Co-transplantation of bone marrow-derived mesenchymal stem cells with hematopoietic stem cells does not improve transplantation outcome in class III beta-thalassemia major: A prospective cohort study with long-term follow-up.

Bone marrow transplantation is the only curative treatment for beta-thalassemia major. Data on the co-transplantation of MSCs with HSCs in beta-thalassemia major patients are scarce. We aimed to investigate the outcomes of thalassemia major patients who underwent bone marrow-derived MSC co-transplantation with HSCs compared with those who only received HSCs. This prospective randomized study included patients with class III thalassemia major undergoing HSCT divided randomly into two groups: Thirty-three patients underwent co-transplantation of bone marrow-derived MSCs with HSCs, and 26 patients only received HSCs. Five-year OS, TFS, TRM, graft rejection rate, and GVHD were estimated. The 5-year OS was 66.54% (95% CI, 47.8% to 79.9%) in patients who underwent co-transplantation of MSCs with HSCs vs 76.92% (95% CI, 55.7% to 88.9%) in patients who only received HSCs (P = .54). No significant difference was observed in the 5-year TFS between the two groups (59.1% vs 69.2%; P = .49). The 5-year cumulative incidence of TRM was not statistically significant among patients who underwent co-transplantation of MSCs with HSCs (27.27%) vs those who only received HSCs (19.23%; P = .61). There was no statistically significant difference in graft rejection, acute GvHD, and chronic GvHD between the two groups. Based on our findings, the co-transplantation of MSCs and HSCs to class III thalassemia major patients does not alter their transplantation outcomes including OS, TFS, rejection rate, transplant-related mortality, and GvHD.