Dermatomyositis and MIG.

Several studies demonstrated the presence of an elevated expression of chemokine (C-X-C motif) ligand (CXCL)9/monokine induced by interferon (IFN)-γ (MIG) on macrophages and in T cells in perimysial infiltrates of patients with dermatomyositis (DM), and of chemokine (C-X-C motif) receptor (CXCR)3 expression on the majority of T cells in the same patients. This underlines the importance of T helper 1-mediated immunity, and in particular the MIG/CXCR3 interaction, in the immunopathogenesis of DM. The importance of MIG has been confirmed by a study on patients with DM about the presence of chemokines and their receptors in infiltrating cells at the level of lesional skin. This study showed that type I IFN chemokines, in particular MIG, are firmly related with the active disease and its clinical score in juvenile DM, suggesting the importance of chemokines trend in monitoring disease activity and in the treatment indication.