Thrombotic Microangiopathy in the Renal Allograft: Results of the TMA Banff Working Group Consensus on Pathologic Diagnostic Criteria

Transpl Int. 2023 Aug 23:36:11590. doi: 10.3389/ti.2023.11590. eCollection 2023.

Abstract

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.

Keywords: Banff; Delphi; kidney; pathology criteria; thrombotic microangiopathy; transplant.

MeSH terms

  • Allografts
  • Amines
  • Anticoagulants
  • Consensus
  • Humans
  • Kidney
  • Kidney Transplantation* / adverse effects
  • Thrombotic Microangiopathies* / diagnosis
  • Thrombotic Microangiopathies* / etiology

Substances

  • Amines
  • Anticoagulants

Grants and funding

This study was performed under the auspices of the Banff Foundation on Allograft Pathology and supported by grants from the Banff Foundation (for publication fees) and Alexion Pharmaceuticals (#100288). The funders were not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.