Rheumatoid arthritis is auto-immunoreaction to collagen II in cartilage happened in synovial tissue

Rheumatoid arthritis is complex and not clear on the mechanism of pathogenesis. On the basis of analysis of the symptom and pathology of rheumatoid arthritis patients, we raised a new hypothesis. The content of the hypothesis is as follows: (A) Collagen II or collagen II-Iike substance in human cartilage is the cross-autoantigen of some infecting virus or bacteria because of the structure's similarity. (B) The inflammation in synovial tissue is auto-immunoreaction to collagen II in cartilage. (C) The proliferation and attachment of synovial tissue to the surface of cartilage is due to the chemotaxis of collagen II in cartilage for the immunocytes in synovial tissue. (D) The collagenase secreted from synovial cells and immunocytes are the direct elements in the destruction of cartilage. The fallen collagen II from cartilage is one of the most important inducer on the synovial cells and immunocytes for the production of collagenase.