OBJECTIVETo study the effect of anti-CD25 monoclonal antibody (mAb) combined with antithymocytic globulin (ATG) in the treatment of severe steroid-resistant acute graft-versus-host disease (aGVHD) after unrelated donor hematopoietic stem cell transplantation (UD-HSCT).

METHODSTen leukemic patients who developed severe steroid-resistant aGVHD during UD-HSCT received a standard dose of anti-CD25 mAb and a medium or low dose of ATG. The effect on aGVHD control, patients' survival, infection and relapse after the therapy were analyzed.

RESULTSEight of the 10 patients had complete remission and 2 had partial remission after the combined therapy. In the 8 patients with complete remission, 2 developed third degree aGVHD 3-3.5 months after the transplantation, and were managed with a second combined therapy to successfully achieve complete remission. In the total of 12 combined treatments, the median time of therapeutic effect was 5 days (3-10 days); the median complete relief time was 12 days (8-30 days) in the 10 cases. Among the 8 patients who survived for more than 3 months, 7 were diagnosed to have chronic GVHD including 4 with extensive chronic GVHD. No relapse of leukemia was found in these patients. Five patients survived the 2-year-long follow-up after the transplantation with survival time over 2 years; of the 5 patients who died within 2 years after the transplantation, 1 survived for more than one year, and 4 for less than 6 months. Two patients died from invasive fungal infection, two from aGVHD and one from cGVHD-induced multiple organ failure.

CONCLUSIONAnti-CD25 mAb combined with ATG has good therapeutic effect on steroid-resistant sever aGVHD and may help achieve high complete remission rate and long-term survival in leukemic patients after UD-HSCT.