Comorbidity in myasthenia gravis

INTRODUCTION. Myasthenia gravis is an autoimmune disorder characterized by pathological muscle weakness and fatigability. Patients with myasthenia often present with various comorbidities, including cardiovascular and thyroid diseases, systemic autoimmune disorders, as well as mental health conditions such as depression and anxiety disorders. The impact of these comorbidities on the severity of myasthenia remains ambiguous. AIM. To evaluate the structure and influence of comorbid conditions on the course of myasthenia gravis in patients with varying disease severity.

MATERIALS AND METHODS. A clinical analysis was conducted on 102 patients with myasthenia gravis who underwent treatment between 2020 and 2023 at the Almazov National Medical Research Centre and the City Multidisciplinary Hospital No. 2 at St. Petersburg. Demographic characteristics, comorbidities, and myasthenia severity (MGFA classification) were assessed. A comparative analysis was performed for groups with different disease severities.

RESULTS. The most common comorbid conditions were anxiety disorders, depression (40.2 %) and hypertension (37.3 %). Mental health disorders were more prevalent in patients younger than 40 years, whereas cardiovascular diseases dominated in patients over 60 years. No significant association was found between these comorbidities and the severity of myasthenia.

CONCLUSION. Despite the high prevalence of comorbid conditions, their impact on the severity of myasthenia gravis has not been identified. Further research is required to elucidate the mechanisms of interaction between myasthenia gravis and comorbidities.

1. Gilhus N. E., Nacu A., Andersen J. B., Owe J. F. Myasthenia gravis and risks for comorbidity. Eur J Neurol. 2015;(22):17–23.

2. Bernardo Cacho Diaz, Paola Flores-Gavilán, Guillermo García-Ramos, Nydia A. Lorenzana-Mendoza. Myasthenia Gravis and Its Comorbidities. J Neurol Neurophysiol. 2015;(6):1–5.

3. Misra U. K., Kalita J., Singh V. K., Kumar S. A study of comorbidities in myasthenia gravis. Acta Neurol Belg. 2020;120( 1):59–64.

4. Laakso S. M., Myllynen C., Strbian D., Atula S. Comorbidities worsen the prognosis of generalized myasthenia gravis post-thymectomy. J Neurol Sci. 2021;(427):1–6.

5. Alekseeva T. M., Kreis O. A., Gavrilov Y. V., Valko P. O., Weber K. P., Valko Y. Impact of autoimmune comorbidity on fatigue, sleepiness and mood in myasthenia gravis. J Neurol. 2019;(266):2027–2034.

6. Basta I. Z., Pekmezović T. D., Perić S. Z., Kisić-Tepavčević D. B., Rakočević-Stojanović V. M., Stević Z. D., Lavrnić D. V. Assessment of health-related quality of life in patients with myasthenia gravis in Belgrade (Serbia). Neurol Sci. 2012;(33):1375–1381.

7. Machado-Alba J. E., Calvo-Torres L. F., GaviriaMendoza A., Augusto C. MejíA-Vélez. Prescription profile of pyridostigmine use in a population of patients with myasthenia gravis. Muscle Nerve. 2017;56(6):1041–1046.

8. Klimiec-Moskal E., Quirke M., Leite M. I. Comorbidities in older patients with myasthenia gravis – Comparison between early- and late-onset disease. Acta Neurol Scand. 2022;145(3): 371–374.

9. Khalmurzina A. N., Alekseeva T. M., Lobzin S. V., Rudenko D. I., Kryuchkova V. V. Analysis of clinical manifestations and diagnosis of late-onset myasthenia gravis. Neuromuscular diseases. 2020;(10):53–63. (In Russ.).

10. Yu L., Qiu L., Ran H., Ma Q., Lu Y. R., Liu W. B. Studying the relationship between clinical features and mental health among late-onset myasthenia gravis patients. World J Psychiatry. 2022;(12):470–482.