Acquired hemolytic anemia due to “auto”‐anti‐A or “auto”‐anti‐B induced by group O homograft in renal transplant recipients

Abstract
Three patients developed severe but self-limited hemolytic anemia within 2 wk of renal transplantation. All 3 had received kidneys from cadaver donors who were blood group O. Two of the recipients were blood group B while the 3rd was blood group A. There was no pretransplant preparation of the donors or the recipients. Preoperative crossmatch and antibody screen were negative; however, subsequent to the hemolytic episodes, group-specific blood was incompatible and the patients were transfused with group O crossmatch-compatible blood. Blood bank serological tests showed a positive direct antiglobulin test (DAT), and anti-A and ant-B were eluated from group A and B patients, respectively. There was no evidence of hemolysis despite the positive DAT at 37 days following transplantation in 2 of 3 patients who were maintained on cyclosporine immunosuppression. Retrospective analysis of renal transplant records showed that these autoantibodies appeared in 3 of 4 renal transplant recipients who were on an immunosuppressive regimen of cyclosporine, with or without prednisone, but not in the 21 recipients who received radiotherapy to the donor kidney in addition to cyclosporine or azathioprine (P = < 0.001). The possible pathogenetic mechanism for autoantibody formation by donor kidney and the role of immunosuppressive agents are discussed.