Suppressed antidonor MLC responses in renal transplant candidates conditioned with donor-specific transfusions that carry the recipient's noninherited maternal HLA haplotype.

Forty-seven patients with end-stage renal disease were entered into a donor-specific transfusion protocol consisting of three infusions of whole blood every two weeks prior to transplantation. Fourteen of the patients became sensitized following transfusion and were not transplanted. Thirty-one patients received a transplant from the DST donor and have an estimated two-year graft survival of 97%, three-year survival of 88%, and four-year survival of 69%. Cells of eleven of the 36 recipients tested in one-way MLC before and two weeks after completion of DST exhibited a significantly decreased antidonor MLC response. Deletion of CD8+ positive lymphocytes from suppressed MLCs resulted in restoration of antidonor MLC reactivity in four of six patients. An analysis of the family HLA profile in patients exhibiting a decreased donor-directed MLC response revealed a significant (P less than 0.02) association between decreased MLC reactivity following DST and the expression of noninherited maternal HLA antigens by cells of the transfusion donor. These alterations in cellular immune responses noted in some patients following DST are consistent with the appearance of specific antidonor T suppressor cells as a result of donor-specific transfusion.