DIALYSIS – TRANSPLANTATION
Kidney International (1999) 55, 713–723; doi:10.1046/j.1523-1755.1999.00299.x
The Banff 97 working classification of renal allograft pathology
LORRAINE C RACUSEN, KIM SOLEZ, ROBERT B COLVIN, STEPHEN M BONSIB, MARIA C CASTRO, TITO CAVALLO, BYRON P CROKER, A JAKE DEMETRIS, CYNTHIA B DRACHENBERG, AGNES B FOGO, PETER FURNESS, LILLIAN W GABER, IAN W GIBSON, DENNIS GLOTZ, JULIO C GOLDBERG, JOSEPH GRANDE, PHILIP F HALLORAN, H E HANSEN, BARRY HARTLEY, PEKKA J HAYRY, CLAIRE M HILL, ERNESTO O HOFFMAN, LAWRENCE G HUNSICKER, ANNE S LINDBLAD, NIELS MARCUSSEN, MICHAEL J MIHATSCH, TIBOR NADASDY, PETER NICKERSON, T STEEN OLSEN, JOHN C PAPADIMITRIOU, PARMJEET S RANDHAWA, DAVID C RAYNER, IAN ROBERTS, STEPHEN ROSE, DAVID RUSH, LUIS SALINAS-MADRIGAL, DANIEL R SALOMON, STALE SUND, EERO TASKINEN, KIRIL TRPKOV and YUTAKA YAMAGUCHI
The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA, University of Alberta, Edmonton, Alberta, Canada, Massachusetts General Hospital, Boston, Massachusetts, University of Arkansas, Little Rock, Arkansas, USA, São Paulo University, São Paulo, Brazil, University of Cincinnati, Cincinnati, Ohio, University of Florida, Gainesville, Florida, University of Pittsburgh, Pittsburgh, Pennsylvania, University of Maryland, Baltimore, Maryland, Vanderbilt University, Nashville, Tennessee, USA, University of Leicester, Leicester, England, United Kingdom, University of Tennessee, Memphis, Tennessee, USA, University of Glasgow, Glasgow, Scotland, United Kingdom, Hopital Broussais, Paris, France, Institute of Pathology, Buenos Aires, Argentina, Mayo Clinic, Rochester, Minnesota, USA, University of Aarhus, Aarhus, Denmark, Guys and St. Thomas Hospital, London, England, United Kingdom, University of Helsinki, Helsinki, Finland, Queens University, Belfast, Ireland, United Kingdom, Louisiana State University, New Orleans, Louisiana, University of Iowa, Iowa City, Iowa, EMMES Corp., Potomac, Maryland, USA, University of Basel, Basel, Switzerland, University of Manitoba, Manitoba, Winnipeg, Canada, University of Manchester, Manchester, England, United Kingdom, National Institutes of Health, NIAID, Bethesda, Maryland, St. Louis University, St. Louis, Missouri, Scripps Institute, La Jolla, California, USA, National Hospital, Oslo, Norway, Jikel University, Chiba-Ken, Japan
Correspondence: Lorraine C. Racusen, M.D., The Johns Hopkins Medical Institutions, 519 Ross Building, 720 Rutland Avenue, Baltimore, Maryland 21205, USA. E-mail: lracusen@welchlink.welch.jhu.edu
Received 15 July 1998; Revised 18 September 1998; Accepted 18 September 1998.
Abstract
The Banff 97 working classification of renal allograft pathology.
Background
Standardization of renal allograft biopsy interpretation is necessary to guide therapy and to establish an objective end point for clinical trials. This manuscript describes a classification, Banff 97, developed by investigators using the Banff Schema and the Collaborative Clinical Trials in Transplantation (CCTT) modification for diagnosis of renal allograft pathology.
Methods
Banff 97 grew from an international consensus discussion begun at Banff and continued via the Internet. This schema developed from (a) analysis of data using the Banff classification, (b) publication of and experience with the CCTT modification, (c) international conferences, and (d) data from recent studies on impact of vasculitis on transplant outcome.
Results
Semiquantitative lesion scoring continues to focus on tubulitis and arteritis but includes a minimum threshold for interstitial inflammation. Banff 97 defines "types" of acute/active rejection. Type I is tubulointerstitial rejection without arteritis. Type II is vascular rejection with intimal arteritis, and type III is severe rejection with transmural arterial changes. Biopsies with only mild inflammation are graded as "borderline/suspicious for rejection." Chronic/sclerosing allograft changes are graded based on severity of tubular atrophy and interstitial fibrosis. Antibody-mediated rejection, hyperacute or accelerated acute in presentation, is also categorized, as are other significant allograft findings.
Conclusions
The Banff 97 working classification refines earlier schemas and represents input from two classifications most widely used in clinical rejection trials and in clinical practice worldwide. Major changes include the following: rejection with vasculitis is separated from tubulointerstitial rejection; severe rejection requires transmural changes in arteries; "borderline" rejection can only be interpreted in a clinical context; antibody-mediated rejection is further defined, and lesion scoring focuses on most severely involved structures. Criteria for specimen adequacy have also been modified. Banff 97 represents a significant refinement of allograft assessment, developed via international consensus discussions.
Keywords:
biopsy interpretation, allograft pathology, lesion scoring, kidney, transplantation
