The transfusion effect.

1. There was a "transfusion effect" for cadaver kidney transplant recipients and the improvement of 1-year graft survival with transfusions was 7.1% (p0.0002) in 1987. 2. Two or 3 pretransplant transfusions are sufficient to obtain the maximum transfusion effect. 3. In 1988, about a quarter of the patients received first cadaver kidney transplants without any pretransplant transfusions, whereas only 10% were nontransfused during the period between 1981 and 1984. 4. The transfusion effect diminished as patients aged. The increase in 1-year graft survival with transfusions was 17% in patients aged 16-25, 4% in patients aged 46-55, and 1% in patients over 55. 5. Both transfused and nontransfused patients had as high as 83% 1-year graft survival rates when they received 0 A, B, DR-mismatched kidneys. Transfusions improved graft survival by as much as 8% for recipients with mismatched grafts. 6. There was no transfusion effect in recipients of 0 DR-mismatched kidney transplants. Transfusions improved the 1-year graft survival rate by 8-10% for transplant recipients with 1 or 2 DR-mismatched kidneys. 7. The transfusion effect was greater in black (8%) than white (4%) recipients; however, the 77% 1-year graft survival rate for transfused black recipients of 0 DR-mismatched kidneys did not differ from that of transfused whites. 8. Considering the transfusion effect on graft failure rather than graft survival, the failure rate in nontransfused patients could have been reduced by 30% in transplants performed between 1976 and 1979, 17% in transplants from 1980 through 1983, and 21% in transplants since 1984 with blood transfusions.