This study is to determine the efficacy and safety of combined Low dose Ruxolitinib With Methylprednisone as Initial Therapy for the aGVHD(acute graft-versus-host disease )

Corticosteroid is used as a first-line treatment for acute GVHD. However, it is effective in only about half of patients. In this prospective study, the investigators prospectively combined low dose ruxolitinib and 1mg/kg methylprednisolone in the initial treatment of acute GVHD. In order to effectively control GVHD without exposing acute GVHD patients to more intense and prolonged immunosuppression, we used ruxolitinib (20mg/day, 10mg/day, 5mg/day, 2.5mg/day) combined with 1mg/kg methylprednisolone. To ally steroid-related complications, we decreased steroid exposure time (39 days) and cumulative methylprednisolone doses (15.4 mg/kg) to spare the associated toxicity of glucocorticoid therapy.

Inclusion Criteria:

1. diagnosed with hematological diseases.
2. Have undergone first allogeneic hematopoietic stem cell transplantation (allo-HSCT) from any donor source using bone marrow, peripheral blood stem cells, or cord blood for hematologic malignancies.
3. new onset of grade II~IV aGVHD or high risk aGVHD [based on suppression of tumorigenicity 2 (also ST2), Regenerating Islet Derived Protein 3 Alpha (also REG3a), experimental objects) within 100 days post-transplantation.

Exclusion Criteria:

1. recipients of second allogeneic stem cell transplant.

2. acute GVHD induced by donor lymphocyte infusion, interferon.

3. received first line aGVHD treatment before enrollment.

4. overlap GVHD syndrome.

5. pregnant or breast-feeding women.

6. absolute neutrophil count (ANC) <0.5×10e9/L or platelet count (PLT) < 20×10e9/L

7. Serum creatinine > 2.0 mg/dL or creatinine clearance < 40 mL/min measured or calculated by Cockroft-Gault equation.

8. uncontrolled infection

9. human immunodeficiency virus infection

10. active hepatitis b virus, hepatitis C virus infection and need antivirus treatment.

11. Subjects with evidence of relapsed primary disease, or subjects who have been treated for relapse after the allo-HSCT was performed, or graft rejection.

12. allergic history to Janus kinase inhibitors.

13. Severe organ dysfunction unrelated to underlying GVHD, including:

    Cholestatic disorders or unresolved veno-occlusive disease of the liver (defined as persistent bilirubin abnormalities not attributable to GVHD and ongoing organ dysfunction). Clinically significant or uncontrolled cardiac disease including unstable angina, acute myocardial infarction within 6 months from Day 1 of study drug administration, New York Heart Association Class III or IV congestive heart failure, circulatory collapse requiring vasopressor or inotropic support, or arrhythmia that requires therapy. Clinically significant respiratory disease that requires mechanical ventilation support or 50% oxygen.

14. Received Janus kinase inhibitor therapy after allo-HSCT for any indication.

15. Any condition that would, in the investigator's judgment, interfere with full participation in the study, including administration of study drug and attending required study visits; pose a significant risk to the subject; or interfere with interpretation of study data.](streamdown:incomplete-link)