MTX and Steroid for III-IV aGVHD Treatment

Inclusion Criteria: 1. Patients who are fully informed and sign informed consent by themselves or their guardians; 2. Patients receiving allogeneic hematopoietic stem cell transplantation; 3. Patients with acute graft-versus-host disease of grade III-IV were diagnosed after transplantation; 4. Patients with stable implantation of granulocytes and platelets. Exclusion Criteria: 1. Patients who have received more than one transplant; 2. Patients with overlap syndrome; 3. Patients within six months after the failure of the first transplantation; 4. Patients with uncontrollable active infection; 5. Patients with recurrence of primary malignant hematopathy; 6. Patients with donor lymphocyte infusion induced graft-versus-host disease after first intervention; 7. Patients with serious respiratory diseases; 8. Patients with severe renal insufficiency; 9. Patients with serious and uncontrolled heart disease; 10. Patients with severe hepatobiliary diseases unrelated to graft-versus host disease; 11. Within one week patients who need to use more than 1mg/kg/d methylprednisolone for reasons other than graft-versus-host disease; 12. patients who have participated in other clinical trials within 1 month; 13. The researcher judges that there are other factors that are not suitable for participating