Growing evidence provides new insights about myasthenia gravis (MG) with antibodies against muscle-specific tyrosine kinase (MuSK-MG), including its pathogenesis, clinical and electrophysiological manifestations, and treatment. Data now support the presence of both presynaptic and postsynaptic dysfunction in MuSK-MG. This is 1 of many key differences between MuSK-MG and acetylcholine receptor antibody-MG (AChR-MG), especially as it pertains to potential therapeutic implications. In comparison to AChR-MG, MuSK-MG is generally more refractory to treatment. However, because MuSK-MG is better understood and more readily recognized today, there are more reports of a relatively benign course. The most effective immunotherapies for MuSK-MG are corticosteroids, plasmapheresis, and rituximab. With appropriate therapy, most patients with MuSK-MG achieve minimal manifestation status or better on the postintervention status outlined by the Myasthenia Gravis Foundation of America. A minority of patients remain refractory to treatment, and optimal management for this group remains a considerable challenge. Muscle Nerve 58: 344-358, 2018.
Keywords: acetylcholine receptor; antibody; immunotherapy; muscle-specific tyrosine kinase; myasthenia gravis; neuromuscular junction.
© 2018 Wiley Periodicals, Inc.