Allogeneic hematopoietic stem-cell transplantation (allo-HSCT) is the only curative therapy for severe aplastic anemia (SAA), yet the prognostic impact of the diagnostic-to-transplant interval on first allo-HSCT remains contentious. To determine whether a waiting time > 1 year from diagnosis to first allo-HSCT compromises engraftment, virus reactivation, GVHD, OS and GRFS in SAA. A single-center retrospective cohort study of 255 consecutive SAA patients receiving their first allo-HSCT between 2018 and 2025. After 1:2 propensity-score matching (caliiper 0.2), patients were stratified into Early (≤ 1 year, n = 170) and Delayed (> 1 year, n = 85) groups. Baseline characteristics were well balanced. The Early group exhibited a significantly lower CMV reactivation rate (24.1% vs. 40.0%, P = 0.008). No significant differences were observed in grade II-IV aGVHD, cGVHD, 5-year OS or GRFS. Subgroup analyses demonstrated superior survival among patients aged ≤ 40 years, those with MSD donors and received FABT-based regimen. Early allo-HSCT improves transplant outcomes in SAA by reducing CMV reactivation, especially in very severe cases. Eligible patients should be referred promptly and transplanted without delay.
Tan et al. (Wed,) studied this question.