Consistencies and controversies in the application of the International Society for Heart and Lung Transplantation working formulation for heart transplant biopsy specimens. Rapamycin Cardiac Rejection Treatment Trial Pathologists.

Abstract

First, there was agreement among the trial pathologists and the index diagnosis (excluding minor discrepancies) in 85% of biopsy specimen interpretations. Second, of 53 major discrepancies, 43 (81%) involved grades 1A/B versus 2, 2 versus 3A, and Quilty B versus 2/3A. Third, in 54% of instances in which biopsy findings other than rejection were misdiagnosed as rejection grades, the grade was sufficiently high to have adverse treatment implications. Fourth, the ISHLT working formulation provides for a high degree of diagnostic consistency among experienced observers, and concordance could be further enhanced by clarification of criteria for grade 2 rejection and Quilty B lesions.