Interleukin 6 in Systemic Sclerosis and Potential Implications for Targeted Therapy

OBJECTIVE: The purpose of this study was to review the potential importance of interleukin 6 (IL-6) in systemic sclerosis (SSc). METHODS: PubMed and Scopus databases and American College of Rheumatology (from 2009-10) and European League Against Rheumatism abstracts (2009-11) were searched using keywords "scleroderma; SSc; cytokines; interleukins; interleukin 6" and publications were excluded if not pertaining to IL-6 in SSc. Data were extracted from selected articles to construct a cell interaction model of the effects of IL-6 in SSc. RESULTS: A total of 416 reports were found (PubMed, n = 82; Scopus, n = 331; 3 abstracts); 372 were excluded (irrelevant) leaving 41 publications and 3 abstracts (39 from PubMed, 18 from Scopus; but 16 were repeated from PubMed search), where 40 suggested IL-6 was important in SSc and 4 did not. Effects of IL-6 in SSc were summarized schematically. CONCLUSION: Of the 44 publications, 40 suggested that IL-6 may be important in SSc, allowing for a conceptual framework within SSc including effects on macrophages, fibroblasts, plasma cells, monocytes, and extracellular matrix.