The transfusion effect is influenced by the nature of MHC antigen presentation.

We designed a study to determine whether the mode of presentation of major histocompatibility antigens is important for the ability of donor-specific blood transfusions to prolong organ allograft survival. Donor BN rat whole blood, isolated RBC, RBC ghosts, RBC membrane fragments, or whole blood lysates were administered to Lewis rat recipients 7 days before heterotopic allotransplantation of BN hearts. Only allogeneic whole blood or RBC significantly prolonged cardiac allograft survival in this histoincompatible donor-recipient pair. Whole blood lysates or RBC ghosts and membrane fragments transfused pretransplant did not prolong cardiac allograft survival when compared with syngeneic, transfused control rats. These results suggest that the immunosuppressive effects of donor-specific pretransplant blood transfusion may depend on a three-dimensional spatial relation between cells bearing donor major histocompatibility antigens and recipient responder cells responsible for the transfusion effect.