Reduced BUCY 2 and G-CSF-primed bone marrow associates with low graft-versus-host-disease and transplant-related mortality in allogeneic HSCT.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the ideal treatment for several diseases. However, the morbidity and mortality associated with the procedure might limit its widespread use; therefore, we implemented reduced BUCY2 as conditioning method along with the use of G-CSF-primed bone marrow (G-BM) in order to reduce complications, including graft-versus-host-disease (GVHD), and to improve survival in these patients. An analysis of transplant characteristics, complications, and survival of patients undergoing an allo-HSCT using this conditioning regimen (busulfan 12 mg/kg and cyclophosphamide 80 mg/kg) plus G-BM was performed. Forty patients were included from 1999 to 2015. All of them had a HLA-matched donor, with a median age of 32 years (range 16-59), and 55% were male. The most frequent diagnosis was myelodysplastic syndrome (MDS) in 14 patients (35%), followed by acute lymphoid leukemia (ALL) in 12 (30%). The mean of CD34+ was 2.09 × 106/kg. The mean time to neutrophil and platelet recovery was 20 and 18 days, respectively. The most common toxicity was mucositis (75%) with grade III-IV in 53% of cases. Acute GVHD appeared in 12.5 and 35% of patients developed chronic GVHD. Transplant-related mortality (TRM) was 10%. Five-year relapse-free survival was 69%, and the 5-year overall survival was 69.5%. Our conditioning method along with G-BM preserves an immunosuppressive and myeloablative effect allowing eradication of the malignant clone and achieving adequate bone marrow engraftment with acceptable toxicity, low incidence of GVHD, and low TRM, representing a favorable alternative for allo-HSCT.