The role of HLA-specific antibodies in kidney transplant rejection: published studies and local data.

The post-transplantation production of antibodies directed against donor HLA class I and class II mismatches has been shown to be associated with transplant rejection. Recipient sensitization against donor HLA plays a key role in transplant rejection; this risk is best minimized by efficient pre-transplant antibody detection and definition, effective pre-allocation cross-matching, and minimization of HLA mismatches between donor and recipient. The term "PRA" is of little value. Identification of the HLA specificity to which an antibody is directed is essential and now possible using contemporary methodology. It is now recognized that antibody-mediated rejection should be diagnosed on the basis of allograft dysfunction, characteristic features of histology, C4d immunohistology, and the presence of donor-specific antibodies. HLA-DP is becoming recognized as a "transplantation antigen." For the future, the repertoire of a histocompatibility laboratory must expand to include typing organ transplant recipients and donors for HLA-DP and also the definition of antibodies to DP. Antibodies to non-HLA targets should be an important consideration when assessing factors that influence transplant outcome.