[Diagnosis and treatment of rheumatoid arthritis:toward the best practice. The Pathophysiology in Rheumatoid Arthritis.]

Rheumatoid arthritis(RA)is one of the systemic autoimmune diseases characterized by progressive joint destruction with chronic synovitis. In the synovium, activated osteoclasts with plenty of inflammatory cytokines and metalloproteinases induce bone and cartilage destruction. Anti-cyclic citrullinated protein antibodies(ACPA)was recognized not only as a diagnostic marker but also as direct inducer of synovitis. In addition, environmental factors and background of daily life also contribute to the pathogenesis of RA, especially smoking and periodontitis are considered to be important factors for disease activities.