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Journal of Neurology

, Volume 259, Issue 7, pp 1312–1316 | Cite as

Anti-voltage-gated potassium channel Kv1.4 antibodies in myasthenia gravis

  • Fredrik Romi
  • Shigeaki Suzuki
  • Norihiro Suzuki
  • Axel Petzold
  • Gordon T. Plant
  • Nils Erik Gilhus
Original Communication

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.

Keywords

Myasthenia gravis Anti-Kv1.4 antibodies 

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

Notes

Acknowledgments

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.

Conflicts of interest

None.

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Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Fredrik Romi
    • 1
  • Shigeaki Suzuki
    • 2
  • Norihiro Suzuki
    • 2
  • Axel Petzold
    • 3
    • 4
  • Gordon T. Plant
    • 5
    • 6
    • 7
  • Nils Erik Gilhus
    • 1
    • 8
  1. 1.Department of NeurologyHaukeland University HospitalBergenNorway
  2. 2.Department of NeurologyKeio University School of MedicineTokyoJapan
  3. 3.Department of NeuroimmunologyUCL Institute of NeurologyLondonUK
  4. 4.Department of NeurologyFree University Medical CenterAmsterdamThe Netherlands
  5. 5.National Hospital for Neurology and NeurosurgeryLondonUK
  6. 6.Department of Neuro-OphthalmologyMoorfields Eye HospitalLondonUK
  7. 7.Medical Eye UnitSt. Thomas’ HospitalLondonUK
  8. 8.Department of Clinical MedicineUniversity of BergenBergenNorway

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