title: Expression of tumor necrosis factor-alpha in muscles of polymyositis.
abstract: We immunohistochemically examined biopsied muscles from nine untreated patients with polymyositis (PM) and five patients with other neuromuscular diseases (ONMD), using monoclonal antibodies to tumor necrosis factor-alpha (TNF-alpha) and lymphoid surface markers. In muscles of three patients with PM, we observed many TNF-alpha positive macrophages and lymphocytes in endomysium and around vessels in the muscles. By contrast, there were few, weakly TNF-alpha stained cells in muscles of three patients with ONMD. The ratio of TNF-alpha-positive cells to the muscle fibers and the ratio of TNF-alpha-positive cells to the mononuclear cells were significantly higher in PM compared with ONMD. In addition, we observed atrophic muscle fibers more frequently in TNF-alpha-positive muscles than TNF-alpha-negative ones. We conclude that, at least, in a part of PM patients, TNF-alpha produced locally may contribute to the pathogenesis of PM.
authors.affiliation: Department of Neurology, Tohoku University School of Medicine, Miyagi, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tateyama
authors.forename: I
authors.initials: I
authors.lastname: Nagano
authors.forename: M
authors.initials: M
authors.lastname: Yoshioka
authors.forename: K
authors.initials: K
authors.lastname: Chida
authors.forename: S
authors.initials: S
authors.lastname: Nakamura
authors.forename: Y
authors.initials: Y
authors.lastname: Itoyama
mesh_terms: D000328:Adult; D001706:Biopsy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016131:Lymphocyte Subsets; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000737:chemistry* / Q000276:immunology / Q000473:pathology; D009468:Neuromuscular Diseases / Q000378:metabolism / Q000473:pathology; D017285:Polymyositis / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis*
chemical_list: D014409:Tumor Necrosis Factor-alpha