Association of early-onset myasthenia gravis and primary Sjögren’s syndrome: a case-based narrative review

Coexistent myasthenia gravis (MG) and primary Sjögren’s syndrome (pSS) is an absolute rarity. That is kind of a surprise as both entities seem to share the same corresponding immunologic mechanisms. We hereby report the case of a 41-year-old woman with coincident early-onset MG (EOMG) and pSS. Because EOMG was the leading clinical feature, she was primarily treated by innovative non-intubated uniportal subxiphoid video-assisted thoracoscopic surgery (VATS) thymectomy. As the association of EOMG and pSS is so unusual, we contextualize our findings with the relevant literature. Particular relevance is an anti-nuclear antibody screening throughout the clinical course of MG and—in reverse—a screening for MG variables when pSS patients complain either muscle fatigability or fatigable ptosis. As pSS patients do not develop any serious morbidity, supervising MG progress in patients with both diseases is of utmost importance. Apart from conscientious pSS diagnosis, prompt adjusting of EOMG progress is the essential aspect of targeted treatment. In this context, it is relevant that therapeutic decisions are made in a multidisciplinary approach. Due to its rarity, multicenter prospective studies of larger sample sizes are indispensably needed to obtain a better understanding of this unusual link.