DONORSPECIFIC CYTOTOXIC T LYMPHOCYTE HYPORESPONSIVENESS FOLLOWING RENAL TRANSPLANTATION IN PATIENTS PRETREATED WITH DONORSPECIFIC TRANSFUSIONS

Our purpose was to investigate the mechanism of the continuing beneficial effect of donor-specific transfusions in the cyclosporine era. We describe the development of donor-specific cytotoxic T lymphocyte hypore-sponsiveness in peripheral blood lymphocytes obtained up to 2 years posttransplant in patients preconditioned with 3 DST plus azathioprine. In a group of 12 such patients, hyporesponsiveness developed gradually, becoming detectable in some patients as early as 1 month posttransplant and becoming statistically significant for the entire group at 9–12 months posttransplant. A complete specificity for donor alloantigens was seen in the hyporesponsiveness of some patients; in others, partial suppression of the response to a third party HLA-mismatched control was also seen. Although slight suppression of the mixed lymphocyte culture response was seen in some patients, overall there were no statistically significant differences in MLC responses to control or donor stimulators at any time point posttransplant as compared with pretransplant, pre-DST.