Similar outcomes of peripheral blood stem cells vs. bone marrow for human leukocyte antigen‐matched unrelated donor transplantation in adult patients with acute myeloid leukemia using risk‐adapted graft‐versus‐host disease prophylaxis

Abstract

In unrelated donor allogeneic stem cell transplantation (URD-SCT), most studies reported that peripheral blood stem cells (PBSC) resulted in higher incidence of acute and/or chronic graft-versus-host disease (GVHD) without survival benefits compared with bone marrow (BM). To overcome these shortcomings of PBSC, we have used a risk-adapted GVHD prophylaxis for patients that received HLA-matched URD-SCT, which was adding low-dose rabbit antithymocyte globulin (Thymoglobulin(®) , 1.25 mg/kg for 2 d) to conditioning in the transplants with PBSC and not BM. To determine whether this strategy is effective, we analyzed 115 adult patients with acute myeloid leukemia who received HLA-matched URD-SCT with PBSC (n = 70) or BM (n = 45) using our risk-adapted GVHD prophylaxis strategy. The PBSC group showed faster neutrophil (11 d vs. 13 d; P < 0.01) and platelet (12 d vs. 18 d; P < 0.01) engraftment compared with the BM group. No difference was observed in the incidence of acute GVHD grade II-IV at 100 d (54.3% vs. 64.4%; P = 0.38) and chronic GVHD at 4 yr (65.1% vs. 60.0%; P = 0.83). Other outcomes including the incidence of relapse (30.8% vs. 31.2%; P = 0.53), non-relapse mortality (13.5% vs. 6.9%; P = 0.24), disease-free survival (55.7% vs. 61.9%; P = 0.68), and overall survival (62.2% vs. 63.2%; P = 0.96) at 4 yr were not significantly different. Our risk-adapted GVHD prophylaxis strategy resulted in similar transplant outcomes including comparable incidence of GVHD between the PBSC and BM groups in HLA-matched URD-SCT.