Background The pathogenesis of Systemic sclerosis (SSc) involves fibrosis, vascular changes and autoimmunity. Some research has postulated that interleukin-6 (IL-6) a pleitropic cytokine is important in SSc. However, not all studies agree.
Objectives This analysis reviewed the potential importance of IL-6 in SSc making a framework for IL-6 effects in SSc.
Methods PubMed & Scopus databases and ACR (2009-10) & EULAR abstracts (2009-11) were searched using keywords “scleroderma; cytokines; interleukins and IL- 6”. A cell cytokine interactions model of IL-6 effects in SSc was constructed.
Results 416 reports were found (Pub Med N=82; Scopus N=331; 3 abstracts); 372 were excluded (irrelevant); leaving 41 publications and 3 abstracts (39 from Pub Med, 18 from Scopus but 16 were repeated from Pub Med search); where 40 suggested IL-6 was important in SSc and 4 did not. IL-6 is elevated in serum & skin from SSc patients, especially early dcSSc and is related to disease activity, higher skin scores, ESR and CRP and is negatively associated with FVC and digital ulcer healing. SSc serum have anti-IL-6 Abs which bind to IL-6 receptors. Figure shows model of IL-6 in SSc. There are interactions with macrophages, neutrophils, T and B cells, endothelial effects and fibroblasts.
Conclusions Forty of 44 citations suggested that IL-6 may be important in SSc allowing for a conceptual framework within SSc. This review is timely as a RCT is underway studying IL-6 inhibition in SSc.
Disclosure of Interest C. Muangchant Grant/Research support from: Research Fellow at University of Western Ontario, J. Pope Grant/Research support from: Dr. Muangchant is a Research Fellow at UWO.