The aim of the study is to identify the efficacy and safety of methotrexate (MTX) combined corticosteroid treatment for grade III-IV acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Allo-HSCT is an effective treatment of malignant hematopoietic diseases. However, aGVHD remains a major complication after allo-HSCT and the destruction of recipient tissues by alloantigen-activated T cells is a key event in the development of aGVHD. Corticosteroid is the standard first-line therapy for aGVHD due to their roles in suppressing T cell responses. However, the response rate of corticosteroid was approximate 50%, and the clinical outcomes of patients with corticosteroid refractory GVHD were poor. Thus far, no combination therapy had been prove to be superior to corticosteroid alone as initial therapy for aGVHD. The study hypothesis: MTX combined corticosteroid treatment could help to further ameliorate the activity of T cells and control aGVHD.

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