Blood transfusion in renal transplantation--the induction of tolerance by incompatibility for class I antigen.

Blood transfusion given before renal transplantation has been shown to have a powerful immune modulating effect on recipient response to kidney allograft. The mechanism responsible for this effect is still unknown. Here it is assumed that, due to incompatibility for HLA-A related class I antigens between blood donor and recipient, pretransplant blood transfusion may allospecifically induce in the recipient the generation of T cells that have a suppressive effect on T lymphocyte response to incompatible HLA class II antigens present on kidney allograft. Although in many respects this interpretation is still speculative, it is in accord with findings reported from clinical and experimental studies of the effect on graft survival of blood transfusion, both random and donor specific.