel disease (IBD) and the impact of IST on these new tests. Methods: MEDLINE and EMBASE, were searched (up to June 2011) to identify studies evaluating the performance of three IGRAs (QuantiFERON-TB Gold (GFT-2G), QuantiFERON-TB Gold In-Tube (GFT-3G) and T-SPOT.TB) in individuals with IBD. A hierarchy of outcomes for the evaluation of IGRAs was used to facilitate data extraction. Forest plots and pooled estimates using random effects models were created where applicable. For pooled estimates, QFT-2G and QFT-3G were considered equivalent Results: 9 unique study populations, encompassing 1309 patients with IBD were included for analysis. The pooled concordance between the TST and QFT-2G/QFT-3G was 85% (95% CI 77 - 90%) in comparison to the concordance of the TST and TSPOT.TB which was 72% (95% CI 64 - 78%). All studies assessing % agreement reported a greater proportion of IGRA-/TST+ results compared to IGRA+/TST- results. The pooled % of indeterminate results was 5% (95% CI 2 - 9%) for QFT-2G/QFT-3G. TSPOT.TB showed similar results. IST significantly influenced both positive QFT-2G/QFT-3G results (pooled OR 0.37; 95% CI 0.16 - 0.87) and positive TST results (pooled OR 0.28; 95% CI 0.10 - 0.80) (both p = 0.02). The negative impact of IST continued throughout sub-analyses concerning almost all forms of IST. Conclusions: Our results suggest that while it remains difficult to determine superiority between the IGRAs and the TST in identifying LTBI in IBD, both are negatively affected by IST. Therefore, current guidelines which propose screening before anti-TNF therapy may want to consider suggesting screening prior to other forms of IST as well.

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A255 A PRESENTATION OF INFANTILE-ONSET COLITIS AND THE IDENTIFICATION OF A NEW IL10R POLYMORPHISM P. Valentino1, C. Guo2, S. Benseler3, C. Roifman4, A. Griffiths1, A. Muise1 1. Division of Gastroenterology, Hospital for Sick Children, Toronto, ON, Canada; 2. Program in Cell Biology, University of Toronto, Toronto, ON, Canada; 3. Division of Rheumatology, Hospital for Sick Children, Toronto, ON, Canada; 4. Division of Immunology and Allergy, Hospital for Sick Children, Toronto, ON, Canada. Aims: Infantile colitis is a distinct entity, different from later-onset inflammatory bowel disease (IBD). These children may have specific mutations in genes involved in the regulation of the immune system leading to disregulation and autoimmunity. Methods: We present the case of a Caucasian female child who developed symptoms of colitis at six months of age, which was caused by a single gene mutation. Results: The child first presented due to fever in the first week of life. She was hospitalized four times by age 2 months due to recurrent febrile illnesses requiring antibiotics including: rotavirus infection, peri-orbital cellulitis, and aseptic meningitis. At 3 months of age she developed a scalp cellulitis with pustules, generalized erythroderma and eczema. An immunodeficiency was suspected at this point, however subsequent investigations, including a thymic biopsy, were non-contributory. At approximately age 5 months, she developed unremitting bloody diarrhea as well as peri-anal disease with skin tags that progressed to rectovaginal fistulae requiring a diverting loop-ileostomy at age 23 months. Endoscopy was significant for the identification of colonic ulcerations with friability and both acute and chronic colitis on histology without granulomata. Her symptoms improved slightly with intravenous steroids, but there was poor response to sulfasalazine, azathioprine, anakinra, intravenous immunoglobulins or antibiotics. Subsequently, she developed large joint polyarthritis that impaired ambulation and required steroid injections. Genetic investigations identified a novel mutation at the 5’ splice site of the IL10 receptor alpha chain. This impaired normal RNA splicing leading to a frame-shift, incorporation of an early stop codon at P206X and a truncated protein product. Both parents were heterozygous carriers of this mutation and were consanguineous from the same geographically isolated region of Canada. Conclusions: IL10 polymorphisms were identified via GWAS analysis to be associated with IBD. The literature reports 2 children with homozygous mutations of the IL10 gene and 6 children with homozygous mutations of the IL10 receptor, with impaired signaling through STAT3. All children developed colitis before age 12 months. Here we describe a novel mutation of the IL10 receptor that was associated with infantile-onset colitis, arthritis, pustular rashes, and recurrent infections. We suspect there are other mutations causing infantile-onset colitis that have yet to be elucidated, the identification of which will have major impact on disease management.

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A256 RESOURCE UTILIZATION DURING PEDIATRIC TO ADULT TRANSFER OF CARE IN INDIVIDUALS WITH IBD N. Bollegala, H. Brill, J. Marshall McMaster University, Hamilton, ON, Canada. Aims: The transition from pediatric to adult care within Inflammatory Bowel Disease (IBD) is poorly understood. Purpose: To compare health resource utilization during the last year of pediatric care and first year of adult care. Methods: Patients transferred between 1999 and 2008 were studied. Utilization of health resources one year before transfer and one year after transfer were compared. The resource units assessed included: i) Emergency Department (ED) visits; ii) hospitalizations; iii) clinic visits; iv) surgical procedures; and v) endoscopies. Secondary outcomes included: i) documentation of patient non-compliance; ii) reason(s) for ED visit; iii) diagnoses most responsible for hospital admission; iv) medications; v) indications for surgery; vi) endoscopic findings; vii) and disease activity. Results: 95 subjects were identified (48 female), of whom 69 had Crohn’s disease (CD) and 26 had ulcerative colitis (UC). The average age of diagnosis was 12.9 years. Over their adult care interval, subjects had fewer clinic visits (2.56 vs. 3.05 (p=0.01)) and more documented non-compliance (43% vs. 29% (p=0.01)). No differences in ED visits (0.15 vs. 0.18 (p=0.71)), hospitalizations (0.13 vs. 0.13 (p=0.23)), surgical intervention (0.03 vs. 0.05 (p=0.53)) or endoscopies (0.37 vs. 0.25 (p=0.11)) were observed. Active disease was seen at 66.7% of endoscopies under pediatric care vs. only 23.8% under adult care (p=0.003). The average activity of CD was also higher during the last year of pediatric care (HBI 3.1 vs. 1.84 (p=0.03)). Conclusions: The transition from pediatric to adult care is a challenging experience for patients with IBD, their families and care providers. This is the first study to measure quantifiable markers of care during the transfer period. Comprehensive transition programs that address all of these potential shortfalls are needed to optimize resource utilization, compliance, health outcomes, and the satisfaction of patients, families and healthcare providers.

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A257 ENDOMETRIOSIS MIMICKING SYMPTOMS OF MICROPERFORATION IN A TEENAGE GIRL WITH INFLAMMATORY BOWEL DISEASE H. Evangeliou, S. MacDonald, M. Blumenkrantz, V. Morinville Montreal Children's Hospital, McGill University Health Centre, Montreal, QC, Canada. Aims: Crohn’s disease (CD) and Ulcerative Colitis (UC) are systemic conditions that can cause both local intestinal and more distant complications. However, not all abdominal symptomatology in a patient known for inflammatory bowel disease (IBD) is necessarily related to the condition itself. We hereby report a case of a teenage girl diagnosed with UC at age 15, who presented with cyclic episodes of peritoneal symptoms, initially attributed to potential microperforations, but subsequently diagnosed with serosal endometriosis. Methods: Chart review. Results: A 16-year old girl was hospitalized 3 times over a 9-month period for episodes of severe, sudden onset abdominal pain with peritoneal signs. Her past medical history was significant for a diagnosis of pancolitis UC at age 15, initially treated with steroids and immunomodulator. Despite the diagnosis of UC and the patient being well in between episodes, the recurrent presentations were felt to be concerning for mis-labelled CD complicated by microperforations. The patient was managed with bowel rest, intravenous antibiotics and steroid therapy on each occasion. The proposed diagnosis began to be questioned as several ancillary tests did not suggest CD: cross-sectional imaging did not demonstrate fistulizing disease; repeat gastroscopy, colonoscopy, and capsule endoscopy failed to reveal small bowel involvement; and antibody serologies were consistent with UC. Upon review of history, pain crises were found to be cyclical, corresponding to menses or missed menstrual cycles. Pelvic magnetic resonance imaging search for endometriosis was negative, but showed non-specific inflammation of the right lower pelvis. Due to ongoing symptoms, the patient underwent a diagnostic laparoscopy, with findings of a macroscopically diseased appendix. Appendectomy pathologic specimen revealed serosal endometriosis. The patient was placed on continuous oral contraceptive pill hormonal therapy and cyclical crises ceased. Conclusions: IBD may present a myriad of symptoms and complications. This case highlights the importance of considering non-IBD related diagnoses, especially if the clinical presentation is unusual. Bowel endometriosis may present with peritoneal symptoms and occasionally may be found in the appendix (prevalence of appendiceal location in bowel endometriosis estimated at 5 to 18%). Magnetic resonance imaging frequently confirms the diagnosis, but gold standard remains laparoscopic examination. Endometriosis is not believed to be related to IBD, but has occasionally been described a mimicker of IBD, either at initial presentation or subsequently, as in our patient. Treating physicians must remain vigilant to consider endometriosis as a possible etiology in females with IBD presenting with peritoneal signs.

A258 ANGIOEDEMA ASSOCIATED WITH CROHN'S DISEASE: RESPONSE TO BIOLOGICS V. Huang, F. Habal University Health Network, University of Toronto, Toronto, ON, Canada. Aims: To present the first known case report of chronic idiopathic urticaria with angioedema coexistent with Crohn’s disease that was successfully treated with anti-TNF-alpha agents, and to propose a hypothesis of the common pathophysiology of angioedema and Crohn's disease. Methods: A case review of a patient with Crohn's disease and angioedema is presented. A literature review was conducted on angioedema in inflammatory bowel diseases and a hypothesis generated. Results: A 46 year old patient with terminal ileum Crohn’s disease and ankylosing spondylitis presented with recurrent angioedema and urticaria. Investigations ruled out hereditary angioedema, and environmental or food allergen triggers. She was diagnosed with chronic idiopathic urticaria with angioedema, and was treated with a trial of IVIG immunotherapy, danazol, prednisone, and hydroxyzine. Due to ongoing bowel and arthritic complaints, she was started on Infliximab infusions and within 2 treatments, she had complete resolution of the angioedema and urticaria, as well as of the bowel and arthritic symptoms. Unfortunately she developed allergic reactions to the Infliximab and was switched to another anti-TNF alpha agent, adalumimab. Since then, she has had no further angioedema or urticaria, and her Crohn’s disease has been quiescent. Conclusions: Studies have shown that there is a strong autoimmune involvement in the pathophysiology of urticaria and angioedema. There are increases in pro-inflammatory cytokines, such as IL-1 beta, IL-12p70, TNF-alpha, IL-6, IL-10, and IL-17, in chronic idiopathic urticaria. Crohn’s disease also has autoimmune involvement, and there is evidence for an altered cytokine milieu leading to mucosal inflammation. Recent studies have shown that T-cell production of certain cytokines play a strong role. One common thread in the pathophysiology of chronic idiopathic urticaria and Crohn’s disease is the derangement in cytokine levels, in particular, IL-17, and TNF-alpha. The IL-17 cytokines are T-cell derived cytokines that stimulate various cells to secrete cytokines and chemokines, and therefore play an important role in many autoimmune diseases. It has been shown that IL-17A positive cells are increased in the inflamed mucosa of IBD patients, and IL-17F mRNA expression is elevated in the mucosa of Crohn’s disease patients. Infliximab and Adalumimab are anti-TNF-alpha agents that block the inflammatory cascade. Given the similarity in cytokine derangements found in chronic idiopathic urticaria and in Crohn's disease, medications that target these cytokines, such as anti-TNF-alpha agents should be effective in both conditions. This case brings to attention the common pathophysiology between autoimmune diseases, and the need for further research looking into the changes in the cytokine milieu as potential targets for treatment.

Angioedema and urticaria of the face.

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A259 INDIRECT COMPARISON OF BIOLOGICS IN CROHN’S DISEASE; COST PER REMITTER AND NUMBER NEEDED TO TREAT M. Hubert1, D. Parison1, M. Martel2, D. Lafontaine1 1. Abbott Laboratories, St-Laurent, QC, Canada; 2. Abbott Laboratories, Abbott Park, IL. Aims: As no head-to-head trial has compared the efficacy of biologics for Crohn’s disease, an indirect comparison was undertaken in a Canadian setting. Two biologics are currently used to treat moderate to severe active Crohn’s disease. In order to distinguish adalimumab from infliximab, CDAI remission rates and annual drug cost were contrasted between them. Methods: Two methods assessed the cost per remitter, a measure integrating the burden of patients not achieving remission. The first drew on two randomized, double-blind, placebo-controlled trials, namely ACCENT I for infliximab and the Crohn’s Trial of the Fully Human Antibody Adalimumab for Remission Maintenance (CHARM) for adalimumab. The absolute risk reduction seen in trial patients generated a number needed to treat in the second method, from which a second cost per remitter was derived. Results: Using remission rates at week 26 for adalimumab and at week 30 for infliximab, the estimated cost per remitter was $30,393 and $48,205, respectively. The number needed to treat was 4.3 for adalimumab and 5.5 for infliximab, drawing costs per remitter of $52,725 and $104,277, respectively. Conclusions: The indirect comparison outlines considerable differences in cost and efficacy. Adalimumab is associated with both the lowest number needed to treat and lowest cost per remitter, demonstrating increased value for patients as well as for payers and the Canadian healthcare system.

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A260 INDUCTION OF REMISSION WITH ADALIMUMAB IN PATIENTS WITH MODERATE CROHN’S DISEASE: SUBANALYSIS OF CLASSIC I W. Sandborn1, J. Colombel2, M. Castillo3, Q. Zhou3, R. Thakkar3 1. University of California, San Diego, La Jolla, CA; 2. Centre Hospitalier Univ de Lille, Lille, France; 3. Abbott Laboratories, Abbott Park, IL. Aims: CLASSIC I,1 a randomized, double-blind, placebo-controlled, dose-ranging trial, demonstrated that adalimumab (ADA) 160 mg at week 0, followed by 80 mg at week 2 is the optimal induction regimen in anti-TNF-naïve patients with moderate to severe Crohn’s disease (CD). It also showed that patients with baseline C-reactive protein (CRP) concentration ≥10mg/L achieved higher rates of clinical remission (CDAI score <150) at week 4. Methods: This post hoc analysis evaluated efficacy in patients with moderate CD (baseline CDAI≤300) and whether elevated (CRP≥10mg/L) in this subgroup would similarly improve efficacy, compared with results for patients with severe CD. Clinical remission at week 4 was assessed for patients who received induction with ADA (160mg/80mg or 80mg/40mg) or placebo in CLASSIC I. Patients with the following characteristics were included in the analysis: baseline CRP≥10mg/L; moderate CD (baseline CDAI≤300); moderate CD with baseline CRP≥10mg/L; severe CD (baseline CDAI>300); and severe CD with baseline CRP≥10 mg/L. Results: A greater proportion of patients treated with ADA induction (160mg/80mg) achieved clinical remission compared with patients treated with placebo (Table). The highest efficacy was seen in patients with moderate CD and elevated baseline CRP, with more than half achieving clinical remission after induction with ADA 160mg/80mg. Conclusions: In CLASSIC I, ADA 160mg/80mg was effective at inducing remission in all subgroups studied, including the subgroup of patients with moderate CD; in this subgroup, high baseline CRP was associated with substantially higher remission rates. This analysis suggests that patients with moderate disease can be treated effectively with adalimumab, especially when there is evidence of inflammation. Prospective studies are warranted to confirm these findings. Reference: 1. Hanauer SB, et al. Gastroenterology. 2006;130:323-33.

Table. Percent of Patients in Clinical Remission at Week 4 Placebo ADA 80/40 ADA 160/80

All Patients 12% (9/74) 24% (18/75) 36% (27/76)** CRP ≥10mg/L, % (n/N) 4% (1/28) 27% (9/33)* 43% (12/28)**

CDAI ≤300, % (n/N) 17% (8/46) 29% (13/45) 46% (19/41)** CRP ≥10mg/L, CDAI ≤300, % (n/N) 7% (1/15) 26% (6/23) 57% (8/14)**

CDAI >300, % (n/N) 4% (1/28) 17% (5/30) 23% (8/35)* CRP ≥10mg/L, CDAI >300, % (n/N) 0% (0/13) 30% (3/10) 29% (4/14)

*P <0.05 versus placebo. **P <0.005 versus placebo.

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A261 UBIQUITIN E3 LIGASE A20 LIMITS INTESTINAL INFLAMMATION P. Yang1, H. Song1, Z. Liu2 1. McMaster University, Hamilton, ON, Canada; 2. Tongji University, Shanghai, China. Aims: Macrophages (Mos) are one of the inflammatory cell populations in the intestinal mucosa of inflammatory bowel disease (IBD). The proinflammatory cytokines from Mos and nuclear factor-kappa B (NF-kB) play a critical role in IBD. The ubiquitin E3 ligase A20 (A20) plays an important role in limiting the activation of NF-kB. This study aims to elucidate the role of A20 in regulating the intestinal inflammation. Methods: IBD colon biopsies were collected and observed with immune staining for A20 expression. A20-deficient and wild macrophages were prepared to characterize the role of A20 in limiting intestinal inflammation. Results: We collected colon biopsies from 14 UC, 11 CD and 8 colon polyp patients (using as non-IBD control). The immune staining results showed significantly less A20+ Mos in colonic mucosa of IBD patients as compared to controls (Numbers of A20+ Mos: 32.2 ± 3.6/mm2 and 16.5 ± 2.4/mm2 in colonic mucosa of IBD and control, respectively; p<0.01). We next tested the role of TNFa on the expression of A20 in Mos. Bone marrow derived Mos (BMos) were stimulated by a representative microbial product, peptidoglycan (PGN) in culture at graded doses. The expressions of both NF-kB and A20 in BMos were increased in a PGN dose-dependent manner. The addition of TNF-alpha into the culture significantly suppressed the levels of A20 (reduced 3.5 ± 1.2 folds), but markedly increased the levels of NF-kB (increased 4.8 ± 1.4 folds) in BMos. To confirm the results, the TNFa receptor (TNFaR) gene was knocked down from BMos by RNA interference (RNAi) via transducing with lentiviral vector carrying TNFaR shRNA. Indeed, subsequent exposure to PGN did not alter the levels of A20 and NF-kB in the TNFaR-deficient BMos. The above results indicate that A20 is a repressor of NF-kB in Mos. We then knocked down the A20 gene in BMos by RNAi with lentiviral constructs carrying shRNA of A20. The A20-deficient BMos were stimulated with PGN that resulted in significant increases in TNFa (increased 3.8 ± 1.6 folds) and IL-1beta (increased 5.3 ± 1.8 folds) in the culture supernatants. The control shRNA did not alter the PGN-induced proinflammatory cytokines in BMos. Subsequently, we adoptively transferred the PGN-stimulated A20-deficient Mos (10 million Mos/mouse) to BALB/c mice and then treated with a small dose of TNBS (1.2 mg TNBS/mouse) via published procedures. The mice were sacrificed one week later to examine the colon. The results showed that mice treated with the small dose of TNBS alone did not show detectable signs of colitis while the mice treated with PGN-stimulated A20-deficinet BMos and a small dose of TNBS had severe inflammation in the colon. Conclusions: A20 plays an important role in limiting intestinal inflammation.

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A262 A DANGEROUS GAME OF PAC-MAN: HEMOPHAGOCYTOSIS IN A PATIENT WITH ULCERATIVE COLITIS AND PSC L. Crabbe, B. Lumb McMaster University, Hamilton, ON, Canada. Aims: Hemophagocytic syndromes (hemophagocytic lymphohistiocytosis, HLH) represent a severe hyperinflammatory condition with the cardinal symptoms of prolonged fever, cytopenias, elevated ferritin, elevated triglycerides, hepatosplenomegaly, and hemophagocytosis by activated, morphologically benign macrophages. As patients with hemophagocytosis generally present with a severe systemic inflammatory response they are often mistaken for sepsis and the diagnosis can be challenging. Reactive hemophagocytic syndromes are associated with infection, malignancies or autoimmune disorders. Methods: We describe a patient with a history of Ulcerative Colitis (UC), not on immunosuppressive therapy, and Primary Sclerosing Cholangitis (PSC) with hemophagocytic syndrome. Results: A 37 year old male with a history of UC (dx 1994) and PSC (dx 2009) was admitted to hospital due to high fevers, tachycardia and hypotension. The patient was started on broad spectrum antibiotics and a subtotal colectomy was performed for a recent diagnosis of high grade adenocarcinoma of the proximal transverse colon. The patient had further deterioration post-operatively and was admitted to ICU for worsening SIRS criteria and query sepsis. All infectious work up remained negative. The diagnostic criteria of HLH were reviewed. The patient met the majority of the criteria: fever, splenomegaly (20cm), cytopenias (hb 72, wbc 4.7, plts 55), hypertriglyceridenemia or hypofibrinogenemia (TG 3.61, fibrinogen 1.0), hepatitis (AST 209, Alk phos 150, bili 208, conj 140), elevated ferritin >3000 (ferritin 49 478, peaked at 141 682). Bone marrow was consistent with hemophagocytosis. Natural killer levels are generally decreased in hemophagocytois but were slightly increased in this case at 14%. A soluble CD 25 was not measured. Conclusions: A pubmed literature review revealed 14 cases of HLH in adults (≥18 years) with inflammatory bowel disease. In all of these cases the patients were on immunosuppressive therapy with azathioprine, prednisone or biologics, which was attributed by the authors as related to the development of HLH. Our case describes a patient with UC who had not been on therapy for several years suggesting the macrophage activating syndrome may be due to the underlying inflammatory condition itself. The role of PSC in hemophagocytic syndrome is unknown. Currently there are no identified cases of hemophagocytosis reported related to PSC. The literature surrounding the diagnosis of HLH in colon cancer is limited. The majority of this literature surrounds diagnosis of a T cell lymphoma, including a recent case report in the Canadian Journal of Gastroenterology of a hepatosplenic lymphoma presenting with hemophagocytosis. To our knowledge this is the first case of a patient with UC and PSC diagnosed with hemophagocytosis without immunosuppressive therapy present.

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A263 CROHN’S DISEASE GENOTYPE IS SIMILAR BETWEEN PATIENTS WHO SUSTAIN A LONG TERM REMISSION AND THOSE WHO RAPIDLY RELAPSE AFTER DISCONTINUING INFLIXIMAB C. Lu1, A. Waugh1, R. Bailey2, R. Cherry3, L. Dieleman1, L. Gramlich2, K. Matic2, M. Millan3, K. Kroeker1, D. Sadowski2, C. Teshima1, D. Todoruk2, C. Wong2, K. Wong1, R. Fedorak1 1. Center of Excellence for Gastrointestinal Inflammation and Immunity Research, Division of Gastroenterology, University of Alberta, Edmonton, AB, Canada; 2. Royal Alexandra Hospital, University of Alberta, Edmonton, AB, Canada; 3. Misericordia Hospital, University of Alberta, Edmonton, AB, Canada. Aims: The majority of patients with Crohn’s disease (CD) who have obtained an infliximab-induced clinical remission will relapse after their anti-TNFα (tumor necrosis factor) therapy has been discontinued. Interestingly, factors such as concomitant drug therapy, age, gender, and disease location do not affect the duration of remission. This finding lends support to the hypothesis that a patient-unique genotype of CD may play a role in determining the duration of long-term remission after the discontinuation of anti-TNFα agent therapy. We aimed to compare genetic differences (IBD5, NOD2/CARD 15) between CD patients who experienced a sustained corticosteroid-free clinical remission after discontinuing infliximab to those patients who relapsed over a period of up to 10 years. Methods: Genetic analyses were performed on 14 CD patients (6 remission, 8 non-remission) identified from a longitudinal cohort study from a university-based IBD referral center. All of these patients had obtained full clinical remission and had discontinued infliximab for reasons other than loss of response. Results: There was no significant increase in frequency of the NOD2/CARD15 polymorphisms, R702W, G908R and L1007fs, and the IBD5 polymorphisms, IGR2060a1 and IGR3081a1, in either the CD patients who relapsed early or in the patients who remained in extended remission following the discontinuation of infliximab. Of the genetic variants analyzed, there was no significant higher chance of disease relapse compared to the patients without mutation in the study population. Conclusions: In a cohort of infliximab-treated CD patients who respond with a sustained corticosteroid-free clinical remission and then discontinued infliximab, the NOD2 and IBD5 polymorphisms are similar between the two subgroups; those who relapse early and those who have an extended remission. This study was the first to attempt to identify genetic polymorphisms in these two subgroups. The potential role of IBD5 and NOD2/CARD15 mutations in predicting remission response rates with infliximab and the duration of such therapy to maintain remission in CD remains elusive. However, the possibility of a genetic explanation for varying patient responses to anti-TNFα remains high.

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A264 DEVELOPMENT OF A SPECIALIST NURSE EDUCATIONAL PROGRAM: THE NIICE (NURSES INITIATIVE IN IBD CARE AND EDUCATION) IN CANADA PROGRAM J. Nadin1, F. Bernard2, U. Chauhan3, B. Currie4, M. Dy5, W. Fehr6, K. Frost7, M. Stone8, Y. Verklan9, S. Lolley10, K. McHugh11 1. University of Calgary IBD Clinic, Calgary, AB, Canada; 2. HSFA/CHUQ, Quebec City, QC, Canada; 3. McMaster University Medical Centre, Hamilton, ON, Canada; 4. QEII Health Sciences Centre, Halifax, NS, Canada; 5. PGA & GI Research Institute, Vancouver, BC, Canada; 6. Royal University Hospital, Saskatoon, SK, Canada; 7. Sick Kids Hospital, Toronto, ON, Canada; 8. McGill University Health Centre, Montreal, QC, Canada; 9. CSGNA, Edmonton, AB, Canada; 10. Glia Scientific Communication, Montreal, QC, Canada; 11. Abbott, Montreal, QC, Canada. Aims: Although the management of IBD has greatly evolved in the past decade, particularly with the introduction of biologic therapies, nurses have had few opportunities to formally learn about the evolution of care and even less of a chance to discuss how these changes affect their provision of care. Methods: In 2007, a national mixed-method needs assessment conducted with 46 gastroenterologists, 40 gastroenterology nurses, and 9 patients with Crohn’s disease queried participants on Crohn’s disease management. Nurses working with patients with Crohn’s disease reported a lack of clarity around their roles and responsibilities across the continuum of care, and communication gaps within the health care team that undermined their ability to effectively provide care for patients with Crohn’s disease.1 Results: In 2010, a group of 7 gastroenterology nurses with subspecialties in IBD and a member of the Canadian Society of Gastroenterology Nurses and Associates (CSGNA) developed a 7-module, interactive, educational program for small-group learning sessions, named the NIICE (Nurses Initiative in IBD Care and Education) in Canada program. Each module aims to increase nurses’ knowledge of a particular aspect of IBD and its management, refine their clinical skills in this area, and offer insight into the social aspects of caring for patients with IBD. There is always a heavy focus on practical advice. There are also open-ended discussion questions, which encourage participants to share their clinical experience and, hopefully, learn practical solutions from the other nurses present. In this way, the modules are sufficiently flexible to allow for discussion of specific regional issues, such as access to care, reimbursement, or special population needs. Between September 2010 (the time of the program launch) and December 2010, the program was run 41 times in Canada, with 445 nurses participating. Conclusions: A follow-up needs assessment will determine whether Canadian gastroenterology nurses feel that their roles and responsibilities have been more clearly defined and whether their comfort level with IBD care has increased. Future plans include the creation of additional modules. 1 Dupuis M, Marshall JK, Hayes SM, et al. Can J Gastroenterol.2009;23(12):805-10

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Poster of Distinction A265 AUTOPHAGY REGULATES EXPRESSION OF THE RISC COMPONENT AGO2 - A CRITICAL REGULATOR OF THE MIRNA SILENCING PATHWAY M. Sibony1, H. Mascarenhas1, D. Raju1, E. Galindo-Mata1, M. Silverberg2, D. Philpott3, N. Jones1 1. Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada; 2. Zane Cohen Centre for Digestive Diseases, IBD group, Mount Sinai Hospital, Toronto, ON, Canada; 3. Department of Immunology, University of Toronto, Toronto, ON, Canada. Aims: Genome-wide association studies have repeatedly associated a variant of the autophagy dependent gene ATG16L1 with Crohn’s disease (CD), thus implicating autophagy, a novel and unexpected pathway, in the development of inflammation. The functional relevance of the ATG16L1-CD variant is unclear, as it was shown to be unnecessary for canonical autophagy, and whether it affects bacterial mediated autophagy remains controversial. We hypothesized that the ATG16L1-CD variant is involved in a different process that contributes to persistent inflammation, the miRNA silencing pathway. MiRNA are short non-coding RNA that bind to target mRNA to repress their translation and promote their degradation. Emerging data suggest that altered regulation of pro- and anti-inflammatory genes by miRNA is involved in the pathogenesis of IBD. In order to exert their function, miRNA are loaded onto an RNA induced silencing complex (RISC). AGO2 is a critical component of the RISC complex and the only AGO protein with Slicer activity which results in the generation of unique mature miRNA. RISC formation and turnover occurs on endosomal membranes. Since autophagy and endosomal membranes are closely related, we hypothesized that autophagy and the ATG16L1-CD variant affect RISC components, hence modulating miRNA silencing. Methods: In order to test our hypothesis we performed immunoblotting assays to compare the expression of RISC components in control cells or cells with increased or disrupted autophagy using bafilomycin, knockdown of ATG dependent genes or treatment with the H. pylori vacuolating cytotoxin (VacA) which disrupts autophagy. We determined the colocalization of autophagic vacuoles with RISC components using confocal microscopy. Results: Our data show increased AGO2 expression in epithelial cells in which autophagy is disrupted by knocking-down the expression of autophagy proteins atg16, atg5 and atg12, as well as treatment with VacA in comparison with control cells. Increased AGO2 expression was also detected by confocal imaging of cells with disrupted autophagy. In addition, human peripheral blood mononuclear cells also show increased AGO2 when autophagy was disrupted. Conclusions: Taken together, these results suggest that autophagy is involved in degradation of the critical RISC component AGO2 in both epithelial and myeloid cells. We propose a compelling mechanism by which autophagy may affect miRNA expression and is involved in the etiology of CD.

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A266 CHRONIC ADHERENT INVASIVE ESCHERICHIA COLI INFECTION IN MICE LEADS TO PERSISTENT COLONIZATION AND FIBROSIS. C. Small, B. Coombes McMaster University, Hamilton, ON, Canada. Aims: Crohn’s disease (CD) is a chronic inflammatory bowel disease (IBD), which primarily affects the ileum and colon. CD is characterized by chronic inflammation and severe intestinal pathology, which can extend throughout the intestinal wall causing symptoms of diarrhea, abdominal pain and nausea. Several genetic and environmental factors are implicated in CD pathogenesis, including the composition of the enteric microbiota. Of particular interest is a pathotype of E. coli known as adherent-invasive E. coli (AIEC) that is frequently isolated from the ileal mucosa of CD patients. However, the potential role of AIEC in the initiation or progression of CD is unclear. To address this, we have developed a mouse model of chronic AIEC-induced colitis that leads to intestinal fibrosis and immunopathology. Methods: Various mouse strains were pre-treated with streptomycin prior to infection with the human clinical AIEC isolate NRG857c. At several times after colonization, colonic and cecal tissues were assessed for maintenance of AIEC colonization, tissue pathology, inflammation and fibrosis. Results: AIEC infection in mice led to chronic and persistent colonization and reduction in size of the cecum, which was not indicative of body weight loss. The duration and severity of tissue colonization differed among mouse strains. Chronic AIEC infection in mice was associated with severe crypt hyperplasia, massive epithelial sloughing, cellular infiltration, desquamation as well as transmural inflammation. Extensive submucosal edema was primarily evident in the cecum, while mucosal ulceration was only observed in the colon of mice by day 7 and was still present by day 63. Heavy and extensive extracellular matrix deposition indicative of fibrosis was detected by day 7 in the mucosa and extending throughout the submucosa and muscularis mucosa. Moreover, increased number of fibrils in submucosal and muscularis mucosal collagen could be observed in the cecum of all mouse strains except C57BL/6 mice. Conclusions: Our new animal model of AIEC-induced colitis and intestinal fibrosis will facilitate understanding of the role of AIEC in chronic gut inflammation and help to uncover the bacterial and host genetic determinants underlying the observed pathology.

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A267 REPEATED TREATMENTS WITH BONE MARROW-DERIVED ALTERNATIVELY ACTIVATED MACROPHAGES INHIBIT COLITIS AND DO NOT ELICIT FIBROSIS G. Leung, A. Wang, M. Fernando, V. Phan, D. McKay University of Calgary, Calgary, AB, Canada. Aims: Alternatively activated macrophages (AAMs) are associated with T helper-2 cell responses and the resolution of inflammation. We showed that adoptive transfer of AAM derived from peritoneal macrophages protected mice from DNBS (dinitrobenzene sulphonic acid)-induced colitis, as a proof-of-principle study for the treatment of inflammatory bowel disease (IBD). However, given that AAMs are also linked to the pathogenesis of pulmonary fibrosis, we sought to determine whether they were associated with adverse effects (specifically fibrosis) when mice were given multiple AAM treatments. We also tested whether bone marrow (BM)-derived macrophages were effective in protecting mice from DNBS colitis, as haematopoietic stem cells are a more efficient method of deriving macrophages from both experimental and clinical perspectives. Methods: Macrophages from male Balb/c mice were obtained by culturing BM cells for 7 days with macrophage colony stimulating factor (20ng/ml), and alternative activation was elicited by a 48h treatment with interleukin (IL)-4 and IL-13 (both 20ng/ml). Macrophages (1 million) were given by intraperitoneal injection 6hr prior to the intra-rectal instillation of 3mg DNBS in 100μl 50% ethanol to induce colitis. Three cycles of DNBS±AAMs were performed at 3 weekly intervals and 72h after the final treatments, mice were necropsied, colitis assessed by standard measures and fibrosis in the colon, small bowel, lung and liver assessed by collagen measurement, Masson’s trichrome stain and Q-PCR for collagen and fibronectin. Results: AAM differentiation was confirmed by increased mRNA and protein expression of arginase 1 and Ym1, established AAM markers. BM-derived AAMs significantly protected mice from DNBS-induced colitis, and while the severity of the disease decreased with each round of DNBS (as gauged by body weight changes), on each occasion AAM-treated mice fared better and on necropsy had lower disease activity scores, longer colons and less evidence of histological derangement than DNBS only-treated mice. Quantification of collagen, Masson’s trichrome stain and Q-PCR revealed no evidence of increased fibrosis in the liver, lung, small intestine, or colon of AAM-treated mice. Conclusions: Mice receiving BM-AAMs are protected against DNBS-induced colitis, and this benefit was sustained for 3 cycles of colitis and was not accompanied by evidence of fibrosis. We speculate that adoptive transfer of AAMs could be a viable anti-colitic therapy, that can remain effective over multiple rounds of treatments and, in this experimental paradigm, is not associated with the deleterious side-effects of collagen deposition and fibrosis.

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A268 VITAMIN D DOWNREGULATES NLRP3 AND PROTECTS AGAINST CLOSTRIDIUM DIFFICILE TOXIN-INDUCED CELL DEATH S. Tulk, S. Hirota, J. MacDonald, P. Beck University of Calgary, Calgary, AB, Canada. Aims: Infections and deaths caused by Clostridium difficile (Cdif) are rapidly increasing, giving rise to a demand for new therapeutic strategies. Cdif-induced colonic damage by its toxins A and B (TcdA/B) is, in part, mediated by NLRP3 inflammasome activation (Ng et al., 2010) resulting in production of IL-1B. Vitamin D has been found to play a protective role in the gut. Patients with inflammatory bowel disease are often deficient in vitamin D and are also markedly more susceptible to Cdif. Since vitamin D has been shown to upregulate NOD2 (Wang et al, 2010), an NLR protein in the same family as NLRP3, we hypothesized that vitamin D may impact inflammasome activity and thus play a role in the pathogenesis of Cdif-induced intestinal injury. Methods: PMA-differentiated THP-1 cells were stimulated with vitamin D and assessed for inflammasome activation (NLRP3, ASC western blot and real-time qPCR; IL-1B ELISA and real-time qPCR). Cell death and apoptosis was assessed following incubation with vitamin D (or vehicle) and Cdif toxins A and B (TcdA/B). Results: Vitamin D markedly reduced Cdif TcdA/B-induced cell death as assessed by LDH release (62% reduction in LDH release vs vehicle, p<0.05) but there was no marked impact on apoptosis as assessed by PARP cleavage. This protection was associated with markedly decreased expression of NLRP3 mRNA as assessed by real time qPCR (reduction of 61% vs vehicle, p<0.05) as well as NLRP3 protein production as assessed and western blotting (reduction of 54% vs vehicle, p<0.05). Surprisingly, vitamin D was found to upregulate expression of inflammasome associated molecules including pro-caspase-1 and its product IL-1B. Studies on expression of other inflammasome NLRs, work on NLRP3 and ASC deficient cell lines as well as other associated signaling pathways are currently underway to determine the mechanism involved in the both the protection associated with vitamin D exposure and the increase in IL-1B in the setting of decreased NLRP3 expression. Conclusions: Vitamin D downregulated expression of NLRP3 and protected macrophages against death induced by Cdif toxin (TcdA/B)-induced intestinal injury. This is in agreement with our previous findings that deletion of NLRP3 reduces TcdA/B-induced IL-1B release in vitro, and that treatment with the IL-1B receptor agonist anakinra in vivo protects against TcdA/B-induced inflammation and damage [Ng et al., 2010]. Future studies will investigate the effects of vitamin D on TcdA/B-induced damage in vivo using VDR-/- animals as well we will assess the role of vitamin D in protection against Cdif-induced injury using human colonic biopsies incubated with Cdif toxin as we have described previously. To date, our studies suggest that vitamin D could possibly be used to prevent and/or treat Cdif-induced intestinal injury.

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A269 PROLONGED PRODUCTION OF REACTIVE OXYGEN SPECIES (ROS) DRIVES THE INTERNALIZATION OF COMMENSAL BACTERIA INTO STRESSED INTESTINAL EPITHELIA I. Schoultz, C. McKay, V. Phan, D. McKay University of Calgary, Calgary, AB, Canada. Aims: Colonic biopsies from patients suffering from inflammatory bowel diseases (IBD) can show signs of disrupted mitochondria in enterocytes, this could be indicative of increased reactive oxygen species (ROS) production. Studies in our laboratory have shown that disruption of the mitochondria in model colonic epithelia results in increased internalization of non-pathogenic, non-invasive E. coli: the epithelial internalization of commensal flora could drive and/or initiate intestinal inflammation resulting in IBD. We hypothesized that the production of ROS in metabolically-stressed epithelia is at the hub of the increased internalization of E. coli. Methods: The production of ROS in T84 epithelial cells was determined 6 and 16h after exposure to metabolic stress, induced by 2,4-dinitrophenol (DNP; 0.1mM; uncouples oxidative phosphorylation) and non-pathogenic, non-invasive E. coli (strain HB101; 105 cfu) using CM-H2DCFDA which fluoresces upon exposure to ROS. The effect of metabolic stress on epithelial internalization of E. coli was monitored using the gentamicin assay. The involvement of ROS in the internalization process was tested by inclusion of the known ROS scavengers in the culture medium: vitamin C (1mM), 2R-4R APDC (0.1mM), and the green tea extract epigallocatechin gallate (EGCG; 0.1mM). Results: Exposure of T84 epithelia to DNP, E. coli, and DNP+E. coli all resulted in significant and prolonged production of ROS as detected by the CMH2DCFDA probe. Use of vitamin C effectively reduced the amounts of detectable ROS. As before, DNP+E. coli-treated epithelia displayed substantial epithelial transcytosis and internalization of the E. coli, which were reduced to baseline levels by co-treatment with ROS-scavengers. Furthermore, addition of vitamin C 4h after exposure to the metabolic stressor was found to decrease the internalization of E. coli. Conclusions: Thus, metabolic stress, induced by DNP+ E. coli, elicits prolonged production of ROS, and the use of antioxidants (e.g. vitamin C) ablated this response and reduced the concomitant increase in epithelial internalization of commensal bacteria that occurs in this model paradigm. The data indicate a novel role for ROS in the gut, that of increasing epithelial internalization of commensal flora which could have disease implications. Should these finding be reflective of in vivo conditions, we speculate that increased dietary intake of antioxidants can be beneficial in early stages of gastrointestinal inflammation as well as after stress-induced disease relapses.

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A270 THE IMMUNE-ENDOCRINE AXIS: ROLE OF IL-13 IN EC CELL BIOLOGY AND 5-HT PRODUCTION M. Manocha1, M. Shajib1, H. Wang1, M. Rahman1, M. Bogunovic2, L. Mayer2, W. Khan1 1. McMaster University, Hamilton, ON, Canada; 2. The Mount Sinai School of Medicine, New York, NY. Aims: Enterochromaffin (EC) cells in the epithelium of the gastrointestinal (GI) tract are the largest producers of serotonin (5-hydroxytryptamine; 5-HT) in the body. 5-HT is considered an important regulator of intestinal homeostasis and is implicated in the pathophysiology of many GI disorders which include functional and inflammatory bowel diseases. Nevertheless, the mechanism by which 5-HT is produced from EC cells remains to be determined. Previously we have shown up-regulation of 5-HT expressing EC cell numbers and 5-HT production in a mouse model of nematode infection in association with increased Th2 immune response. We also reported presence of interleukin (IL) - 13 receptor α1 on EC cells revealing a potential link between IL-13 and EC cell biology. Hypothesis: IL-13 plays an important role in generation of EC cell hyperplasia and in production of 5-HT. Methods: IL-13 KO and wild-type mice were infected with nematode, Trichuris muris and sacrificed on different days post-infection (pi) to study 5-HT expressing EC cells, and 5-HT amount in colon. Naïve IL-13 KO mice were treated with recombinant IL-13 (2 µg/mouse/day; ip) or vehicle (PBS) for 5 days, upon which time the colon was excised and 5-HT content of colon and the numbers of 5-HT expressing EC cells were examined. To further confirm the role of IL-13 in 5-HT production BON cells (human carcinoid tumour of EC cell origin) were stimulated in vitro with recombinant IL-13. 5-HT amount was assessed in the culture media and the number of BON cells was counted using both a haemocytometer and alamarBlue cell proliferation assay. Results: 5-HT expressing EC cells numbers and 5-HT amount in colon were significantly lower in IL-13 KO mice as compared to the wild type mice after T. muris infection. Reconstitution of IL-13 in IL-13 KO mice resulted in a significant increase of 5-HT content in the colon, which was accompanied by a significantly increased number of 5-HT expressing EC cells. Treatment of BON cells with human recombinant IL-13 resulted in a small but significant increase of 5-HT content in the cell culture media and this was associated with a 26-45% increase in the number of BON cells in culture. Conclusions: Our results demonstrate an important role for IL-13 in EC cell biology. IL-13 facilities the increase of 5-HT expressing EC cells numbers in both an in vivo mouse model and in culture human model of EC cells, These observations provide new information on the immuno-endocrine axis in gut which may ultimately lead to effective strategies to modulate 5-HT response in various GI disorders.

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A271 ROLE OF CUX1 DURING INTESTINAL EPITHELIAL CELL RESTITUTION FOLLOWING INJURY R. Latreille, M. Darsigny, F. Boudreau Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: Our laboratory has recently shown that mutant mice for the transcriptional regulator Cux1 can initiate a severe intestinal inflammatory response as compared to control mice. One characteristic associated with the phenotype of these mutant mice was the inability to renew their intestinal epithelium following the induction of a chemical stress with dextran sodium sulfate (DSS). We hypothesize that the transcription factor Cux1 could be functionally involved during the process of epithelial restitution in the context of inflammatory bowel diseases. Methods: Rat intestinal epithelial cells (IEC-6) were stably infected with lentivirus/shRNA in order to downmodulate the expression of Cux1. Wounding assays were performed by scratching IEC-6 confluent cells with a razor blade to provide migration of cells in the injury. TGFb was supplemented into Petri dishes to stop proliferation and promote cell migration. Quantitative PCR and Western bloting analysis were performed to identify signalling targets of Cux1 under TGFb dependent stimulation. These targets were also studied in a hypomorphic mouse model for Cux1 treated with DSS to induce intestinal inflammatory disorders. Results: Inducing an injury on Cux1 deficient IEC-6 cells resulted in their inability to migrate as compared to control cells. Supplementation of TGFb under these conditions led to a reduction of cell proliferation as determined by BrdU incorporation and immunofluorescence assays. However, TGFb promoting effect on cell migration was significantly impaired in IEC-6 cells that harboured reduced Cux1 expression. Real-time PCR and Western blot analysis identified the TGFb associated kinase 1 (TAK1) to be downmodulated in the absence of Cux1. In addition, IRAK4, a crucial kinase involved in Toll-like receptor signalling, was reduced more than 40% in Cux1 deficient IEC-6 cells. This tendency was also observed at the level of the gene transcript in the intestine of Cux1 mutant mice. Conclusions: Our results highlight an important role of the transcription factor Cux1 during the restitution process of the intestinal epithelium. The nature of Cux1 functional interaction with TAK1 and IRAK4 in a context of inflammatory bowel diseases is currently under investigation. Supported by the CCFC.

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A272 C5AR INHIBITION AMELIORATES PIROXICAM INDUCED COLITIS IN IL-10-/- MICE U. Jain1, T. Woodruff2, A. Stadnyk1 1. Department of Microbiology and Immunology,Dalhousie University, Halifax, NS, Canada; 2. School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia. Aims: Piroxicam accelerates the development of colitis in IL-10-/- mice; however, the mechanisms of piroxicam induced pathogenesis are incompletely known. Piroxicam enhances mucosal exposure to bacteria and since complement is among the first processes activated to protect self from bacteria, we hypothesized that complement is locally activated and that the generation of anaphylatoxins contribute to the intestinal pathology in piroxicam fed IL-10-/- mice. Methods: Colitis was elicited in 6 week old IL-10-/- mice (C57BL/6 background) by adding piroxicam (250ppm) to their food for 1 week. Mice were gavaged daily with the selective C5aR antagonist (PMX205; 150μg/mouse) or water (control) starting on the same day as piroxicam. On the day of euthanasia, intestinal permeability was examined using FITC-dextran, and the mice were exsanguinated and their colons excised and the length measured. Half the colon was used to obtain histological scores based on the extent of crypt damage, cell infiltration, edema, ulceration and epithelial hyperplasia. The other half was cultured and 24 hour supernatants were analyzed for cytokines and anaphylatoxins. Spleen cells were stimulated with anti-CD3/CD28 antibodies and 72 hour culture supernatants analysed for cytokines. Results: Piroxicam administration to IL-10-/- but not wildtype mice resulted in increased generation of mucosal anaphylatoxins, increased intestinal permeability and severe pathology. Oral gavaging with PMX205 during the period of piroxicam ingestion significantly prevented the intestinal barrier loss and colon shortening observed in piroxicam control mice. PMX205 treated mice also showed less crypt damage, cellular infiltration and epithelial hyperplasia in colon sections. PMX205 significantly prevented the colonic production of IL-12 and IL-1β but not of IFN-γ compared to the control mice. Mucosal generation of anaphylatoxins, C3a and C5a was unaffected by PMX205 administration. The in vitro stimulated production of IFN-γ but not IL-12 was significantly less in splenocytes recovered from the PMX205 treated animals. Conclusions: Piroxicam induces increased generation of anaphylatoxins in IL-10-/- mice. C5a in turn, contributes to colon damage by increasing intestinal permeability and the local production of pro-inflammatory cytokines. Our data suggest that targeting the C5aR may therefore be a viable therapeutic option to treat inflammatory bowel disease.

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A273 SONIC HEDGEHOG SIGNALING IS CRITICAL FOR GOBLET AND PANETH CELLS TERMINAL DIFFENTIATION AND PROTECT AGAINST INTESTINAL INFLAMMATION J. Gagné Sansfaçon, D. Ménard, N. Perreault Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: Hedgehogs (Hh) are morphogenes known to regulate numerous cell processes in various tissues. In the gastrointestinal tract, Sonic (Shh) and Indian (Ihh) hedgehog proteins have been shown to play roles in morphogenesis and cancer. Complete abrogation of Hh signaling revealed abnormal epithelial cell proliferation and defective enterocytes and myofibroblasts specification leading to mucosal inflammation with age. Also, it has been shown that loss of Ihh alone leads to increase epithelial proliferation, excessive deposition of type IV collagen and fibronectin. However, the specific role of Shh on intestinal mucosal homeostasis in the adult has not yet been explored. We propose to specifically address the molecular relevance of the Shh on intestinal homeostasis and mucosal integrity during intestinal inflammation. Methods: With the use of the Cre/loxP system, we have generated a mouse with the Shh gene deleted exclusively in the small and large intestinal epithelium. Histological analysis was performed with H&E staining. Proliferation was analyzed by immunofluorescence. Cell specification of the main four cell types were analyzed with specific cellular staining (alcian blue and Periodic-Acid Schiff), immunostaining, Western blot, qPCR and ultrastructural analyses. The epithelial-specific Shh-null and control mice were subjected to dextran sulfate sodium induced experimental colitis and their clinical and histological symptoms were assessed. Results: Macroscopic, histological and proliferation analyses showed no important morphological abnormalities and deregulation in mutant mice. No modulation was observed in enterocyte and enteroendocrine cells specification. Alcian blue and PAS staining revealed a significant decrease of 17% in goblets cells number and the mucin glycosylation process was altered according to the complete loss of UEA marker in mutant mice. Immunohistological analysis of Paneth cells revealed a significant 27% decrease of this cell population. Reduction in lysozyme and cryptin proteins expression was confirmed in the mutant mice. Electron microscopy analysis showed Paneth cells with a reduction in granules size and loose endoplasmic reticulum. Since the latter observation can be related to autophagy we performed a qPCR analysis of ATG16L and showed a significant decrease in its mRNA. Finally, the reduction in mucus protection coat and antimicrobial agents seen in mutant mice suggested a possible involvement in inflammatory response. Experimental colitis demonstrated increased susceptibility to the disease in Shh mutant mice. Conclusions: Our results have highlighted an important role played by Shh signaling in goblet and Paneth cells specification and autophagy. Thus, Shh might play a protecting role in immune defense and inflammatory diseases.

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A274 AN ALTERNATIVE ENZYMATIC SOURCE OF HYDROGEN SULFIDE SYNTHESIS IN EXPERIMENTAL COLITIS K. Flannigan, J. Wallace McMaster University, Hamilton, ON, Canada. Aims: Hydrogen sulfide (H2S) is a modulator of inflammation and an important contributor to gastrointestinal mucosal defense. During a bout of colitis in rats, the capacity of colonic tissue to produce H2S is markedly increased, and contributes significantly to driving the resolution of inflammation and injury (Gastroenterology 2009; 137: 569-578). Based on studies using inhibitors, the enzymes cystathionine-β-synthase (CBS) and to a lesser extent cystathionine-γ-lyase (CSE), appeared to be responsible for the observed increase in colonic H2S synthesis. However, inhibition of these enzymes did not completely abolish colonic H2S production. There is emerging evidence for a third pathway for H2S synthesis, via the enzymes cysteine aminotransferase (CAT) and 3-mercaptopyruvate sulfurtransferase (3MST) (Antioxid. Redox Signal. 2009; 11: 703-714). We hypothesized that these enzymes are present in the colon and are an important source of H2S during colitis. Methods: The capacity of tissue to produce H2S was measured from homogenized tissue in the presence of exogenous substrate and/or inhibitors using a zinc-trapping assay. All reactions required exogenous L-cysteine for H2S synthesis to occur. H2S production via CSE and CBS, also required the presence of pyroxidal-5’-phosphate (P5P). Production of H2S via the CAT-3MST pathway was explored using L-aspartate, a competitive inhibitor of CAT, and O-carboxymethyl-hydroxylamine hemihydrochloride (CHH), an inhibitor of aminotransferases, including CAT. Colitis was induced in rats by administering 0.5 mL of a 60-mg/mL solution of dinitrobenzene sulfonic acid (DNBS) in 50% ethanol. Results: In the presence of L-cysteine and α-ketoglutarate, colonic tissue produced H2S at a level 10-fold greater than that produced via the previously studied pathways (via CBS and CSE). In the inflamed colon, the capacity of tissue to produce H2S when α-ketoglutarate was present markedly increased (> 4-fold) compared to healthy controls. This increased H2S production was suppressed by both L-aspartate and CHH. Immunofluorescent staining revealed that CAT and 3MST were co-localized in the colonic epithelium. Moreover, staining for CAT in inflamed tissue was most intense in the epithelium adjacent to ulcers. Conclusions: These data suggest that in the colon, CAT and 3MST represent the primary pathway for H2S synthesis. This is the case for both healthy and inflamed tissue. The increase in H2S production is to some extent related to an increase in CAT protein expression. Further understanding of the mechanisms and regulation of H2S production will be useful in determining the therapeutic potential of this mediator for promoting resolution of colitis.

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A275 MUC2-DEFICIENT MICE EXHIBIT DEFECTS IN TIGHT JUNCTION PROTEINS AND COLONIC PERMEABILITY E. Trusevych, C. Hirota, F. Moreau, K. Tran, J. Meddings, W. MacNaughton, K. Chadee University of Calgary, Calgary, AB, Canada. Aims: The intestinal mucosal barrier serves as the first line of host defence in the gastrointestinal (GI) tract, and has two main constituents: the mucus-gel and the underlying single layer of epithelial cells connected by tight junctions. MUC2 produced by goblet cells is the main structural component of the mucus layer. It is unknown if MUC2 regulates epithelial barrier function. During inflammatory bowel diseases, MUC2 levels are diminished and epithelial permeability is increased. In this study we investigated whether mice lacking Muc2 mucin (Muc2-/-) have a compromised epithelial barrier that increases their susceptibility to intestinal inflammation. Methods: Full thickness segments of ileum and colon from Muc2-/- and Wt mice were mounted in Ussing chambers to access ion transport, transepithelial resistance (TER) and mucosal to serosal flux of FITC-dextran (3-5kDa). In other experiments, protein was isolated from intestinal tissues and processed for western blotting for tight junction proteins. To determine site-specific and temporal permeability changes in vivo, Muc2-/- and Wt mice were gavaged once per week for 3 months with a solution containing sucrose (permeability marker: gastric), lactulose (small intestine), mannitol (small intestine) and sucralose (colon). Urine samples collected for 22h post-gavage were analyzed for the presence of the oligosaccharides using HPLC. Results: Baseline short-circuit current was similar in Muc2-/- and Wt mice, however Muc2-/- mice had increased TER in the proximal and distal colon compared to Wt mice. Additionally, the mucosal to serosal flux of FITC-dextran was lower in Muc2-/- mice than Wt mice, indicating that Muc2-/- mice have reduced paracellular permeability. Of the tight junction proteins tested, barrier-forming occludin was increased at every age (3wk, 2mo and 5mo) in Muc2-/- mice, whereas cation-selective claudin-2 was only increased in Muc2-/- mice after 2mo of age. In vivo permeability measurements indicate no change in gastric permeability, decreased small intestinal permeability in Muc2-/- mice, and an age-dependent increase in Muc2-/- colonic permeability. Conclusions: Surprisingly colonic epithelial barrier functions were enhanced in the absence of Muc2 mucin. However, in vivo permeability measurements show temporal changes in colonic permeability that were not identified with ex vivo techniques suggesting that multiple barrier function defects may occur in the absence of Muc2.

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A276 INTESTINAL INFLAMMATION UPREGULATES THE EXPRESSION OF TRANSPORTER MRP2 - POTENTIAL INVOLVEMENT IN IBD AND COLORECTAL CANCER V. Vinette, D. Grbic, F. Gendron Université de Sherbrooke, Sherbrooke, QC, Canada. Aims: During intestinal inflammation, the expression of certain purinergic P2Y receptors (P2YRs) is upregulated, and their activation stimulates the adhesion of macrophages to the intestinal epithelium. Moreover, the multidrug resistance-associated ABC transporter MRP2 is active during events of intestinal inflammation. Blocking its function has been shown to inhibit the transepithelial migration of neutrophils, one of the first steps in the initiation of inflammatory bowel diseases (IBDs). MRP2 is also known to be involved in the export of a plethora of compounds, including anticancer drugs. As such, we investigated the possible interaction between MRP2 and P2YRs during intestinal inflammation. Methods: Human intestinal Caco-2 cells were grown to 15 days post-confluence for enterocyte-like differentiation. Intestinal epithelial cells (IECs) were stimulated for 3, 6 or 18 hours with 100 μM ATP or UTP. Analysis of MRP2 expression was performed by real-time quantitative PCR (qPCR) upon stimulation. Likewise, MRP2 protein expression was measured by Western blot analysis. Caco-2 cells infected with human shRNA against MRP2 were generated to observe the effects of a decrease in MRP2 expression, and their validity verified by Western blot and qPCR. In parallel, drug cytotoxicity assays were conducted to observe the resistance of Caco-2 cells transfected or not with shMRP2, as well as stimulated or not with nucleotides. Results: Analysis by qPCR and Western blot demonstrated an increase of MRP2 expression in polarized Caco-2 cells stimulated with nucleotides in a time-dependent manner compared to the non-stimulated controls. Drug cytotoxicity assays suggest that IECs transfected with shMRP2 are less resistant to cytotoxic drugs cisplatin and doxorubicin compared to the non-transfected parental cell line, as determined by the survival curve, IC50 and relative resistance factor (RR). Conclusions: These results demonstrate that mRNA and protein expression of MRP2 is upregulated in IECs following stimulation with nucleotides and activation of P2YRs. This may prove to be important in the recruitment of neutrophils, whose presence contributes to the development of inflammation, and are consequently involved in IBDs and colorectal cancer. Additionally, the decreased resistance of shMRP2-infected IECs to drugs used in chemotherapy suggests an important role for MRP2 in colorectal cancer. As such, identifying the signalization cascade following MRP2 activation and determining if cooperation exists between MRP2 and P2YR may contribute to the development of new methods in the treatment of intestinal inflammation, as observed in IBDs or colorectal cancer.

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Microbiology and Parasite-Host Interactions

Poster of Distinction A277 ATG16L1 INTERACTS WITH NOD1 AND NOD2 TO CONTROL AUTOPHAGY AND INFLAMMATION M. Sorbara, L. Travassos, M. Ramjeet, S. Hussey, S. Girardin, D. Philpott University of Toronto, Toronto, ON, Canada. Aims: Crohn's Disease (CD) is a chronic inflammatory disease of the gastrointestinal tract, and is characterized by a dysregulation of the mucosal immune system. This leads to inappropriate responses against the local microbial flora. Both environmental and genetic risk factors for the development of CD have been identified and recent genome-wide association studies have linked polymorphisms in several genes involved in the innate immune response to CD. These include Nod2, a pattern-recognition receptor sensing murmamyldipeptide (MDP), a fragment of peptidoglycan, and the autophagy genes ATG16L1 and IGRM. Recently, our laboratory uncovered a role for Nod2 in regulating autophagy through its association with ATG16L1. The aim of this study was to determine if ATG16L1 and the autophagy machinery regulates the Nod1/Nod2-driven inflammatory response. Methods: Knockdown of proteins in the autophagy pathway was performed using shRNA delivered into ModeK intestinal epithelial cells using a lentiviral system. Autophagy-silenced cells were infected with Shigella flexneri, Listeria monocytogenes, and Salmonella typhimurium and the expression of inflammatory cytokines was measured by qPCR and ELISA. In addition, cells were stimulated with ligands for different PRR pathways. Results: We show that inflammatory cytokine production is enhanced in ATG16L1-silenced cells following bacterial infection. This increase is not dependent on enhanced bacterial replication in the autophagy-deficient cells, and occurs at a transcriptional level. In addition, we further characterize the link between Nod2 and ATG16L1 and show that loss of ATG16L1 results in increased inflammatory cytokine production in response to Nod1 and Nod2 stimulation in epithelial cells. This enhanced cytokine response in ATG16L1-silenced cells is reflected in increased NFκB activation and activation of the Nod1/Nod2 signalling pathway. Conclusions: These preliminary investigations suggest a possible link between the Nod2-ATG16L1 axis and the regulation of inflammation at the level of the epithelial barrier.

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Poster of Distinction A278 CLOSTRIDIUM DIFFICILE TOXIN-INDUCED UDP RELEASE TRIGGERS THE PRODUCTION OF IL-8 FROM INTESTINAL EPITHELIAL CELLS - A NOVEL ROLE FOR THE P2Y6 RECEPTOR IN THE INDUCTION OF CLOSTRIDIUM DIFFICILE-ASSOCIATED DISEASE. S. Hirota, V. Lam, M. Grassie, J. MacDonald, P. Beck University of Calgary, Calgary, AB, Canada. Aims: C. difficile is a gram-positive spore-forming bacterium that is the leading cause of nosocomial diarrhea in the developed world. Recent outbreaks have been caused by strains with enhanced virulence due to their increased production of toxin A (TcdA) and toxin B (TcdB), the major secreted factors that contribute to disruption of the intestinal epithelial barrier. Neutrophils play a key role in the inflammatory response and the induction of pseudomembranous colitis triggered by TcdA and TcdB. Previous reports have described that intestinal epithelial cell (IEC) intoxication triggers the release of IL-8, a potent neutrophil chemokine, however little is known about the surface receptors mediating this effect. In the current study we sought to assess whether toxin-induced IL-8 release is driven by the activation of the P2Y6 receptor following the release of UDP, a danger signal, from intoxicated IECs. Methods: Caco-2 cells were grown to confluence on standard culture plates and differentiated for 7-days. Cells were treated with a mixture of TcdA and TcdB, purified from C. difficile cultures, and the supernatant and cell lysates isolated. UDP and IL-8 were detected in the supernatant with HPLC and ELISA, respectively. To probe the signaling pathways involved we utilized the following: MRS 2578 - P2Y6 receptor antagonist; BAY 11-7085 - NFκB inhibitor; PD98059 - MEK1 inhibitor; AG1478 - EGFR inhibitor. Results: Treatment of Caco-2 cells with TcdA/TcdB (10 μg/mL; 16hrs) led to UDP release into the culture supernatant which was also associated with the release of IL-8. TcdA/TcdB treatment also led to a significant increase in ERK activation. Inhibition of the P2Y6 receptor completely abolished toxin-induced IL-8 release, suggesting a role for UDP in this response; however, no inhibitory effect on ERK was observed. To probe the pathways downstream of the P2Y6 receptor we inhibited the ERK pathway and blocked EGFR activation. Both inhibition of ERK and the EGFR led to a significant reduction (~50% reduction) in TcdA/TcdB-induced IL-8 release. Interestingly, inhibition of NFκB signaling completely abolished TcdA/TcdB-induced IL-8 release. Conclusions: Exposure of IECs to TcdA/TcdB triggers the release of UDP that acts in an autocrine fashion to activate the P2Y6 receptor and induce NFκB-dependent IL-8 release. These data suggest that strategies aimed at inhibiting the inflammatory effects of endogenous danger signals, such as UDP, may prevent the production of mediators that drive neutrophil migration to site of cellular intoxication, thus reducing immune-mediated tissue damage and disease progression.

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A279 DIETARY LIPIDS MODULATE THE INTESTINAL MICROBIOME AND ALTER THE BASAL IMMUNOLOGICAL RESPONSES R. Ethendhar, D. Gibson Department of Biology,UBC Okanagan, Kelowna, BC, Canada. Aims: To determine the effect of different high lipid diets (corn oil, fish oil, canola oil) in modulating ecology of the intestinal microbiota and host immune responses. These high lipid diets are isocaloric and composition of oil are as follows corn oil (20% wt/wt of corn oil), fish oil (18% wt/wt of corn oil addition to 2% wt/wt of fish oil), canola oil (20% wt/wt of canola oil), and low lipid diet (5% wt/wt of corn oil) Methods: Mice were fed the lipid diets for 5 week and then the intestinal tracts were removed for analysis of microbiota and host inflammatory responses. Quantitative Polymerase Chain Reaction (qPCR) technique was used to study the gut microbiota changes using specific primers directed to the 16s rRNA sequence of bacteria. Immunohistochemistry and apoptosis staining were carried out to determine the host immune responses Results: Fish oil fed mice had high level of Lactobacillus and Bifidobacterium species and significantly lower level of bacteria from Enterobacteriaceae when compare to all other diet groups. Importantly, Segmented Filamentous Bacteria(SFB), Clostrium coccoides sp. deemed to be important in modulated Th17 and regulatory T cells respectively, were significantly decreased in mice fed fish oil supplemented diets. In addition, fish oil diet impaired the epithelial cell renewal capacity and distinct absence of resident immune cells in the colons of mice. Furthermore, fish oil supplemented diets increased the intestinal oxidative responses confirmed by 4-hydroxy-2-nonenal, a marker for oxidative stress. All high fat diets, regardless of composition, had significant decreases of the Bacteroides sp and invasive adherent bacteria such as Enterococcus fecalis Conclusions: Our research suggests that high lipid PUFA diets alter the resident gut microbiota and modulates redox status of gut. Particularly, fish oil supplementation appears to increase some beneficial microbes and decrease essential (SFB, Clostrium coccoides), invasive microbes (Enterococcus fecalis). This corresponds with decreased immune cells and increased oxidation of the mucosal surfaces

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A280 DIFFERENTIAL INFLAMMASOME ACTIVATION AND INDUCTION OF APOPTOSIS BY COMMENSAL E. COLI AND PROBIOTIC E. COLI NISSLE 1917 IN INTESTINAL EPITHELIAL CELLS H. Becker1, A. Apladas2, M. Scharl2, P. Beck1, G. Rogler2 1. University of Calgary, Calgary, AB, Canada; 2. University Hospital Zurich, Zurich, Switzerland. Aims: The probiotic bacterial strain E. coli Nissle 1917 (EcN) has been used in the treatment of ulcerative colitis (UC) and other intestinal disorders. Although several several studies have shown that EcN is beneficial in the treatment of UC, the mechanism of action on the cellular level is still unclear. Several bacterial recognition and downstream signalling pathways have been proposed to play a role in inflammatory bowel diseases. One target of studies is the Nod2 family of intracellular pattern recognition receptors including NLRP3. The observed upregulation of proinflammatory IL-18 in UC and the fact that the inflammasome complex together with NLRP3 and caspase-1 is an activator of IL-18 has led to the notion that this pathway may be involved in the aetiology of the disease. Therefore, we aimed to investigate whether the beneficial effect of EcN exerts its function via this signalling pathway. Methods: To compare effects of gram negative strains of probiotic E. coli Nissle 1917 (EcN) and a commensal E. coli strain MG1655 K12 (K12), they were applied to the intestinal epithelial cell line Caco-2. Stimulations with different concentrations of bacteria, which were calculated as multiplicity of infection (MOI) and different time points, as well as a pulse-chase stimulation were conducted. Supernatants and lysates were harvested for ELISA of IL-18 and Western blot analysis, respectively. Results: Both EcN and the commensal K12 bacterial strains increased the release of IL-18 after 24 h incubation from human intestinal epithelial cells, but the probiotic EcN strain triggered significantly lower amounts of IL-18 than the K12 strain (35%, p<0.001). This was evident at an MOI of 1 for the 24 h time point. The pulse stimulation for 1 h with an MOI of 100 followed by 24 h incubation without bacteria was sufficient to induce the same effect (160 %, p< 0.05). Cleavage of caspase-3 and PARP revealed that bacterial incubation for 24 h at MOIs of 0.1 and 1 triggered apoptosis to some extent, but again more pronounced in response to the K12 strain than to the probiotic EcN strain. Furthermore, both E. coli strains induced the expression of the tight junction protein occludin, but no marked differences were noted between the two strains. Conclusions: The two tested E. coli strains had very distinct effects on intestinal epithelial cells. Inflammasome activation (resulting in release of proinflammatory IL-18) and induction of apoptosis were more pronounced in cells stimulated with the commensal K12 strain as compared to the probiotic EcN strain. This may point towards the clinically observed beneficial effect of the probiotic E. coli Nissle, which may exert its effects by regulating and limiting the growth of commensal bacteria.

A281 INTESTINAL DYSBIOSIS IN CLOSTRIDIUM DIFFICILE INFECTION R. Bechara, E. Petrof Queens University, Kingston, ON, Canada. Aims: To illustrate the fecal microbiome in a patient with recurrent refractory Clostridium difficile infection treated with stool transplant and to compare this with the fecal microbiome of the healthy donor stool. Also, to show similarities in the microbiome of two patients with refractory clostridium difficile infection. Methods: Fecal samples of two patients with recurrent refractory Clostridium difficile infection(CDI) receiving stool transplant were analyzed in addition to the sample of the healthy donor. This was done by terminal-restriction fragment length polymorphism (TRFLP) analysis in which the 16S rRNA gene is amplified from the fecal bacterial DNA and then cut with known restriction digest enzymes yielding DNA fragments of different lengths which are characteristic for different bacteria. These fragments were then aligned by length, resulting in a graph with peaks illustrating the richness (number of peaks) and abundance (height of peaks) of the organisms in the sampled microbial community. Results: A difference between pre and post-transplant fecal bacterial communities was demonstrated. In addition, a difference between the microbial communities in the donor and patient stool was shown. Five months post bacteriotherpy the changes in the patient’s microbioal communities was sustained and they were still in clinical remission. There was also commonality between the microbiome of the two patients with CDI. Conclusions: A difference in the bacterial flora in patients with recurrent CDI exists. Perhaps there is an inability of certain individuals to re-establish their normal protective bacterial flora. Eventually, with adequate sample size specific commonalities can be found and perhaps the specific "protective" species can be identified by sequencing the 16S rDNA that appear to be associated with the healthy donor stool that are not present in the patients prior to fecal transplant. This will aid in leading to more targeted treatment for CDI.

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Poster of Distinction A282 HELICOBACTER PYLORI ACTIVATES SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 IN DENDRITIC CELLS D. Rizzuti1, C. Reardon2, M. Ang1, N. Jones3 1. University of Toronto, Toronto, ON, Canada; 2. Campell Family Cancer Research Institute, Toronto, ON, Canada; 3. The Hospital for Sick Children, Toronto, ON, Canada. Aims: The gram-negative bacterium H. pylori infects approximately 50% of the human population worldwide. All infected individuals develop a chronic low-level gastritis which is insufficient to eliminate the bacteria, indicating that this pathogen is able to subvert the host immune response. Dendritic cells (DCs) play key roles in both the innate and adaptive immune response. Immature DCs function as antigen-presenting cells (APCs); they phagocytose pathogens and undergo a maturation process to present the pathogen’s antigens to effector cells of the immune system. In previous studies we identified a subset of infiltrating immune cells with activation of the transcription factor STAT3 in H. pylori infected gastric tissue. Importantly, previous studies indicate that activation of STAT3 inhibits dendritic cell maturation. Therefore, we hypothesized that H. pylori infection may alter DC maturation by activating STAT3. Methods: Bone marrow was obtained from wildtype and STAT3 CD11c-Cre K.O. mice to generate wildtype or specific STAT3 K.O. dendritic cells. DCs were incubated with wildtype or isogenic cagA mutant H. pylori, lipopolysaccharide or IL-6. Activation of STAT3 was determined by phosphostat3 immunoblotting. DC maturation was characterized by flow cytometry for MHC-II, CD80 and CD86 expression. Cytokine production from DCs were measured by ELISA. Results: IL-6 treated DCs showed STAT3 activation but no increase in maturation markers compared to untreated DCs. H. pylori infection activated STAT3 in wildtype but not STAT3 K.O. DCs as demonstrated by immunoblotting for STAT3. However, infected wildtype DCs showed increased expression of MHC-II, CD80 and CD86 comparable to LPS treated cells which did not exhibit STAT3 activation. Furthermore H. pylori treated wildtype DCs exhibited an enhanced IL-10:IL-12 ratio in comparison with control or LPS treated cells. Conclusions: H. pylori activates STAT3 in dendritic cells in association with an immunoregulatory phenotype. Ongoing studies will determine the exact functional effect of STAT3 activation.

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A283 ENTEROPATHOGENIC E. COLI (EPEC)-INDUCED EPITHELIAL HYPORESPONSIVENESS TO SECRETAGOGUES IS ASSOCIATED WITH DECREASED MEMBRANE LOCALIZATION OF CFTR C. Ohland, R. DeVinney, W. MacNaughton University of Calgary, Calgary, AB, Canada. Aims: EPEC infection causes severe diarrhea in humans, leading to substantial infant mortality in developing countries. The mechanisms of infection are well characterized, including the formation of a type III secretion system (TTSS) to inject bacterial effector proteins into the host cell. However, little is known about how EPEC affects intestinal epithelial ion and water secretion. We hypothesized that EPEC decreases epithelial ion secretion via alteration of host signalling pathways. Methods: Monolayers of the human intestinal cell line T84 were exposed to log phase EPEC at a multiplicity of infection of 100 for 4 hr. The secretagogue-induced ion transport was measured by change in short circuit current of cells mounted in Ussing chambers. Protein levels of the cystic fibrosis transmembrane conductance regulator (CFTR) were measured by Western blot and densitometry. Apical membrane localization of CFTR was determined by cell surface protein biotinylation followed by Western blot. Results: Exposure of T84 cells to EPEC for 4 hr decreased (p<0.05) the response to the cAMP-dependent secretagogue forskolin (control, 124.7±7.2; EPEC, 81.1±14.1 μAmp/cm2), without altering Ca2+)-dependent secretion. Exposure to an EPEC mutant lacking the TTSS ATPase or either bacterial pore protein (ΔescN, or ΔescC and ΔescV, respectively) caused similar hyposecretion, indicating that translocation of effector proteins was not involved. Interestingly, EPEC mutants lacking the TTSS filament proteins (EspA, B or D) caused a partial reversal of the hyporesponsiveness to forskolin. This suggests that EspA, B and D are interacting with the epithelial cell independent of a functional TTSS in an unknown manner to cause decreased responsiveness to forskolin. We next investigated whether epithelial ion channel expression or localization was altered by EPEC to decrease chloride secretion. While total CFTR protein was increased, cell surface expression was significantly decreased (64.1% of uninfected control) after exposure to EPEC. As the ΔescN mutant did not induce cell depolarization (as shown by basolateral transporters being biotinylated on the apical surface) but still decreased ion secretion and apical membrane levels of CFTR, we conclude that CFTR is being mislocalized to the cytosol which results in hyposecretion. This may be due to decreased recycling of the channel to the apical membrane, rather than increased internalization, as inhibiting endocytosis with phenylarsine oxide did not reverse EPEC-induced hyposecretion. Conclusions: In conclusion, EPEC decreases cAMP-dependent ion secretion of T84 cells by reducing levels of apical membrane CFTR, which is partially associated with TTSS filament protein expression.

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A284 HIGH LACTATE-PRODUCING BIFIDOBACTERIA AS A POTENTIAL PROPHYLACTIC THERAPY FOR NSAID-ENTEROPATHY S. Syer1, G. McKnight1, P. Langella2, A. Aucouturier2, R. Martin2, J. Wallace1 1. McMaster University, Hamilton, ON, Canada; 2. INRA, Jouy en Josas, France. Aims: For patients chronically treated with nonsteroidal anti-inflammatory drugs (NSAIDs), the risk of GI ulceration and bleeding is common and potentially serious. Such damage occurs in the small intestine more frequently than previously recognized, likely with a different pathogenesis than the gastric damage induced by NSAIDs. There is clear evidence for a crucial role of enteric bacteria (particularly gram-negative) in NSAID-enteropathy. We recently demonstrated that suppression of gastric acid secretion with proton pump inhibitors (PPIs) exacerbates NSAID-enteropathy by altering the small intestinal flora; specifically, PPIs cause a diminution of intestinal levels of Bifidobacteria (Wallace et al. 2011). Here we examined the possibility that treatment with Bifidobacteria would protect the intestine from NSAID-damage. We further attempted to determine if the ability of Bifidobacteria to produce lactate was important in any observed protective effect, given that lactate has recently been shown to reduce NSAID-induced intestinal damage in rats (Watanabe et al. 2009). Methods: Rats (n≥5 per group) were orally treated with vehicle, Bifidobacterium adolescentis DSM20219 (BA; high lactate-producing) or Bifidobacteria longum DSM 20083(BL; low lactate-producing) at various concentrations once-daily for 9 days. During the final 4 days, the rats were treated orally, twice-daily, with an anti-inflammatory dose of naproxen (10 mg/kg). Small intestinal damage was blindly scored at the end of the treatment period. Samples of cecum and small intestine were taken for PCR analysis of the microbiota. To determine if general increases in Actinobacteria could be protective against NSAID enteropathy, groups of rats (n≥5 per group) were given drinking water supplemented with 1% inulin (from chicory) starting one week prior to, and continuing during naproxen administration. Results: BA , but not BL (both at 109 CFU), significantly reduced naproxen-induced small intestinal damage as compared to controls. There was an ~82% decrease in intestinal damage when BA treated animals compared to controls (P=0.02). Rats given water supplemented with inulin exhibited naproxen-induced small intestinal damage comparable in severity to that seen in controls. Conclusions: A lactate-producing species of Bifidobacteria significantly reduced the severity of NSAID-enteropathy in rats, while a species of Bifidobacteria not producing lactate had no effect. Similarly, inulin, which has been shown to increase intestinal Bifidobacteria levels, did not attenuate NSAID-enteropathy. This suggests that lactate production is a key factor in the beneficial effects observed with Bifidobacteria. Lactate-producing Bifidobacteria may represent a viable prophylactic therapy for NSAID-enteropathy.

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A285 THE MODULATION OF THE HUMAN INTESTINAL MICROLFORA COMPOSITION AND STRUCTURE BY CAMPYLOBACTER JEJUNI S. Akierman, J. Beatty, P. Beck, K. Rioux, A. Buret University of Calgary, Calgary, AB, Canada. Aims: Campylobacter jejuni (C. jejuni) is the worldwide leading cause of human bacterial enteritis. There is recent evidence that indicates that acute gastroenteritis may contribute to the production of post-infectious symptoms in patients with inflammatory bowel disease (IBD). While the postulated causes of IBD are various, evidence suggests a role of modulation of the intestinal microflora in the pathophysiology. There is currently a lack of knowledge as to whether the exposure to enteropathogens may lead to an imbalance amongst the gastrointestinal microflora thus prompting an inappropriate immunological response, leading to the development of IBD. Our study served to investigate whether C. jejuni is capable of modulating the human intestinal microflora biofilms generated from colonic biopsies. Methods: Mucosal biopsies of the colon were obtained from healthy donors undergoing screening colonoscopy. Homogenates of the biopsies were used to seed anaerobic biofilms in the Calgary Biofilm Device. The resulting multispecies bacterial biofilms were then exposed to live C. jejuni and assessed by viable cell counting, XTT assay, terminal restriction fragment length polymorphism (T-RFLP), confocal scanning laser microscopy (CSLM), and scanning electron microscopy (SEM). Results: CSLM imaging of the biofilms demonstrated a decrease in biofilm thickness when exposed to C. jejuni. Additionally, SEM demonstrated a reduction in the extracellular matrix of the multispecies biofilms when exposed to C. jejuni. At the same time, viable cell counts showed C. jejuni adheres with the microflora biofilms. Lastly, data obtained from T-RFLP showed an increase in the order Clostridiales relative growth when exposed to C. jejuni. Conclusions: Our preliminary results indicate a C. jejuni induced thinning of cultured multi-species biofilm as well as a modification in the microbial representatives polysaccharide expression. Moreover C. jejuni modulates the multi-species biofilms composition by increasing the relative growth of Clostridiales. We postulate that these findings may play an important role in the development of symptoms in susceptible patients with IBD as well as the pathogenesis of campylobacterosis and suggests a need for additional investigation.

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A286 ROLE OF CATHEPSIN-LIKE CYSTEINE PROTEASES IN GIARDIA PATHOLOGY A. Bhargava1, J. Cotton1, B. Dixon2, R. Yates3, P. Beck4, J. Ferraz4, A. Buret1 1. Biological Sciences, University of Calgary, Calgary, AB, Canada; 2. Health Canada, Ottawa, ON, Canada; 3. Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada; 4. Faculty of Medicine, University of Calgary, Calgary, AB, Canada. Aims: Giardia duodenalis, a non-invasive protozoan parasite of the upper small intestine, closely associates with the intestinal epithelial cells (IECs) and induces pathophysiological effects including heightened rates of IEC apoptosis, intestinal barrier dysfunction, and diffuse shortening of the brush border microvilli; this results in malabsorptive diarrhea. Giardia products that may initiate disease have yet to be identified. Cysteine proteases have been linked to pathology caused by other protozoan parasites, including Entamoeba and Leishmania. The Giardia genome contains several cathepsin B-, C-, and K/L-like cysteine protease genes of unknown function. The purpose of this study is to characterize cathepsin B- and L-like cysteine protease activity in Giardia infections, and determine if these play a role in the pathogenesis of giardiasis. Methods: Human colonic (Caco-2) monolayers were co-incubated with G. duodenalis trophozoites (Assemblage A isolates NF, S2, WB or Assemblage B isolate GS/M)(MOI: 10:1 : 24h). Giardia trophozoite and Caco-2 cell lysates and supernatants were incubated with cathepsin fluorogenic substrates to measure cathepsin activity. Experiments were performed in the presence or absence of a general cysteine protease inhibitor (E-64d), or a cathepsin B inhibitor (Ca-074) and processed for Western blotting to analyze for induction of apoptosis (caspase-3 activation) and intestinal barrier dysfunction (ZO-1). Results: Giardia trophozoites secrete cathepsin L-like proteases in an isolate-independent manner in the presence and absence of Caco-2 monolayers. Supernatants from ex vivo human small intestinal biopsy tissues co-incubated with Giardia trophozoites showed a trend towards increased cathepsin B/L activity. Giardia trophozoites expressed cathepsin B activity in the presence or absence of Caco-2 cells in an isolate-dependent manner. Whole cell lysates collected from Caco-2 monolayers co-incubated with Giardia trophozoites showed an increase in intracellular cathepsin B activity in an isolate-independent manner. This required direct contact between Caco-2 cells and Giardia trophozoites. Inhibition of Giardia-induced increased intracellular cathepsin B activity with Ca-074 failed to block cleavage of ZO-1 and caspase-3. Conclusions: Giardia trophozoites express and release cathepsin B- and L-like cysteine proteases, and induce epithelial cathepsin B-like activity when directly contacting enterocytes. Giardia-induced cathepsin B-like cysteine proteases do not appear to be responsible for activation of caspase-3 or disruption of ZO-1.

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A287 ENTAMOEBA HISTOLYTICA INDUCES A ROBUST ACUTE INFLAMMATORY RESPONSE WITH INCREASED COLONIC PERMEABILITY AND ALTERED TIGHT JUNCTION PROTEINS IN MUC2-/- MICE V. Kissoon-Singh, F. Moreau, K. Chadee Gastrointestinal Research Group, University of Calgary, Calgary, AB, Canada. Aims: The intestinal MUC2 mucus layer is the first line of innate host defense against pathogens. Mice deficient in Muc2 spontaneously develop colitis and are more susceptible to DSS induced injury. The colonic parasite Entamoeba histolytica (Eh) exploits the mucus layer by binding of the parasite Gal/GalNAc lectin to mucin oligosaccharides to facilitate colonization leading to infectious disease in humans. Methods: In this study we investigated the innate host defenses in Muc2-/- mice challenged with virulent Eh in a colonic loop model of infection. Results: Eh induced a time dependent robust secretory response in Muc2-/- mice associated with increased pathology and leakage of serum albumin (p<0.01). The acute inflammation was dominated by elevated IFN-γ and TNF-α protein secretion. Surprisingly, Eh caused an increased expression of the pore forming tight junction protein claudin-2 and a corresponding decreased expression of claudin-4 and occludin (p<0.05). Conclusions: In the absence of Muc2, Eh elicits a robust acute inflammatory response and expression of TJ proteins leading to increased intestinal permeability emphasizing the role of Muc2 in luminal and epithelial barrier functions.

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Motility and Nerve –Gut Interactions

A288 LONG-TERM OUTCOM IN PATIENTS WITH ACHALASIA AFTER PNEUMATIC DILATATION M. Al Beshir1, N. Diamant2, M. Li1, L. Liu1 1. University of Toronto, Toronto, ON, Canada; 2. Queen University, Kingston, ON, Canada. Aims: Achalasia is a chronic primary esophageal motor disorder characterized by impaired lower esophageal sphincter (LES) relaxation and aperistalsis of the esophagus. Management modalities are aimed to lower the LES pressure. Pneumatic dilatation (PD) is the most effective non-surgical therapy; however, its long-term efficacy is still under active research. The objective of this study is to describe the long-term efficacy of PD in patients with achalasia. Methods: We performed a retrospective review of all pre-identified achalasia patients from 1969 to 2011 in a single tertiary referral centre. Patients who received PD either as an initial treatment or as secondary measure after failed medical or botulinum toxin injection were included. Patient demographics, presenting symptoms, method of diagnosis, achalasia sub-type, duration of symptoms prior to the intervention and presence of co-morbidities were documented. We constructed a Kaplan-Meier survival curve using the product limit method to model time to recurrent achalasia symptoms. Subjects were censored if they were lost to follow-up, withdrew from the study, died, or were symptom free at the end of the study period. In a secondary analysis, we examined predictors of successful pneumatic balloon dilation. We defined success as time to recurrent achalasia symptoms greater than or equal to 8 weeks. Cox proportional regression (STATA 7.0) was used to identify significant predictors of success. Results: One hundred and sixty-two of the 170 patients with achalasia were included (88 men and 74 women, mean age 41.2 years) in the analysis. Dysphagia was found in all patients. Sixty-eight patients (42 %) received pharmacological therapy (calcium channel blockers and nitrates) and 2 patients received botulinum toxin injection prior to the PD. Five patients had vigorous achalasia. Forty-seven patients (29%) underwent ≥2 PD and 10 patients (6%) required surgical myotomy. Perforation was found in 6 patients out of the total 170 patients (2.6 % of 230 PD performed). 5 had myotomy and 1 recovered with conservative therapy). Ten (6.2%) patients developed GERD. The preliminary average follow-up to-date was 67.8± 6.7 mo (median 33 mo). The mean symptom-free duration after successful PD was 62.8± 6.2 mo (median 24 mo). Patients who had not been seen in the last 12 months are being contacted. Kaplan-Meier curve and the final symptom-free duration will be determined once all 162 patients included in the study had been contacted. Conclusions: This is the longest follow-up study in achalasia patients who received PD in a single tertiary centre. It supports the notion that PD is a safe and effective treatment in achalasia patients and should be discussed as an effective long-term management option.

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A289 CHARACTERIZATION OF ASCENDING AND DESCENDING COLONIC NEUROMUSCULAR REFLEXES IN WILD TYPE AND INTERSTITIAL CELL OF CAJAL (ICC)-DEFICIENT MICE. Y. Zhang, W. Paterson GI Diseases Research Unit, Kingston General Hospital, Kingston, ON, Canada. Aims: Ascending and descending neuromuscular reflexes induced by distension play an important role in gastrointestinal motility, however, the mechanisms involved in colon are incompletely understood. It has been postulated that intramuscular ICCs play an important role in these peristaltic reflexes, either by facilitating neurotransmission or by acting as mechanotransducers. Methods: Nerve stimulation (NS) and balloon distension (BD)-mediated ascending and descending responses were investigated using conventional intracellular recordings from distal colonic circular and longitudinal smooth muscle (CSM; LSM) in W/Wv wild-type and mutant mice, which lack intramuscular ICCs. Results: Ascending responses: In the CSM, NS evoked monophasic inhibitory junction potentials (IJP), whereas BD induced depolarization with superimposed action potentials that reached a peak in 4 - 7 s and was maintained until the termination of the BD. Atropine (3 µM) significantly increased the NS-induced IJP from 35.4 ± 1.8 mV to 38.5 ± 1.8 mV, but abolished the BD-induced depolarization. In LSM, NS produced a biphasic IJP (fast IJP following by slow IJP (sIJP)). BD evoked an initial IJP following by a train of action potentials. MRS-2500 (1 µM), a P2Y1 antagonist, abolished the initial IJP, whereas atropine abolished the action potentials. In CSM from W/Wv mutant mice, responses to NS were no different from controls. However, the depolarization in response to BD was attenuated and delayed in onset until after the balloon was deflated. In LSM from W/Wv mutant mice, NS-induced ascending sIJPs were diminished and BD-evoked action potentials were absent. Descending responses: NS produced comparable descending monophasic IJPs in distal colonic CSM and LSM, while BD induced transient descending monophasic IJPs as well. These IJPs were abolished by MRS-2500. Unlike ascending excitation in W/Wv wild-type and mutant mice, there was no difference in the descending IJPs evoked by NS and BD between the wild and mutant types. Conclusions: These data indicate that in the murine distal colon: 1) Ascending response induced by BD differs from that induced by the NS, while NS and BD produce similar descending inhibition; 2) Ascending response evoked by the BD in CSM differs from LSM. In contrast, descending inhibition is similar in both CSM and LSM; 3) Only cholinergic nerves are involved in ascending excitation to both CSM and LSM, and purinergic nerves play a dominant role in descending inhibition; 4) In distal colonic CSM and LSM of mice deficient in intramuscular ICCs, ascending excitation to BD is impaired whereas descending responses to BD and NS are intact.

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A290 EFFICACY OF PRUCALOPRIDE IN THE TREATMENT OF CHRONIC CONSTIPATION: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS E. Cheng, A. Rezaie, M. Storr University of Calgary, Calgary, AB, Canada. Aims: Chronic constipation (CC) is a common condition where symptoms can be severe and can significantly affect quality of life. Prucalopride is a highly selective 5-HT4 receptor agonist that increases colonic motility and represents a new therapeutic option in the management of CC. We aimed to assess the efficacy and safety of prucalopride for the treatment of patients with CC. Methods: Articles were identified through MEDLINE, EMBASE, Web of Science, the Cochrane Central Register of Controlled Trials and the Cochrane IBD/FBD Group Specialized Register. Reference lists of articles and proceedings of major gastroenterology meetings were manually searched. Randomized controlled trials (RCT) comparing prucalopride to placebo that met predetermined selection criteria were included. Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Analyses were performed using the Mantel-Haenszel test. Random effects models were used when heterogeneity was noted. Results: Six RCTs were identified. A total of 2693 patients were randomized to once daily prucalopride (0.5, 1, 2 or 4 mg) or placebo. Intervention duration was 4 to 12 weeks. Prucalopride 2 mg treatment resulted in a significantly higher proportion of patients reaching an average of three or more (≥ 3) spontaneous, complete bowel movements (SCBM) per week compared with placebo (OR 2.56; 95% CI 1.97 - 3.32). Additional efficacy endpoints were also significantly improved, including the proportion of patients experiencing an increase of ≥ 1 SCBM/wk (OR 2.31; 95% CI 1.91 - 2.78) and an improvement of ≥ 1 point on the Patient Assessment of Constipation - Symptoms (PAC-QOL) satisfaction subscale (OR 2.21; 95% CI 1.80 - 2.71). There was no significant benefit with prucalopride 4 mg compared to 2 mg in the proportion of patients achieving ≥ 3 SCBMs/wk (OR 0.96; 95% CI 0.77 - 1.20), an increase of ≥ 1 SCBM/wk (OR 1.04; 95% CI 0.86 - 1.27) or an improvement of ≥ 1 point on the PAC-QOL satisfaction subscale (OR 0.98; 95% CI 0.80 - 1.21). The most frequently reported adverse effects (headache, abdominal pain, nausea and diarrhea) occurred mainly on the first day of treatment. The rates of occurrence of these adverse effects after day 1 were similar between prucalopride and placebo. There were no differences observed in the incidence of new cardiac events or QTc prolongation. Conclusions: Prucalopride 2 mg daily is more effective than placebo for the treatment of CC as evidenced by clinically meaningful endpoints reflecting normalization of bowel function, treatment satisfaction and QOL. Prucalopride 4 mg daily is no more effective than 2mg daily. Prucalopride is relatively well tolerated. Further studies are needed to determine efficacy and safety over longer treatment durations.

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A291 SPATIOTEMPORAL MAPS OF EX VIVO PERISTALSIS REVEAL DETAILS OF PROBIOTIC EFFECTS ON MOUSE JEJUNUM MOTILITY R. Wu1, D. Zhang3, J. Bienenstock1, M. Pasyk1, W. Kunze2 1. McMaster Brain-Body Institute St Joseph's Healthcare, Hamilton, ON, Canada; 2. Farncombe Family Digestive Health Research Institute, Hamilton, ON, Canada; 3. University of Waterloo, Waterloo, ON, Canada. Aims: A Lactobacillus rhamnosus strain (JB-1) is peripherally neuroactive in that it alters enteric neuron excitability1 and reduces the peristaltic contraction amplitude2. Yet, clinically relevant parameters of motility include not only the contraction amplitude but frequency and propagation speed. To examine this, we used video imaging and spatiotemporal maps of jejunal diameter changes for the actions of JB-1 and L. reuteri (DSM 17938, BioGaia AB, Stockholm, Sweden). JB-1 is analgesic in models of colorectal distension, and DSM is effective in treating infantile colic3. Methods: A 5 cm long segment of mouse jejunum was placed into a carbogenated, Krebs buffer perfused, organ bath and canulated at both ends. The serosal and intraluminal compartments were separately perfused. The lumen was first filled with Krebs buffer, and then with buffer plus added bacteria: all test were paired Wilcoxon. Probiotic concentrations were 9 log cfu/mL or 7 log cfu/mL for JB-1 or DSM respectively. Drugs were added to the serosal compartment. Contacting segments were videoed, and digitally analyzed with in-house software, with the diameter at each point along the intestine long axis represented as a single pixel of greyscale value. Successive lines of pixels were then stacked to yield a spatiotemporal map from which the motility parameters were read by the software. Results: A luminal filling pressure of 3-5 hPa delivered using a Mariotte bottle elicited regular peristaltic motor complexes (MCs) that were abolished by 0.5 µM tetrodotoxin. JB-1 decreased MC frequency from 0.046±0.04 to 0.014±0.006 Hz (n=8, P=0.001) and DSM reduced it from 0.19±0.06 to 0.04±0.04 Hz (n=11, P=0.0001). JB-1 increased MC propagation speed from 2.0±2.6 to 6.0±5.0 mm/s (n=8, P=0.002) but DSM decreased it from 2.3±5.1 to 0.41±0.80 mm/s (n=8, P=0.008). The effects plateaued within 20 min and did not wash out; there was no rundown when just Krebs was applied for 40 min. Adding 0.3 µM TRAM-34 (serosally) decreased MC frequency (n=8, P=0.008) from 0.07±0.11 to 0.002±0.006 Hz and increased speed from 1.5±0.7 to 4.9±3.7 mm/s (n=7, P=0.05). Conclusions: Spatiotemporal maps allow for added important clinically relevant parameters to be measured compared to pressure recordings for probiotic effects on gut motility. JB-1 had actions similar to the IKCa channel blocker TRAM-34 consistent with this channel being a target for the probiotic. DSM had analogous actions but differed concerning effects on propagation speed suggesting additional molecular targets may be involved. 1. Kunze, W. A. et al. J Cell Mol Med 13, 2261, 2009 2. Wang, B. et al. FASEB J 24, 4078, 2010 3. Savino, F. et al. Pediatrics 126, e526, 2010

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A292 SLEEP DISRUPTION SECONDARY TO OVERNIGHT CALL SHIFTS IS ASSOCIATED WITH IRRITABLE BOWEL SYNDROME IN RESIDENTS: A CROSS-SECTIONAL STUDY M. Wells1, L. Roth2, N. Chande1 1. University of Western Ontario, London, ON, Canada; 2. McMaster University, Hamilton, ON, Canada. Aims: Sleep disruption and shift work have been associated with irritable bowel syndrome (IBS). Overnight call shifts during residency training leads to sleep disruption. To our knowledge, no previous study has investigated any potential association between residency overnight call shifts and IBS. We hypothesized that Canadian residents who have greater sleep disruption secondary to intermittent overnight call shifts will have a higher prevalence of irritable bowel syndrome. Methods: All postgraduate residents at The University of Western Ontario were invited to complete an anonymous web-based survey that included demographic data, frequency and characteristics of call shifts, the Rome III questionnaire, and the irritable bowel syndrome-quality of life measure (IBS-QOL). The prevalence of IBS and quality of life secondary to those symptoms were determined. Results: Data were available for 226 residents. Sleep disruption secondary to intermittent twenty-four hour call shifts was significantly associated with an increased prevalence of IBS (p=0.01). For every hour of sleep deprivation while on call compared to off call, the odds ratio for an increased likelihood of IBS was 1.32, after adjusting for age and gender. There was no significant association between the presence of IBS and age, gender, year of residency, specialty/family medicine, number of call shifts per block, number of hours of sleep while on call, and number of hours of sleep while not on call. However, the mean number of calls per block (p=0.009), sleep deprivation while on call (p=0.035) and specialty program versus family practice (p=0.013) each predicted the severity of IBS as measured by the IBS-QOL instrument. Conclusions: Sleep disruption secondary to overnight call in Canadian residents was associated an increased prevalence of IBS.

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A293 PREOPERATIVE ESOPHAGEAL MANOMETRY AS A PREDICTOR OF PATIENT OUTCOME FOLLOWING ADJUSTABLE GASTRIC BANDING O. Landon-Cardinal, J. Cote-Daigneault, P. Leclerc, J. Joubert, M. Bouin Gastroenterology Service, research center of St-Luc hospital (CRCHUM), Montreal, QC, Canada. Aims: There is a high prevalence of postoperative adverse symptoms in patients with laparoscopic adjustable gastric banding (LAGB). We previously demonstrated a high prevalence of esophageal dymotilities in obese patients. The aim of this study is to evaluate if the result of preoperative manometry was correlated with patients outcome after LAGB. Methods: Prospective study from January 2009 to December 2011 at the University of Montreal Hospital Research Center (CRCHUM). All patients undergoing bariatric surgery were included and had a preoperatory standardized esophageal manometry and gastrointestinal symptoms survey. Patients included were subsequently divided into two groups according to their manometry results (normal vs abnormal). File reviews were performed to assess these postoperative criteria: upper digestive tract symptoms, LAGB revision and weight loss. Results: Ninety-one patients were included (average age: 44 ± 9 years old, average BMI: 47 ± 10). Esophageal dysmotility was found in 54% of patients (n=49). Patients were similar between the two groups (normal vs abnormal manometry) in terms of age, sex, BMI and comorbidities. There was no association found between preoperative oesophageal tract function and postoperative adverse upper digestive tract symptoms (57% vs 47%; statistically non significant (NS)) and LAGB revision rates (41% vs 37%; NS). Mean postoperative weight loss between 1 and 3 months was similar between our two groups (11,4% vs 9,3%; NS). Nonetheless, patients with a normal manometry presented with a more significant weight loss between 1 and 3 months (10-25% weight loss from weight at surgery: 43% vs 22%). Conclusions: There is no association found in our study between preoperative oesophageal tract function and patient outcome after gastric banding.

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A294 EXCITABILITY OF COLONIC NOCICEPTIVE DORSAL ROOT GANGLIA NEURONS IS SUPPRESSED BY ENDOGENOUS OPIOIDS IN A MOUSE MODEL OF CHRONIC INFLAMMATORY BOWEL DISEASE E. Valdez-Morales, J. Benson, A. Lomax, S. Vanner Queen's University, Kingston, ON, Canada. Aims: Acute inflammation in the colon enhances excitability of colonic nociceptive dorsal root ganglia (DRG) neurons but the relative proportion of pro- and anti-nociceptive mediators varies with the duration of inflammatory bowel disease (IBD). Therefore, we examined the effects of chronic inflammation on the excitability of nociceptive DRG neurons using patch clamp recordings in a chronic IBD model and characterized the mediators underlying this effect. Methods: C57BL/6 mice were treated three cycles of 2% DSS (each cycle has 5 days of DSS and 5 days of water) to induce chronic inflammation. At the end of the third DSS cycle, mice were euthanized and colonic tissue taken to make supernatants. DRG neurons were incubated overnight with supernatant from DSS colons or from controls. The excitability of neurons was measured by perforated patch clamp, recording changes in rheobase and action potential discharge. Voltage clamp studies were used to analyze changes in voltage-gated potassium currents. Endogenous opioid expression was measured by ELISA, immunohistochemistry, and flow cytometry. Results: The rheobase was increased 45% (p= 0.025) while action potential number at twice rheobase was decreased 68% (p= 0.035) in neurons incubated with DSS supernatans versus control supernatant. These effects were inhibited by the µ-opioid receptor antagonist naloxone (10 µM). In addition, DRG neurons incubated overnight with the µ-opioid receptor agonist DAMGO (10 nM) also exhibited decreased excitability (rheobase increased 31%, p= 0.034). In neurons incubated with DSS supernatans, transient K+ IA currents were increased (p<0.01), consistent with decreased excitability. In chronic DSS colonic tissue, ELISA demonstrated a >10 fold increased in endogenous β endorphin levels (p=0.03), immunohistochemistry showed a marked increase in β endorphin immunoreactive cells in the lamina propria, and flow cytometry showed a >75% increase in CD4+ cells expressing β endorphin. Conclusions: These studies demonstrate that chronic inflammation increases levels of endogenous opioids which could inhibit peripheral pain signalling, at least in part, by increasing IA K+ currents. Changes in endogenous opioid signalling during chronic inflammation could modulate pain expression and alter requirements for analgesia in patients.

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Pancreatico-Biliary Disease

A295 ENDOSCOPIC MANAGEMENT OF ANASTOMOTIC STRICTURES IN DECEASED VERSUS LIVING DONOR LIVER TRANSPLANTATION C. Chan1, F. Donnellan1, M. Byrne1, A. Coss1, C. Scudamore2, U. Steinbrecher1, A. Weiss1, E. Yoshida1 1. Department of Medicine, Division of Gastroenterology, Vancouver General Hospital and University of British Columbia, Vancouver, BC, Canada; 2. Department of Surgery, Vancouver General Hospital and University of British Columbia, Vancouver, BC, Canada. Aims: Endoscopic therapy has been successful in the management of biliary complications following both deceased donor (DDLT) and living donor liver transplantation (LDLT). LDLT is thought to be associated with higher rates of biliary complications, but there are few data on direct comparisons of the success of endoscopic management of anastomotic strictures (AS) between the two groups. The aim of this study is to compare a single center’s experience of endoscopic management of AS in DDLT compared to LDLT. Methods: A retrospective database review of all liver transplant patients who underwent ERCP from May 2003 to August 2011. Data was expressed as mean +/- standard error. The Student’s t-test and Fisher’s exact test were used to analyse the results. A P value of less than 0.05 was considered statistically significant. Results: 362 patients underwent liver transplantation during the study period, including 29 LDLT. Of these, 111 (33.3%) DDLT and 14 (48.3%) LDLT were referred for ERCP management of biliary complications (p=0.11). Biliary cannulation was successful in all patients, with 3 patients in DDLT requiring precut for biliary access. The main diagnoses at ERCP were as follows: AS in 33 (10.0%) DDLT versus 8 (27.6%) LDLT (p=0.01); bile leak in 24 (7.2%) DDLT versus 2 (6.9%) LDLT (p=1.0); choledocholithiasis in 14 (12.6%) DDLT versus 1 (7.1%) LDLT (p=1.0); rising LFTs with normal cholangiogram in 28 (25.2%) DDLT and 4 (28.6%) LDLT (p=0.31). 6 (1.8%) DDLT were found to have non anastamotic strictures, compared to 0 LDLT. For AS, no difference was found in the mean time to development of stricture (98+/-17 days for DDLT versus 172+/-65 days for LDLT, p=0.11), mean time to resolution of stricture (268+/-77 days for DDLT versus 125+/-37 days for LDLT, p=0.34), likelihood of response to ERCP [21 (63.6%) DDLT versus 6 (75%) LDLT, p=0.69], and number of ERCPs required to achieve resolution (3.9 +/-0.4 DDLT versus 4.7 +/-0.9 LDLT, p=0.38). Conclusions: Endoscopic treatment is effective in the majority of biliary complications relating to liver transplantation. Anastomotic strictures occurs more frequently in LDLT compared to DDLT, with equivalent endoscopic treatment response and outcomes for both groups.

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A296 RACIAL AND INSURANCE DISPARITIES ARE INDEPENDENTLY ASSOCIATED WITH IN-HOSPITAL MORTALITY IN PATIENTS ADMITTED WITH CHOLANGITIS: A NATIONAL SURVEY J. McNabb-Baltar1, Q. Trinh2, A. Barkun1 1. McGill University, Montreal, QC, Canada; 2. Henry Ford Health System, Detroit, MI. Aims: Outcomes may differ according to race, insurance status and day of admission. The objective of this study was to examine factors associated with in-hospital mortality, prolonged length of stay (LOS) and increased hospital charges (HC) in patients presenting with acute cholangitis. Methods: Within the Health Care Utilization Project Nationwide Inpatient Sample (NIS), we focused on patients, 18 years and older, admitted to the emergency department with cholangitis as primary diagnosis (1998-2009). Models were fitted to predict the likelihood of in-hospital mortality, prolonged LOS and increased HC. Covariates included race, day of admission, insurance status, socio-economical status and other patient and hospital characteristics. Results: Overall, 50859 patients were identified, of which 2770 (5.5%) died during the admission. Multivariable analyses revealed that relative to Caucasian patients, African American (AA), Hispanic and Asian and Pacific Islander (API) patients admitted with cholangitis were more likely to die (OR=1.63, p<0.001, OR=1.21, p=0.007 and OR=1.26, p=0.009), to experience a prolonged LOS (OR=1.79, p<0.001, OR=1.30, p<0.001, 1.34, p<0.001) and to incur high HC (OR=1.71, p<0.001, OR=1.46, p<0.001, OR=1.60, p<0.001). Moreover, Medicaid and Medicare patients were more likely to die (OR=1.64, p<0.001, OR=1.23, p=0.001), to experience a prolonged LOS (1.75, p<0.001, OR= 1.24, p<0.001) and to incur high HC (OR=1.22, p=0.002, OR=1.12, p=0.001) compared to privately insured patients. Conclusions: In patients presenting with cholangitis, race and insurance status represent independent predictors of in-hospital mortality and adverse outcomes. Whether these disparities are due to biological predisposition or unequal quality of care require further investigation.

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A297 SPYGLASS® CHOLANGIOSCOPY: EARLY EXPERIENCE IN A CANADIAN UNIVERSITY HOSPITAL T. AlAmeel, G. Sandha University of Alberta, Edmonton, AB, Canada. Aims: The single operator Spyglass® cholangioscopy system offers endoscopists direct visualization of the biliary duct as well as an array of diagnostic and therapeutic interventions that are beyond what can be achieved with standard ERCP techniques. Although Spyglass® cholangioscopy has slowly gained popularity elsewhere, its use in Canada has been limited. The object of this study is to describe the experience of a Canadian tertiary care centre with Spyglass® cholangioscopy in managing biliary disease. Methods: This is a retrospective review of all cases undergoing Spyglass® cholangioscopy at the University of Alberta Hospital in Edmonton, Alberta. Patient characteristics, indications for procedure, interventions and outcomes are described. Results: Since April 2011, 11 patients 8 females and 3 males median age 69 (range 52-89) years (SD 12.5) , underwent 12 procedures by a single experienced biliary endoscopist under general anesthesia. The indications were biliary stricture assessment (6 patients), CBD stones that had failed conventional therapy (5 patients) and confocal biliary endomicroscopy (1 patient). Spybite® forcep biopsies, taken in 4/6 patients with strictures, were reported inflammatory. Two patients had smooth, benign-appearing strictures that were not biopsied. Electrohydraulic lithotripsy of large stones was performed in 4/5 patients. All stones were successfully fragmented. No stone was found in 1 patient. The average procedure time was 54.7 minutes (SD 18.97). One patient developed mild post-ERCP pancreatitis. Conclusions: Our initial experience reaffirms published data that single operator Spyglass® cholangioscopy is safe and effective in managing biliary pathology. However, the procedure is tedious, time-consuming and complex and, therefore, its use should be limited to experienced biliary endoscopists.

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A298 AUTOIMMUNE PANCREATITIS: A RARE CAUSE OF ABDOMINAL PAIN IN A CHILD A. Alqahtani, H. Brill, R. Issenman, N. Stein, M. Sherlock McMaster Univsersity, Hamilton, ON, Canada. Aims: Autoimmune pancreatitis is a rare cause of recurrent pancreatitis amongst adults with only a small number of pediatric cases reported. We aim to highlight this entity and present a case report in a pediatric patient, along with a literature review of autoimmune pancreatitis in pediatric patients. Methods: A review of the case is presented followed by a literature review exploring clinical characteristics, diagnostic work-up and treatment strategies for pediatric patients with autoimmune pancreatitis. Results: Case Report: A previously healthy 6 year-old boy presented with a history of severe central abdominal pain and failure to thrive. Physical examination was normal apart from evidence of poor growth (weight was 17.4kg (<5th percentile) and height 112 cm (5-10th percentile)). Initial investigations revealed iron deficiency anemia and hypoalbuminemia. Lipase and amylase were initially normal. He underwent an extensive work-up for inflammatory bowel disease including upper endoscopy, colonoscopy and barium follow-through, all of which were normal. An abdominal CT revealed prominent lymphadenopathy, which remained stable on serial ultrasounds; pancreas was always reported as normal. His abdominal pain continued and became associated with intermittent fevers. Infectious work-up including TB testing was negative. A repeat lipase and amylase were found to be elevated at 995 U/L and 2535 U/L, respectively, and a diagnosis of pancreatitis was made. Ultrasound revealed no evidence of gallstones. Triglycerides and cholesterol were normal. MRCP revealed marked enlargement of the pancreatic head and tail. The pancreatic body appeared normal. The common bile ducts and main biliary tree were dilated proximal to the pancreatic head. Genetic testing for cystic fibrosis and for hereditary pancreatitis was negative. IgG4 was elevated at 2.25 g/l. Based upon the combination of MRI findings and elevated IgG4, a diagnosis of autoimmune pancreatitis was made. The patient has been commenced on oral prednisone and has had no recurrence of his abdominal pain. Literature review: We identified 16 cases of autoimmune pancreatic in pediatric patients, with ages ranging from 2 to 18 years. Abdominal pain and weight loss were common presenting symptoms. Diagnostic workup and treatment strategies varied. Conclusions: Conclusions: Autoimmune pancreatitis is extremely rare amongst pediatric patients. To date there have only been 16 cases reported, with only 2 children presenting prior to 10 years of age. A diagnosis of autoimmune pancreatitis should be considered in children presenting with recurrent acute or subacute pancreatitis, in whom other investigations have not revealed a cause.

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A299 EARLY EXPERIENCE USING A NEW CORE EUS BIOPSY NEEDLE FOR THE DIAGNOSIS OF SOLID MASS LESIONS P. D'Souza, G. Sandha, C. Wong, C. Teshima University of Alberta, Edmonton, AB, Canada. Aims: Endoscopic ultrasound (EUS) is an established method used to assess mass lesions within and in proximity to the gastrointestinal tract. It is often necessary to perform EUS-guided biopsies using fine needle aspiration (FNA), which obtains tissue samples for cytological assessment. Recently, a new technique of fine needle biopsy (FNB) was introduced that is designed to obtain core samples for histology, in the hopes of improving the diagnostic yield and accuracy of EUS-FNA. This Echotip® ProCore™ needle (Cook Medical) has been available in Canada since March 2011. While the initial European experience with this new needle has been quite promising, we subjectively believed that our own results have not been as encouraging. Thus, we sought to assess the diagnostic yield of the new ProCore needle for EUS-FNB of solid mass lesions in the first 6 months of its use in Edmonton. Methods: A retrospective chart review was performed of all EUS-guided biopsy cases that used the 19 or 22 gauge ProCore needle from April 1 to September 24, 2011 at the University of Alberta Hospital and the Royal Alexandra Hospital in Edmonton. The patient demographics, indications, EUS findings, and histology report for each case were determined. Results: There were 44 cases of EUS-FNB of solid mass lesions using the ProCore needle during the study period; average age 64 years, 50% women. The indication for EUS was primarily for masses in the pancreas (29), but also included solid lesions in the peri-pancreatic area (4), stomach (4), esophagus (3), lymph nodes (2), adrenal gland (1) and liver (1). Early technical failures resulted in no biopsy acquisition in 6 cases. After eliminating these technical failures, a total of 38 biopsies were available. A core sample was obtained in 28 (74%) cases with only 20 (71%) of these being diagnostic. An additional 2 cases provided a diagnosis from cytology that had been performed when the endoscopist believed no core was obtained. The confirmed diagnoses consisted of 16 pancreatic adenocarcinomas, 1 pancreatic neuroendocrine tumor, 1 malignant melanoma, 1 lymphoma, 1 GIST and 2 benign diagnoses (normal pancreas and liver fibrosis). In the remaining 16 (42%) cases, the biopsy sample was considered insufficient to provide a clear diagnosis, or consisted primarily of blood clot. No significant difference was seen in the yield between the 19 and 22 gauge needle. Conclusions: Our early experience with the new ProCore needle has been disappointing and sharply differs from the success achieved by centres involved with the needle’s development. However, challenges with the ideal biopsy method hindered our outcomes. To better clarify the utility of EUS-FNB and having overcome a presumed learning curve, a prospective trial has been started comparing the ProCore needle to conventional FNA.

A300 INTRADUCTAL PAPILLARY ONCOCYTIC NEOPLASM: A RARE CYSTIC PANCREATIC NEOPLASM M. Brahmania, D. Khangura, M. Cantor University of Manitoba, Winnipeg, MB, Canada. Aims: Intraductal papillary mucinous neoplasms (IPMNs) are mucin producing pancreatic cystic neoplasms involving the main pancreatic duct and/or its major side branches. Histologically, IPMNs are divided into 4 distinct subtypes: gastric, intestinal, pancreatobiliary and oncocytic. Intraductal oncocytic papillary neoplasm (IOPN) is a rare subtype of IPMN, the clinical and diagnostic features of which remain unclear. We highlight an unusual example of IOPN outlining its clinical, imaging and pathologic features. Methods: A previously healthy forty-five year old Caucasian female presented with a six year history of intermittent nausea and vomiting. A CT scan of the abdomen was performed showing a 3.8 cm x 4.5 cm cystic mass at the junction of the head and body of the pancreas as well as a 1cm cystic lesion in the head of the pancreas. Results: A follow up MRI and MRCP demonstrated a lobulated unilocular 5x3 cm cystic lesion in the body of the pancreas that appeared to directly communicate with the main pancreatic duct. An endoscopic ultrasound was carried out and demonstrated a 2.7cm X 3.9cm cystic lesion in the neck of the pancreas with two small mural nodules measuring up to 7 mm (Figure 1). Fine needle aspiration showed no malignant cells on cytology. The cyst fluid showed a CEA of 2.09ug/L, and amylase of 6,330U/L. The patient underwent an extended distal pancreatectomy and splenectomy given the suspicion of a side branch IPMN. Microscopically, most of the cells showed an oncocytic appearance with enlarged nuclei, prominent nucleoli and scattered mitotic figures consistent with an IOPN and high grade dysplasia. The surgical resection margin was positive for low grade dysplasia. Two year follow-up with MRI and EUS has demonstrated no evidence of recurrence or progression. Conclusions: Intraductal oncocytic papillary neoplasm (IOPN) is a term used to describe a distinct cystic intraductal tumor with oncocytic features and mucin production. Data regarding the accuracy of pre-operative imaging and natural history of these lesions is limited. MRI and MRCP can assist with the diagnosis in its ability to demonstrate main pancreatic duct communication which occurs in most but not all cases of IOPN. Although MR may also provide enhanced morphologic detail, subtle features such as mural nodularity may be missed. As in our case, EUS may provide superior imaging detail of the cyst architecture which can upstage the lesion and alert the clinician that a more sinister pathology is present. Unfortunately, cyst fluid CEA and cytology can be inaccurate. Identification of additional cyst fluid markers are needed in order to enhance diagnostic accuracy. Standard surgical intervention remains the recommended treatment in cases that are deemed resectable.

Figure 1: Endoscopic ultrasound (EUS) showing two mural nodules.

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A301 EUS-GUIDED BILIARY ACCESS FOR RENDEZVOUX ERCP T. AlAmeel, G. Sandha University of Alberta Hospital, Edmonton, AB, Canada. Aims: ERCP has become the mainstay of biliary therapeutics. However, in some situations, ERCP may be unsuccessful necessitating a rendezvous procedure following transhepatic biliary access. We undertook a previously described alternative using EUS-guided biliary access to perform rendezvous ERCP. Methods: Case Report Results: A 65 year male with acute biliary pancreatitis had 2 unsuccessful attempts (2 endoscopists unable to identify the ampulla) at ERCP before and after a laparoscopic cholecystectomy. The patient was referred for ongoing RUQ pain. Mild elevation of liver enzymes and lipase was documented. EUS identified 2 distal CBD stones. ERCP failed again for same reason by another endoscopist. Under fluoroscopy, EUS-guided transduodenal puncture of the CBD was performed using a 19-gauge needle. A 0.035 inch guidewire was then advanced antegrade through the papilla into the duodenum. Leaving the wire in place, the echoendoscope was then removed. Alongside the wire, a duodenoscope was advanced to the descending duodenum. The wire, seen entering the duodenum from a diverticulum, was captured with a snare and brought out through the duodenoscope. A sphinctertome was then advanced over the wire and introduced into the distal CBD and the transduodenal wire removed. A wire was then advanced retrograde into the CBD and sphincterotomy performed followed by balloon sphincteroplasty. The stones were removed with a balloon extraction catheter and the CBD cleared. The patient underwent a repeat ERCP a day later and a stent was placed for mild leakage seen from the distal CBD. Conclusions: EUS-guided biliary access is a proven and effective approach for rendezvous ERCP where conventional ERCP has failed. Because of the complexity of the procedure, it should be performed by endoscopists experienced in interventional EUS and therapeutic ERCP.

A302 A CASE REPORT OF DIABETIC KETOACIDOSIS COMPLICATED BY HYPERTRIGLYCERIDEMIA-INDUCED PANCREATITIS N. Narula, A. Prebtani, J. Marshall McMaster University, Hamilton, ON, Canada. Aims: Patients with diabetic ketoacidosis (DKA) have altered lipid metabolism which may result in elevated triglycerides. One complication of hypertriglyceridemia is acute pancreatitis. Here we present a case report of hypertriglyceridemia-induced pancreatitis in a patient with diabetes that resolved with insulin therapy, and review the current literature for similar cases. Methods: Illustrative case report and review of current peer-reviewed literature Results: A 26-year old woman presented to hospital with DKA and pancreatitis. Her history did not identify any obvious etiology for her pancreatitis. Her laboratory studies on admission revealed evidence of DKA, serum triglyceride level of 9.96 mmol/L (886 mg/dL), and lipase of 286 U/L. Computerized topography confirmed pancreatitis without any obstructing stones or necrosis. The patient was treated with aggressive intravenous fluids, intravenous insulin-glucose infusion, and slow advancement of her diet. By the fourth day of hospitalization, her serum lipase and triglycerides decreased to 61 U/L and 2.41 mmol/L respectively. The patient was discharged on subcutaneous insulin injections, and has had no recurrence of diabetic ketoacidosis or pancreatitis. A review of the literature reveals severe hypertriglyceridemia (>11 mmol/L) in DKA has been reported at a frequency of 8%, and half of these cases resulted in pancreatitis. High fasting glucose levels are associated with defects in lipoprotein lipase, which is responsible for removal of triglycerides. Further, insulin deficiency leads to lipolysis, and free fatty acids are delivered to the liver and are metabolized into very low-density lipoprotein triglycerides. Several cases have been reported of DKA complicated by hypertriglyceridemia-induced pancreatitis where treatment of the DKA resulted in lower triglycerides and resolution of the pancreatitis. Conclusions: This case report and literature review suggest that hypertriglyceridemia-induced pancreatitis in DKA is not uncommon, is transient and can resolve with insulin therapy in patients with DKA. In patients with the triad of DKA, pancreatitis, and elevated triglyercides, it is worthwhile to observe and see if the pancreatitis and hypertriglyceridemia will resolve with insulin treatment alone.

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A303 DISTINCT ACTIONS OF ETHANOL METABOLITES IN PATHOLOGIC RAT PANCREATIC ACINAR EXOCYTOSIS UNDERLYING ALCOHOLIC PANCREATITIS. S. Dolai, T. Liang, P. Lam, N. Fernandez, S. Chidambaram, H. Gaisano University of Toronto, Toronto, ON, Canada. Aims: In alcoholic pancreatitis, it is not ethanol (EtOH) per se, but its oxidative (acetaldehyde) and non-oxidative metabolites (ethylpalmitate, ethyloleate) that mediate toxic injury. We previously demonstrated that EtOH pre-treatment of pancreatic acini induced blockade of cholecystokinin(CCK-8)-stimulated apical exocytosis and redirection of exocytosis to basolateral plasma membrane (PM) causing interstitial pancreatitis. We now examine how each EtOH metabolite contributes to these pathologic exocytoses. Methods: Dispersed rat pancreatic acini pre-treated with clinically-relevant doses of EtOH (20-50mM) or EtOH metabolites (1-3mM) were stimulated with CCK-8. We performed real-time exocytosis imaging (FM1-43 epiflourescence, single zymogen granule (ZG) exocytosis by spinning-disk microscopy) and ultrastructural electron microscopy study to explain the reduction in amylase secretion. Confocal microscopy showed the itinerary of VAMP8-residing ZGs. Coimmunoprecipitation revealed distinct Munc18/SNARE (soluble NSF attachment protein receptor) complexes mediating apical (ZG-apical PM) exocytosis, basolateral exocytosis, and ZG-ZG fusion. Results: While all three metabolites reduced CCK-8-stimulated apical exocytosis, acetaldehyde and ethyloleate redirected exocytosis to basal and lateral PM (all imaging assays) and translocation of VAMP8-containing ZGs towards basolateral PM, culminating in reduction of maximal amylase secretion. Consistently, acetaldehyde and ethyloleate induced basolateral exocytotic complex formation (Munc18c/[Syntaxin-4,SNAP23,VAMP8]); all three reduced apical exocytotic complexes (Munc18b/[Syntaxin-2,SNAP23,VAMP2]). Acetaldehye, like EtOH, promoted ZG-ZG fusion complexes (Munc18b/[Syntaxin-3,SNAP23,VAMP8]), whereas ethylpalmitate and ethyloleate reduced these complexes. Conclusions: All three metabolites contribute to EtOH-induced perturbation in three different exocytotic events (apical blockade, basolateral exocytosis, ZG-ZG fusion); however, acetaldehyde, and to lesser degree ethyloleate, mimicked the pathologic effects of EtOH on CCK-8-stimulated exocytosis contributing to alcoholic pancreatitis.

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Pediatric Liver Disease

Poster of Distinction A304 THE PELTQL: A VALID AND RELIABLE DISEASE-SPECIFIC INSTRUMENT TO EVALUATE HEALTH-RELATED QUALITY OF LIFE (HRQOL) IN CHILDREN POST-LIVER TRANSPLANT A. Otley1, A. Dhawan2, N. Yazigi3, M. Stormon4, L. Ee5, S. Gilmour6, D. Nicholas7, P. Andreou1, V. Ng8 1. IWK Health Centre, Halifax, NS, Canada; 2. King's College Hospital, London, United Kingdom; 3. Cincinnati Children's Hospital Medical Center, Cincinnati, OH; 4. The Children's Hospital at Westmead, Sydney, NSW, Australia; 5. Royal Children's Hospital, Brisbane, QLD, Australia; 6. Stollery Children's Hospital, Edmonton, AB, Canada; 7. University of Calgary, Calgary, AB, Canada; 8. Hospital for Sick Children, Toronto, ON, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A305 IS THE MODEL OF END-STAGE LIVER DISEASE (MELD) A SATISFACTORY PREDICTOR OF PRE-TRANSPLANT MORTALITY IN THE ADOLESCENT WITH CHRONIC LIVER DISEASE LISTED FOR LIVER TRANSPLANTATION? S. Khorsheed1, A. Shaheen2, K. Burak2, A. Aspinal2, R. Myers2, S. Martin1 1. Division of Gastroenterology and Nutrition, Department of Pediatrics, University of Calgary, Calgary, AB, Canada; 2. Liver Unit, Division of Gastroenterology and Hepatology, Department of Medicine, University of Calgary, Calgary, AB, Canada. Aims: The Model for End-Stage Liver Disease (MELD) was adopted by UNOS in 2002 for liver transplant (LT) allocation among adolescents with chronic liver disease. However, the MELD score has not been validated in children and its reliance on serum creatinine, in particular, may disadvantage adolescents due to their greater renal reserve and lower muscle mass compared with adults. Our objective was to assess whether MELD is superior to the Pediatric End-Stage Liver Disease (PELD) score in predicting mortality of adolescents on the LT waiting list, and to determine if incorporating serum sodium and albumin in MELD to yield the 5-variable MELD score (5vMELD; Myers et al., Hepatology 2010;52[4]:375A)can improve prediction of mortality in this patient population. Methods: Adolescents (12-17 years of age) registered for their first LT in the United States between 03/2002 and 12/2007 were identified using the UNOS STAR database. Patients listed for multiple organs, Status 1A or 1B, and those who were granted exception points were excluded from the analysis. C-statistics modified for survival data were used to evaluate the discrimination of PELD, MELD and 5vMELD for the prediction of mortality at 3 and 12 months. Patients were censored at the time of liver transplantation. Results: Of a total of 4977 patients, 417 met the inclusion criteria; 17 patients (4.1%) died and 119 (28.5%) underwent LT within 3 months of listing. 26 patients (6.2%) died and 184 (44.1%) underwent LT within 12 months of listing. The median PELD, MELD, and 5vMELD scores at waiting list registration were 3 (IQR 3-12), 16 (IQR 12-22), and 19 (IQR 14-25), respectively. Due to the limited number of deaths at 3 months, the 12 month end point was chosen for the primary analysis. For this outcome, the c-statistics for PELD, MELD, and 5vMELD were 0.825 (95% CI 0.743-0.908), 0.848 (95% CI 0.761-0.934), and 0.867 (95% CI 0.794-0.941), respectively. For the prediction of 3 and 12 month mortality, MELD and PELD had similar performance (both p=0.13). However, 5vMELD was superior to PELD for the prediction of mortality at 3 (c-statistics 0.920 and 0.889; p=0.09) and 12 months (p=0.01). Conclusions: The MELD score does not outperform PELD for the prediction of LT waiting list mortality among adolescents with chronic liver disease. Since the incorporation of serum sodium and albumin in MELD to yield 5vMELD is associated with superior prediction of mortality, additional validation of 5vMELD in this patient population is warranted.

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A306 PARENTERAL NUTRITION IN NEONATES: IS CHOLESTASIS A REAL PROBLEM? K. Jolin-Dahel2, E. Ferretti1, C. Montiveros1, R. Grenon1, C. Jimenez-Rivera1 1. Children's Hospital of Eastern Ontario, Ottawa, ON, Canada; 2. University of Ottawa, Ottawa, ON, Canada. Aims: We aim to describe our patient population and to determine risk factors for developing PN cholestasis. Methods: Retrospective chart review of newborns admitted from January 2006 to May 2011 to the Neonatal Intensive Care Unit (NICU) at the Children’s Hospital of Eastern Ontario and received PN >14 days. Cholestasis was defined as serum conjugated bilirubin >50 mmol/L. Patient characteristics and biochemical parameters were recorded. Significance levels were adjusted using the Bonferroni Correction for multiple comparisons. Results: There were 2,487 neonates admitted to the NICU during the study period. Eighty-seven newborns met study criteria and were included; 18 (20.7%) developed PN cholestasis and the remaining 69 served as a control group. The most frequent surgical condition was gastroschisis (8/87; 9.2%) in addition, 32.2% of the neonates had at least one episode of necrotizing enterocolitis during the study period. There were no significant differences between the cholestasis and control groups for the following parameters: birth weight, gestational age, intra-uterine growth restriction, Apgar scores and day of life at initiation of enteral feeds. Duration of PN in days was significantly higher in the cholestasis group than the control group (39 vs. 20; p= .003). Dosage of carbohydrates in g/kg/day was also significantly greater in the cholestasis group than the control group (14.2 vs.11.97; p=0.002). The dosage of aminoacids and lipids were similar in both groups. Six newborns (6/18; 33.3%) in the cholestasis group and 1 in the control group received Omegaven starting at mean day 21 into PN (range=8-39 d). Within the cholestasis group there were no significant differences between the children who received Omegaven (n=6) and those who did not (n=12). Conclusions: PN-related cholestasis was not common in our patient population as only presented in one fifth of neonates receiving PN for more than two weeks. Longer duration of PN as well as higher dosage of carbohydrates seem to be risk factors for developing PN cholestasis in the neonatal period.

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A307 NOVEL MPV17 GENE MUTATION IN A SAUDI INFANT CAUSING FATAL PROGRESSIVE LIVER FAILURE A. Alsunaid3, A. Sarkhy2, A. Alzaben3, A. Abdullah3, W. ALeiyad3, M. Albalwi1 1. King Abdulaziz Medical City/Department of Pathology, Riyadh, Saudi Arabia; 2. King Abdulaziz Medical CityKing Khalid University hospital/pediatric department, Riyadh, Saudi Arabia; 3. King Abdulaziz Medical City/pediatric department, Riyadh, Saudi Arabia.

NOT PUBLISHED AT AUTHORS REQUEST

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Viral Hepatitis

Poster of Distinction A308 HEPATOMA CELLS INFECTED WITH HEPATITIS C VIRUS SECRETE VLDL WITH LESS TRIACYLGLYCEROL CONTENT AND HAVE A DEFICIENCY IN A PUTATIVE TRIACYLGLYCEROL LIPASE, ARYLACETAMIDE DEACETYLASE. M. Nourbakhsh, D. Douglas, C. Hao Pu, J. Lewis, N. Kneteman University of Alberta, Edmonton, AB, Canada. Aims: There is compelling evidence that hepatocellular lipid droplets (LDs) and the VLDL (very low density lipoprotein) secretory pathway play an essential role in the production of infectious HCV by cell cultures. The hydrophobic core of LDs consists mainly of triacylglycerol (TG) and the majority of lipid that is assembled and secreted with hepatic VLDL is derived from the lipolysis and re-esterification of TG stored in hepatocellular LDs. Little is known about the lipases that mediate this process. In this study, we examined the impact of HCV infection on VLDL assembly/secretion pathway. We tested the hypothesis that HCV infection reduces the availability of LDs as a VLDL substrate pool. Methods: Using the JFH-1/Huh7.5 cell culture system, the impact of HCV infection on cellular TG levels and secreted TG levels (as VLDL) was determined after generation of a large intracellular TG store (as LDs) by supplementing the culture media with oleic acid. Other cellular factors relevant to hepatic VLDL assembly/secretion pathway were also evaluated including: analysis of apolipoprotien B100 (ApoB: an obligatory structural protein for VLDL) synthesis and secretion (by metabolic labeling and immunoprecipitation and/or ELISA), activity and expression analysis for microsomal triacylglycerol transfer protein (MTP) which primarily transfers TG from cytosolic LDs into the newly synthesized ApoB to form nascent but poorly lipidated VLDL (by MTP activity assay and immunoblot/qRT-PCR analysis) and putative lipases (by activity based probe-labeling and immunoblot/qRT-PCR analysis). Results: We found reduced secretion of intracellular TG stores in HCV infected cells, which resulted in accumulation of TG in these cells, while synthesis and secretion of ApoB remained unchanged. These results indicate the secretion of VLDL with relatively lower amounts of TG in infected cell culture and were explained by modification of key intracellular regulatory steps involved in the lipidation process of VLDL as both MTP and cellular lipase activities were diminished in lysates from infected cells. Using activity based probe-labeling assay, we found that labeling of a polypeptide corresponding to arylacetamide deacetylase (AADA) was ablated in infected cells and this correlated with an absence of detectable AADA protein and greater than 95% reduction in cellular AADA transcript abundance. We found that AADA has TG lipase activity in Huh7.5 cells. Conclusions: These results demonstrate altered regulatory steps of VLDL assembly/secretion and reduced availability of LDs for VLDL assembly/secretion and also show a possible role for AADA in this process.

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A309 A CANADIAN RETROSPECTIVE CHART REVIEW EVALUATING THE IMPACT OF CYCLOSPORINE VERSUS TACROLIMUS ON SUSTAINED VIRAL RESPONSE IN PATIENTS WITH POST-LIVER TRANSPLANTATION HEPATITIS C INFECTION E. Yoshida1, L. Lilly2, P. Marotta3, A. Mason4, M. Bilodeau5, J. Leclerc6, L. Tran6, M. Vaillancourt6 1. UNIVERSITY OF BRITISH COLUMBIA, Vancouver, BC, Canada; 2. TORONTO GENERAL HOSPITAL, Toronto, ON, Canada; 3. UNIVERSITY OF WESTERN ONTARIO, London, ON, Canada; 4. UNIVERSITY OF Alberta, Edmonton, AB, Canada; 5. HOSPITAL ST-LUC, Montreal, QC, Canada; 6. NOVARTIS PHARMACEUTICALS CANADA INC, Dorval, QC, Canada. Aims: Recurrent hepatitis C virus (HCV) infection is a major challenge in liver transplantation. The primary objective of this study was to compare the rate of sustained viral response (SVR) in patients with post-liver transplantation HCV infection treated with either cyclosporine or tacrolimus. Methods: Multicenter, observational, retrospective chart review on patients who underwent a liver transplantation between January 1996 and December 2006 due to hepatitis C cirrhosis and who received either cyclosporine or tacrolimus as initial immunosuppressive therapy. The proportion of patients reaching SVR stratified by HCV genotype, as well as post-transplant complications, were also assessed. Results: A total of 458 patients were included in the analysis. Mean (SD) age was 51.9 (7.5) years, 74.4% were male, and 69.5% had HCV genotype 1 (types 1, 1a, 1b, 1c). SVR was achieved by 66.7% and 52.8% of patients in the Cyclosporin and Tacrolimus cohorts, respectively (OR=1.52, P=0.083). Subgroup analysis revealed that patients who had an interferon-based therapy had a greater SVR in the cyclosporine group compared to the tacrolimus group (65.1% vs. 51.6%; P=0.087). SVR in genotype 1 patients treated with an interferon-based therapy was 51.6% and 35.2% for cyclosporin and tacrolimus respectively, and they had a lower odds ratio (OR) of achieving SVR relative to patients with other genotypes [OR (95%CI) =0.11 (0.05-0.23); P<0.001]. No significant between-group differences were observed in the incidence of new onset diabetes mellitus, de novo hepatocellular carcinoma, fibrosing cholestatic hepatitis, HCV-related graft loss, HCV-related mortality, or acute/chronic rejection. A significantly (P<0.001) greater proportion of patients switching from Cyclosporin to Tacrolimus experienced acute/hyperacute rejection compared to the Cyclosporin and Tacrolimus groups or patients switching from Tacrolimus to Cyclosporin (75.9% vs. 48.9%, 45.8% and 57.1% respectively). Similar results were observed in the incidence of chronic rejections (20.4% of patients switching from Tacrolimus to Cyclosporin vs. 3.8%, 2.7%, and 2.9%, respectively). Conclusions: In this retrospective study, there were no statistically difference inn SVR in patients treated with a cyclosporine-based regimen relative to patients in the tacrolimus-based group, and there were no significant differences in the incidence of HCV-related complications.

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A310 COST-EFFECTIVENESS ASSESSMENT OF TELAPREVIR COMBINATION THERAPY COMPARED WITH PEGYLATED INTERFERON AND RIBAVIRIN ALONE IN THE MANAGEMENT OF CHRONIC HEPATITIS C VIRUS INFECTION IN CANADA A. Brogan1, B. Deniz2, J. Miller1, D. Mladsi1, W. Herring1, J. Thompson1, S. Talbird1 1. RTI Health Solutions, Research Triangle Park, NC; 2. Vertex Pharmaceuticals Incorporated, Cambridge, MA. Aims: Telaprevir (T) in combination with peginterferon alfa-2a/ribavirin (PR) for the treatment of genotype 1 chronic hepatitis C virus (HCV) infection substantially increased sustained virologic response (SVR) compared with PR alone in the multinational phase 3 studies ADVANCE (in treatment-naïve patients) and REALIZE (in prior relapsers, partial responders, and null responders to a previous course of PR therapy). A decision-analytic model was developed to explore the potential long-term clinical and economic consequences of T/PR compared with PR alone from a Canadian Ministry of Health perspective. Methods: A lifetime two-phase (treatment; post-treatment) Microsoft Excel model was developed to follow parallel hypothetical cohorts treated with T/PR or PR alone. Patients first moved through the 72-week decision-tree treatment phase of the model and then entered the cyclic Markov post-treatment phase. In any 1-year cycle, patients could remain in or transition among the following health states: four pre-cirrhosis health states, compensated cirrhosis, decompensated cirrhosis, hepatocellular carcinoma, liver transplantation, HCV-related death, and non-HCV-related death. Clinical data, including patient characteristics and SVR attainment rates, were obtained from ADVANCE and REALIZE. Drug costs were obtained from public sources for each province and averaged. Health state transition probabilities (which varied by SVR status, age, and gender), other costs, utilities, and mortality were obtained from the trials and published sources. All costs were in 2011 Canadian dollars; all outcomes except HCV-related complications were discounted at 5% per year; and sensitivity analyses were conducted. Results: In treatment-naïve patients and treatment-experienced patients (prior relapsers, partial responders, and null responders), the lifetime model projected that T/PR reduced HCV-related complications by 20% to 80% and increased life expectancy (0.4-1.2 more years) and quality-adjusted life expectancy (0.7-1.7 more quality-adjusted life years [QALYs]) compared with PR alone. Increased treatment costs with T/PR over PR alone were partially offset by lower other medical costs, yielding incremental cost-effectiveness ratios between $1,467 and $36,255 per QALY gained. Conclusions: Using traditional benchmarks for acceptable cost-effectiveness, results from this model suggest that telaprevir combination therapy is a cost-effective treatment strategy in Canada compared with peginterferon/ribavirin alone in treatment-naïve and previously treated patients.

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A311 AUTOANTIBODIES DIRECTED AGAINST A NOVEL CYTOPLASMIC COMPARTMENT (RODS AND RINGS) IN HEPATITIS C INFECTION L. Stinton, R. Myers, C. Coffin, M. Fritzler University of Calgary, Calgary, AB, Canada.

NOT PUBLISHED AT AUTHORS REQUEST

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A312 THE DOWN-REGULATION OF VIRAL TRANSLATION BY HEPATITIS C VIRUS NON-STRUCTURAL PROTEIN 5A (NS5A) IS DEPENDENT UPON THE PRESENCE OF THE POLY-U/UC REGION IN THE 3’UNTRANSLATED REGION B. Hoffman1, Q. Liu2 1. School of Public Health, University of Saskatchewan, Saskatoon, SK, Canada; 2. Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada. Aims: Hepatitis C virus (HCV) NS5A protein, which is essential for the viral replication, has been implicated in the modulation of viral translation. However, the role NS5A plays in viral translation remains controversial as contradictory studies have been published suggesting that NS5A either stimulates, inhibits or has no effect on viral translation. Possible reasons for these discrepancies include the use of reporter constructs that lack the HCV 3’UTR, where NS5A binds to the poly-U/UC region, as well as use of plasmid encoded reporters that do not accurately reflect the role of the 3’UTR in HCV translation. In this study, we investigated the role of NS5A in the modulation of HCV translation and the function of the 3’UTR poly-U/UC region in this modulation Methods: We used monocistronic RNA reporter constructs containing the 5’ and 3’UTRs of HCV and an internal Renilla luciferase gene in combination with an NS5A expression plasmid. The HCV 5’UTR contains the internal ribosome entry site (IRES) that drives expression of the internal Renilla luciferase gene, which can be quantified as a measurement of HCV-IRES mediated translation. A Δpoly-U/UC construct is used to investigate the role of this region. Results: Our results showed that NS5A specifically down-regulates viral translation in a dose-dependent manner that requires the presence of the poly-U/UC region of the viral 3’UTR. This modulation was found to be independent of the phosphorylation status of the hyperphosphorylation sites found within NS5A. Furthermore this modulation appears to compete with the cellular factor IGF2BP1, which enhances viral translation, for the effect on HCV translation. In addition, the viral NS5B protein appears to reduce NS5A down-regulation of viral translation, possibly by binding to it and preventing NS5A from binding to the 3’UTR. Conclusions: In conclusion, HCV NS5A plays an important role in the modulation of viral translation and the poly-U/UC region of the viral 3’UTR is necessary for this modulation, suggesting that NS5A binding to this region leads to down-regulation of viral translation.

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A313 HEPATITIS C VIRUS-INFECTED CELLS RAPIDLY INHIBIT NATURAL KILLER CELL FUNCTIONS K. Harris, S. Stapleton, R. Russell, M. Grant Memorial University of Newfoundland, St. John's, NF, Canada. Aims: Hepatitis C virus (HCV) persistently infects approximately 200 million people worldwide. Viruses employ numerous mechanisms to avoid host immune responses; hepatitis C virus (HCV) may do so by modulating natural killer (NK) cell function. With the advent of the HCV cell culture (HCVcc) system, we can directly study the biological impact HCV-infected human hepatoma cells (Huh-7.5) have on natural killer cells. Previous studies demonstrated NK cell function was decreased by exposure to immobilized HCV particles or overnight incubation with HCV-infected human hepatoma cells. We hypothesize that rapid decrease in NK cell function is due to negative signalling, caused by their direct interaction with infected cells. Methods: To test this, a microtitre assay was developed; titred virus stocks of 6.5x105 ffu/ml were generated by transfecting Huh-7.5 cells with tissue culture adapted JFH1 HCV (JFH1T). A multiplicity of infection (MOI) and duration was determined through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide and immunofluorescence assays to monitor cell viability and viral spread respectively. This microtitre assay was then used to assess the ability of NK cells to lyse labelled target cells in the presence of HCV-infected Huh-7.5 cells. Briefly, Huh-7.5 cells were seeded in a 96-well plate and infected with JFH1T supernatant at various MOIs. 72hrs post-infection, fresh peripheral blood mononuclear cells (PBMC) and 51Cr-labeled K562 target cells were added and incubated for 5hrs. Subsequently, cell-based Elisa (CELISA) is performed to assess the degree of virus infection. Results from the cytotoxicity assay were corroborated by flow cytometry. Briefly, 72hrs post-infection, infected cells were incubated with fresh PBMC and K562 cells for 5 hours in the presence of brefeldin A. PBMC were removed and stained for surface CD3, CD56, and CD107a, fixed, permeabilized then stained for intracellular IFN-γ and analyzed by flow cytometry. Results: At a high MOI and 60:1 E:T, we observe a greater than 20% decline in target cell lysis by NK cells when cocultured with infected versus uninfected cells. Preliminary flow cytometry data show a concomitant decrease in CD107a expression and 50% decline in INF-γ production. Conclusions: A system was developed to analyze NK function in the presence of HCV-infected cells. CELISA on infected cells after cytotoxic assays showed that inhibition of NK cytotoxicity is proportional to the level of HCV protein expression. Preliminary flow cytometry data show that NK cytokine production (IFN-γ) and degranulation is reduced by HCV-infected cells. Thus, we have demonstrated that HCV-infected Huh-7.5 cells have a direct and rapid effect on NK functions.

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A314 USP18 BLUNTS THE ANTI-HCV ACTIVITY OF TYPE I AND III IFN AND INCREASES HCV INFECTIVITY IN VITRO L. Chen1, M. Ma1, B. Qin1, J. Sun1, L. Lin2, C. Richardson2, N. Selzner1, J. Feld1, I. McGilvray1 1. University of Toronto, Toronto, ON, Canada; 2. Dalhousie University, Halifax, NS, Canada. Aims: Patients chronically infected by HCV who have upregulation of the ubiquitin-like ISG15 and its protease, USP18, respond poorly to IFN-based treatment. USP18 has both ISG15-dependent and independent effects; having previously shown that its downregulation potentiates the effect of Type I IFN, we investigated whether and how its upregulation alters HCV infection and its susceptibility to both Type I and III IFN. Methods: Over-expression of wild type (wt) or catalytically inactive mutant (m) USP18 was examined for effects on HCV replication in the absence and presence of IFNα and IFNλ using both the J6/JFH1 infective model and HCV replicon cells (Genotype 1b and 2a). IFN signaling was assessed via Jak/STAT activation (phospho-STAT1 Western blot) and downstream ISG expression (qPCR). Mechanistic roles were sought by quantifying microRNA122 levels and J6/JFH1 infectivity of Huh7.5 cells. Results: Over-expression of either wtUSP18 or mUSP18 stimulated HCV production and blunted the anti-HCV effect of IFNα and IFNλ in the infective model but not the replicon system. Over-expressed USP18 inhibited neither Jak/STAT signaling nor ISG expression. Consistent with an effect independent of HCV RNA replication, there was no effect on microRNA 122 levels; however, USP18 overexpression markedly increased J6/JFH1 infectivity of Huh7.5 cells. Conclusions: USP18 stimulates HCV production and blunts the effect of both Type I and III IFN in a manner independent of ISG15 protease activity, Jak/STAT signaling, and HCV RNA replication. Instead, it fosters a cellular environment that promotes HCV infectivity. This study demonstrates how a distinct host ISG response can paradoxically lead to a pro-HCV environment and contribute to treatment failure.

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A315 INFECTION OF HUMAN CD4+ AND CD8+ T LYMPHOCYTES WITH MOLECULARLY INTACT HEPATITIS C VIRUS G. Skardasi, T. Michalak Memorial University of Newfoundland, St. John's, NF, Canada. Aims: Accumulated molecular and clinical evidence indicate that hepatitis C virus (HCV) propagates not only in hepatocytes but also in immune cells. To study HCV-immune cell interactions and potential direct effects of HCV on T cell function, an in vitro HCV replication system has been previously established in which mitogen-induced T cell cultures derived from peripheral blood mononuclear cells (PBMC) served as targets for plasma occurring, wild-type HCV. To advance investigations on the interplay between molecularly intact HCV and individual T cell subsets in the absence of pressure exerted by other immune cells, the development of HCV replication system using affinity-purified normal human CD4+ and CD8+ T lymphocytes was the focus of this study. Methods: Plasma from 7 patients chronically infected with HCV genotype 1, 3 or 4, carrying viral loads between 1.5 x 103 and 3 x 107 vge/ml, were found to be infectious to PBMC-derived T cell cultures. To optimize conditions for infection of virus-naive CD4+ and CD8+ T cells (>97% pure by flow cytometry), HCV inocula most efficiently infecting total T cells were employed. Affinity-purified normal human CD4+ and CD8+ T lymphocytes were pre-stimulated with PHA (5 µg/ml), exposed to HCV and cultured under alternating stimulation with PHA and/or interleukin-2 (IL-2) for 14 days post infection (d.p.i.). HCV RNA positive (genomic) and negative (replicative) strands were detected by strand-specific RT-PCR followed by nucleic acid hybridization (RT-PCR/NAH). Intracellular HCV NS5a and core proteins were identified by confocal microscopy. HCV RNA-reactive particles released to culture supernatants were examined by gradient ultracentrifugation. Results: HCV RNA positive and replicative strands, as well as NS5a and core proteins were detected in both CD4+ and CD8+ T cells after infection with wild-type HCV. HCV RNA-reactive particles displaying distinct sedimentation velocity and buoyant density occurred in inocula and culture supernatants from CD4+ and CD8+ T cells exposed to HCV-positive plasma. Conclusions: Molecularly intact HCV can infect and establish productive replication in normal human CD4+ and CD8+ T cells, as evidenced by detection of HCV RNA replicative strand and intracellular expression of NS5a and core proteins. De novo infection with HCV of these two T cell subsets was confirmed by identification of distinct physical properties of HCV RNA-reactive particles in cell culture supernatants and those occurring in infectious inocula. In vitro infection of normal human CD4+ and CD8+ T lymphocytes by molecularly intact HCV should represent a valuable tool to further examine the nature of HCV lymphotopism and how HCV may directly influence the fate and function of these immune cells.

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A316 LIVER-RESTRICTED CHRONIC INFECTION BY LYMPHOCYTIC CHORIOMENINGITIS VIRUS (LCMV) P. Lapierre1, F. Alvarez2, A. Lamarre1 1. INRS Institut Armand-Frappier, Laval, QC, Canada; 2. CHU Sainte-Justine, Montreal, QC, Canada. Aims: Several viruses target the liver and many of them are responsible for chronic infections of this organ. Several hypotheses have been put forward to explain this phenomenon including the natural tolerogenic environment of the liver and the ability of viruses to counteract immune responses in the liver. Many viruses, including HCV and LCMV can inhibit the type 1 interferon response in infected cells. The aim of this project is to study factors responsible for the establishment of a chronic liver infection in an immune competent host. Methods: TTR-NP transgenic mice, that express the LCMV nucleoprotein (NP) specifically in hepatocytes, were infected with either LCMV-Arm or LCMV-WE, which normally induce an acute infection in immune competent B6 mice. T cell responses against LCMV were characterized by tetramer staining, cytotoxicity assay (CTL), proliferation assay, intracellular cytokine staining and flow cytometry. Results: TTR-NP mice showed higher serum ALT levels than infected B6 mice. TTR-NP mice developed normal CD8+ T cell responses against the NP396-404 and GP33-41 epitopes, showing that TTR-NP mice are not tolerant to NP despite its expression in hepatocytes. CTL and proliferation assays and intracellular cytokine staining showed that the immune response by TTR-NP mice to LCMV was functional. Memory T cell responses to LCMV were normal in TTR-NP mice but high numbers of CD8+CD44-CD62L- activated T cell and very low numbers of CD8+CD44-CD52L+ naïve T cells were observed in these mice, indicative of an active immune response against LCMV. While LCMV-Arm or -WE are cleared by day 8 post-infection in B6 mice, TTR-NP mice remained chronically infected up to 147 days post-infection. However, this chronic infection was restricted to the liver; all other organs tested (spleen, kidney, brain, blood) were free of virus. Conclusions: These observations indicate that liver-specific alteration(s) of the local immune response, in this case owing to the expression of NP in hepatocyte, can lead to a chronic infection despite the presence of an active T cell response against the virus. These findings have wide-ranging impact on our understanding of susceptibility factors to the development of chronic viral infection in the liver.

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A317 ANEMIA HAD NO EFFECT ON EFFICACY OUTCOMES IN TREATMENT-NAÏVE PATIENTS WHO RECEIVED TELAPREVIR-BASED REGIMEN IN THE ADVANCE AND ILLUMINATE PHASE 3 STUDIES N. Afdhal1, M. Sulkowski2, A. Di Bisceglie3, R. Reddy4, S. Zeuzem5, F. Poordad6, L. Bengtsson7, C. Wright7, R. Kauffman7, N. Adda7 1. Beth Israel Deaconess Medical Center, Boston, MA; 2. Johns Hopkins University School of Medicine, Baltimore, MD; 3. Saint Louis University School of Medicine, Saint Louis, MO; 4. University of Pennsylvania School of Medicine, Philadelphia, PA; 5. Johann Wolfgang Goethe University Medical Center, Frankfurt am Main, Germany; 6. Cedars-Sinai Medical Center, Los Angeles, CA; 7. Vertex Pharmaceuticals Incorporated, Cambridge, MA. Aims: The ADVANCE and ILLUMINATE phase 3 studies evaluated safety and efficacy of telaprevir in genotype 1 HCV treatment-naïve patients. In this retrospective pooled analysis, efficacy outcomes were assessed based on anemia and ribavirin dose reductions. Methods: ADVANCE and ILLUMINATE patients who received 12 weeks of telaprevir (T)-based regimen (T12PR) in combination with either 24 or 48 weeks of peginterferon/ribavirin (PR) based on their extended rapid virologic response (eRVR, HCV RNA undetectable at weeks 4 and 12) were compared to ADVANCE patients who received 48 weeks of PR (control group). All randomized patients who received at least one dose of study medication and underwent hemoglobin measurement at baseline and at least once during the treatment phase were included. Sixteen patients (1%) who received erythropoiesis-stimulating agents for anemia were excluded. Results: Of the 1239 patients included, 41% (361/885) and 26% (92/354) of patients in the T12PR and PR groups, respectively, developed anemia (hemoglobin < 10 g/dL) during treatment. Seventy four percent (267/361) and 50% (46/92) of T12PR and PR patients with anemia, respectively, achieved SVR. Seventy-two percent (260/361) and 58% (53/92) of T12PR and PR patients without anemia, respectively, achieved SVR. Seventy-two percent (260/361) and 58% (53/92) of T12PR and PR patients with anemia, respectively, had ribavirin dose reduction due to adverse events compared to 11% (60/524) and 6% (16/262) of T12PR and PR patients without anemia, respectively. SVR was achieved by 76% (243/320) and 54% (37/69) of patients with ribavirin dose reduction in the T12PR and PR groups, respectively, compared with 72% (408/565) and 41% (117/285) of patients without ribavirin dose reduction in the T12PR and PR groups, respectively. Conclusions: Anemia was more frequent in patients who received a telaprevir-based regimen than patients in control. In patients treated with telaprevir-based therapy, anemia as well as ribavirin dose reduction had no apparent effect on SVR rates as compared with patients treated with peginterferon/ribavirin alone. These data suggest that management of treatment-related anemia with ribavirin dose reduction appeared not to impact SVR with telaprevir-based therapy.

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A318 VIRAL DETERMINANTS OF THE OUTCOME OF INTERFERON THERAPY AGAINST HEPATITIS C VIRUS M. Abdel-Hakeem1, T. Fabre1, J. Gélinas1, M. El-Far2, D. Murphy5, J. Bruneau4, B. Willems3, N. Shoukry1 1. Centre de Recherche du Centre Hospatlier de l’Université de Montréal (CR-CHUM), Montréal, QC, Canada; 2. Department de microbiologie et immunologie, Université de Montréal, Montréal, QC, Canada; 3. Department de médicine, Université de Montréal, Montréal, QC, Canada; 4. Department de médicine familiale, Université de Montréal, Montréal, QC, Canada; 5. Institut National de Santé Publique du Québec, Montréal, QC, Canada. Aims: We have previously demonstrated that early initiation of interferon-alpha (IFN-α) therapy can rescue polyfunctional HCV-specific CD8+ T cells. In contrast, no HCV-specific immune responses were detected when therapy was initiated late during chronic HCV. This leaves the virus as the major determining factor for the differential responses to therapy during the chronic phase. One potential mechanism of HCV-resistance to therapy is blocking the IFN signalling pathway. The direct inhibitory effects of core and NS5A HCV proteins on IFN signalling have been shown using reference laboratory HCV strains. However, the effect of core and NS5A isolated from patients with differential responses to IFN therapy remains to be examined. Our aim is to identify HCV sequences from clinical isolates that impair IFN signalling and define mechanisms underlying this impairment. Methods: We have amplified and sequenced the core region from patients infected with HCV genotype 1 (n=13), with differential responses to IFN therapy. Results: No significant differences were observed amongst genotype 1a sequences from responders versus non-responders. In contrast, genotype 1b sequences from one non-responder displayed specific amino acid (aa) substitutions; Q70R and M91L in 25% and 90% of the molecular clones before therapy, respectively. Similar aa substitutions have been associated with resistance to therapy in several Japanese cohorts. The resistant substitutions were selected-for during therapy and became dominant at the end of the therapy period (100% Q70 and M91). In addition, non-responder sequences showed a higher degree of quasispecies diversity pre-therapy compared to responders. The IL28B genotype is currently being analysed for all patients. Sequencing more patients is ongoing to determine whether specific aa substitutions can serve as prognostic markers for response to IFN therapy in the North American population, combined with IL28B genotyping. Conclusions: Whether the identified sequences have differential capacities to impair IFN signalling, remains to be determined.

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A319 TELAPREVIR IN COMBINATION WITH PEGINTERFERON ALFA-2A AND RIBAVIRIN IN CANADIAN PATIENTS WITH CHRONIC GENOTYPE 1 HCV INFECTION E. Yoshida1, K. Kaita2, R. Myers3, M. Sherman4, L. Bengtsson5, N. Adda5, E. Heathcote6 1. University of British Columbia, Vancouver, BC, Canada; 2. University of Manitoba, Winnipeg, MB, Canada; 3. University of Calgary, Calgary, AB, Canada; 4. Toronto General Hospital, Toronto, ON, Canada; 5. Vertex Pharmaceuticals Incorporated, Cambridge, MA; 6. Toronto Western Hospital, Toronto, ON, Canada. Aims: The 3-arm double-blind, randomized, placebo-controlled Phase 3 ADVANCE study assessed efficacy and safety of two telaprevir (TVR, T)-based response-guided regimens compared with peginterferon alfa-2a 180 µg/week and ribavirin 1000-1200 mg/day (PR) in treatment-naïve patients with chronic genotype 1 HCV infection. A retrospective analysis of efficacy and safety in Canadian patients is presented here. Methods: Treatment arms were (a) T 750 mg q8h in combination with PR for 12 weeks, followed by additional weeks of PR; (b) T 750 mg q8h in combination with PR for 8 weeks, followed by additional weeks of PR; (c) PR for 48 weeks (control arm). Patients in T arms achieving an extended rapid viral response (eRVR, undetectable HCV RNA at weeks 4 and 12) received a total of 24 weeks of therapy while those who did not received a total of 48 weeks of therapy. Results: Forty-seven Canadian patients were enrolled and received at least one dose of study drug. Of 47 patients, 35 (74%) completed treatment and 43 (91%) completed the study; 41 (87%) had HCV RNA ≥800,000 IU/mL, 33 (70%) were genotype 1a, 25 (53%) male, 5 (11%) Asian, 11 (23%) had bridging fibrosis, and 1 (2%) had compensated cirrhosis. The most common (>25%) AEs observed in Canadian patients in the telaprevir arms were fatigue, headache, nausea, pruritus, rash, diarrhea, alopecia, insomnia, anorexia, and hemorrhoids. Discontinuation of treatment due to AEs occurred in 1 (2%) T12PR patient, 2 (4%) T8PR patients, and none occurred in PR48 patients. One (2%) T8PR patient discontinued telaprevir due to rash and no patient discontinued all three drugs due to rash. One (2%) T8PR patient discontinued telaprevir due to anemia. Conclusions: A substantially higher proportion of Canadian patients achieved SVR with 12-week and 8-week telaprevir-based combination regimens (85% and 75%, respectively), compared with PR48 control arm (47%). The safety and tolerability profile of telaprevir in Canadian patients was consistent with the profile previously reported in the overall population. Table:

T12PR T8PR PR48

Canadian patients N=13

All patients N=363

Canadian patients N=17

All patients N=364

Canadian patients N=17

All patients N=361

Patients achieving RVR, n (%) 10 (77) 246 (68) 12 (71) 242 (66) 2 (12) 34 (9) Patients achieving eRVR, n (%) 10 (77) 212 (58) 9 (53) 207 (57) 2 (12) 29 (8)

Patients with HCV RNA undetectable at end of treatment

(EOT), n (%) 11 (85) 314 (87) 15 (88) 295 (81) 10 (59) 229 (63)

Patients achieving SVR, n (%) 11 (85) 271 (75) 13 (76) 250 (69) 8 (47) 158 (44) Patients with relapse†, n/N (%) 0/11 (0) 27/314 (9) 1/15 (7)* 28/295 (9) 2/10 (20) 64/229 (28)

†Denominator is number of patients with HCV RNA undetectable at EOT *Data missing for 1 patient

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A320 HCV-SPECIFIC IL-21-PRODUCING T-CELLS ARE INDUCED IN HIV/HCV COINFECTED INDIVIDUALS AND ARE ASSOCIATED WITH HAART THERAPY AND HCV VIRAL CONTROL. S. MacParland1, V. Mihajlovic1, S. Fadel1, D. Wong2, M. Ostrowski1 1. University of Toronto, Toronto, ON, Canada; 2. Toronto General Hospital, Toronto, ON, Canada. Aims: Approximately 13,000 Canadians suffering from Human Immunodeficiency Virus (HIV) are also infected with Hepatitis C virus (HCV). Since the introduction of highly active antiretroviral therapy (HAART) for HIV infection, HCV-related end-stage liver disease has become an important cause of morbidity and mortality in this population. Coinfection with HIV enhances liver damage in patients with chronic HCV infection and leads to higher HCV viral loads. The immune mechanisms responsible for this faster liver disease progression are yet unclear. Previously, the cytokine IL-21, which is responsible for viral control by preventing CD8+ T-cell exhaustion, was found to be produced by CD4+ T-cells during LCMV infection (Elsaesser et al., 2009; Yi et al., 2009). As well, in individuals infected with HIV, the presence of virus-specific IL-21-producing CD4+ T-cells correlated with better viral control (Yue et al., 2010). We will examine the presence of IL-21-producing T-cells in HCV-monoinfected and HIV/HCV-coinfected patients. The purpose of this study is to test the hypothesis that an absence or reduced activity of IL-21-producing CD4+ T-cells may play a role in the more severe disease observed in HIV/HCV coinfection. Methods: Mononuclear cells, isolated from peripheral blood and liver biopsies were obtained from HIV/HCV-coinfected and HCV-monoinfected individuals during acute and chronic infection. In vitro assays including intracellular cytokine flow cytometric assay, tetramer staining, cell-surface staining, and multiplex assays assessed T-cell responses to HCV antigens measured by expression of IL-2, IL-17, IL-21 and IFN-γ. All immunological findings will be related to clinical data including HIV viral load; HAART status; CD4+ T cell count; HCV viral load, alcohol use, age and liver disease markers with the aim of uncovering immune correlates of viral persistence or clearance. Results: Chronic HCV monoinfection was characterized by significantly less IL-21 secretion by HCV-specific CD4+ T-cells when compared to a group of HAART-treated and naïve HIV/HCV-coinfected subjects (P=0.016). Longitudinal analysis indicates that during acute HIV/HCV coinfection, subjects with HCV control show a transient expansion of IL-21-producing HCV-specific CD4+ T-cells. Conclusions: Stronger IL-21-producing T-cell responses in coinfected individuals may provide insight into the mechanism of enhanced liver damage observed in these persons. The finding that IL-21 is secreted by HCV-specific T-cells in HIV/HCV-coinfected individuals with apparent viral control may lend support for the development of IL-21-based therapies for HCV.

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A321 BIPOLAR PATIENTS CAN SAFELY AND SUCCESSFULLY RECEIVE INTERFERON-BASED HEPATITIS C ANTIVIRAL TREATMENT E. Kelly, J. Emery, C. Cooper University of Ottawa, Ottawa, ON, Canada. Aims: Patients with bipolar disease are often not considered for HCV antiviral treatment and excluded from clinical trials for fear of interferon-induced exacerbation of their underlying mood disorder. As this risk has not been well quantified in bipolar patients, we evaluated HCV treatment safety and efficacy in this population. Methods: A retrospective analysis of HCV patients evaluated at The Ottawa Hospital between January 2000 and February 2008 (n=910) was conducted. Information regarding demographics, psychiatric history and treatment, baseline liver biopsy and blood work, treatment initiation, adherence, and therapeutic outcomes was collected. This was compared between bipolar patients (B), those with a history of depression (D) and those with no mental health disorders (N). Results: 38 bipolar patients (4.2%) were identified of which 16 (42.1%) initiated HCV treatment. This rate was similar to patients with a history of depression (41.4%) and those without psychiatric illness history (32.6%). On treatment psychiatric complications occurred in 68.8% of bipolar patients, 54.8% of depression patients (p=0.29), and 37.1% of patients without psychiatric illness (p=0.01). Manic episode were rare in each group: B=2 (12.5%), D=1 (0.9%), N=1 (0.7%). Interferon dose reduction or discontinuation rates for psychiatric complications were similar between groups [B=12.5%, D=7.9%, N=7.4% (p=NS)]. Treatment completion rates were similar [B=50%, D=69%, N=58%]. SVR rates were comparable [genotype 1: B=33%, D=45%, N=49%]. Conclusions: Patients with a history of bipolar disorder have similar rates of on-treatment psychiatric complications as patients with a history of depression. With pharmacologic intervention and close clinical monitoring, well selected bipolar patients can successfully complete treatment and achieve outcomes comparable to non-bipolar patients.

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A322 IDENTIFICATION OF PROGRAMMED DEATH 1 (PD-1) IN THE PEKIN DUCK Q. Yao1, K. Fischer2, L. Tyrrell3, K. Gutfreund1 1. Department of Medicine, University of Alberta, Edmonton, AB, Canada; 2. Medical Microbiology & Immunology, University of Alberta, Edmonton, AB, Canada; 3. Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB, Canada. Aims: The aim of this study was to identify and characterize duck PD-1 (DuPD-1) and to study the role of PD-1 in duck cellular immune responses. Methods: The open reading frame of DuPD-1 was obtained by RT-PCR with primers based on chicken sequence and RNA isolated from duck splenocytes. Sequences of the 5’ and 3’ ends of the ORF and untranslated regions were determined by RACE. DuPD-1 transcript levels were assessed by real-time PCR. Results: The predicted 283 amino acid DuPD-1 protein has an identity of 70%, 32% and 31% with chicken, murine and human PD-1 proteins, respectively. DuPD-1 shares a similar exonic structure and domain organization with its chicken homologue and mammalian orthologues but avian genes are more compact. DuPD-1 sequence analysis and modeling based on the crystal structure of soluble murine PD-1 were consistent with an IgV-like domain structure and there was a considerable degree of conservation of residues implicated in ligand binding. Within the cytoplasmic domain residues implicated in signal transduction within both the immunoreceptor tyrosine-based inhibitory motif (ITIM) and immunoreceptor tyrosine-based switch motif (ITSM) were highly conserved across all species. DuPD-1 transcripts were predominately expressed in thymus, spleen, bursa and lung. Mitogen stimulation of PBMCs markedly increased DuPD-1 mRNA expression levels. Conclusions: Residues implicated in structure and function of PD-1 are highly conserved in DuPD-1, the chicken homologue and mammalian orthologues. The identification of DuPD-1 will facilitate the study of the role of PD-1 signaling in the immunopathogenesis of duck hepatitis B virus (DHBV) infection and the exploration of therapeutic approaches that aim at enhancing antiviral immunity in the duck model of chronic hepatitis B infection.

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A323 PREVALENCE AND IMPACT OF TORQUE TENO VIRUS INFECTION IN IMMUNOSUPPRESSED CHILDREN WITH ORTHOTOPIC LIVER TRANSPLANTATION M. Dore-Nguyen1, K. Beland1, M. Gagné3, N. Patey2, A. Houde3, J. Brassard3, F. Alvarez1, U. Halac1 1. Gastroenterology, Hepatology&Nutrition, Department of Paediatrics, CHU Sainte-Justine, University of Montreal, Montreal, QC, Canada; 2. Division of Pathology & Cellular Biology, CHU Sainte-Justine, Montreal, QC, Canada; 3. Agriculture&Agri-Food Canada, Food Research and Development Centre, St-Hyacinthe, QC, Canada. Aims: Torque Teno Virus (TTV) is a ubiquitous agent in general population. TTV is believed to replicate in the liver but its pathogenic role is unclear. The aim of this project was to evaluate the prevalence and the impact of TTV infection in paediatric patients after orthotopic liver transplantation (OLT). We also aimed to study TTV infection as possible cause of chronic hepatitis and persistently increased serum transaminases without defined aetiology in liver-transplanted children. Methods: Liver-transplanted children between 1992-2010 were classified in two groups: group 1 (control group) (n=66) with normal serum aminotransferases; and group 2 (n=14) with persistently increased serum aminotransferases and histological features of chronic hepatitis. Available serum samples (n=221 for group 1 and n=112 for group 2) were screened for TTV DNA using TaqMan real-time PCR. Viral load was estimated. TTV genogroup was assessed using specific degenerated primers. Co-infection with Hepatitis E virus (HEV) was assessed. Charts were reviewed for post-transplant medical history, immunosuppressive drugs regimen, serum transaminases fluctuations and liver histology results (METAVIR score). Results: TTV DNA was detected in 97,5% of tested serum. Viral load was significantly lower in patients of group 2 (p<0,0001), of whom 11 out of 14 patients had liver fibrosis scores of 2 or higher. No significant relationship was evidenced with serum ALT levels (p=0,175). In all patients, viral load decreased during the post-transplant follow-up (Pearson’s correlation -0.373, p<0,0001), as patient’s grew old (Pearson’s correlation -0.457, p<0,0001) and in case of co-infection with acute HEV infection (p=0,040, 58% of patients in group 2). Viral load was significantly higher in patients taking multiple immunosuppressive drugs (p<0,0001). TTV genogroups were not associated with poor outcome after OLT but higher viral load was present in patients who were infected with multiple genogroups of TTV (p<0,0001). Conclusions: TTV infection is very common in liver-transplanted children. Its replication is closely related to immune status of patients and concomitant viral infection. TTV infection does not seem to worsen the outcome after OLT but, conversely, liver inflammatory activity seems to impair TTV replication. Better understanding of endemic liver-tropic viral infections is important to improve the management in liver-transplanted patients. Further studies are needed to seize the impact of TTV infection in immunocompromised patients.

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A324 EFFICACY OF HEPATITIS C ERADICATION THERAPY IN A GEOGRAPHICALLY LARGE AND REMOTE COMMUNITY CLINIC. M. Crosby, P. Melanson, C. Mahoney North Island Liver Service, Vancouver Island Health Authority, Campbell River, BC, Canada. Aims: The recently published observational study (APPROACH) compared the response rates of HCV therapy between academic and community based treatment centers; revealed a lower SVR for community based treatment of Genotype 1 (geno 1) patients with no clear explanation. We want to compare our treatment experience. North Island Liver Services is a large, community based HCV support & treatment clinic covering Northern Vancouver Island, approximate population 100,000. It includes 2 nurses, 2 treating physicians and dedicated mental health and addiction support. In 2003 we began treatment with pegylated interferon based regimens. We have SVR determination on 218 of our treated patients. Treatment follow up is coordinated by clinic nurses and significant treatment decisions are made by the treating physician. Methods: Retrospective chart review comparing our results to the APPROACH Study results. Results: The cohort for this abstract includes 218 patients treated with pegylated interferon alpha 2a or 2b and ribavirin according to standard protocols with weight based ribavirin dosing. The baseline characteristics of our treated cohort is similar to that of the APPROACH cohort except 50% of our Geno 1 cohort had fibrosis scores of F3/F4(Metavir) on liver biopsy or clinical cirrhosis. Our overall SVR of 56% is similar to the academic SVR from the APPROACH study (58.5%). Our Geno 2/3 combined SVR of 76.6% is higher than both the academic (64.4%) and community (67%) rates in APPROACH. Our overall Geno 1 SVR was 38% compared to the academic rate of 51.9% and community rate of 31.5%. Overall 43% of the academic cohort (APPROACH) was biopsied, 22% being F3/F4. In comparison, 74% of our total cohort was biopsied revealing 46.2% with F3/F4. For geno 1, 50% showed F3/F4 staging or had clinical cirrhosis. For F0 - F2 the SVR was 53% and for F3/F4 or clinical cirrhosis the SVR was 26%. Conclusions: The SVR rates for our cohort show a capacity for a large community based treatment center with dedicated clinic nurses, serving a geographically large area to have a success rate comparable to the best academic and community based centers in Canada. Our Geno 1 SVR was strongly influenced by the pretreatment fibrosis stage but not influenced by dose reductions in either interferon or ribavirin. The strength of this cohort is that no patients on treatment were lost to follow up during treatment and all significant management decisions were made by the treating physician, thus minimizing the potential impact of fragmented care. Community based Hepatitis C treatment clinics can provide overall and geno 2/3 eradication rates equivalent to academic centers. Geno 1 SVR’s remain lower than the academic arm of the APPROACH study and were strongly influenced by the pretreatment fibrosis scores.

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A325 TREATING THE DIFFICULT TO TREAT: A COMMUNITY-BASED, COLLABORATIVE CARE, PEER SUPPORT MODEL OF HCV CARE DELIVERY J. Powis1, E. Cooper2, K. Mason2, S. Woolhouse2 1. Toronto East General Hospital, Toronto, ON, Canada; 2. South Riverdale Community Health Centre, Toronto, ON, Canada. Aims: Despite high seroprevelance rates, few illicit substance users receive treatment for Hepatitis C (HCV). The East Toronto Hepatitis C Program (ETHCP) is a community-based, collaborative care, peer group support model of HCV care delivery focused on improving access to interferon-based antiviral therpy for HCV. The aim of this study is to describe treatment outcomes among clients utilizing the ETHCP. Methods: A retrospective chart review of clients who attended at least one Hepatitis C support group at the East Toronto Hepatitis C Program (ETHCP) between March 2007 and July 2010, was performed. Data was abstracted from patients charts utilzing a standardized tool. REB approval for this study was obtained through the University Health Network, Toronto. Results: There were 133 clients who attended at least one group at the ETHCP. Most clients were male (72.2%) with an average age of 48 years. There were high rates of unemployment (84.0%), and 36.2% of clients were either homeless or under housed at program enrolment. Rates of self-reported substance use were high with 44.4% indicating crack cocaine use in the past month, 33.8% reporting daily or frequent binge use of alcohol, and 7.5% reporting IVDU within the past month. Mental health comorbidities were common, with 29.3% requiring prescription psychotropic medications. HCV PCR was completed on 88.0% of clients. HIV co-infection was uncommon (6.7%). Of the 78 clients with genotype 1, 46 (59.0%) went on to have a liver biopsy. Advanced liver histology (Stage 3 or 4) was seen in 10 clients (21.7%). In total 24 clients (18. 0%) went on to receive HCV antiviral treatment during the study period. Of the 39 clients with genotype 2 or 3, 11 went on to receive antiviral treatment with and SVR of 90.9%. Twenty-nine clients with genotype 1 and a fibrosis stage ≥ 2 were eligible for provincially-reimbursed interferon-based antiviral therapy, of which 10 went on to receive antiviral treatment. Among the 13 genotype 1 patients who initiated therapy SVR was available on 10 with an SVR rate of 40.0%. Conclusions: The population served by the ETHCP is highly marginalized with high rates of unemployment, substance use, mental health comorbidities and homelessness. Despite these obstacles, of the 68 patients eligible for provincially-reimbursed interferon-based antiviral therapy, 30.9% went on to receive therapy with SVR rates comparable to those seen in clinical trial data. A community based, collaborative care, peer based model for delivery of HCV care is a promising model for delivery of HCV antiviral therapy to marginalized populations.

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A326 DRUG INTERACTION PROFILE OF TELAPREVIR V. Garg1, R. Kauffman1, M. Beumont2, R. van Heeswijk2 1. Vertex Pharmaceuticals Incorporated, Cambridge, MA; 2. Tibotec BVBA, Beerse, Belgium. Aims: Telaprevir, a hepatitis C virus (HCV) NS3/4A protease inhibitor, is a substrate and inhibitor of cytochrome P-450 3A (CYP3A) and a substrate and inhibitor of P-glycoprotein (P-gp). A number of studies were conducted to examine the clinical significance of drug interactions between telaprevir and other medications. Methods: Multiple clinical studies were conducted in healthy volunteers to determine the drug interaction potential of telaprevir with substrates, inhibitors, and inducers of CYP3A as well as digoxin, a substrate of P-gp. Results: Drugs that had substantially increased exposure (AUC) when co-administered with telaprevir included atorvastatin (8-fold), cyclosporine (4.6-fold), oral midazolam (9-fold), and tacrolimus (70-fold). Other notable interactions included a significant reduction in the exposure of the ethinyl estradiol (28%) component of oral contraceptives and in the exposures of ritonavir-boosted HIV protease inhibitors, darunavir (40%) and fosamprenavir (47%), when telaprevir was co-administered. Rifampin, an inducer of CYP3A, caused a substantial (92%) reduction in telaprevir exposure. Telaprevir exposure was also reduced significantly by efavirenz (26%) and by ritonavir-boosted HIV protease inhibitors, lopinavir (54%), darunavir (35%), and fosamprenavir (32%). Other drugs that had increased exposures in the presence of telaprevir were alprazolam (1.35-fold), amlodipine (2.8-fold), digoxin (1.85-fold), i.v. midazolam (3.4-fold), raltegravir (1.31-fold), and tenofovir (1.1 to 1.3-fold); drugs that had lowered exposure in the presence of telaprevir were escitalopram (35%), zolpidem (47%) and R-methadone (29%). For methadone, while the total levels of R-methadone in the plasma were reduced in the presence of telaprevir, the protein-unbound levels were similar before and after co-administration of telaprevir, suggesting a lack of clinically significant interaction based on protein-binding displacement. Additionally, telaprevir did not have a clinically significant effect on the exposure or pharmacodynamics of buprenorphine. Conclusions: The interaction profile of telaprevir was similar to that of protease inhibitors for HIV and has been well-characterized in drug interaction studies with a broad range of commonly used drugs. Based on the degree of interaction and the clinical consequences, certain drugs are contraindicated with telaprevir and several others require dose modification and/or monitoring for adverse events. Health practitioners should consult the product monograph prior to and during treatment for potential drug interactions.

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A327 SMALL MOLECULE-MEDIATED PERTURBATION OF HCV-ASSOCIATED HOST PATHWAYS REVEAL POTENTIAL ANTIVIRAL MODULATIONS IN MIRNA EXPRESSION R. Singaravelu1, D. Jones2, R. Russell2, J. Pezacki1 1. NRC Steacie Institute for the Molecular Sciences, Ottawa, ON, Canada; 2. Immunology and Infectious Diseases, Memorial University, St. John's, NF, Canada. Aims: MicroRNAs (miRNAs) are a class of endogenous small RNAs that play major regulatory roles in virtually all cellular processes. Aberrant expression of these genes is linked to diseased states with hepatitis C virus (HCV) infection being no exception. The modulations in miRNA expression result from both HCV-induced changes in cellular physiology to propagate the viral life cycle and host-induced innate cellular antiviral mechanism. Characterization of both pro- and anti-viral miRNAs will aid in elucidation of new therapeutic targets and aspects of the HCV lifecycle. Methods: In order to characterize both the host pro- and anti-viral signature, a comprehensive miRNA microarray analysis was performed using human hepatoma cells treated with HCV antivirals (25-hydroxycholesterol and benzamide) which target lipid metabolism in the presence of infection with a cell culture adapted JFH-1 strain. Validation of these candidates was performed by qRT-PCR. Results: Probing for anti-correlated miRNA profile changes induced by viral infection compared to HCV-antiviral treatment revealed potential pro- and anti-viral miRNAs. Validation of these differentially expressed candidates was performed by qRT-PCR. Conclusions: Modulations in the miRNA profile induced by the virus may reflect the anti-viral response of the host miRNA milieu, or pro-viral changes in miRNAs which play regulatory roles in pathways essential to HCV. Distinguishing the nature of these perturbations in miRNA profiles is possible using complementary profiling of the HCV "anti-viral" state, inducing by small molecules, and the HCV infected "pro-viral" state. The influence of these differentially expressed miRNAs on HCV are currently being evaluated in SGR, FGR, and HCVcc models.

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A328 EVALUATION OF THE PSYCHOMETRIC PROPERTIES OF THE HCV STIGMA SCALE USING CLASSICAL TEST THEORY AND ITEM RESPONSE THEORY C. Cabrera1, K. Corace2, L. Balfour2, G. Tasca2, C. Cooper2, G. Garber2 1. University of Ottawa, Ottawa, ON, Canada; 2. The Ottawa Hospital, Ottawa, ON, Canada. Aims: It is estimated that 300,000 individuals in Canada are infected with Hepatitis C (HCV). HCV can be a significant source of stigma. HCV stigma can contribute to decreased quality of life, and be a barrier to accessing health care services or adhering to prescribed treatments. Currently, no psychometrically sound instrument exists for the measurement of HCV stigma. A sound instrument is critical to ensure valid and reliable measurement. This study will evaluate the psychometric properties of a measure developed to assess self-perceived HCV stigma using both classical test theory (CTT) and novel item response methodology (IRT). Methods: From June 2008 to December 2008, HCV patients seen at the Viral Hepatitis Clinic at TOH were recruited to participate in a questionnaire study. The questionnaire package contained: Sociodemographic information, HCV Stigma Scale, Center for Epidemiological Studies-Depression Scale, and the SF-12 Health Survey. The questionnaire package took approximately 40 minutes to complete. Results: The final sample size was 95 HCV patients. Results from both CTT and IRT indicated that the HCV stigma scale is internally reliable (α = .87; 0.93). Pearson correlations indicated that the HCV stigma scale was significantly positively correlated to depression (r=.42, p<.00) and significantly negatively correlated to general mental health and well-being (r=-.37, p<.00). IRT results yielded discrimination values (α) ranging from 0.49 to 9.95. Item 1 (α = .49) was the only item with a discrimination level below α=.65, the recommended level. Item difficulty indicated that items cluster at the middle of the continuum. Conclusions: Overall, both CTT and IRT methodology indicate that the HCV Stigma Scale is a sound measure that is both reliable and valid. Moreover, IRT added significant information to the psychometric evaluation suggesting the scale was most accurate for those with moderate levels of stigma (middle of continuum) and which items were most valuable (e.g. Item 1 did not yield sufficient discrimination). The latter information could be used to shorten the scale to 9 items for further brevity. The HCV Stigma scale is a brief and easy-to-use tool to measure self-perceived stigma, which is ideal for a clinical setting. It is useful and accurate at identifying patients who feel stigmatized and who consequently may be at higher risk for less than optimal adherence to many aspects of their HCV treatment.

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A329 CASE REPORT OF REACTIVATION OF HEPATITIS B CAUSING NEPHROTIC SYNDROME IN A PATIENT WHO RECEIVED A HEPATITIS B CORE POSITIVE LIVER TRANSPLANT S. Kenshil Memorial University, St. John's, NF, Canada. Aims: Reporting a rare complication Methods: Case report Results: Case report Conclusions: Case report of a 53 year old female post orthotopic liver transplant requiring treatment for reactivation of Hepatitis B that manifested as nephrotic syndrome. She had received a graft from a Hepatitis B core positive donor after her initial transplant was complicated by a hepatic artery thrombosis.

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A330 HEPATITIS B VIRUS (HBV) LYMPHOTROPISM IN HUMAN IMMUNODEFICIENCY VIRUS-TYPE 1 (HIV-1) COINFECTED PATIENTS Z. Lee, S. Nisikawa, B. Eksteen, M. Gill, G. van Marle, C. Coffin University of Calgary, Calgary, AB, Canada. Aims: HIV infection adversely affects HB-related liver disease. The woodchuck HBV model shows that mitogen stimulation can upregulate low-level hepadnavirus within lymphoid cells where replication occurs. We hypothesize that in HIV-1 coinfected hosts, lymphoid cells are a reservoir for HBV, and coinfection modifies HBV lymphotropism and cytokine responses. The aims of this study were to determine whether HBV replication occurs within lymphoid cells and if so, whether this affects cytokine responses and if a specific immune cell subset is targeted in HBV monoinfected compared to HBV/HIV-1 coinfected patients. Methods: Peripheral blood mononuclear cells (PBMC) from healthy, chronic HB carriers (CHB), HIV-1 monoinfected, and CHB/HIV coinfected patients were cultured in media alone, with T/B cell supporting cytokine interleukin-2 (Il-2), or with T cell mitogen concanavalin A (ConA/Il-2) or T/B cell mitogen pokeweed (PWM/Il-2). Immune cell subsets were isolated by flow cytometry (FACS) or magnetic beads (MACS®) using monoclonal antibodies to CD4+ T cells, CD8+ T cells, CD14+ monocytes, CD19+ B cells and CD56+ natural killer cells (purity by FACS ~90-95%). Following 72-hour culture, PBMC were pelleted, the supernatant collected and treated with DNAse and trypsin to remove extracellular virus particles. Cells were evaluated for HBV replicative intermediates by reverse transcription of HBV or HIV mRNA to cDNA followed by detection of HBV core and surface genes or HIV polymerase gene by sensitive direct and nested PCR nucleic hybridization assay. The cell culture supernatant was analyzed by 40-plex human cytokine/chemokine assay (Luminex). Results: We found that mitogen stimulation upregulated HBV and HIV mRNA in PBMC and virus replication was more enhanced with PWM compared to ConA. HBV and HIV genomes within immune cell subsets showed HBV absence in HBV monoinfected patients’ CD8+ T cell population and less presence within CD14+ monocytes, yet presence within all immune cell subsets in coinfected PBMC. HIV-1 was predominantly within CD4+ T cells. Comparison of cytokine responses from coinfected patients compared to HIV or HBV monoinfected patients showed reduced levels of pro-inflammatory and anti-inflammatory cytokines in serum (IL-2, -4, -6, -10, IFN-γ, TNF-α), yet increased cytokine responses in PBMC after ConA stimulation (IL-3, -4, -12, -13, IP-10). Conclusions: Lymphoid cells are a reservoir for replicating HBV. The immune cell subset targeted by HBV and cytokine responses in serum and from ex-vivo mitogen stimulated PBMC is affected by concomitant HIV-1 coinfection. The altered inflammatory cytokine responses from HBV/HIV coinfected lymphoid cells may have immunopathological consequences including accelerated HBV-related liver disease.