OBJECTIVETo investigate the efficacy and safety of haploidentical allo-HSCT in combination of reduced intensity preconditioning combined with cyclophosphamid (CTX)-induced immune tolerance after transplanitation for treatment of severe aplastic anemia (SAA).

METHODSA total of 15 patients with SAA received the haploidentical allo-HSCT of reduced intensity preconditioning combined with CTX-induced immune tolerance after transplartation in the General hospital of Beijing military command of chinese PLA from June 2012 to December 2014. The reduced intensity preconditioning regimen consisted of CTX, fludarabine, busulfex and amti-lymphocyte immunoglobin; the immune tolerance was induced with CTX (50 mg/kg·d) on day 3 after transplantation; the HSC donors were father and mother of patients. The GVHD was prevented by inmunosuppression consisted of cyclosporine A(CsA), methotrexate and tacrolimus. The aduvese reaction and disease-free survival (DFS) were observed in all the patients.

RESULTSAll the SAA patients achieved hematopoietic reconstitution with 100% donor hematopoiesis, and all the T lymphocyte subsets increased. Out of 15 patients, 3 cases died of complication, and the DFS rate was 80% with a median follow-up of 19.8 month (6-36 months).

CONCLUSIONThe haploidentical allo-HSCT of reduced intensity preconditioning combined with CTX-induced immune tolerance after transplantation is safet and effective for SAA patients, that may be applied to clinical therapy.