Tohoku J. Exp. Med., 2024 January, 262(1)
The Clinical Course and Treatment of a Case of Refractory Systemic Juvenile Myasthenia Gravis Successfully Treated with Thymectomy
Moriei Shibuya,1,* Minobu Shichiji,2,* Miki Ikeda,1 Kaori Kodama,1 Takuya Miyabayashi,1 Ryo Sato,1 Yukimune Okubo,1 Wakaba Endo,1 Takehiko Inui,1 Noriko Togashi,1 Mika Nagao,3 Kaname Sato,3 Takatoshi Sato,2 Masato Kanzaki,4 Osamu Segawa,5 Kenta Masui,6 Keiko Ishigaki2 and Kazuhiro Haginoya1
1Department of Pediatric Neurology, Miyagi Children's Hospital, Sendai, Miyagi, Japan
2Department of Pediatrics, Tokyo Women's Medical University School of Medicine, Tokyo, Japan
3Department of Pediatrics, Ohta Nishinouchi Hospital, Koriyama, Fukushima, Japan
4Department of Thoracic Surgery, Tokyo Women's Medical University, Tokyo, Japan
5Department of Pediatric Surgery, Tokyo Women's Medical University, Tokyo, Japan
6Department of Surgical Pathology, Tokyo Women's Medical University, Tokyo, Japan
Juvenile myasthenia gravis (JMG) exhibits a more favorable response to glucocorticoids and has a better prognosis than adult myasthenia gravis. However, no established treatment exists for refractory JMG. Although thymectomy has been performed in several patients with refractory systemic JMG, there are few detailed clinical descriptions of patients who underwent thymectomy. Here, we present the case of a 10-year-old boy with refractory systemic JMG who was successfully treated with thymectomy. The patient developed symptoms, including dysphagia, malaise, diurnal ptosis, and weakness in the trunk muscles, and he was diagnosed with generalized JMG. Despite undergoing various treatments, including steroids, tacrolimus, steroid pulse therapy, intravenous immunoglobulin, azathioprine (AZT), and rituximab, his symptoms did not improve. Therefore, he underwent a thoracoscopic thymectomy 24 months after disease onset. Thymectomy led to remission, as demonstrated by a significant reduction in the quantitative myasthenia gravis score and anti-acetylcholine receptor antibody levels, which persisted for 43 months after surgery. Our case demonstrates the effectiveness of thymectomy in systemic JMG patients with positive anti-acetylcholine receptor antibodies, despite therapeutic failure with AZT and rituximab, within 2 years of disease onset.
Key words —— anti-AchR antibody; azathioprine; juvenile myasthenia gravis; rituximab; thymectomy
© 2024 Tohoku University Medical Press
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Tohoku J. Exp. Med., 2024 January, 262(1), 29-31.
*These two authors contributed equally to this study.
Correspondence: Kazuhiro Haginoya, Department of Pediatric Neurology, Miyagi Children's Hospital, 4-3-17 Ochiai, Aoba-ku, Sendai, Miyagi 989-3126, Japan.
e-mail: khaginoya@kha.biglobe.ne.jp
Keiko Ishigaki, Department of Pediatrics, Tokyo Women's Medical University School of Medicine, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
e-mail: ishigaki.keiko@twmu.ac.jp