The efficacy and safety of third-party umbilical blood/umbilical cord mesenchymal stem cell assisted related haploid hematopoietic stem cell transplantation in pediatric patients with acute leukemia: an observational study

Abstract

Background: There is limited data on third-party umbilical cord blood (UCB) or mesenchymal stem cell (MSC) transplantation-assisted haploidentical hematopoietic stem cell transplantation (haplo-HSCT) in pediatric patients. Objective: To evaluate the efficacy and safety of UCB and MSC transplantation-assisted haplo-HSCT in pediatric patients with acute leukemia (AL). Design: Observational study. Methods: Clinical data of 152 children with AL undergoing haplo-HSCT at the Children’s Hospital of Soochow University between January 2020 and June 2022 were collected. The patients were divided into the haplo-HSCT + UCB group ( n = 76), haplo-HSCT + MSC group ( n = 31), and haplo-HSCT group ( n = 45). Hematopoietic reconstruction time, complications within 30 days after transplantation, and survival and recurrence at 3 years after transplantation were compared among the groups. Results: Multivariate analysis revealed that haplo-HSCT with MSC and human leukocyte antigen (HLA) matching ⩾6/10 were independent factors reducing engraftment syndrome (ES) incidence. There were no significant differences among the groups in the hematopoietic reconstruction time or incidence of complications within 30 days after transplantation ( p > 0.05). Overall survival, relapse-free survival, cumulative incidence of relapse, cumulative incidence of hematological relapse, and 3-year transplant-related mortality were not significantly different ( p > 0.05). The incidence of adverse reactions in the haplo-HSCT + UCB group was 97.3% within 4 h after UCB infusion, with a particularly high occurrence rate of 94.7% for hypertension. No transfusion-related adverse reactions occurred after the transfusion of umbilical cord MSC in the haplo-HSCT + MSC group. Conclusion: MSC-assisted haplo-HSCT can reduce ES incidence after transplantation in pediatric patients with AL. UCB infusion is associated with a high incidence of reversible hypertension. However, no adverse reactions were observed in umbilical cord MSC transfusion.