The influence of HLA and ABO antigens on graft rejection and survival.

The major histocompatibility complex (MHC) initially was identified by its strong association with the outcome of transplanted tissues. As in other species, disparity for MHC antigens in humans (especially HLA-A, B, DR) is a good predictor of allograft rejection. Although new immunosuppressive agents have improved graft survival in clinical transplantation, they have not obviated the benefits of avoiding mismatched HLA antigens or incompatible ABO blood group antigens. This article examines the role of HLA and ABO antigens in graft rejection from the perspective of both immunologic mechanisms and clinical outcome.