Abstract：Objective: To investigate the therapeutic effect of methotrexate (MTX) to mouse collageninduced arthritis (CIA) and its possible mechanism. Methods: MTX was injected into local joint of CIA mice three times a week from the 22nd day to the 50th day after primary immunization, and PBS was set up as negative control. The incidence and arthritis score in joint were calculated and compared between each group. The histopathological changes were evaluated in paraffin sections. The percent of Th17 cells and Treg cells in inguinal lymph nodes were analyzed by Flow cytometry (FCM). Results: MTX reduced the arthritis incidence and severity score of CIA mice effectively (P＜0.001). Paraffin sections showed that MTX inhibited the inflammatory cells infiltration, pannus formation, and destruction of cartilage and bone. MTX decreased the percent of Th17 cells and increased the percent of Treg cells effectively (P＜0.05). Conclusion: MTX inhibited the development of rheumatoid arthritis effectively. The mechanism may be involved in which the ratio of Th17/Treg cells was decreased.
2012, Vol. 22 
