IL6 and rheumatoid arthritis: This cytokine is one of the main mediators of pro-inflammatory responses, mainly secreted by macrophages, fibroblasts and endothelial cells14; IL-6 promotes vascular endothelial activation by an increase of E-selectin, intercellular adhesion molecule 1 (ICAM-1) and vascular cellular adhesion molecule 1 (VCAM-1) expression which is important for leukocyte migration to muscle tissue15, otherwise, IL-6 elevated levels have been reported in other rheumatic diseases including rheumatoid arthritis, Sjögren’s syndrome, and Crohn’s disease16–18.