Umbilical Cord Blood Transplantation without Antithymocyte Globulin Results in Similar Survival but Better Quality of Life Compared with Unrelated Peripheral Blood Stem Cell Transplantation for the Treatment of Acute Leukemia-A Retrospective Study in China

Although previous studies have demonstrated improved outcomes in umbilical cord blood transplantation (UCBT) by omitting antithymocyte globulin (ATG) in the conditioning regimen, this approach has not been comparatively studied in unrelated peripheral blood stem cell transplantation (UPBSCT). To compare the risks and benefits between UCBT without ATG and UPBSCT in patients with acute leukemia (AL), we conducted a multicenter retrospective study of 79 patients who underwent UCBT (myeloablative conditioning without ATG) and 96 patients who underwent UPBSCT (myeloablative conditioning with ATG). The outcomes were graft failure, neutrophil engraftment, platelet engraftment, acute graft-versus-host disease (aGVHD), chronic graft versus -host disease (cGVHD), transplantation-related mortality (TRM), relapse, overall survival (OS), and leukemia free survival (LFS). Follow-up was censored on October 31, 2016. Engraftment was similar between the 2 groups but granulocyte and platelet recovery were slower in the UCBT group (both P<.001). The incidences of aGVHD, TRM, OS, and LFS were similar between the 2 groups (all P>.05). Without ATG, the UCBT group displayed less cGVHD and less moderate and severe cGVHD (P<.001 and P=.004). The incidences of Epstein-Barr virus viremia and post-transplantation lymphoproliferative disease were significantly lower in the UCBT group (P<.001 and P=.037). UCBT recipients had higher activity Karnofsky performance scores and 3-year GVHD-free/relapse-free survival than the UPBSCT group (P=.03 and P=.04). We observed similar survival when comparing UCBT without ATG and UPBSCT, but we also observed better quality of life in patients undergoing UCBT without ATG. We can therefore conclude that patients with primary AL for whom an appropriate HLA-matched sibling donor is not available could select either UCBT or UPBSCT. (C) 2017 American Society for Blood and Marrow Transplantation.