Pretreatment of renal allograft recipients with azathioprine and donor-specific blood products.

Improvement of renal allograft survival by induction of immunologic unresponsiveness was attempted in 24 patients by the pretransplant administration of donor-specific whole blood or buffy coat under continuous azathioprine immunosuppression. All patients and their donors had one or two disparate HLA haplotypes. Crossmatch (CM) testing (22 degrees C) for T cells (Amos and antiglobulin enhanced) and B cells identified sensitization in two patients (8%). One developed a low titer (1:2) positive B-cell CM, which did not preclude successful transplantation. The second, with a preexisting high titer (1:16) positive B-cell CM, developed a low titer (1:1) T-cell antiglobulin CM and had hyperacute graft rejection. Twenty-one recipients received kidneys from their blood donors. Except for one patient who had hyperacute rejection (across positive T-cell CM), none have rejected their kidneys. Three patients died at 2, 13, and 23 months, respectively, with good renal function. Seventeen patients are alive at 3 months to 10 years with a mean serum creatinine concentration of 1.3 +/- 0.4 mg/dl. Donor-specific transfusion with immunosuppressive coverage improves renal allograft survival without significant sensitization.