The influence of ultraviolet irradiation on the blood transfusion effect

Reports of improved survival of allografts in recipients of donor-specific blood prompted an attempt to determine the relationship of the antigenic composition of the blood product transfused to the development of immunologic unresponsiveness in rats. Cardiac allografts were transplanted from Fischer, Brown-Norway (BN), and Lewis (L) X BN (LBN) f1 hybrids to recipients treated with three weekly transfusions of 1 ml of donor-specific whole blood, erythrocytes, or ultraviolet-irradiated whole blood. Despite moderate improvement in survival with whole blood alone in the LBN- greater than L group (11.6 +/- 1.0 days), it was only with the ultraviolet-irradiated whole blood that marked prolongation was seen in all three strain combinations: Fischer- greater than L: 25.5 +/- 5.2, LBN- greater than L: 17.3 +/- 1.2, and BN- greater than L: 11.1 +/- 0.4 days compared with respective controls: 10.3 +/- 1.2, 7.3 +/- 0.5, and 7.4 +/- 0.6 days. Unlike reports for renal allografts, erythrocyte suspensions provided minimal protection for the cardiac allografts (14.2 +/- 0.8, 9.0 +/- 1.1, and 11.0 +/- 0.4 days, respectively), and adjunctive treatment with antilymphocyte serum had a similar small effect (16.3 +/- 1.4, 13.4 +/- 1.9, and 8.3 +/- 0.8 days, respectively). The elimination or inactivation of functional class 2 major histocompatibility complex antigens from the blood used for donor-specific blood transfusion may be an effective means of prolonging allograft survivals over those seen with whole blood alone; however, the degree of resultant unresponsiveness is still clearly influenced by dosage schedule, the organ transplanted, histocompatibility barrier, and adjunctive immunosuppression.