Potential of modulatory cytokines in the rheumatoid arthritis process

Rheumatoid arthritis is a chronic systemic disorder of unknown etiology. It is now generally accepted that the proinflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor-alpha are key mediators in the pathology of rheumatoid arthritis. Controlling the production and the activity of these mediators represents a major therapeutic goal. First data from clinical trials that showed efficacy, however, also revealed that blockade of these cytokines did not fully control the arthritis in all patients. Recent discoveries of novel cytokines in the pathology of arthritis such as IL-17, IL-18 and RANK ligand (RANKL) will help us better understand the pathogenesis of chronic arthritis and may contribute to improvement of current therapies. IL-4 and IL-10 are pleiotropic cytokines and are considered promising modulators in the control of rheumatoid arthritis.