Efficacy and Prognostic Factors of Nonmyeloablative Allogeneic Hematopoietic Stem Cell Transplantation for Patients with Acute Myeloid Leukemia

Abstract

To retrospectively analyze the efficacy and complications of our institution's modified nonmyeloablative allogeneic hematopoietic stem cell transplantation (NST) in treating intermediate-risk acute myeloid leukemia (AML) - first complete remission (CR1) and prognostic factors. Clinical data of 50 intermediate-risk AML-CR1 patients who underwent matched related NST at the Fifth Medical Center of Chinese People's Liberation Army General Hospital from August 2004 to April 2021 were collected, the hematopoietic recovery, donor engraftment and complications were observed, and overall survival (OS) rate, leukemia-free survival (LFS) rate, treatment-related mortality (TRM), and cumulative relapse rate were calculated. Statistical analysis of factors affecting prognosis was also preformed. The median times for neutrophil and platelet recovery after transplantation were 10 (6-16) and 13 (6-33) days, respectively. One month after transplantation, 22 patients (44%) achieved full donor chimerism (FDC), and 22 patients (44%) achieved mixed chimerism (MC), among whom 18 cases gradually transited to FDC during 1-11 months, 4 cases maintained MC status. The overall incidence of acute graft-versus-host disease (aGVHD) was 36%, with a rate of 18% for grade II-IV aGVHD and a median onset time of 45 (20-70) days after transplantation. The overall incidence of chronic GVHD (cGVHD) was 34%, with 20% and 14% of patients having limited or extensive cGVHD, respectively. The incidence rates of infections, interstitial pneumonia, and hemorrhagic cystitis were 30%, 10%, and 16%, respectively. The 5-year OS rate, LFS rate, TRM, and cumulative relapse rate were 68%, 64%, 16%, and 20%, respectively. The increase of the number of CD34+ cells infused had shortened the recovery time for neutrophils and platelets (r =0.563, r =0.350). The number of CD34+ cells infused significantly influenced the occurrence of extensive cGVHD (OR =1.36, 95%CI : 1.06-1.84, P =0.024). Modified NST is effective in treating intermediate-risk AML-CR1 patients, however, further expansion of sample size is needed to study prognostic factors.