Unrelated Umbilical Cord Blood Following HLA-haploidentical Hematopoietic Stem Cell Transplantation in Patients With β-thalassemia Major

Allo-hematopoietic stem cell transplantation(HSCT) is the only way to cure β-thalassemia major at present. To expand donor pool，we developed a haplo-identical HSCT (Hi-HSCT) platform. But in prior Hi-HSCT using high dose post-transplant Cyclophosphamide in patients with leukemia, cytopenia post-transplant often developed, which was considered as a symptom of GVHD. Therefore, the investigators add unrelated umbilical cord blood (UCB) to the Hi-HSCT. It has reported that, as third-party cells, UCB will reduce GVHD.The purpose of this study is to determine whether unrelated UCB following Hi-HSCT can improve outcomes of Hi-HSCT in patients with β-thalassemia major.