Hematopoietic stem cell transplantation for beta-thalassemia major]

OBJECTIVE: To discuss the feasibility of hematopoietic stem cell transplantation for beta-thalassemia major. METHODS: Bone marrow or cord blood of sibling was transplanted to 4 children with thalassemia, whose type of gene mutations was homozygous. All of them were diagnosed as beta-thalassemia major. HLA type was matched in 2 cases, and mismatched with 1 locus in the other 2. RBC type was mismatched in 1 cases. Pretransplant condition including busulfan (BU) 16 mg/kg, cyclophosphamide (CY) 200 mg/kg and anti-thymocyte globulin (ATG) 90 mg/kg. Graft-versus-host disease (GVHD) prophylaxis was cyclosporine-A (Cs-A) and methotrexate (MTX). RESULTS: Two Children had "serum sickness" during pretransplant condition; two children had grade II acute GVHD and 1 developed chronic GVHD, 1 case veno-occlusive disease (VOD), 1 case cytomegalovirus (CMV) interstitial pneumonia and 1 case fungemia post-transplant, which had been cured. The average time for peripheral WBC recovery > 1.0 x 10(9)/L was 16 days, 18 days for neutrophile granulocyte > 0.5 x 10(9)/L, 59 days for Plt > 50 x 10(9)/L and 39 days for Hb > 100 g/L. The average time for WBC recovery to normal was at day 24. The average time of last blood transfusion for patients was 29 days. The patients had to receive about 100 ml blood infusion per 2 months pretransplant, while not infused for 7 approximately 15 months up to now with Hb > 100 g/L. Gene mutation type of patients had changed to donor's. CONCLUSION: We report a successful transplantation of bone marrow and cord blood stem cells for thalassemia major in China. This will give a new strategy for treatment of the disease and further expand the use of stem cells transplantation.