HUMAN AORTIC-VALVE ALLOGRAFTS ELICIT A DONOR-SPECIFIC IMMUNE-RESPONSE

Objective: The nature and magnitude of the immunologic response to imp lantation of human cryopreserved aortic valve allografts was investiga ted. Methods: Twenty aortic valve allograft recipients were investigat ed for donor-specific antibody and T-cell-mediated responses with seri al how cytometric and microlymphocytotoxic crossmatch assays and one-w ay mixed lymphocyte cultures. Results: Donor-specific immunoglobulin G antibodies to class I and II human leukocyte antigens were first dete cted in the serum of ail aortic valve allograft recipients at 30 days after implantation and persisted in substantial amounts in all but one of the recipients at day 365. Recipient T-cell alloreactivity toward donor lymphocytes was significantly increased at day 30 compared with levels before and 10 days after operation, Conclusions: Cryopreserved aortic valve allografts elicit a substantial allogeneic response in re cipients, This alloreactivity may contribute to the observed morpholog ic changes in aortic valve allografts and eventual long-term deteriora tion of allograft function.