Clinical study of haploid allogeneic hematopoietic stem cell transplantation in the treatment of children with relapsed or refractory acute lymphoblastic leukemia

Objective To explore efficacy and safety of haploid allogeneic hematopoietic stem cell transplantation (allo-HSCT) for the children with relapsed or refractory acute lymphoblastic leukemia. Methods 20 cases of childhood acute lymphoblastic leukemia treated with haploid allo-HSCT were collected in Beijing Military General Hospital Hematology from Jan 2010 to Jan 2013, including 12 males and 8 females, with median age 9 (1-14) years old. There were 14 cases of B-ALL and 6 cases of T-ALL. When transplation, 10 cases were relapsed without remission, and 10 cases were relapsed after 2 or 3 times to obtain remission. 6 cases received bone marrow plus peripheral blood stem cell transplantation, and 14 cases received peripheral blood stem cell transplantation. Pretreatment program mainly were busulfan (Bu), fludarabine (Flu), cyclophosphamide (CTX) and anti-thymocyte immunoglobulin (ATG), plus cytarabine, etoposide or semustine and total body irradiation in some patients. Graft-versus-host disease (GVHD) was prevented by cyclosporine (CsA), mycophenolate mofetil (MMF) and methotrexate (MTX) (+ 1, + 3, + 6, + 11 day). After transplantation, adverse reactions, complications and disease-free survival were observed. Results The hematopoiesis in all of children were rebuilded, and 1 month after transplantation, donor cells chimeric rate was 100 %. After transplantation, the median time of granulocyte plant alive was 12.5 d (9-23 d), and that of platelet plant alive was 15 d (12-40 d). Follow-up until Jun 2014, the median follow-up time was 25 months (2-50 months) with 8 cases of acute GVHD, 11 cases of chronic GVHD, and 5 cases of death including GVHD in 2 cases, infection in 1 case and recurrence in 2 cases. The overall survival rate was 75 % (15/20). Conclusion Haploid allo-HSCT for children with recurrent refractory lymphocytic leukemia scheme is safe, which could improve the long-term survival rate without increasing the complications and recurrence rate after transplantation. Key words: Haploid type; Hematopoietic stem cell transplantation; Children; Acute lymphoblastic leukemia; Relapsed or refractory