Allogeneic hematopoietic stem cell transplantation for acquired severe aplastic anemia: a summary of a 20-year experience

INTRODUCTION Severe aplastic anemia (SAA) is a rare but potentially fatal disorder characterized by hypocellular bone marrow and resulting in pancytopenia. It can be cured with allogeneic hematopoietic stem cell transplantation (allo -HSCT), especially in young individuals. OBJECTIVES The main objective of the study was to assess the safety of the procedure and to identify the factors influencing long -term post -transplant outcome. PATIENTS AND METHODS Using our institutional database, we performed a retrospective analysis of the patients with SAA allotransplanted in the years 2001-2021. RESULTS Seventy patients (49 men) at a median age of 25 years at transplantation underwent allo -HSCT. Thirty-eight patients received immunosuppressive treatment (IST) before transplantation. Twenty-one patients received grafts from human leukocyte antigen-matched sibling, 44 from unrelated donors, and 5 from haploidentical related donors. Peripheral blood remained the source of stem cells in the majority of patients. Primary graft failure was observed in 2 cases. The incidence of acute graft -versus -host disease (GVHD) was 44%, whereas chronic GVHD was observed only in 4 patients. Median follow -up was 3 years (interquartile range, 0.45-11.5). Post -transplant outcome was comparable between patients with upfront allo -HSCT and those who relapsed after IST. In the univariable analysis, only a higher Eastern Cooperative Oncology Group (ECOG) score at transplantation and infections in the post -transplant period were found to be associated with unfavorable outcome. Fifty -three patients were alive at last contact. Most transplanted patients died due to infectious complications. A 2 -year overall survival was 73%. CONCLUSIONS The results of allo -HSCT in SAA are satisfactory and offer long -term survival and good quality of life. Higher ECOG score and the presence of infections are associated with poor post -transplant outcome.