title: Novel autoantibodies to a voltage-gated potassium channel Kv1.4 in a severe form of myasthenia gravis.
abstract: Sera from patients with myasthenia gravis (MG) were screened for autoantibodies to skeletal muscle-specific antigens by immunoprecipitation assay, using rhabdomyosarcoma and leukemia cell lines. Eleven of 61 MG sera immunoprecipitated a rhabdomyosarcoma-specific 70-kDa protein, which was identified as the voltage-gated K+ channel 1.4 (Kv1.4). This antibody specificity was not detected in 30 patients with polymyositis/dermatomyositis, 9 with thymoma alone, or 30 healthy controls. Clinical features associated with anti-Kv1.4 antibody included bulbar involvement, myasthenic crisis, thymoma, myocarditis, and QT prolongation on electrocardiogram. These findings suggest that anti-Kv1.4 antibody is a novel autoantibody associated with a severe MG subset and thymoma.
authors.affiliation: Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Tokyo 160-8582, Japan.
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Suzuki
authors.forename: Takashi
authors.initials: T
authors.lastname: Satoh
authors.forename: Hidekata
authors.initials: H
authors.lastname: Yasuoka
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Hamaguchi
authors.forename: Kortaro
authors.initials: K
authors.lastname: Tanaka
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Norihiro
authors.initials: N
authors.lastname: Suzuki
authors.forename: Masataka
authors.initials: M
authors.lastname: Kuwana
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000097:blood; D005260:Female; D006801:Humans; D047468:Immunoprecipitation; D051665:Kv1.4 Potassium Channel / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D018482:Muscle, Skeletal / Q000276:immunology; D009157:Myasthenia Gravis / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology*; D012333:RNA, Messenger / Q000378:metabolism; D012720:Severity of Illness Index; D013950:Thymus Gland / Q000378:metabolism
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D051665:Kv1.4 Potassium Channel; D012333:RNA, Messenger