Clinical profile and outcome of patients with myasthenia gravis, post-thymectomy versus non-thymectomy. A 10-year retrospective study in a tertiary care hospital

Abstract

To study the clinical profile and outcome of post-thymectomy versus non-thymectomy in patients diagnosed with Myasthenia Gravis followed at King Fahad Specialist Hospital-Dammam, Saudi Arabia. A retrospective, observational study was conducted in a tertiary care hospital in Dammam, Saudi Arabia. Data from 75 patients’ files diagnosed with myasthenia gravis across ten years, between January 2008 to December 2018, were analyzed by Statistical Package for Social Sciences (SPSS). All patients were above the age of 16 years. Fifty-five patients are female (74%), and 20 patients are male (26%). At diagnosis, the majority of the patients had a generalized type (66.6%), and ocular/oculobulbar accounts for 33.4%. Using the Myasthenia Gravis Foundation of America (MGFA) classification, 44 % of patients fell under Class 3. Acetylcholine receptor (AchR) antibody was positive in 50 patients (66.7%), and antiMUSK antibody was positive in 14 patients (18.7%). The most common thymic histopathology was normal (57.3%) followed by follicular hyperplasia (18.7%) and thymoma (13.3%). Thymoma was only found in patients with AchR antibody positive. Thymectomy was done for 39 patients (52%). Patients who underwent thymectomy achieved stable and pharmacological remission more than non-thymectomy patients (p-value <0.000). No significant difference in the clinical outcome was found between patients taking Azathioprine versus Mycophenolate. Thymectomy appears to provide a high rate of stable remission as compared to non-thymectomy. Moreover, Mycophenolate seems to be as effective as Azathioprine in the long term therapy of Myasthenia Gravis.