The purpose of this study is to evaluate the efficacy of mesenchymal stem cells in patients with chronic graft-versus-host disease.

Allogeneic hematopoietic stem cell transplantation(allo-HSCT) can cure many hematologic diseases. Although great progress has been made in the prevention and treatment of side effects associated with transplantation,chronic graft-versus-host disease(cGVHD) remains an important complication that occurs in about 50% patients. The mortality of cGVHD and its complication could reach up to 50%,and cGVHD seriously influence the quality of life. At present, the first line treatment of cGVHD remains in discussion.

Mesenchymal stem cells (MSCs) are a form of multipotent adult stem cells that can be isolated from bone marrow (BM), adipose tissue, and cord blood. Clinical applications of human MSCs are evolving rapidly with goals of improving hematopoietic engraftment, preventing and treating GVHD after allo-HSCT and so on. However, the efficacy of treatment of cGVHD remains undetermined.

In the present study, the investigators will prospectively evaluate the efficacy and safety of ex-vivo-expanded MSCs in treating patients with cGVHD.

Inclusion Criteria:

• A patient age of 18-65 years
• Recipients of allogeneic hematopoietic stem cell transplantation Patients with moderate/ severe cGVHD without systemic treatment
• Subjects (or their legally acceptable representatives) must have signed an informed consent document indicating that they understand the purpose of and procedures required for the study and are willing to participate in the study

Exclusion Criteria:

• Any abnormality in a vital sign (e.g., heart rate, respiratory rate, or blood pressure)
• Primary disease relapse
• Expected lifetime less than 3 months
• Patients with any conditions not suitable for the trial (investigators' decision)