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

Rheumatoid arthritis(RA)has been a disease of unknown cause for many years. However, the etiology is becoming obvious due to the use of biological products in recent years, arthritis model mice in basic immunology and genome wide analysis in genetics etc. In particular, the knowledge of what is effective and what is not effective for biological products directly reveals the pathology of RA. It has also been found that the cytokine dependence of arthritis model mice and RA is not necessarily the same. It is pointed out that the difference may be derived from the presence of anti-citrullinated protein antibody(ACPA). Studies of immune responses against self antigens such as citrullinated protein will provide a clue to elucidate the pathogenesis of RA. Further analysis of genetic polymorphism and epigenome in combination with human immunity is expected to promote understanding of RA.