The role of IL-17 and family members in the pathogenesis of arthritis.

Interleukin (IL)-17 is a T-cell-derived cytokine that is expressed in the synovium of patients with arthritis. IL-17 contributes to the pathogenesis of arthritis, and demonstrates additive or even synergistic effects with IL-1 and tumor necrosis factor (TNF) in inducing joint pathology. It is a potent inducer of receptor activator of nuclear factor-kappa B. IL-17 also has the capacity to induce joint destruction in an IL-1-independent manner. The discovery of IL-17 family members may further elucidate the role of this cytokine family in arthritis pathology, with IL-17F a promising candidate. Anti-IL-17 cytokine therapy may be an interesting new antirheumatic approach to the prevention of joint destruction, in addition to anti-TNF and anti-IL-1 therapy.