Transplantation antigens on renal endothelium

This study provides evidence that both MHC and E-M antigens are accessible on the surface of the renal endothelium in vivo. Analysis of antibodies eluted from rejected renal allografts revealed that the most frequent single antibody specificity in these eluates are E-M-directed antibodies, followed by B-cell antibodies and T-cell antibodies, respectively. Analysis of the factors that predispose to E-M antibody formation showed that all patients who form E-M antibodies in association with irreversible rejection of a first renal allograft are HLA-DRw6-positive individuals. Furthermore, most patients who formed E-M antibodies in association with irreversible rejection of a second or third kidney appeared to be patients who never received a blood transfusion prior to their first graft. Further analysis of the allo-antigenic profile of the renal endothelium as well as of the factors that influence the immune responsiveness against these antigens will lead to a better understanding of the rejection reactions and may ultimately provide the tools to increase allograft survival.