Background Idiopathic Inflammatory myopathies (IIM) are an heterogeneous group of autoimmune diseases that include Polimyositis (PM), Dermatomyositis (DM), Inclusion Body Myositis (IBM) and Connective Tissue Disease-related Myositis (CTD-M). Several molecules, such as cytokines, chemokines and growth factors can play an important role in triggering and substain inflammation and the consequent muscle damage (1,2,3).
Objectives To measure serum levels of some proinflammatory molecules to assess their hypothetical role in the development of chronic inflammatory myositis and the hypothetical differences among the different forms of myopathies.
Methods We enrolled 24 patients (M/F =7/17; mean age =55,75yrs; mean disease duration =105,2 months) affected by PM (n=7), DM (n=10), IBM (n=2), and CTD-M (n=5), diagnosed according to clinical and histological criteria. We also enrolled 12 age and sex matched healthy controls. In all patients we investigated serum levels of 17 molecules: CTACK, β-NGF, HGF, IFNα, IL 2rα, M-CSF, MIG, SCFG-β, IL-1α, IL-3, LIF, MCP, SCF, SDF-1α, TNF-β and TRAIL, using a multiplex method (Human Cytokine Standard 23-Plex, Bio-Rad Laboratories).
Results We detected a statistically significant increase of β-NGF (median 1,72 pg/ml vs 0,94 pg/ml; p=0.0051), HGF (median 625 pg/ml vs 400 pg/ml; p=0,0053), IFNα (median 46,61 pg/ml vs 29,63 pg/ml; p=0,05), IL-2 rα (median 139,9 pg/ml vs 82,7 pg/ml; p=0,018), LIF (median 15pg/ml vs 4,13 pg/ml; p=0,05), M-CSF (median 30,87 pg/ml vs 19,15 pg/ml; p=0,033), MIG (median 2492,49 pg/ml vs 900,84 pg/ml; p=0,0008) and SCFG- β (median 20198,1 pg/ml vs 13976,65 pg/ml; p=0,0066) serum levels in patients with IIM respect to healthy controls. We didn't find any significant difference among the various forms of myopathies nor for the main clinical and laboratory features.
Conclusions Our study shows that several proinflammatory molecules can be involved in the pathogenesis of IIM. Their exact role needs to be better assessed and requires further investigations assuming that these molecules may be used, in addition to the histopathological analysis, as a useful diagnostic tool for these rare diseases.
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Disclosure of Interest None declared