Allogeneic hematopoietic stem cell transplantation for relapsed acute myeloid leukemia in ETO positive with reduced-intensity conditioning

OBJECTIVE: This research is conducted under the intention of exploring the efficacy and safety of reduced-intensity conditioning for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of relapsed ETO positive acute myeloid leukemia (AML). MATERIALS AND METHODS: Treatment of 15 cases referring to recurrent ETO positive acute myeloid leukemia in an army hospital from January 2010 to January 2013 through allo-HSCT with reduced-intensity conditioning. All participants belonged to the recurrent or refractory type, including 10 males and 5 females, aging from 16 to 48 years old, with the average age of 32.5 years old. Before transplantation, 6 cases were remission while 9 were not, 10 cases were HLA-identical matching and 5 cases were HLA-haploidentical. Donors received G-CSF to mobilize and used peripheral blood stem cell transplantation. Patients received a combination of Fludarabine, Busulfex and cytarabine as conditioning regimen. Preventive donor peripheral blood stem cell infusion was used 3 months after transplantation in order to observe toxicity, graft versus host disease(GVHD) and disease-free survival. RESULTS: All patients reached hematopoietic reconstitution, the average time were 15.5d and 16.8d respectively with neutrophils > 0.5 × 10(9)/L and platelets > 20 × 10(9)/L. Engraftment was confirmed by the evidence of 100% donor hematopoiesis and T lymphocyte subsets counts increased significantly before and after transplantation. Univariate analysis showed that the levels of CD3+, CD4+, CD8+, CD19+ significantly increased after transplantation (P < 0.05) . Until June 2016 after the duration of 27.5 months, 8 cases presented the presence of GVHD, one died of complication, another 4 died of relapse and the other three remained disease-free survival, the DFS rate of 2-year was 66.7%, with the longest DFS up to 54 months. Considering of the transplantation cases with remission into relief groups (6 cases), and not ease group (9 cases), 2 years of disease-free survival rates were 66.7% and 66.7%. The survival curves of the two groups are demonstrated with no significant statistical significance (P > 0.05). CONCLUSIONS: Reduced-intensity allogeneic hematopoietic stem cell transplantation remains effective for relapsed AML with ETO positive, with safe and effective features and can be used as the method for relapsed AML with ETO positive.