HLA-DR matched transfusions - Development of donor-specific T- and B-cell antibodies and renal allograft outcome

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 (autoantibody-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.