Abstract: AIM: To investigate the therapeutic method of fludarabine combined with subsequent cyclophosphamide in the prevention of GVHD in haploid hematopoietic stem cell transplantation.  METHODS: A total of 52 patients receiving PTCY (50 mg/kg, on days 3 and 4) were matched with 29 patients receiving ATG. RESULTS: The median follow-up time was 359 days. Complete donor chimerism was achieved in all patients by STR DNA detection on days +30, +60. The median time to neutrophils ≥0.5×109/L and platelets ≥20×109/L were (11.5 vs. 12) days and (12 vs. 13) days respectively, between PTCy group and ATG group, The cumulative incidence of grade II-IV acute GVHD (aGVHD), grade Ⅲ-IV aGVHD, and chronic GVHD were (30.8%vs. 31%), (19.2%vs. 24.1%) and (5.8%vs. 24.1%) respectively. The cumulative overall survival (OS) and disease-free survival (DFS) were 65.5%vs. 62.1%, the non-relapse-mortality (NRM) at 1 years were 75% and 77%. Incidence of CMV infection and EBV infection were (48.3%vs. 50%) and (6.9%vs. 3.7%). CONCLUSION: HLA-haploidentical HSCT with PTCy is a viable option when lack of HLA matched sibling and unrelated donors. The rate of severe GVHD is acceptable. But post-transplant relapse and infection still are major hinder,and the protocol should be modified.

Key words: anti-thymoglobulin, post-transplant cyclophosphamide, haploidentical, graft-versus-host disease, hematopoietic stem cell transplantation