IL-17 levels in synovium of patients with rheumatoid arthritis, psoriatic arthritis and osteoarthritis: Target validation in various forms of arthritis. (22nd February 2011)

• Record Type: Journal Article
• Authors: van Baarsen, L G M; Lebre, M C; van der Coelen, D; Snoek, B C; Gerlag, D M; Tak, P P
• Is Part Of: Annals of the rheumatic diseases. Volume 70(2011)Supplement 2
• Page Start: A79
• Page End: A79
• Publication Date: 2011-02-22
• Subjects: Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/ard.2010.149013.27
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : Background: Accumulating evidence suggests an important role for interleukin 17 (IL-17) in the pathogenesis of several inflammatory diseases, including rheumatoid arthritis (RA). IL-17A has been well studied in models of arthritis, but little is known about the relative expression of IL-17A, IL-17F, and their receptors in human synovial tissue. Objective: To determine the expression of IL-17A, IL-17F and their receptors IL-17RA and IL-17RC in synovial tissues of patients with RA, psoriatic arthritis (PsA) and osteoarthritis (OA). Methods: Synovial biopsy specimens were obtained by arthroscopy from patients with RA (n=13), PsA (n=15) and inflammatory OA (n=14). For comparison synovial tissues from non-inflammatory controls (n=7) were included. Immunohistological analysis was performed using monoclonal antibodies specific for IL-17A, IL-17F, IL-17RA and IL-17RC. Stained sections were evaluated by digital image analysis. Results: Levels of IL-17A, IL-17F, IL-17RA and IL-17RC were abundantly present in synovial tissues of all patient groups and highly variable between patients. Digital image analysis showed a significant increase of IL-17A and IL-17RC, but not of IL-17F and IL-17RA in patients with arthritis compared to non-inflamed control tissues, while the expression of IL-17A, IL-17F and IL-17RA was similar between the different patient groups. Expression of IL-17RC in the synovial lining was significantly increased in PsA compared to OA patients. Conclusions: Increased expression of IL-17A is not restricted to synovial tissues of RA patients but also observed in other forms of inflammatory arthritis. In contrast, the expression of IL-17F is not significantly increased. IL-17A blockade could provide a novel therapeutic approach in a variety of arthritides.