The role of IL-17A in axial spondyloarthritis and psoriatic arthritis: recent advances and controversies

• Published in: Annals of the rheumatic diseases Vol. 78; no. 9; pp. 1167 - 1178
• Main Authors: McGonagle, Dennis G, McInnes, Iain B, Kirkham, Bruce W, Sherlock, Jonathan, Moots, Robert
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd and European League Against Rheumatism 01.09.2019; BMJ Publishing Group LTD; BMJ Publishing Group
• Subjects: Ankylosing spondylitis; Antibodies, Monoclonal, Humanized - therapeutic use; Arthritis; Arthritis, Psoriatic - drug therapy; Arthritis, Psoriatic - metabolism; Biomarkers - metabolism; Bone growth; Chronic illnesses; Cytokines; Defects; Disease; Gene expression; Genes; Genetic engineering; Humans; Immune response; Immunity (Disease); Immunology; Infections; inflammation; Inflammatory diseases; Interferon; Interleukin-17 - antagonists & inhibitors; Interleukin-17 - physiology; Kinases; Lymphocytes; Osteogenesis; Pathogens; Psoriasis; Psoriatic arthritis; Review; Rheumatic diseases; Salmonella; Spondylarthritis - drug therapy; Spondylarthritis - metabolism; Spondylitis; spondyloarthritis; Tuberculosis; Yeast; spondyloarthritis; psoriatic arthritis; inflammation; ankylosing spondylitis
• ISSN: 0003-4967; 1468-2060
• DOI: 10.1136/annrheumdis-2019-215356

Although the pathogenic mechanisms underlying axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) are not fully elucidated, several lines of evidence suggest that immune responses mediated by interleukin 17A (IL-17A) play a pivotal role in both diseases. This is best highlighted by the significant clinical efficacy shown with inhibitors of IL-17A in treating axSpA and PsA. Nevertheless, a number of knowledge gaps exist regarding the role of IL-17A in the pathophysiology of spondyloarthritis in man, including its cellular origin, its precise role in discrete disease processes such enthesitis, bone erosion, and bone formation, and the reasons for the discrepant responses to IL-17A inhibition observed in certain other spondyloarthritis manifestations. In this review, we focus on the latest data from studies investigating the role of IL-17A in ankylosing spondylitis (AS) and PsA that build on existing and emerging scientific knowledge in the field. Key remaining research questions are also highlighted to guide future research.