Association between haploidentical hematopoietic stem cell transplantation combined with an umbilical cord blood unit and graft- <i>versus</i> -host disease in pediatric patients with acquired severe aplastic anemia
Di Yao, Yuanyuan Tian, Jie Li, Bohan Li, Jun Lu, Jing Ling, Defei Zheng, Yanhua Yao, Peifang Xiao, Lijun Meng, Shaoyan Hu
Abstract
Background: Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) based on granulocyte colony-stimulating factor plus anti-thymocyte regimens (‘Beijing Protocol’) provides a salvage treatment for patients of acquired severe aplastic anemia (SAA) in China. However, graft- versus-host disease (GVHD) is a major impediment of haplo-HSCT due to human leukocyte antigen disparity. Recently, haplo-HSCT combined with umbilical cord blood (UCB) (haplo-cord HSCT) is performed in clinical trials to potentially reduce the risk of severe GVHD. Nevertheless, studies comparing GVHD in pediatric patients receiving haplo and haplo-cord HSCT for SAA are limited. Objective: The objective of this study was to investigate the impact of UCB co-infusion on GVHD in pediatric patients receiving haplo-HSCT for SAA. Design: We conducted a retrospective study of 91 consecutive SAA children undergoing haploidentical transplantation based on the ‘Beijing Protocol’ with or without co-infusion of UCB in our center. Methods: All patients received uniform non-myeloablative conditioning and GVHD prophylaxis. We compared baseline characteristics and transplant outcomes between the haplo ( n = 35) and haplo-cord ( n = 56) recipients. Results: All 91 patients achieved hematopoietic recovery from haploidentical donors, with a higher incidence of peri-engraftment syndrome observed with the haplo-cord group as compared with the haplo group (75.0% versus 48.6%, p = 0.029). Notably, the haplo-cord group showed a lower incidence of II–IV acute GVHD (aGVHD) than the haplo group (16.1% versus 42.9%, p = 0.002). Observed incidences of chronic GVHD (cGVHD) and moderate to severe cGVHD in the haplo-cord group were also lower than that in the haplo group (25.6% versus 51.3%, p = 0.019; 16.2% versus 41.3%, p = 0.016, respectively). Haplo-cord HSCT was identified as the only factor associated with a lower incidence of II–IV aGVHD and cGVHD in multivariate analysis. However, no differences were observed between the two groups for infections and survival outcomes. Conclusion: Our data indicated that co-infusion of UCB in ‘Beijing Protocol’-based haplo-HSCT may be effective for reducing the risk of severe GVHD in SAA children.