Background: Pretransplant blood transfusions are reported to decrease acute rejection rate and increase graft survival after renal transplantation. This has been attributed to matching for HLA-DR with the transfusion donor, which also results in a lower rate of sensitization.
Methods: The development of donor-specific T- and B-cell antibodies was measured by National Institutes of Health and two-color fluorescence assays after one transfusion in 247 naive patients. Auto-cross-matches were performed to exclude autoantibodies. Patients were grouped according to DR-matching (n=107) or nonmatching (n=140) with the transfusion donor. In 103 renal allograft recipients, acute rejection rate and graft survival were analyzed by Cox regression.
Results: T-cell antibodies developed in 6.5% of the patients. There was no difference between the DR-matched and nonmatched group. No auto-antibodies against T-cells developed, whereas one quarter of the sera had a positive B-cell auto-cross-match. There was no difference with regard to B-cell antibodies (auto-antibody-positive sera excluded) between the DR-matched (15.8%) and nonmatched (18.6%) group. Sharing of HLA A and/or B antigens did not result in a lower frequency of donor-directed T- or B-cell antibodies. None of the risk factors, including DR sharing with transfusion donor, contributed significantly towards graft survival (odds ratio for DR sharing: 1.02; 95% confidence interval: 0.45-2.32; P=0.97). DR sharing was no risk factor towards acute rejection either, in contrast to DR mismatch with kidney donor (odds ratio: 2.9), and use of cyclosporine versus tacrolimus (odds ratio: 4.4).
Conclusions: Development of donor-directed T-cell antibodies after one transfusion of leukocyte-poor blood is low and irrespective of HLA-DR match with transfusion donor. B-cell antibodies develop more frequently and independent of HLA-DR match. In 26% of the sera, B-cell auto-antibodies are detected. Rejection rate and graft survival are not significantly different between HLA-DR-matched and nonmatched transfusions.