LACK OF ALLOIMMUNIZATION TO D-ANTIGEN IN D-NEGATIVE IMMUNOSUPPRESSED LIVER-TRANSPLANT RECIPIENTS

Background: Orthotopic liver transplantation (OLT) sometimes requires large amounts of blood. An adequate supply of Rh-negative blood for Rh-negative patients is not always available. Study Design and Methods: Seventeen Rh-negative patients, out of 327 receiving OLT In this hospital, received from 5 to 41 units of Rh-positive red cells during surgery. Each of the 17 patients was followed for 7 weeks to 70 months after OLT for detection of unexpected antibodies. Cyclosporin A and prednisone azathioprine and adjunctive rabbit antilymphocyte globulin or monoclonal OKT3 antibody were used to prevent graft rejection. Results: Evidence of immunization, either to D or to antigens in the rest of the red cell antigen systems, did not appear in any patients. Conclusion: It is hypothesized that cyclosporin A affects the immune humoral response, inhibiting lymphocyte activation and the primary immune response; consequently, Rh-positive blood may be transfused to Rh-negative OLT recipients so treated with little or no risk of alloimmunization.