IL-23, which is composed of p19 and p40 subunits, is a proinflammatory
cytokine that contributes to the formation and maintenance of Th17 cells in inflammatory
autoimmune diseases.
IL-23 is a human osteoclastogenic
cytokine and anti-IL-23 antibody attenuates paw volume and joint destruction in CIA rats.
IL-23 levels in serum and synovial fluid are high in
rheumatoid arthritis (RA) patients, and
IL-23 may be a useful
biomarker for the diagnosis of RA. In addition,
IL-23 affects the pathogenesis of
inflammation and bone destruction through interaction with other
cytokines such as
IL-17 and TNF-α. Furthermore, polymorphisms of IL23R are a risk factor for
ankylosing spondylitis (AS) and
psoriatic arthritis (PsA), which indicates that
IL-23 is also involved in the pathogenesis of spondyloarthritis (SpA). Finally,
IL-17 and
IL-23 inhibitors reduce the clinical manifestations of SpA. Thus, the IL-23/Th17 pathway is a therapeutic target for the treatment of inflammatory
arthritis.