title: High specificity of myositis specific autoantibodies for myositis compared with other neuromuscular disorders.
abstract: Myositis specific autoantibodies (MSAs) are proven to be specific for myositis compared with other inflammatory connective tissue diseases. Their specificity compared, however, with other neuromuscular disorders, which are included in the differential diagnosis of patients in whom the diagnosis myositis is under consideration, is unknown. We prospectively screened sera from 107 patients with various neuromuscular disorders for the most common MSAs and compared the results with the findings in a group of 97 myositis patients, published previously. Special attention was paid to patients with facioscapulohumeral muscular dystrophy (FSHD), an autosomal dominant muscle disease with marked inflammation in skeletal muscle tissue. Only one patient in the neuromuscular disorders group tested positive for an MSA, compared with 41 in the myositis group, resulting in a specificity of 99%. None of the FSHD patients tested positive. We conclude that the tested MSAs are highly specific for myositis and that they are not merely associated with muscle inflammation.
authors.affiliation: Neuromuscular Centre Nijmegen, Dept. of Neurology, University Medical Centre Nijmegen, 9101, 6500 HB, Nijmegen, The Netherlands. g.hengstman@neuro.umcn.nl
authors.forename: G J D
authors.initials: GJ
authors.lastname: Hengstman
authors.forename: L
authors.initials: L
authors.lastname: van Brenk
authors.forename: W T M
authors.initials: WT
authors.lastname: Vree Egberts
authors.forename: E L
authors.initials: EL
authors.lastname: van der Kooi
authors.forename: G F
authors.initials: GF
authors.lastname: Borm
authors.forename: G W A M
authors.initials: GW
authors.lastname: Padberg
authors.forename: W J
authors.initials: WJ
authors.lastname: van Venrooij
authors.forename: B G M
authors.initials: BG
authors.lastname: van Engelen
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D016001:Confidence Intervals; D006801:Humans; D009220:Myositis / Q000097:blood*; D009468:Neuromuscular Diseases / Q000097:blood; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D001323:Autoantibodies
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