Sensitization.

1. Sensitization increases the time waiting for a transplant. In Southern California, more than half the patients waiting more than 3 years are broadly sensitized. 2. First transplants in patients with greater than 50% PRA had 8% lower 1-year graft survival and retransplants in patients with greater than 10% PRA had 5-10% lower 1-year graft survival rates than nonsensitized patients respectively. 3. In sensitized recipients, 5-8% of kidneys that do not function in the early posttransplant period may be due to unrecognized antibody reactive to the donor. 4. The greatest risk of antibody-associated graft loss is in the first 2 weeks posttransplant. Some losses may be due to unrecognized hyperacute rejection though cellular rejection and other complications may be missed in the patient with a nonfunctioning graft. 5. Giving small numbers of blood transfusions reduces the risk of sensitization for never transplanted patients without significant loss of the beneficial transfusion effect. Transfusions following a graft loss should be avoided as they confer no benefit and significantly increase the likelihood of sensitization. 6. The effect of HLA matching on graft survival in sensitized and nonsensitized patients was the same. Matching for HLA-A and B antigens is influenced by sensitization through selection at the crossmatch. 7. More sensitive crossmatch tests should be carefully evaluated so that the price of improving early function and decreasing early graft loss is not condemning an excess of patients to a lifetime of dialysis.