Impact of transfusions and acute rejection on posttransplantation donor antigen-specific responses in two study populations

Background. We participated in a protocol supported by the National Institu tes of Allergy and Infectious Disease, Cooperative Clinical Trial Transplan tation (CCTT), which was designed to investigate: the effect of peritranspl ant donor-specific transfusion in non-HLA-identical living donor kidney rec ipients. Methods We determined the donor antigen-specific responses at 1 year after transplantation for the 79 CCTT donor-recipient combinations in this study. A lower rate of donor antigen-specific hyporeactivity was seen in the CCTT recipients (6 of 79=8%) versus our recipients at the University of Minneso ta who underwent transplantation in the same period (9 of 55=16%,. P=0.16) and versus our combined historical data (33 of 131=25%, P=0.002), Therefore , we studied the differences in the two recipient populations to determine why hyporeactivity was lower in the CCTT group than at our center. Results. Significant differences were seen in the acute rejection rates and the frequency of pretransplantation random transfusion. Overall and early (<3 month) acute rejection rates were higher in CCTT versus Minnesota recip ients (overall: 51% vs. 20%, P=0.001) (early: 43% vs. 16%, P=0.001). The fr equency of pretransplantation random transfusion was 40% for CCTT recipient s (34%) versus 80% for Minnesota recipients (75%) (P=0.0004). Conclusions. These results provide provocative, although not conclusive, ev idence for the importance of pretransplantation transfusion and acute rejec tion episodes in the development of donor antigen-specific hyporeactivity, Pre-, peri-, and posttransplantation clinical events undoubtedly have an im pact on posttransplantation immune parameters.