Pro- and antiinflammatory cytokine balance in rheumatoid arthritis

High levels of proinflammatory cytokines such as IL-1, TNF-alpha and IL-6 are produced by the rheumatoid synovitis. These cytokines, mainly produced by monocytes/macrophages, are thought to play a major role in chronic inflammation and in the final joint degradation. IL-4, IL-10, and IL-13 have been classified as antiinflammatory cytokines as they inhibit the production of the proinflammatory cytokines by monocytes. Acting on the balance between these two groups of cytokines may lead to new therapeutic approaches to controlling chronic inflammation without interfering at the level of the antigen.