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

Abstract

Introduction: Severe aplastic anemia (SAA) is rare but potentially fatal disorder characterized by hypocellular bone marrow resulting in pancytopenia. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) can be curable especially for young individuals.

Objectives: The main objective of the study was to assess the safety of the procedure and identification of factors influencing long-term post-transplant outcome.

Patients and methods: Using our institutional database the retrospective analysis of patients with SAA allotransplanted in years 2001-2021 was performed.  

Results: Seventy patients (49 males) at median age of 25 years at transplant underwent allo-HSCT.  Thirty eight patients received immunosuppressive treatment (IST) before transplantation. 21 patients received grafts from HLA-matched sibling, 44 - from unrelated donors and 5 from haploidentical related donor. Peripheral blood remained the source of stem cells in 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 (IQR 0.45-11.5). Post-transplant outcome was comparable between patients with upfront allo-HSCT and with those who relapsed after IST. In univariable analysis, only ECOG score at transplant and infections in post-transplant period were found to be associated with unfavorable outcome. Fifty-three patients are 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 promise long term and good quality of life. ECOG score and the presence of infections are associated with poor post-transplant outcome.