Haematopoietic stem cell transplantation for children with transfusion-dependent thalassaemia in Malaysia

Abstract Introduction: The study aimed to determine the outcome of children with transfusion-dependent thalassaemia (TDT) who underwent haematopoietic stem cell transplantation (HSCT) at Universiti Malaya Medical Centre, Malaysia. Methods: This was a retrospective analysis of 115 children (aged <18 years) who underwent 128 transplant procedures between 1 June 1987 and 30 December 2023. Results: The study included 53 boys, and the median age at time of HSCT was 5 years. One-third of patients were in Pesaro class 3. The 15-year overall survival and thalassaemia-free survival (TFS) were 83% and 71%, respectively. Transplant-related mortality (TRM) was 16%. Multivariate analysis revealed that patients who were aged >7 years and did not receive pre-HSCT anti-thymocyte globulin (ATG) had the worst outcomes (TFS 52%). In 62 patients who received busulfan–cyclophosphamide conditioning, 32 had addition of ATG that improved TFS (78% vs. 64%, P = 0.02). Graft failure, seen in 26% of patients, was the main contributing factor to TRM. Omission of ATG in the conditioning regimen was the main cause of graft failure (relative risk [RR] 8.26, 95% confidence interval [CI] 1.68–40.51; P = 0.009). The incidence of Grade II–IV graft-versus-host disease (GVHD) was 26%. Non-inclusion of ATG also significantly increased the risk of GVHD (RR 8.52, 95% CI 1.95–37.25; P = 0.04). Conclusion: Haematopoietic stem cell transplantation is a feasible curative option for children with TDT in Malaysia, with the best outcomes observed in patients undergoing transplantation before the age of 7 years. Our study also highlights the role of ATG in improving HSCT outcomes in this population.