Comparisons of unmanipulated haploidentical donor, unrelated cord blood donor and matched unrelated donor hematopoietic stem cell transplantation in pediatric acquired severe aplastic anemia: a single center study.

We retrospectively analyzed the outcomes of 240 pediatric SAA patients who underwent unmanipulated alternative HSCT between September 2012 and November 2020 at our center. The incidence of GF (PGF + SGF) was higher in the UCBD cohort compared to the MUD and HID cohorts [(13.5% ± 6.5%) vs (0%), and (1.6% ± 5.3%), respectively, p  = .0001]. The incidence of platelet engraftment within 180 days post-HSCT was lower in the UCBD cohort (82.4% ± 2.3%) compared to the HID group (96.2% ± 1.3%) and the MUD group (97.4% ± 0.5%) ( p  = .020). the median duration time for platelet engraftment in the UCBD cohort was 29 days, longer than in HID cohort 14 days and the MUD cohort 13 days ( p  = .005). UCBD cohort had a lower 3-year failure-free survival (FFS) (70.5% ± 8.4%) compared to the HID cohort (81.1% ± 4.3%) and the MUD cohort (92.5% ± 3.1%) ( p  = .030) and lower 3-year GVHD/relapse free survival (GRFS) (63.3% ± 9.5.4%) compared to the HID cohort (75.5% ± 6.8%) and MUD cohort (87.9% ± 4.5%) ( p  = .002). UCBD-HSCT had inferior FFS and GRFS compared to an HSCT with an HID or MUD in pediatric patients with acquired SAA. A UCBD-HSCT had a higher GF and lower incidence of platelet engraftment and longer platelet engraftment time.