Preoperative immunomodulation of renal allograft recipients by concomitant immunosuppression and donor-specific transfusions.

The induction of immunologic unresponsiveness to improve renal allograft survival was attempted in 113 patients by the pretransplant administration of donor-specific whole blood or buffy coat in conjunction with continuous Aza immunosuppression. All donor/recipient combinations were at least 1-haplotype disparate and 17 were 2-haplotype disparate. Presensitization, defined as a positive Amos or antiglobulin T cell CM or a positive high-titer (greater than or equal to 1:8) B cell CM was present in 10 patients and not present in 103 patients. Attempts at desensitization of the already sensitized group were uniformly unsuccessful. Treatment of the 103 nonpresensitized patients resulted in transient sensitization in 3 patients, permanent sensitization in 8, and no evidence of sensitization in 92. Ninety-one nonsensitized patients underwent renal transplantation from the specific blood donor, and only 5 have experienced renal allograft rejection loss during a mean follow-up period of 26 months (6 to 70 months). Fifty-four percent have never experienced a rejection episode. The allograft survival rate at 2 years (91%) and 5 years (89%) is significantly better (P less than .01) than our historical experience with 1-haplotype living-related transplants at 2 years (66%) and 5 years (64%). The low rate of sensitization (8%) has permitted almost all patients to undergo eventual renal transplantation from the specific blood donor. This and the low rate of rejection (5%) argues for a modification of the immunologic response rather than a selecting out process as the mechanism for improved allograft survival.