Thymic Involvement in the Pathophysiology of Myasthenia Gravis

Chung, Hye Yoon; Kim, Seung Woo; Shin, Ha Young

doi:2026.44.4.259

J Korean Neurol Assoc > Volume 44(4); 2026 > Article

Review Article

Journal of the Korean Neurological Association 2026;44(4): 259-265. doi: https://doi.org/10.17340/jkna.2026.0039

중증근무력증에서 가슴샘의 역할과 병태생리

정혜윤^1,2, 김승우¹, 신하영¹

¹연세대학교 의과대학 신경과학교실
²연세대학교 의과대학 용인세브란스병원 신경과

Thymic Involvement in the Pathophysiology of Myasthenia Gravis

Hye Yoon Chung MD, PhD^1,2, Seung Woo Kim MD, PhD¹, Ha Young Shin MD, PhD¹

¹Department of Neurology, Yonsei University College of Medicine, Seoul, Korea
²Department of Neurology, Yongin Severance Hospital, Yonsei University Health System, Yongin, Korea

Corresponding Author: Ha Young Shin ,Tel: +82-2-2228-1600, Fax: +82-2-393-0705, Email: hayshin@yuhs.ac

Received: June 1, 2026 Revised: June 29, 2026 Accepted: June 29, 2026 Published online: November 1, 2026

Abstract

The precise mechanisms underlying autoantibody generation in myasthenia gravis (MG) remain incompletely understood. Evidence suggests an important role of the thymus in the initiation and maintenance of the autoimmune response. Thymic abnormalities, including thymic follicular hyperplasia and thymoma, are frequently observed in MG and are associated with distinct pathological features. In thymic hyperplasia, ectopic germinal center formation promotes B-cell activation and sustained autoantibody production, whereas thymoma is associated with impaired T-cell development and may also exhibit ectopic germinal center formation. These contribute to the dysfunction of central immune tolerance and the dysregulation of peripheral immune responses. This review summarizes the immunological mechanisms linking thymic pathology to MG pathogenesis.

Key Words: Myasthenia gravis | Thymus gland | Physiopathology