Possible mechanism of action of transfusion effect in renal transplantation.

The mechanism by which blood transfusions given before renal transplantation improves allograft survival was studied in 31 transplant recipients. The presence of non-cytotoxic, Fc receptor blocking antibodies to donor and leukaemic B lymphocytes in pre-transplant sera correlated with both improved graft survival (p less than 0.03 and less than 0.1, respectively) and the number of blood transfusions given (p less than 0.05 and less than 0.03, respectively). Moreover, 6 out of 10 previously untransfused prospective transplant recipients developed these potentially protective antibodies during a course of elective blood transfusions. These results indicate that such non-cytotoxic, Fc receptor blocking antibodies in pretransplant recipient sera (a) are associated with improved allograft survival, (b) correlate with the number of blood transfusions given, and (c) can develop in response to blood transfusion.