Comparable Outcomes of First-Line Hematopoietic Stem Cell Transplantation from Unrelated and Matched Sibling Donors in Adult Patients with Aplastic Anemia: A Retrospective Single-Center Study

ABSTRACT To explore the feasibility of upfront unrelated donor (URD) hematopoietic stem cell transplantation (HSCT) in the treatment of adult aplastic anemia (AA), we conducted a retrospective, single-center study and compared the outcomes of adult patients who underwent first-line URD HSCT or matched sibling donor (MSD) HSCT between August 2012 and June 2018. In all, 23 URD HSCT recipients had an increased cumulative incidence of grade II acute graft-versus-host disease (aGVHD) (21.7% versus 3.4%; P =.007), but similar rates of secondary graft failure (8.7 ± 6.0% versus 6.9 ± 3.4%; P  = .764), chronic GVHD (cGVHD) (18.2% versus 8.8%; P  = .285), extensive cGVHD (9.1% versus 3.5%; P  = .328), 5-year estimated overall survival (87.0% versus 94.2%; P  = .501), and 5-year estimated failure-free survival (82.0% versus 89.3%; P  = .404) compared with 58 MSD HSCT recipients treated during the same period. After using propensity score matching to reduce the influence of potential confounders, the 2 groups were well balanced in terms of pretransplantation clinical factors. The median survival time was similar, and no significant differences in the aforementioned outcomes were observed between the 2 groups. Our results suggest that URD HSCT may be an effective and feasible option for first-line therapy in adult AA patients who lack an MSD.