A study of comorbidities in myasthenia gravis

Management of myasthenia gravis (MG) in the presence of comorbidities may be difficult. We report the effect of comorbidities in the outcome of MG. The patients with MG during 1991-2016 were included and evaluated including their demographic variables, clinical findings, Myasthenia Gravis Foundation of America (MGFA) score. The patients were categorized into early onset (≤ 40 years) and late onset (> 40 years) MG. The comorbidities (autoimmune and miscellaneous) and iatrogenic complications were compared between early and late onset, and in good and poor outcome groups. Out of 81 patients with MG, 48 patients had early and 33 late onset. In 71 (88%) patients, comorbidities were present and were autoimmune in 8 (10%) and miscellaneous in all the patients (88%). Iatrogenic complications were present in 54 (67%) patients. Thymectomy was done in 19 patients; 16 had thymoma and 3 thymic hyperplasia. Myasthenic crisis occurred in 28 patients; 5 (18%) had autoimmune and all had miscellaneous comorbidities. The patients with poor outcome had ≥ 2 comorbidities, myasthenic crisis, leukocytosis, elevated serum bilirubin and creatinine, and increased number of hospital admissions (P < 0.05). Myasthenia gravis is associated with comorbidities in majority of patients especially in late onset group, and more than two comorbidities are related to poor outcome.