Late-onset myasthenia gravis is predisposed to become generalized in the elderly

Objective: The continuous increase in the number of patients presenting with late-onset myasthenia gravis (LOMG) underscores the need for a better understanding of the clinical course and the establishment of an optimal therapeutic strategy. We aimed to clarify factors associated with clinical outcomes in LOMG.
Methods: We retrospectively reviewed the clinical profiles of 40 patients with early-onset MG (EOMG) (onset age: 49 years or younger), 30 patients with non-elderly LOMG (onset age: 50–64 years), and 28 patients with elderly LOMG(onset age: 65 years or older) and compared the subgroups according to onset age and thymus status. The evaluated parameters were MGFA classification before treatment, MG-ADL score, complicating diseases, antibody titer, treatment, and MGFA post-intervention status.
Results: Elderly LOMG patients showed transition to generalized symptoms at a higher frequency and underwent thymectomyless frequently than EOMG and non-elderly LOMG patients (p < 0.001). The frequencies of crisis and plasmapheresis were significantly lower in thymectomized LOMG patients without thymoma than in thymectomized LOMG patients with thymoma or non-thymectomized LOMG patients (p < 0.01, P < 0.05, respectively). However, the outcome was not significantly different. All of the thymectomized LOMG patients without thymoma presenting with hyperplasia or thymic cyst had a favorable clinical course.
Conclusions: Our study showed that elderly LOMG patients are more prone to severity, suggesting that they require aggressive immunomodulatory therapy.

内容要旨・審査要旨・論文本文の公開
本論文は, 著者Waka Sakaiの学位論文として提出され, 学位審査・授与の対象となっている。

This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).