Effects of blood transfusions given after renal transplantation.

BACKGROUND: Human leukocyte antigen (HLA) antibodies produced after transplantation are frequently measured in transplant recipients, because they are strongly associated with humoral rejection and graft loss. However, antibodies can be induced by posttransplant blood transfusions rather than by the graft, casting doubts about the possible role of antibodies in a patient with graft dysfunction.
METHODS: We recorded the posttransplant transfusions in 746 patients transplanted during a 6-year period. Rejection episodes were evaluated after exclusion of patients who were transfused proximate to the time of rejection. Specimens for solid-phase HLA antibody testing were available in 199 patients.
RESULTS: The frequency of transfusions was 45%, but it was higher in deceased donor transplants (51%) than in live donor transplants (30%). Almost 80% of the transfusions were given during the first month after transplant. However, the incidence of posttransplant antibodies was similar in patients transfused and not transfused, and only 1 of 12 patients who received more than 10 transfusions produced antibodies. There was no evidence that posttransplant antibodies not directed to donor antigens were triggered by transfusions. The incidence of rejection episodes, allograft nephropathy, and graft loss was slightly more in transfused patients but the differences were not statistically significant.
CONCLUSIONS: When HLA antibodies are detected posttransplant, they are likely induced by the graft rather than by any transfusions the patient may have received. The results suggest that posttransplant transfusions do not have the sensitizing or down-regulatory effects of pretransplant transfusions.