Rituximab therapy in anti-musk positive juvenile myasthenia gravis; A case report

Juvenile myasthenia gravis is a rare acquired disease of childhood. It is difficult to differentiate it from congenital myasthenic syndrome due to the negativity of the Acetylcholine receptor antibody. The Muscle Specific Kinase (MuSK) positive Myasthenia gravis is uncommon in children with a different disease courses and response to treatment. We report a 15 Y/O girl presented with prominent oculobulbar manifestation. She experienced multiple exacerbations when receiving corticosteroids, Acetylcholine esterase inhibitors and Azathioprine. Because of the positive anti-MuSK antibody in her follow-up, Rituximab started for her with the diagnosis of MuSK positive JMG. Her symptoms improved dramatically in response to lower dose of Rituximab (in comparison with previous studies) and remission was established. We found that children with MuSK-positive myasthenia respond well to Rituximab despite the failure of other immunosuppressant medications or acetylcholinesterase inhibitors