Combination of Steroid and Humanized CD25 Monoclonal Antibody as First-line Therapy for aGVHD

Inclusion Criteria: * ( 1 ) Diagnosis of grade II to IV acute graft-versus-host disease after hematopoietic stem cell transplantation. ( 2 ) older than or equal to 18 years old. ( 3 ) Informed consent can be signed by themselves. ( 4 ) HIV negative, HBV, HCV negative. ( 5 ) Informed consent must be signed before the start of the study procedure. The informed consent must be signed by the patient himself or his immediate family. Considering the patient 's condition, if the patient 's signature is not conducive to the treatment of the disease, the informed consent will be signed by the legal guardian or the patient 's immediate family. Exclusion Criteria: * • (1) diagnosed as VOD/SOS. * (2) Uncontrolled infection at enrollment; requires mechanical ventilation or is hemodynamically unstable at the time of enrollment; * (3) has severe hepatic insufficiency (defined as Child-Pugh Class C; has serum aspartate aminotransferase (AST) or alanine aminotransferase (ALT) \> 5 xthe upper limit of normal (ULN) or serum total bilirubin \> 2.5 x ULN. * (4) has end-stage renal impairment with a creatinine clearance less than 10 mL/min. * (5) has both moderate hepatic insufficiency AND moderate renal insufficiency; * (6) has documented positive results for human immunodeficiency virus antibody (HIVAb), hepatitis C virus antibody (HCV-Ab) with detectable HCV RNA, or hepatitis B surface antigen (HBsAg) within 90 days prior to enrollments; * (7) has active solid tumor malignancies with the exception of localized basal cell or squamous cell skin cancer or the condition under treatment (e.g., lymphomas). * (8) Suffering from mental disorders or other conditions and unable to cooperate with the requirements of study treatment and monitoring; * (9) unable or unwilling to sign the consent form; * (10) patients with other special conditions assessed as unqualified by the investigator