IL-23/IL-17 axis in spondyloarthritis-bench to bedside.

Cytokines play a critical role in the pathogenesis of psoriatic arthritis, ankylosing spondylitis, and other types of spondyloarthritis (SpA). Besides IFN-γ and TNF-α; IL-23/IL-17 cytokines play a dominant role in the inflammatory and proliferative cascades of SpA. Recently, in a series of elegant experiments using mouse models and human tissues, it has been demonstrated that IL-23-induced Th17 cytokines (IL-17 and IL-22) can contribute to following pathologic events associated with SpA: development of psoriatic plaque, pannus formation in the joint, joint erosion, and new bone formation. In this review article, we have discussed the contributing role of the IL-23/IL-17 cytokine axis in the pathogenesis of PsA and AS. IL-23/IL-17-targeted therapies are very promising for SpA, and we have provided an outline about usefulness of these new groups of biologics in SpA.