Novel autoantibodies to a voltage-gated potassium channel Kv1.4 in a severe form of myasthenia gravis.
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.
Suzuki
Shigeaki
S
Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Tokyo 160-8582, Japan.
Satoh
Takashi
T
Yasuoka
Hidekata
H
Hamaguchi
Yasuhito
Y
Tanaka
Kortaro
K
Kawakami
Yutaka
Y
Suzuki
Norihiro
N
Kuwana
Masataka
M
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
D001323:Autoantibodies; D001324:Autoantigens; D051665:Kv1.4 Potassium Channel; D012333:RNA, Messenger