Clinical characteristics and transplant outcomes in pediatric patients with transfusion-dependent alpha-thalassemia undergoing HSCT

Abstract Introduction：Hematopoietic stem cell transplantation (HSCT) remains the only curative treatment for transfusion-dependent alpha-thalassemia (TDT-α), yet data on clinical indications and long-term outcomes in pediatric patients remain limited. This study aimed to describe the clinical features and transplant outcomes of TDT-α children receiving HSCT. Methods：We retrospectively analyzed pediatric TDT-α patients who underwent HSCT between 2016 and 2025 at the First Affiliated Hospital of Guangxi Medical University. All patients received a standardized myeloablative conditioning regimen (GX-07-TM: busulfan, cyclophosphamide, fludarabine, ATG). GVHD prophylaxis was stratified by donor type. Key outcomes included 2-year overall survival (OS), thalassemia-free survival (TFS), and graft-versus-host disease and relapse-free survival (GRFS). Results：A total of 21 children (median age 8 years; 57.1% female) were included. Most patients (95.2%) had hemoglobin H (HbH) disease, with 81.0% carrying non-deletional α-thalassemia mutations. Common pretransplant complications included splenomegaly (90.5%), extramedullary hematopoiesis (90.5%), and growth delays (71.4%). The median age at first transfusion was 8 months. Alternative donors were used in 57.1% of cases. After a median follow-up of 25 months, the 2-year OS and TFS were both 90.2% (95% CI: 66.2–97.4%), and the GRFS was 82.3% (95% CI: 52.6–94.3%). The transplant-related mortality was 5.0%; no graft failures were observed. Conclusion: This study characterizes the clinical features and transplant outcomes of TDT-α pediatric patients undergoing HSCT. The presence of early severe manifestations —such as non-deletional genotypes, transfusion dependency, growth restriction, and extramedullary hematopoiesis— may support early HSCT consideration. HSCT provides excellent long-term outcomes and should be considered a frontline curative option in this population.