Pretransplant blood transfusions can harm matched kidneys in dogs.

The effect of pretransplant blood transfusion (PBT) and histocompatibility matching on kidney allograft survival was studied in immunosuppressed dogs. PBT was found to be beneficial for related and unrelated mismatched kidney grafts. In contrast, after withdrawal of the immunosuppressants, transfused recipients of related and unrelated matched grafts rejected the kidney significantly more often than non-transfused dogs. Crossimmunisation for minor histocompatibility antigens may be responsible for this adverse effect, but could not be demonstrated in vitro by serology or mixed lymphocyte reactions. The possible deleterious effect of PBT in this model argues against the routine use of pretransplant blood transfusions in man.