Science
Interleukin-17 (IL-17A) is a cytokine critical for the acute defence against extracellular bacterial and fungal infections. Excess production during chronic inflammation has been associated with many inflammatory and autoimmune disorders. In this podcast, the Editor-in-Chief of RMD Open Bernard Combe and Pierre Miossec (Department of Immunology and Rheumatology, University of Lyon, France) discuss a review paper about an update on IL-17A. The review concludes that the use of IL-17 inhibition in psoriatic arthritis (PsA) is easy to understand because of the role of IL-17 in bone destruction. However, the use of the same inhibitors for the treatment of ankylosing spondylitis (AS) implies another understanding. In fact, IL-17 specifically in combination with TNF, induces bone matrix formation by isolated osteoblasts. This is the case at the site of ligaments insertion, where osteoclasts are absent. Local bone formation leads to syndesmophytes. Professor Miossec also explains how these findings might impact clinical practice. For more details about this article, visit the RMD Open website: http://rmdopen.bmj.com/content/3/1/e000284.