Clinical features and outcomes of patients with muscle-specific kinase antibody-positive myasthenia gravis in Japan

Manato Yasuda; Akiyuki Uzawa; Satoshi Kuwabara; Shigeaki Suzuki; Hiroyuki Akamine; Yosuke Onishi; Yukiko Ozawa; Naoki Kawaguchi; Tomoya Kubota; Masanori P Takahashi; Yasushi Suzuki; Genya Watanabe; Takashi Kimura; Takamichi Sugimoto; Makoto Samukawa; Naoya Minami; Masayuki Masuda; Shingo Konno; Yuriko Nagane; Kimiaki Utsugisawa

doi:10.1016/j.jneuroim.2023.578241

Clinical features and outcomes of patients with muscle-specific kinase antibody-positive myasthenia gravis in Japan

J Neuroimmunol. 2023 Dec 15:385:578241. doi: 10.1016/j.jneuroim.2023.578241. Epub 2023 Nov 7.

Authors

Manato Yasuda¹, Akiyuki Uzawa², Satoshi Kuwabara¹, Shigeaki Suzuki³, Hiroyuki Akamine¹, Yosuke Onishi¹, Yukiko Ozawa¹, Naoki Kawaguchi⁴, Tomoya Kubota⁵, Masanori P Takahashi⁵, Yasushi Suzuki⁶, Genya Watanabe⁶, Takashi Kimura⁷, Takamichi Sugimoto⁸, Makoto Samukawa⁹, Naoya Minami¹⁰, Masayuki Masuda¹¹, Shingo Konno¹², Yuriko Nagane¹³, Kimiaki Utsugisawa¹³

Affiliations

¹ Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan.
² Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan. Electronic address: auzawa@chiba-u.jp.
³ Department of Neurology, Keio University School of Medicine, Tokyo, Japan.
⁴ Department of Neurology, Neurology Chiba Clinic, Chiba, Japan.
⁵ Department of Clinical Laboratory and Biomedical Sciences, Division of Health Sciences, Osaka University Graduate School of Medicine, Osaka, Japan.
⁶ Department of Neurology, National Hospital Organization Sendai Medical Center, Sendai, Japan.
⁷ Department of Neurology, Hyogo Medical University, Nishinomiya, Japan.
⁸ Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Hiroshima, Japan.
⁹ Department of Neurology, Kindai University Faculty of Medicine, Osaka, Japan.
¹⁰ Department of Neurology, National Hospital Organization Hokkaido Medical Center, Sapporo, Japan.
¹¹ Department of Neurology, Tokyo Medical University, Tokyo, Japan.
¹² Department of Neurology, Toho University Ohashi Medical Center, Tokyo, Japan.
¹³ Department of Neurology, Hanamaki General Hospital, Hanamaki, Japan.

PMID: 37952282
DOI: 10.1016/j.jneuroim.2023.578241

Abstract

This study included 51 patients with muscle-specific kinase antibody-positive myasthenia gravis (MuSK-MG) from a Japanese multicenter survey to examine clinical features and outcomes. Median onset age was 37 years and female predominance was observed. All patients developed generalized symptoms and almost all (50/51) patients had bulbar symptoms. About half of the patients met the criteria for refractory MG. The refractory group had a lower age of onset, higher severity scores, and higher maximum daily doses of oral prednisolone compared to the nonrefractory group. The outcomes for MuSK-MG patients in Japan are not favorable, indicating the need for more aggressive treatment.

Keywords: Clinical features; MuSK; Myasthenia gravis; Neuroimmunology; Neuromuscular disorder.

Publication types

Multicenter Study
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Autoantibodies / therapeutic use
Female
Humans
Japan
Male
Muscles
Myasthenia Gravis* / diagnosis
Myasthenia Gravis* / drug therapy
Prednisolone / therapeutic use

Substances

Prednisolone
Autoantibodies