This trial is a randomized (1:1) phase III open label study of frontline mini-MTX plus methylprednisolone 2mg/kg/day compared to methylprednisolone 2mg/kg in allogeneic stem cell transplant recipients with grade 2-4 aGVHD.

Allo-HSCT is an effective treatment of malignant hematopoietic diseases. However, aGVHD remains a major complication after allo-HSCT. Corticosteroid is the standard first-line therapy for aGVHD. 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 control aGVHD.

Inclusion Criteria:

1. Patients who are fully informed and sign informed consent by themselves or their guardians;

2. Patients receiving first allogeneic hematopoietic stem cell transplantation;

3. Patients with acute graft-versus-host disease of grade II-IV were diagnosed after transplantation;

4. KPS>60, Estimated survival >3 months;

5. No serious organ damage:

   1. ANC in peripheral blood is greater than 0.5×109/l
   2. Creatinine < 1.5mg/dl
   3. Cardiac ejection index > 55%

Exclusion Criteria:

1. Patients with severe brain, heart, kidney or liver dysfunction unrelated to graft-versus host disease;
2. Patients with uncontrollable active infection;
3. Patients with recurrence of primary malignant hematopathy;
4. Expected survival is less than 3 months
5. Patients who have histories of severe allergic reactions
6. Pregnant or lactating women
7. The researcher judges that there are other factors that are not suitable for participating
8. Patients who received donor lymphocyte infusion