Clinical Outcomes of Haploidentical Transplantation Combined With Umbilical Cord Blood and Mesenchymal Stem Cells Co-Infusion for Aplastic Anemia: A Single-Center Retrospective Study.

Haploidentical hematopoietic stem cell transplantation (HID-HSCT) is a critical therapeutic option for severe aplastic anemia (SAA) patients lacking HLA-matched donors. However, its application has been limited by graft failure and graft-versus-host disease (GVHD). The co-infusion of mesenchymal stem cells (MSCs) or umbilical cord blood cells (UCBs) has emerged as a crucial area to enhance transplant outcomes. This single-center retrospective study evaluates the clinical outcomes of HID-HSCT combined with UCBs and MSCs co-infusion in 108 patients. Patients underwent HID-HSCT between January 2018 and January 2025, with 40 receiving co-infusion of UCBs and MSCs. Transplantation outcomes, including neutrophil and platelet engraftment, GVHD incidence, viral reactivation rates, and long-term survival, were compared. Results showed no significant differences in engraftment or GVHD rates between groups. However, the Co-infusion group exhibited a declining trend in grade II-IV aGVHD and significantly improved 5-year overall survival (OS) and graft-versus-host disease-free, relapse-free survival (GRFS). These findings suggest that UCBs and MSCs co-infusion may enhance long-term survival and quality of life in patients undergoing HID-HSCT, offering a promising strategy for clinical haploidentical transplantation. However, the lack of prospective design and standardized protocols limits the conclusions. Future studies should focus on optimizing co-infusion strategies to improve clinical outcomes in haploidentical transplantation.