The influence on pretransplant blood transfusions from random donors on immune parameters affecting cadaveric allograft survival

The number of pretransplant blood transfusions (BT) from random donors influences the recipient’s immune response status and suppressor cell number and function, as well as allograft survival. The 54% one-year survival rate for 104 cadaveric renal allograft recipients treated with azathioprine and prednisone was divisible into two groups: 74.5% in 51 patients receiving >5 BT and 34% for 53 patients with <5 BT (P < 0.02). Transfusions enhanced the benefit of HLA A, B, and DR compatibility on graft survival: 33 recipients of well-matched grafts (<2 A, B, and 0–1 DR mismatches) had a one-year survival rate of 94% when pretreated with >5 BT, compared with 38% when receiving <5 BT (P < 0.05). The graft survival of 73% (36/49) displayed by patients determined preoperatively to be weak immune responders was significantly better than the 36% survival (20/55) demonstrated by strong immune responders (P < 0.01). The transfusion history correlated with immune responder status: 76% (39/51) of patients receiving >5 BT were weak immune responders, whereas 81% (43/53) of patients receiving <5 BT were strong immune responders (P < 0.001). Ninety-two percent (12/13) of patients with >5 BT, but only 58% (10/17) of patients with <5 BT, had a normal number of OKT8⁺ T suppressor cells. Only 1 × 10⁵ mononuclear cells from patients with >5 BT rather than 4 × 10⁵ cells from patients with <5 BT caused 50% suppression of a third-party MLC. Thus, patients receiving >5 BT are more likely to display weak immune responses, normal numbers of OKT8 cells, strong suppressor function in vitro, and prolonged allograft survival.