[Risk factors for poor graft function after allogeneic hematopoietic stem cell transplantation in children with transfusion dependent thalassemia].

Objective: To analyze the risk factors and outcomes of poor graft function (PGF) following allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with transfusion dependent thalassemia (TDT). Methods: A retrospective cohort study was conducted in 118 pediatric TDT patients who underwent allo-HSCT at the First Affiliated Hospital of Guangxi Medical University from June 30, 2018 to December 31, 2022. Based on PGF diagnostic criteria, patients were categorized into PGF and good graft function (GGF) groups. Clinical features, including pre-transplant baseline characteristics and post-transplant complications, were compared between groups. Inter-group comparisons were conducted by χ² test or Fisher exact test, as appropriate for the data type and distribution. Multivariate Logistic regression identified PGF risk factors, and model performance was assessed by receiver operating characteristic (ROC) curve analysis. Survival analysis was conducted using the Kaplan-Meier method with Log-Rank testing. Results: Among 118 patients, there were 69 males (58.5%) and 49 females (41.5%). Fifteen cases (12.7%) developed PGF while 103 cases (87.3%) achieved GGF. Compared to the GGF group, the PGF group had significantly higher rates of age ≥10 years at transplant, interval from diagnosis to transplant ≥6.7 years, human leukocyte antigen (HLA) mismatch, ABO mismatch, post-transplant BK virus infection, and hemorrhagic cystitis (all P<0.05). Multivariate analysis identified independent risk factors for PGF: age ≥10 years (OR=27.20, 95%CI 2.11-350.91), diagnosis-to-transplant interval ≥6.7 years (OR=23.23, 95%CI 1.39-388.23), post-transplant cytomegalovirus (CMV) infection (OR=57.83, 95%CI 3.01-1 111.71), post-transplant and BK virus infection (OR=67.73, 95%CI 2.56-1 794.52). The ROC curve showed an area under curve of 0.92 (95%CI 0.86-0.97, P<0.001). The 4-year overall survival rate was significantly lower in the PGF group compared to the GGF group ((53.3±12.9)%vs.(90.2±2.9)%,χ²=16.49,P<0.001). Conclusions: Risk factors for PGF in TDT children after allo-HSCT include age ≥10 years at transplantation, time from diagnosis to transplantation ≥6.7 years, post-transplant CMV infection and post-transplant BK virus infection. The PGF patients after allo-HSCT exhibit significantly poorer overall survival compared to those with GGF.