Upfront versus Delayed Allogeneic Hematopoietic Cell Transplantation in Elderly Patients with Acquired Aplastic Anemia: A Multicenter Retrospective Study

The role of allogeneic hematopoietic cell transplantation (alloHCT) as first-line therapy in elderly patients with acquired aplastic anemia (AA) remains uncertain. While immunosuppressive therapy (IST) is the standard initial treatment for patients aged ≥40 years, recent evidence suggests that upfront alloHCT may offer improved outcomes. We conducted a retrospective multicenter study of 173 Korean patients aged ≥40 years who underwent alloHCT between 1999 and 2017. Patients received either upfront alloHCT without prior IST (n=66) or delayed alloHCT following IST failure or relapse (n=107). The upfront group had a higher rate of matched sibling donors (78.8% vs. 50.5%, p<0.001) and shorter time to transplant (median, 3.4 vs. 8.3 months; p=0.046). Rates of engraftment, hematopoietic recovery, and acute and chronic graft-versus-host disease were comparable. Five-year overall survival was higher in the upfront group (73.5% vs. 56.4%, p=0.059). In multivariate analysis, upfront alloHCT (hazard ratio [HR], 2.476; p=0.004) and ECOG performance status ≤1 (HR, 4.736; p<0.001) were independently associated with improved survival. These findings suggest that upfront alloHCT may be a viable first-line option for selected elderly AA patients and support re-evaluation of treatment algorithms that currently prioritize IST.