Renal biopsy seminar

RENAL BIOPSY

DR. VISHAL GOLAY28-10-10

DM Seminar

History of renal biopsy

Iverson and Brun (1951)- first renal biopsy description. Aspiration biopsy of kidney. Am J Med 11:324—330, 1951

Kark and Muehrcke (1954)-blind prone biopsy.

Biopsy of kidney in prone position. Lancet 1:1047—1049, 1954

New era - biopsy guns & imaging

Vim-Silverman needle

OVERVIEW

Indications & contraindications

The procedure

Tissue processing and staining

Brief introduction to microscopy

Some clinical examples

Indications of renal biopsy

Nephrotic syndrome: Adult NS Children with atypical features

Acute renal failure: Undiagnosed Non resolving clinical ATN >3-4 weeks

Systemic diseases with renal dysfunction

Indications of renal biopsy CONtd….

Sub-nephrotic proteinuria >2g/d in DM, early MGN, FSGS, IgAN <2g/d needs clinicians discretion

Hematuria Isolated (Q J Med 2004; 97:739–745)

Associated with proteinuria and abnormal urine sediment

Indications of renal biopsy CONtd….

Post transplant

CKD- generally contraindicated

In moderate dysfunction-potential reversibility and basic disease

Diabetes Mellitus Microscopic hematuria Absence of retinopathy and neuropathy Onset of proteinuria <5years from diagnosis Acute worsening of renal function Systemic features

Renal biopsy; a necessary evil?

276 native renal biopsies; management was altered in 42% of cases overall. Nephrol Dial Transplant. 1994;9(9):1255-9

3 year prospective study involving 80 patients; Pre-biopsy predicted histologic diagnosis was changed in 44% of the patients as a result of the biopsy. Prognosis changed in 57% of the patients. Therapy changed in 31% of the patients. Clin Nephrol. 1986 Nov;26(5):217-21

111 renal biopsies in childern; biopsy altered diagnosis in 24.5%. Post biopsy, treatment was changed in 22.6%. 18.9% had a change in both the diagnosis and treatment. Zhonghua Min Guo. 1998 Jan-Feb;39(1):43-7

contraindications

Preparation of the patient

Prerequisites Relevant history & examination USG KUB Hemogram and Hct PT/aPTT Urine RE/ME & culture

Bleeding time Current Opinion in Nephrology & Hypertension

1999;8: 715-718

Biopsy gun

Biopsy gun choice

14 G guns gives greater number of glomeruli per core than 18-G cores, but the rates of adequate biopsies were similar

Larger needle provided more tissue and glomeruli but were associated with more pain.

16-gauge needles are used as a compromise between the need of a sufficient size of tissue and the need of clinical safety.

Adequate quantity of tissue for diagnosis may be obtained with this needle size in 98.9 per cent of biopsies either in native or in transplanted kidneys.

OTCN

Procedure

Informed consentPatient in prone position with wedge or pillow below

the abdomenLight sedationLocal anesthesia with 1-2% lignocaine from the skin

down to the capsuleStab incision can be given to ease biopsy gun entryAdvance the biopsy gun, when the capsule is reached,

instruct patient to take a deep breath and fire the gun2-3 cores can be taken from the lower pole of the left

kidneyPress on wound for 2-5 minutes

Procedure

Procedure

USG guided vs blind biopsies

Worldwide the trend is towards USG guided biopsies

129 renal biopsies, USG guided Blind P

Mean number of glomeruli

18±9 11±9 0.0001

Repeat biopsy

0% 16% 0.0006

Hematoma requiring intervention

0% 11% 0.006

24 hour Hct 32±5% 30±4% 0.04Semin Dial. 2007 Jul-Aug;20(4):355-8

USG guide to nephrologist

Safer and more efficient then blind biopsy

In one study of 101 biopsies nephrologists used a portable ultrasound machine for location and depth of the kidney. The results are similar to those of previous studies using automatic devices but under direct ultrasound guidance.

AJKD 1999;34:955-959

Post procedure

Hand held lens/dissecting microscope can be used to check for the presence of cortical tissue

Post procedure

Bed rest is instructed for 18-24 hours

BP and pulse are monitored in the following way- Every 15 mins for 1 hour f/b Every 30 mins for 1 hour f/b

Every hour for 4 hours f/b

4 hourly for next remaining 24 hours

Save aliquots of each voided urine sample in clear specimen jars

Hct monitored 6-8 hours and 18-24 hours after biopsy

Complications of renal biopsy

•Complications of percutaneous renal biopsy: a review of 37 years experience. Clin Nephrol 1992;38:135-41.

Complications of renal biopsy

Ateriovenous fistula-post biopsy

Complications of renal biopsy

Page kidney: compression of kidney by a hematoma leads to high renin hypertension. It is believed to result from microvascular ischemia and alteration of small-vessel hemodynamics from external compression.

Outpatient renal biopsy

750 biopsies; Complications were identified 42% patients by 4 h, in 67% patients by 8 h, in 85% patients by 12 h, and in 89% patients at 24 h. After

biopsy, an observation time of up to 24 h remains optimal.

J Am Soc Nephrol 15:142-147, 2004

Maya and Allon et al; 100 renal biopsies. 8 hour observation is safe.

Semin. Dial. 20, 355–358 (2007)

Specimen processing

Specimen division >8mm - LM/IF/EM4-8mm - EM/IF<4mm - EM

Specimen processing

Adequacy of the sample:

two biopsy cylinders with a minimal length of 1 cm and a diameter of at least 1.2 mm.

10–15 glomeruli are optimal; very often 6–10 glomeruli are sufficient

some cases even one glomerulus is enough

Nephrol Dial Transplant (2006)

21: 1157–1161

Biopsy tissue examination

Light microscopy

1. Fixative: Buffered, 10% aqueous formaldehyde solution

(formalin)-most commonly used Bouin’s Duboscq-Brasil Zenker’s

4% paraformaldehyde The material processed for LM can serve as reserve

material for IHC or EM if either of these other modalities is found lacking glomeruli.

Light microscopy

2. Dehydration: done with a series of alcohols, say 70% to 95% to 100%.

3. Clearing: xylene, toluene, chloroform, limolene4. Embedding:

Paraffin Paraplast Plastics-methyl methacrylate, glycol methacrylate,

araldite, and epon.

5. Sectioning: manual/microtome. 2 µm sections are used

Light microscopy

Routine stains (paraffin sections) Haematoxylin and eosin (HE) Periodic acid–Schiff’s (PAS) Fibrous tissue stain (i.e. Sirius red, Trichrome,

Ladewig, etc.) Silver stain Protein stain- acid fuchsin–Orange G stain (SFOG).

Optional stains Kossa stain (calcifications) Congo red stain (amyloid)

Light microscopy

H&E: composition of the tissue (i.e. renal cortex vs medulla, number of glomeruli, cellular infiltration, etc.).

PAS:delineates in great detail glomerular cells, mesangial matrix and potential expansion, as well as potential

modifications of the composition of the matrix, changes of the GBM, i.e. thickening, irregularities, doubling,

rupture fibrinoid necrosis of the glomerular tuft alterations of the vessels, particularly arterial hyalinosis and

fibrinoid necrosis.

Light microscopy

Protein stains: Immune deposits

Silver stain: permits the detection of changes of the GBM

Fibrous tissue stain: extent of fibrosis in the glomerulus or tubular interstitium

Light microscopy-normal

Immunohistochemistry-IF/IP

Preparation:

IF is best performed on unfixed, frozen sections. Tissues can be transported to the laboratory fresh on saline-soaked gauze or in Michel’s fixative. Serial sections are cut at 2–4 mm in a cryostat.

IP staining requires no special tissue preparation in that the same formalin-fixed, paraffin- embedded material used for LM is also used for IP.

Immunohistochemistry-IF/IP

Staining: The antigens that should be routinely examined include: immunoglobulins (primarily IgG, IgM and IgA), complement components (primarily C3, C1q, and C4), fibrin, κ- and –λ light chains collagen IV alpha chains IgG subclasses, virus identification, lymphocyte phenotyping in allografts in suspected cases of PTLD, C4d in allograft biopsies

Immunohistochemistry-IF/IP

Reported as: reaction is positive, pattern of staining, e.g. mesangial vs capillary

staining pattern, linear (or pseudolinear) vs granular staining. describe where the deposits are located, e.g. in a

subendothelial, intramembranous or subepithelial position

Immunohistochemistry-IF/IP

IgGIgA

Idiopathic MGN

IgA Nephropathy

Electron Microscopy

Fixative: 2-3% glutaraldehyde, 1-4 % paraformaldehyde.

Processing: Instead of the clearing fluid, “transitional fluid”-1,2

Epoxypropane is used. Embedding done in epon. Sections must be less than 80 nm thick in order to allow at least

50% of the electron beam to penetrate the sample. Toluidine blue stained 1µm thick sections are used as an initial

guide

Stains: uranyl acetate (stains DNA), lead citrate, gold.

Electron Microscopy

Electron microscopy permits assessment of the following: The presence and degree of cell proliferation (mesangial vs

endothelial cell proliferation) Changes in cell structure (i.e. podocyte foot process fusion

or podocyte vacuolization) Necrosis or apoptosis of cells Changes of glomerular basement membrane (i.e.

thickening, thinning, splicing, irregularities) Localization of immunoglobulin deposits (i.e. mesangial,

subendothelial or subepithelial) In some renal diseases, specific morphological changes

tubuloreticular structures.

Electron Microscopy

Immunohistology is essential for diagnosis in 21% of cases and Electron Microscopy is essential in the diagnosis of 8% of cases OTCN

Electron Microscopy

Reporting a Renal Biopsy

The final report of a kidney biopsy should include information on: The adequacy of the specimen A description of the morphological changes in a systematic

fashion for each of the compartments of interest (glomeruli, tubules, interstititum, vessels

The results of immunofluorescence /immunohistochemical studies.

The results of the electron microscopy

It is useful to give two types of diagnosis:1.Descriptive2.Final

Reporting a Renal Biopsy

Reporting a Renal Biopsy

Reporting a Renal Biopsy

Reporting a Renal Biopsy

Biopsy in special situations

Pediatric age group: Sedation is used (ketamine, midazolam, promethazine, BZDs) 18-G gun is used

Pregnancy: Indications of biopsy Sudden unexplained deterioration of renal function before 30-

32 weeks POG Symptomatic NS before 30-32 weeks POG Active urinary sediments, proteinuria and borderline renal

function

renal biopsy in pregnancy is safe before 30 weeks of pregnancy.

Acta Obstetricia Gynecologica Scandinavica 2001;80:888–893

Biopsy in special situations

Allograft biopsy:Indications-

Failure of the graft to function in the first 7-10 days after surgery

Rapid deterioration of renal function of unknown cause after initial good function

Absence of response to antirejection therapy Unexplained nephrotic range proteinuria

Biopsy technique is the same Supine position USG guidance is necessary-for position and localisation, and

also to exclude presence of intestinal loops, fluid collections 2 cores of tissue is recommended-the sensitivity of a single

core for rejection is 91%; the addition of the second core improves the sensitivity to about 99%

Half the tissue is used for frozen section

CLINICAL EXAMPLES

SHEIKH ABDUL HALIM Kala Azar with Nephrotic

Syndrome

Sushmita Das (SLE Class IV)

Wire loops

Cellular crescent

Fibrinoid necrosis

Global proliferationwith neutrophilic infiltration

Naima KhatoonLupus nephritis Class IV G( A/C)Activity index: 19/24Chronicity index: 4/12

Kalpana Das (FSGS)

Amal Panja (Crescentic GN)

Sabita Majumdar (Pauci-immune CrGN)

Sukumar Bodhak (IgA Nephropathy)

IgA

THANK YOU