Sensitization in renal transplantation

Abstract

1. The 1-year graft survival rate for 2,615 broadly sensitized patients of first cadaver-donor transplants between 1985 and 1990 was 72%, 7% lower than 15,615 nonsensitized patients and 6% lower than 4,824 moderately sensitized patients. For retransplants, 1,752 broadly sensitized patients had 61% 1-year graft survival rates, 12% lower than 1,299 nonsensitized patients and 8% lower than 1,104 moderately sensitized patients. 2. Rejection of a previous transplant, pretransplant blood transfusions, sex, and a history of pregnancies were the dominant causes of sensitization. 3. The percentage of nontransfused recipients of first cadaver transplants has increased yearly from 10% in 1985 to more than 40% in 1990 in both the UCLA and UNOS Registries. Over the same period, the percentage of broadly sensitized recipients has declined from 15% to 8%. 4. The beneficial effect of pretransplant transfusions (a 4% improvement at 1 year) was limited in first transplants to males and nonsensitized females. No difference in survival rates of sensitized patients comparing transfused and nontransfused was observed. Patients retransplanted without ever being transfused had very poor outcomes. 5. Delayed graft function (DGF) occurred in approximately 20% of nonsensitized, 28% of moderately (1-50% peak PRA), and 37% of broadly sensitized first transplant recipients. Among retransplanted patients, 28% of nonsensitized, 37% of moderately, and 48% of broadly sensitized patients had DGF. 6. HLA-A,B, and DR matching overcame the deleterious effect of sensitization on graft survival. Sensitization had no effect on the outcome of transplants from HLA-identical siblings, but survival decreased by 7-10% in sensitized recipients of mismatched transplants from relatives. Sensitized first cadaver transplant recipients matched for HLA-A,B, or HLA-DR antigens had 1-year survival rates comparable to those of mismatched nonsensitized recipients. 7. First transplant recipients who were nonsensitized using their current serum but had been broadly sensitized in an historical sample had 73% 1-year graft survival, the same as that of patients who were broadly sensitized in their current serum and 6% less than patients who were never sensitized (p less than 0.001). 8. Assuming a random distribution of sensitized patients at UNOS transplant centers using different methods to measure preformed antibody, the antihuman globulin (AHG) method was more sensitive than the NIH or 1-Wash tests. With AHG, 31% of first and 58% of retransplanted patients were broadly sensitized, whereas with the NIH and 1-Wash methods, the corresponding figures were 18-21% and 41-44%.(ABSTRACT TRUNCATED AT 400 WORDS)