In situ analysis of interleukin-6 expression at different sites of zygapophyseal joints from patients with ankylosing spondylitis in comparison to controls. (July 2015)

• Record Type: Journal Article
• Authors: Bleil, J; Maier, R; Syrbe, U; Sieper, J; Appel, H
• Is Part Of: Scandinavian journal of rheumatology. Volume 44:Number 4(2015)
• Page Start: 296
• Page End: 301
• Publication Date: 2015-07
• Subjects: Rheumatology -- Periodicals; Arthritis; Rheumatic Diseases; 616.72005
• DOI: 10.3109/03009742.2014.1000371
• Languages: English
• ISSNs: 0300-9742

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <p> <bold>Objectives:</bold> Analysis of interleukin (IL)-6 serum levels in patients with ankylosing spondylitis (AS) has indicated that IL-6 might be a pro-inflammatory cytokine involved in AS. However, two placebo-controlled trials with monoclonal antibodies directed against the IL-6 receptor have failed to demonstrate the efficacy of the monoclonal humanized anti-human IL-6 receptor antibody over placebo for the treatment of symptoms of AS. In this study we conducted an in situ analysis of IL-6 expression at different sites of inflammation in zygapophyseal joints of patients with AS in comparison to osteoarthritis autopsy controls (CO).</p> <p> <bold>Method:</bold> Our immunohistochemical analysis involved 14 patients with AS, 12 autopsy controls (CO), and 11 patients with osteoarthritis (OA). Immunohistochemistry was performed to detect IL-6+ cells at five different sites: within subchondral bone marrow, fibrous tissue replacing subchondral bone marrow, hyaline cartilage, and the subchondral bone plate, and at entheseal sites.</p> <p> <bold>Results:</bold> Apart from changes in subchondral bone marrow, no significant differences were observed at the sites analysed when comparing AS patients and controls. A significantly lower frequency of IL-6+ cells was evident in AS patients compared to controls (p = 0.0043). In addition, AS patients tended to have even lower percentages of IL-6+ cells than controls at subchondral bone plates and entheseal sites. A significantly lower number of IL-6 expressing cells was also seen within the fibrous tissue of AS compared to OA patients (p = 0.0237).</p> <p> <bold>Conclusions:</bold> This in situ analysis confirms that IL-6 is not a key player in the pathogenesis of inflammatory processes in spondyloarthritides (SpA). The relevance of pro-inflammatory agents in axial SpA might be studied better in situ in bony specimens at the primary site of inflammation.</p> </abstract>