The Banff Classification was first developed in 1991 by pathologists, nephrologists, and transplant surgeons to standardize the interpretation of transplant biopsies. It has since evolved through biennial meetings and become the worldwide standard. The classification system aims to improve reproducibility and clinical validation of biopsy results through consensus guidelines. Future meetings will further refine the system based on research findings to best inform clinical practice.

1. The Banff ClThe Banff Classification:assification:
Slide SeminarSlide Seminar
Kim Solez, M.D.Kim Solez, M.D.

2. Slide 2he Banff Schema was first developed by ahe Banff Schema was first developed by a
roup of pathologists, nephrologists, androup of pathologists, nephrologists, and
ansplant surgeons at a meeting in Banff Canadaansplant surgeons at a meeting in Banff Canada
ugust 2-4, 1991.ugust 2-4, 1991.
The Banff Schema was first developed by aThe Banff Schema was first developed by a
group of pathologists, nephrologists, andgroup of pathologists, nephrologists, and
transplant surgeons at a meeting in Banfftransplant surgeons at a meeting in Banff
CanadaCanada
August 2-4, 1991.August 2-4, 1991.
It has continued to evolve throughIt has continued to evolve through
meetings every two years and hasmeetings every two years and has
become the worldwide standard forbecome the worldwide standard for
interpretation of transplant biopsiesinterpretation of transplant biopsies

3. Slide 3
Banff Classification: MilestonesBanff Classification: Milestones
 1991 First Conference1991 First Conference
 1993 First Kidney International publication1993 First Kidney International publication
 1995 Integration with CADI - identical scoring1995 Integration with CADI - identical scoring
 1997 Integration with CCTT classification1997 Integration with CCTT classification
 1999 Second KI paper. Clinical practice guidelines.1999 Second KI paper. Clinical practice guidelines.
Implantation biopsies, microwave.Implantation biopsies, microwave.
 2001 Classification of antibody-mediated rejection2001 Classification of antibody-mediated rejection
 Regulatory agencies participatingRegulatory agencies participating

4. Slide 4

5. Slide 5

6. Slide 6

7. Slide 7

8. Slide 8
Quantitative Criteria forQuantitative Criteria for
Arteriolar Hyaline ThickeningArteriolar Hyaline Thickening
0 = No PAS-positive hyaline thickening0 = No PAS-positive hyaline thickening
1 = Mild-to-moderate PAS-positive hyaline thickening1 = Mild-to-moderate PAS-positive hyaline thickening
in at least one arteriolein at least one arteriole
2 = Moderate-to-severe PAS-positive hyaline thickening2 = Moderate-to-severe PAS-positive hyaline thickening
in more than one arteriolein more than one arteriole
3 = Severe PAS-positive hyaline thickening in many3 = Severe PAS-positive hyaline thickening in many
arteriolesarterioles

9. Slide 9
ChangesChanges notnot considered to be dueconsidered to be due
to rejectionto rejection
 Post-transplant lymphoproliferative disorderPost-transplant lymphoproliferative disorder
 Non-specific changesNon-specific changes
 focal interstitial inflammation without tubulitis: Nodular infiltrates,focal interstitial inflammation without tubulitis: Nodular infiltrates,
perivascular infiltratesperivascular infiltrates
 vascular changes: endothelial reactive changes, vacuolization,vascular changes: endothelial reactive changes, vacuolization,
venulitisvenulitis..
 Acute Tubular InjuryAcute Tubular Injury
 Acute Interstitial NephritisAcute Interstitial Nephritis
 Cyclosporine-associated changes, acute or chronicCyclosporine-associated changes, acute or chronic
 Subcapsular InjurySubcapsular Injury
 Pre-transplant Acute Endothelial InjuryPre-transplant Acute Endothelial Injury
 Papillary NecrosisPapillary Necrosis
 De novo GlomerulonephritisDe novo Glomerulonephritis
 Recurrent DiseaseRecurrent Disease
 Pre-existing DiseasePre-existing Disease

10. Slide
10

11. Slide
11Specimen Adequacy – (BanffSpecimen Adequacy – (Banff
’97) Minimum Sampling’97) Minimum Sampling
 Unsatisfactory – No glomeruli or arteriesUnsatisfactory – No glomeruli or arteries
 Marginal – 7 glomeruli with an arteryMarginal – 7 glomeruli with an artery
 Adequate – 10 or more glomeruli with at least twoAdequate – 10 or more glomeruli with at least two
arteriesarteries
 Minimum Sampling: 7 slides – 3 H&E, 3 PAS orMinimum Sampling: 7 slides – 3 H&E, 3 PAS or
silver stains, and 1 trichromesilver stains, and 1 trichrome

12. Slide
12Standardization of tx biopsyStandardization of tx biopsy
interpretation. Banffinterpretation. Banff
ClassificationClassification Classification begun at 1991Classification begun at 1991
 Banff meeting has become the worldwide standardBanff meeting has become the worldwide standard
 Consensus process has now extended to all solidConsensus process has now extended to all solid
organsorgans
 Meetings continue every two years. Next meeting inMeetings continue every two years. Next meeting in
Edmonton in summer of 2005Edmonton in summer of 2005
 Future meetings planned every two years throughFuture meetings planned every two years through
20092009
 Standardization principles now being extended fromStandardization principles now being extended from
biopsy reporting to tissue typing, imaging, all the otherbiopsy reporting to tissue typing, imaging, all the other

13. Slide
13Standardization of tx biopsyStandardization of tx biopsy
interpretation. Banffinterpretation. Banff
ClassificationClassification Lesion quantitationLesion quantitation
 Reproducibility and clinical validation studiesReproducibility and clinical validation studies
 Involvement of pathologists, clinicians, surgeons,Involvement of pathologists, clinicians, surgeons,
scientists, registries, and regulatory agencies inscientists, registries, and regulatory agencies in
consensus generationconsensus generation
 Meetings have large amount of unstructured timeMeetings have large amount of unstructured time
for deliberation and consensus generationfor deliberation and consensus generation
 Most content online at:Most content online at: http://cnserver0.http://cnserver0.nkfnkf.med..med.
ualbertaualberta.ca/Banff.ca/Banff
 Linked from http://www.cybernephrology.orgLinked from http://www.cybernephrology.org

14. Slide
14

15. Slide
15

16. Slide
16

17. Slide
17Agreed upon clinical practiceAgreed upon clinical practice
guidelines that need buy-inguidelines that need buy-in
generallygenerally
 Implantation biopsiesImplantation biopsies
 Rapid paraffin (microwave) processing for rapidRapid paraffin (microwave) processing for rapid
reading rather than frozen sectionsreading rather than frozen sections
 Routine (“protocol”) biopsiesRoutine (“protocol”) biopsies
 H&E, PAS (+/o silver), and trichrome or Sirius redH&E, PAS (+/o silver), and trichrome or Sirius red
stainsstains

18. Slide
18Perioperative (implantation)Perioperative (implantation)
BiopsyBiopsy
 Core vs wedgeCore vs wedge
 Adequacy of sampleAdequacy of sample
 Preimplantation vs. postimplantationPreimplantation vs. postimplantation
 Consensus:Consensus:
 Perioperative biopsy (? core, ? wedge) isPerioperative biopsy (? core, ? wedge) is
sufficiently safe to be recommended forsufficiently safe to be recommended for
any reasonable defined objectiveany reasonable defined objective
STANDARD OF CARE!STANDARD OF CARE!

19. Slide
19Protocol (routine) biopsiesProtocol (routine) biopsies
 Early and intermediate post-transplant protocolEarly and intermediate post-transplant protocol
biopsiesbiopsies
 Consensus:Consensus:
 Generally done under ultrasound guidanceGenerally done under ultrasound guidance
 Have very low morbidityHave very low morbidity
 Safe enough to be requested of consentingSafe enough to be requested of consenting
patients for research purposes when the objectivespatients for research purposes when the objectives
are clearly formulated and statedare clearly formulated and stated
STANDARD OF SCIENCE!STANDARD OF SCIENCE!

20. Slide
20Future Banff Meetings:Future Banff Meetings:
 2005 - Edmonton, Alberta, Canada2005 - Edmonton, Alberta, Canada
 2007 - Edinburgh, Scotland2007 - Edinburgh, Scotland
 2009 - Banff, Alberta, Canada2009 - Banff, Alberta, Canada

21. Slide
21CloseClose
 Banff ’97 Classification is the new universalBanff ’97 Classification is the new universal
classification of kidney transplant pathologyclassification of kidney transplant pathology
 Future improvements involve participation inFuture improvements involve participation in
Banff meetings via physical presence orBanff meetings via physical presence or
contributions via Internetcontributions via Internet

22. Slide
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