title: Anti-voltage-gated potassium channel Kv1.4 antibodies in myasthenia gravis.
abstract: Myasthenia gravis (MG) is an autoimmune disease characterized by skeletal muscle weakness mainly caused by acetylcholine receptor antibodies. MG can be divided into generalized and ocular, and into early-onset (<50 years of age) and late-onset (≥50 years of age). Anti-Kv1.4 antibodies targeting α-subunits (Kv1.4) of the voltage-gated potassium K(+) channel occurs frequently among patients with severe MG, accounting for 18% of a Japanese MG population. The aim of this study was to characterize the clinical features and serological associations of anti-Kv1.4 antibodies in a Caucasian MG population with mild and localized MG. Serum samples from 129 Caucasian MG patients with mainly ocular symptoms were tested for the presence of anti-Kv1.4 antibodies and compared to clinical and serological parameters. There were 22 (17%) anti-Kv1.4 antibody-positive patients, most of them women with late-onset MG, and all of them with mild MG. This contrasts to the Japanese anti-Kv1.4 antibody-positive patients who suffered from severe MG with bulbar symptoms, myasthenic crisis, thymoma, myocarditis and prolonged QT time on electrocardiography, despite equal anti-Kv1.4 antibody occurrence in both populations. No other clinical or serological parameters influenced anti-Kv1.4 antibody occurrence.
authors.affiliation: Department of Neurology, Haukeland University Hospital, Bergen, Norway. fredrik.romi@haukeland.no
authors.forename: Fredrik
authors.initials: F
authors.lastname: Romi
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Suzuki
authors.forename: Norihiro
authors.initials: N
authors.lastname: Suzuki
authors.forename: Axel
authors.initials: A
authors.lastname: Petzold
authors.forename: Gordon T
authors.initials: GT
authors.lastname: Plant
authors.forename: Nils Erik
authors.initials: NE
authors.lastname: Gilhus
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D005260:Female; D006801:Humans; D007564:Japan; D051665:Kv1.4 Potassium Channel / Q000276:immunology*; D008279:Magnetic Resonance Imaging; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000097:blood* / Q000175:diagnosis / Q000276:immunology* / Q000503:physiopathology; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000378:metabolism; D012737:Sex Factors
chemical_list: D001323:Autoantibodies; D051665:Kv1.4 Potassium Channel; D011950:Receptors, Cholinergic; C095714:MUSK protein, human; D020794:Receptor Protein-Tyrosine Kinases; D020782:Matrix Metalloproteinases