Matched Unrelated Donor (MUD) Transplants Show Promising Outcomes in Thalassemia Patients Aged ≤ 12 Years

Matched unrelated donor (MUD) hematopoietic stem cell transplantation (HSCT) is a viable curative option for children with transfusion-dependent thalassemia major lacking a matched sibling donor. This study aimed to evaluate outcomes of MUD-HSCT in pediatric patients (≤ 12 years) because data on such a cohort are sparse. A retrospective analysis was conducted on 25 patients with thalassemia (≤12 years) who underwent MUD-HSCT. Data on patient demographics, transplant characteristics, post-transplant complications, and survival outcomes were collected. Kaplan-Meier survival analysis was used to estimate overall survival (OS), thalassemia-free survival (TFS), graft-versus-host and relapse-free survival (GRFS), and graft-versus-host and thalassemia-free survival (GTFS). Cox regression analysis was performed to identify predictors of GRFS. Median age at transplantation was 9 years; 60.9% were male. Most patients (68%) were Nanfang Class III. Median ANC and platelet engraftment occurred at 16 and 15 days, respectively. Acute and chronic GVHD were observed in 52% and 16% of patients, respectively. CMV reactivation occurred in 24%. Estimated 5-year OS, TFS, GRFS, and GTFS were 95.8%, 92%, 75.8%, and 92%, respectively. Elevated ferritin levels > 2500 ng/mL were independently associated with inferior GRFS (HR: 0.040; <i>p</i>-value = 0.031). In conclusion, MUD-HSCT yields excellent outcomes for OS and TFS in pediatric patients with thalassemia aged ≤ 12 years. High pre-transplant ferritin adversely impacted GRFS, underscoring the importance of iron control. These findings support MUD-HSCT as a viable option with appropriate pre-transplant optimization and GVHD management.