Partially Matched Related Hematopoietic Stem Cell Transplantation without Ex Vivo T Cell Depletion Compared with Matched Unrelated Transplantation in Adult Patients with Hematologic Malignancies

The optimal alternative donor for adult hematopoietic stem cell transplantation (HSCT) candidates who lack an ideal histocompatible sibling remains controversial. We studied the clinical outcomes of 88 adult patients with hematologic malignancies who received a partially matched related donor (PMRD) transplant (n = 36) or a matched unrelated donor (MUD) transplant (n = 52) with a uniform myeloablative protocol without ex vivo T cell depletion. Age and other characteristics were comparable in the 2 groups, except that the PMRD group had a higher proportion of bone marrow (BM) grafts. Primary engraftment was achieved in nearly 98% of the whole cohort. The incidences of acute grade III-IV and extensive chronic graft-versus-host disease (aGVHD, cGVHD) were 15% and 16% in the PMRD group and 16% and 14% in the MUD group. Although treatment-related mortality (TRM) was 42% in the PMRD group and 31% in the MUD group (P = .29), the relapse rate was < 11% for the whole cohort. With a median follow-up of 30 months, no statistically significant difference was observed in 3-year overall survival (OS) and event-free survival (EFS) between the PMRD group (45% and 38%) and the MUD group (54% and 50%). These data demonstrate that HSCT performed with PMRD can be an alternative option for treating adult patients with hematologic malignancies.