The Banff community summoned the TMA Banff Working Group to develop minimum diagnostic criteria (MDC) and recommendations for renal transplant TMA (Tx-TMA) diagnosis, which currently lacks standardized criteria. Using the Delphi method for consensus generation, 23 nephropathologists (panelists) with >3 years of diagnostic experience with Tx-TMA were asked to list light, immunofluorescence, and electron microscopic, clinical and laboratory criteria and differential diagnoses for Tx-TMA. Delphi was modified to include 2 validations rounds with histological evaluation of whole slide images of 37 transplant biopsies (28 TMA and 9 non-TMA). Starting with 338 criteria in R1, MDC were narrowed down to 24 in R8 generating 18 pathological, 2 clinical, 4 laboratory criteria, and 8 differential diagnoses. The panelists reached a good level of agreement (70%) on 76% of the validated cases. For the first time in Banff classification, Delphi was used to reach consensus on MDC for Tx-TMA. Phase I of the study (pathology phase) will be used as a model for Phase II (nephrology phase) for consensus regarding clinical and laboratory criteria. Eventually in Phase III (consensus of the consensus groups) and the final MDC for Tx-TMA will be reported to the transplantation community.

AeskuLab Pathology and Department of Pathology Charles University Prague Czechia

Arkana Laboratories Little Rock AR United States

Departamento de Parasitologia Instituto de Ciências Biológicas Universidade Federal de Minas Gerais Belo Horizonte Brazil

Department of Anatomical Pathology NSW Health Pathology Callaghan NSW Australia

Department of Clinical Pathology Sahlgrenska University Hospital Gothenburg Sweden

Department of Nephrology Ludwig Maximilian University Munich Germany

Department of Pathology and Clinical Bioinformatics Erasmus MC Transplant Institute University Medical Center Rotterdam Rotterdam Netherlands

Department of Pathology and Immunology Baylor College of Medicine Houston TX United States

Department of Pathology and Immunology School of Medicine Washington University in St Louis St Louis MO United States

Department of Pathology and Laboratory Medicine Emory University Atlanta GA United States

Department of Pathology and Laboratory Medicine King Fahad Specialist Hospital Dammam Dammam Saudi Arabia

Department of Pathology and Laboratory Medicine Mayo Clinic Rochester MN United States

Department of Pathology and Laboratory Medicine Weill Cornell Medicine New York NY United States

Department of Pathology Isfahan Kidney Diseases Research Center Isfahan University of Medical Sciences Isfahan Iran

Department of Pathology Istanbul Faculty of Medicine Istanbul University Istanbul Türkiye

Department of Pathology John Sealy School of Medicine University of Texas Medical Branch at Galveston Galveston TX United States

Department of Pathology Maisonneuve Rosemont Hospital University of Montreal Montreal QC Canada

Department of Pathology Medical University of Vienna Vienna Austria

Department of Pathology Necker Enfants Malades Hospital Université Paris Cité Paris France

Department of Pathology School of Medicine Koç University Sarıyer Türkiye

Department of Pathology School of Medicine University of Zagreb Zagreb Croatia

Department of Pathology The Houston Methodist Hospital Houston TX United States

Department of Pathology Université de Sorbonne Assistance Publique Hôpitaux de Paris Hôpital Tenon Paris France

Institute of Experimental Medicine and Systems Biology RWTH Aachen University Aachen Germany

Kidney Pancreas Transplantation Instituto de Nefrología Nephrology Buenos Aires Argentina

Laboratory Medicine Program University Health Network Toronto ON Canada

New York Medical College Valhalla NY United States

School of Medicine and Public Health University of Newcastle Callaghan NSW Australia

Transpl Int. 2023 Oct 16;36:12047. doi: 10.3389/ti.2023.12047. PubMed

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Delphi: A Democratic and Cost-Effective Method of Consensus Generation in Transplantation