Prophylaxis Roles of IL-2 Treatment on GVHD After Transplantation

Inclusion Criteria: 1. Aged 15-65 years old 2. Acute leukemia in complete remission (CR1/CR2) who received myeloablative haploidentical allo-HSCT 3. WBC engraftment (ANC\>500/ul for continuous 3 days) 4. At least +7d 5. Less than or equal to +15d 6. non T-ALL 7. no active II-IV aGVHD 8. no severe infections 9. Karnofsky score greater than or equal to 90% 10. Haploidentical donor from sibling, children or father 11. Ensure that informed consent signed and faxed to Research Coordinator Exclusion Criteria: 1. Exposure to any other clinical trials prior to enrollment 2. Active malignant disease relapses or MRD positive 3. Active, uncontrolled infection 4. Inability to comply with IL-2 treatment regimen 5. Active, uncontrolled II-IV aGVHD 6. Haploidentical donor from mother or collateral donors 7. Clinical Signs of severe pulmonary dysfunction 8. Clinical Signs of sever cardiac dysfunction 9. Receiving corticosteroids as GVHD treatment