Clinical features and outcomes of patients with myasthenia gravis

To report clinical and laboratory features and outcomes of patients with autoimmune myasthenia gravis (MG) recruited from a single center in Saudi Arabia.

We retrospectively reviewed prospectively collected data obtained from MG patients who have undergone examination and follow-up at our neuromuscular clinic between August 1, 2014 and January 31, 2019.

Ninety-five patients (55 females) were included. The mean age of onset of MG was 40.5+/-18.1 years in males and 31.3+/-15 years in females (p=0.009). The mean duration of follow-up at our clinic was 34.7+/-14.1 months, while the mean duration since MG onset was 8.0+/-7.2 years. Of all patients, 92.6% had generalized MG, 82.1% had acetylcholine receptor (AChR) antibodies, 4.2% had muscle-specific tyrosine kinase (MuSK) antibodies, 78.9% had early-onset MG with no second peak after age of 50 years, 22.1% had myasthenia crisis, 12.6% had refractory MG, 31.6% had thymic hyperplasia, 10.5% had thymoma, and 61.1% required more than or equal 2 immunosuppressive therapies. At the last follow-up, 93 patients had achieved an optimal outcome (MG Foundation of America classification less than or equal II). No patient with double-seronegative (dSN)-MG had thymoma, needed rituximab or intravenous immunoglobulin maintenance therapy, or was classified as refractory MG.

Contrary to other studies, we did not observe a second-peak of MG onset. Clinical outcomes were favorable in the majority of our patients.