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.
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Abbreviations
- AChR:
-
Acetylcholine receptor
- ECG:
-
Electrocardiogram
- GMG:
-
Generalized MG
- HSP:
-
Heat shock protein
- Kv1:
-
Potassium K+ channel α-subunit
- MG:
-
Myasthenia gravis
- MMPs:
-
Matrix metalloproteinases
- MRI:
-
Magnetic resonance imaging
- MuSK:
-
Muscle specific kinase
- OMG:
-
Ocular MG
- VGKC:
-
Voltage-gated potassium K+ channel
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This work was supported a grant from the Japanese Ministry of Education, Science, Sports and Culture (no. 23591255) and a Neuroimmunological Disease Research Committee grant from the Japanese Ministry of Health, Labour, and Welfare.
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Romi, F., Suzuki, S., Suzuki, N. et al. Anti-voltage-gated potassium channel Kv1.4 antibodies in myasthenia gravis. J Neurol 259, 1312–1316 (2012). https://doi.org/10.1007/s00415-011-6344-y
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DOI: https://doi.org/10.1007/s00415-011-6344-y