CYTOKINES IN JUVENILE CHRONIC ARTHRITIS

Cytokines are important mediators of the immune response as well as th e inflammatory response. Those concerned primarily with cell growth, d ifferentiation and activation of cells within the immune system are ca lled interleukins, of which there are now 18. Exposure to antigenic an d environmental stimuli causes T cells to differentiate and polarise i nto Th1 or 2-like cells with different cytokine profiles, and requirin g different cytokines for differentiation (IL-12 for Th1 and IL-4 for Th2). Homeostasis is usually restored as these cells are mutually inhi bitory. Autoimmune diseases have been associated with a persistent imb alance with more Th1-like cells, which are thought to contribute to pa thology. With regard to juvenile chronic arthritis (JCA), there is som e preliminary evidence of this imbalance in the oligoarticular subgrou p. Imbalance of pro-inflammatory cytokines, IL-1 and TNF with their na tural inhibitors has also been shown to contribute to persistence of i nflammation. In the case of JCA, there has been some evidence that the se imbalances could account for some of the disease phenotypes. Furthe rmore, the tendency to imbalance is genetically determined.