The impact of partial T cell depletion on overall transplant-related toxicity, graft function and survival after HLA-identical allogeneic bone marrowtransplantation in standard risk adult patients with leukemia

In this single-center study, a consecutive cohort of 59 adult patients tran splanted with HLA-identical bone marrow and receiving graft-versus-host dis ease (GVHD) prophylaxis with either standard cyclosporine/methotrexate (n = 33) or partial T cell depletion (E-rosetting) (TCD, n = 26 were analyzed). Only patients with chronic myeloid leukemia in first chronic phase or acut e leukemia/myelodysplasia in first or second remission were included. Excep t for age (median 28 vs 42 years), both groups were comparable in terms of diagnosis, conditioning regimen and growth factor support. TCD significantl y reduced >grade II acute GVHD (0 vs 24%, P = 0.02), chronic GVHD (8.5 vs 4 5%, P = 0.007) and other major bone marrow transplant (BMT)-related complic ations (4 vs 36%, P = 0.005). TCD decreased overall transplant-related mort ality (11.5 vs 36%, P = 0.04). In the TCD group faster neutrophil (13 vs 22 days, P = 0.02) and platelet recoveries (18 vs 26 days, P < 0.001) were no ted. The relapse risk was higher after TCD (57.5 vs 211.5%, P = 0.04). Over all survival probability at 10 years was identical in both groups (54 vs 53 .5%, P = 0.33). We found a relationship between the number of T cells in th e graft and the occurrence of major complications (P < 0.001) and relapse ( P = 0.03). This comparative analysis shows that graft-derived T cells have a major role in overall BMT-related toxicity and that partial TCD is an acc eptable approach in terms of survival for patients between 40 and 50 years of age.