Attempts to ameliorate transfusion-induced sensitization to heart grafts by additional multiple blood transfusions

Pretreatment with donor-specific blood transfusions (DSTs) can be a very effective method to improve organ graft acceptance. DSTs involve the risk of sensitization, however. Both phenomena, that is, prolonged acceptance and sensitization, can be evoked in rats using different donor-host combinations. In the BN to WAG model, a single DST invariably leads to prolonged organ graft survival whereas, in the reverse combination, a single pretransplant DST gives rise to accelerated rejection. A biological approach that may possibly reduce the degree of transfusion-induced sensitization is administration of additional multiple transfusions. This approach is based on the clinical finding that patients sensitized by blood transfusions show a decrease or loss in antibody reactivity following additional transfusions and may exhibit a favorable graft outcome. The WAG to BN model was used to investigate whether in this clear-cut model of accelerated rejection multiple blood transfusions could ameliorate the sensitizing effect of a single transfusion.