Effects of a single donor-specific blood transfusion on the survival of rat cardiac allografts.

It is now well recognized that pre-transplant donor-specific blood transfusion (DST) has a beneficial effect on the survival of allografts. To determine the optimal interval between DST and transplantation, and to analyze the mechanisms of this effect, the survival of cardiac allografts to rats which received a single DST was examined. The cardiac allograft survival was found to be prolonged when the DST was performed 1 to 6 weeks before grafting. In addition, recipient rat sera collected 1 to 6 weeks after a single DST showed significant inhibition of a mixed lymphocyte reaction (MLR). This MLR inhibition correlated with prolongation of survival of histoincompatible rat cardiac allografts. It thus appears that a single DST given from 1 to 6 weeks before transplantation has a beneficial effect on allograft survival and that MLR inhibition may be essential for inducing the effect of transfusion on organ transplantation.