Intestinal Inflammation TechLab ® LEUKO-TEST ®
Dec 15, 2015
Diarrhea, Nausea or Vomiting
Patient history plus Fecal Lactoferrin and O&P
Noninflammatory
Vibrio
E.coli
C.perfringens
S.aureus
B.cereus
Giardia, Cryptosporidium
Rotavirus, Norwalk virus
Inflammatory
Shigella
Salmonella
C.jejuni
E.coli
C.difficile
E.histolytica
Parasites
Giardia
Cryptosporidium
Cyclospora
Microsporidia
Dientamoeba fragilis
Blastocystis hominis
Isospora
Approach to diagnosis and Management of Infectious Diarrhea
(R.L Guerrant, Div Geographic Medicine U. Virginia, Charlottesville, VA
Limitations of staining for fecal leukocytes
•Fresh specimen should be collected in cup
•Performed within hours of collection
•Difficulty in interpretation of results
Lactoferrin as a marker of fecal leukocytes
•Lactoferrin is a glycoprotein released from inflammatory cells
•Highly stable
•Can be detected immunologically
•Direct correlation with presence of leukocytes
How does the LEUKO-TEST® work?
•Latex agglutination format
•Beads are coated with antibodies against lactoferrin, a protein released from leukocytes
•Beads agglutinate in the presence of elevated levels of lactoferrin in the specimen
How does the LEUKO-TEST® compare with microscopy?
In an evaluation of over 1700 samples, the following results were observed:
Relative sensitivity 84%
Relative specificity 86%
Predictive negative value 95%
Correlation 85%
Comparison of Fecal Lactoferrin, Fecal Leukocytes and Occult Blood with presence
of Enteric Pathogen (N=92)
Sensitivity
Specificity
PPV
NPV
Lactoferrin
vs Pathogen
94%
55%
58%
94%
Leukocytes
vs PathogenOccult Blood
vs Pathogen69%
89%
81%
82%
37%
76%
52%
64%
Scerpella et al., J.Travel Medicine 1:68-71, 1994
What are the advantages of the LEUKO-TEST® compared to
microscopy?
•Rapid
•Standardized
•Can be done on frozen specimens - outreach
Limitations of Fecal Lactoferrin Test
•Should not be used on breast fed infants
•Not specific for infectious inflammatory diarrhea
•Physician should overrule negative lactoferrin when necessary
FAQ
Can I use the LEUKO-TEST® on children?
The lab can perform their own evaluation (approx 20 samples) and have the data on file to show that the test can be performed in this age group. We did not have enough data collected in our clinical trials to make this statement in our product insert.
What type of sample is suitable for testing?
The test can be performed on fresh or frozen samples - samples in Cary Blair are suitable if the dilution factor is taken into account. Samples in preservatives such as formalin, SAF, PVA etc., are NOT suitable
How do I test a solid sample?
In a nutshell - reintroduce the liquid that the bowel has absorbed out of it. Mix the sample thoroughly with some PBS, saline or water until it’s at a consistency that will allow it to be drawn up into the pipet provided.