The immunopathogenesis of rheumatoid arthritis.

There is little doubt that the immune system plays an integral role in the pathogenesis of rheumatoid arthritis. However, the contributions of various cell types, including lymphocytes, antigen-presenting cells, and mesenchymal cells and their mechanisms of participation, are debatable. Basic research has focused on these questions over the last decade, with particular attention to soluble mediators of inflammation (eg, cytokines) and the activation states of T lymphocytes and synovial lining cells. A brief overview is presented in the context of studies published during the last year.