Rheumatoid arthritis is a chronic systemic disease, which is characterized by chronic inflammation in the synovial tissue. Rheumatoid arthritis will eventually result in the destruction of cartilage, bone and ligaments and joint deformity. The underlying hypothesis is that umbilical cord-derived mesenchymal stem cell (UC-MSCs) has anti-inflammatory effects and thus potentially alleviates the progression of rheumatoid arthritis. The study is to explore the safety and efficacy of UC-MSCs transplantation in treatment of rheumatoid arthritis.

This study was supported by the National Natural Science Foundation of China (30872618)，The Shanxi Province Social Development Public Relations Project (2012K13-02-35), and The Military Medicine and Public Health Plan (CLZ120GA23)

Inclusion Criteria:

• All patients fulfilled the classification criteria (2010) for rheumatoid arthritis, man or woman aged from 18 to 70 years old.
• Patients must be informed of the investigational nature of this study and give written informed consent in accordance with the institutional and hospital guidelines.
• Women of reproductive potential may not participate unless they have agreed to use an effective contraceptive method while on this trial. Women of child-bearing potential must have a pregnancy test performed within 72 hours prior to initiation of treatment.

Exclusion Criteria:

• Any history of ongoing, significant or recurring infections.
• Any active inflammatory diseases other than RA.
• Significant cardiac or pulmonary disease.
• End-stage renal failure.
• Pregnant or nursing women may not participate due to the possibility of fetal harm or harm to nursing infants from this treatment regimen.