Cytokine abnormalities in inflammatory arthritis.

Cytokines are soluble molecules which control communication between cells of the immune and non-immune systems. Studies on their role in the pathogenesis of inflammatory arthritis have been increased with the discovery of new cytokines and the development of assays for their detection. Conditions such as rheumatoid arthritis are characterized by increased production of proinflammatory cytokines in association with reduced control by regulatory cytokines produced by T lymphocytes. The inadequate inhibition of proinflammatory cytokines by anti-inflammatory cytokines and other regulatory mechanisms contributes to this cytokine imbalance. This situation is responsible for the enhanced degradation, without sufficient repair activity. These results have provided the rationale for the use of cytokines as well as for drug targeting of the cytokine network in rheumatoid arthritis. This also includes the modulation of the cytokine network by targeting the level of the receptors as well as the effects and/or the responding cells.