title: Immunopathogenesis of juvenile dermatomyositis.
abstract: There is increasing evidence for involvement of the mechanisms of the innate immune system in the pathogenesis of idiopathic inflammatory myopathies (IIMs), especially in the adult and juvenile forms of dermatomyositis. Juvenile dermatomyositis (JDM) is the most common form of childhood IIM, and this review focuses on recent advances in understanding the actions of the innate immune system in this condition. Over the last few years, great strides have been made in understanding immune dysregulation in IIM, including JDM. Novel autoantibodies have been identified, and new genetic contributions have been described. Among the most striking findings is type I interferon activity in JDM tissue and peripheral blood. This is in conjunction with the description of dysregulation of the major histocompatibility complex (MHC) class I gene and identification of plasmacytoid dendritic infiltrates as the possible cellular source of type I interferons. These findings also point toward the potential prognostic value of muscle biopsies and have helped expand our understanding of the etiopathogenesis of IIM.
authors.affiliation: Division of Rheumatology, Department of Medicine and Pediatrics, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, Minnesota 55905, USA.
authors.forename: Sahil
authors.initials: S
authors.lastname: Khanna
authors.forename: Ann M
authors.initials: AM
authors.lastname: Reed
mesh_terms: D001323:Autoantibodies / Q000032:analysis / Q000097:blood; D015551:Autoimmunity / Q000502:physiology*; D001706:Biopsy / Q000592:standards; D002648:Child; D003713:Dendritic Cells / Q000276:immunology; D003882:Dermatomyositis / Q000235:genetics / Q000276:immunology*; D020022:Genetic Predisposition to Disease / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D007107:Immune System / Q000276:immunology; D007113:Immunity, Innate / Q000502:physiology*; D007370:Interferon Type I / Q000378:metabolism
chemical_list: D001323:Autoantibodies; D015395:Histocompatibility Antigens Class I; D007370:Interferon Type I