Efficiency Study of Low Dose of IL-2 to Prevent Relapse in Standard Risk Leukemia After Transplantation

Hematopoietic stem cell transplantation (HSCT) is one of the best, and sometimes the only, option for the treatment of leukemia. However, relapse rate was still the key question to influence the overall survival after transplantation, even in standard risk leukemia.There were good evidences that natural killer cells and T regulatory cells, which were expanded and stimulated by the application of IL-2, could mediate protection against GvHD while maintaining graft anti-tumor activity as a positive side effect. Meanwhile, it was found in our previous pilot study that low-dose IL-2 subcutaneous administration from 100 days for a prolonged period could be a safe and effective strategy to prevent relapse in acute lymphoblastic malignancy patients with high risk of recurrence after unmanipulated allo-HSCT. The study hypothesis: Prevention of relapse using low dose IL-2 following hematopoietic stem cell transplantation in patients with standard risk acute leukemia can * reduce relapse rate * improve survival