Long-term outcome of a Phase II study of BM transplants, partially depleted ex-vivo of CD5-positive and CD8-positive T-lymphocytes in unrelated and related donor 1 antigen mismatched recipients

Background Mismatched family donor and unrelated donor BM transplants are a ssociated with a high risk of acute GvHD. While T-cell depletion is the bes t method to reduce risk of acute GvHD, there was a reluctance to use T-cell depletion in the mismatched setting because of increased risk of rejection and relapse. Partial T-cell depletion, Ly the panning of CD5 and CD8 posit ive T cells may reduce complications related to GvHD without compromising o utcomes. Method In a long-term follow-up of a Phase II study of partial T-cell deple tion by panning for BM transplant, 32 recipients received transplants from a single-Ag (HLA A, B, or DR) mismatched family donor; or an HLA serologica lly-matched unrelated donor. Patients were studied for engraftment, GVHD, r elapse and survival. Results 30 (94%) of the patients marrow iu engrafted. The cumulative risk o f Grade 2-4 acute GVHD was 62 +/- 9%; of Grade 3-4 GvHD, 11 +/- 6%. The 4-y ear cumulative risk of relapse was 18 +/- 8% and actuarial survival was 44 +/- 9%. Discussion without compromising engraftment or relapse risk.