title: Role of cytokines and chemokines in idiopathic inflammatory myopathies.
abstract: OBJECTIVE
  Cytokines and chemokines are essential players in the initiation and progression of the idiopathic inflammatory myopathies (IIMs). This review focuses on the most recent data and the new insight they provide for the disease mechanisms of dermatomyositis, polymyositis and sporadic inclusion body myositis.
  
  
  RESULTS
  Interferon-alpha and beta are implicated in the innate immune responses underlying dermatomyositis, whereas interferon-gamma stands forward as a more general regulator of the IIMs, reflected by the induction of many interferon-gamma-inducible genes in patients. Interleukin-1beta and interleukin-18 are localized to the inflammatory cells present in IIM muscle, where they may focally induce further recruitment of immune cells. Lymphotoxins are implicated in the cytotoxic activities toward polymyositis and inclusion body myositis muscle fibers, and in the organization and antibody production by B-cells in dermatomyositis. The alpha-chemokines CXCL9, CXCL10 and the beta-chemokines CCL2, CCL3, CCL4, CCL19 and CCL21 are expressed in IIM muscle. The B-cell activator CXCL13 is particularly prominent in the larger perimysial infiltrates of dermatomyositis.
  
  
  CONCLUSIONS
  The cytokine-chemokine patterns described in recent studies provide further evidence for predominance of Th1-mediated reactions in the different IIMs, inflammation-induced degenerative phenomena in inclusion body myositis, and a possible role for lymphoneogenesis in the sustained inflammatory response in dermatomyositis.
authors.affiliation: Department of Neurology and Neuromuscular Reference Center, Laboratory for Myopathology, Ghent University Hospital, Ghent, Belgium.
authors.forename: Boel
authors.initials: B
authors.lastname: De Paepe
authors.forename: Kim K
authors.initials: KK
authors.lastname: Creus
authors.forename: Jan L
authors.initials: JL
authors.lastname: De Bleecker
mesh_terms: D016229:Amyloid beta-Peptides / Q000276:immunology; D018925:Chemokines / Q000276:immunology*; D016207:Cytokines / Q000276:immunology*; D003882:Dermatomyositis / Q000209:etiology / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate; D007372:Interferons / Q000276:immunology; D007375:Interleukin-1 / Q000276:immunology; D018448:Models, Immunological; D009220:Myositis / Q000209:etiology / Q000276:immunology*; D018979:Myositis, Inclusion Body / Q000209:etiology / Q000276:immunology; D017285:Polymyositis / Q000209:etiology / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D016229:Amyloid beta-Peptides; D018925:Chemokines; D016207:Cytokines; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D007372:Interferons