Effects of transfusion on recipient immune status: relationship to transplantation.

Blood transfusion therapy confers an immunosuppressive effect on organ transplant recipients. The nonspecific immunosuppressive effect of third-party transfusions is useful for CAD transplantation, while donor transfusions improve the outcome of LRD grafts. Although there is evidence that erythrocytes, modified lymphocytes and/or platelets mediate some effects, the optimal blood product is unknown. Similarly, the mechanism of the effect, be it related to induction of a suppressive immune response, prophylaxis against CMV, active viral infection or a side effect of blood such as iron overload, remains an important issue for investigation. Dissection of the immunosuppressive effect of transfusions may afford insights into host resistance to allografts and new methods to achieve transplantation tolerance.