Objective      To evaluate the clinical value of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with reduced intensity Bu+Cy conditioning regimen in the treatment of patients with leukemia.       Methods      The reduced intensity Bu+Cy conditioning regimen  including  busulfan (Bu) 4 mg/(kg·d)

for 3 d; cyclophosphamide (Cy) 50 mg/(kg·d)

for 2 d

a

ntithymocyte globulin (ATG) 2.5 mg/(kg·d)

for 2/4 d

  were used in 15 leukemia patients who underwent allo-HSCT in our department from April 2010 to March 2012. There were 2 cases of acute lymphocytic leukemia

3 cases of acute non-lymphoid leukemia

9 cases of chronic myeloid leukemia

and 1 case of Crisis phase of CML.       Results      All patients achieved successful hemopoietic reconstruction. The median time of the neutrophil recovery 0.5×10

9

/L was 12 (ranging from 10 to 17) d and the platelet recovery 20×10

9

/L was 15 (12 to 27) d after transplantation. In 15 patients

short tandem repeat polymerase chain reaction (STR-PCR) confirmed that the donor cells were fully implanted on day 30. Transplant-related complications were acute graft-versus-host disease (aGVHD) in 6 patients (40%) (2 patients with aGVHD=grade Ⅰ

4 patients with aGVHD=grade Ⅱ

and none with aGVHD=grade Ⅲ-Ⅳ)

chronic graft-versus-host disease (cGVHD) in 8 patients (53.3%) (2 cases of extensive-type

and 6 cases of limited-type)

hemorrhagic cystitis in 3 patients (20%)

and infected cytomegalovirus in 4 patients (26.7%). There was no other serious complication. All patients were followed up for a median time of 15.4 months (ranging from 6 to 30). One patient (6.7%) died of side effect related to the conditional regimen. Two patients (13.3%) got recurrence

and the rest (80.0%) survived event-free for 4 to 30 months.       Conclusion      After treated with reduced intensity Bu+Cy conditioning regimen-HSCT

leukemia patients have a better hematopoietic reconstitution and less transplant-related complications. It is also suggested that the pre-conditioning regimen has a low recurrence rate and a lower mortality. Therefore

this method maybe one of the safe and effective treatments for leukemia.