Association between musk antibody concentrations and the myasthenia gravis composite score in 3 patients: A marker of relapse?

ABSTRACT

INTRODUCTION: Muscle-specific tyrosine kinase (MuSK) autoantibody related myasthenia gravis is characterized by bulbar and respiratory manifestations, a poor response to anticholinergics, and a generally good response to plasma exchange and rituximab. It is not known if MuSK-antibody (Ab) levels could be used to predict the clinical course Methods: Three patients for whom frequent long-term monitoring of MuSK-Ab levels and the Myasthenia Gravis Composite (MGC) scores were performed are described. RESULTS: A close relationship existed between the MuSK-Ab concentrations and the MGC score. Furthermore, a rise in Ab concentration preceded a more serious clinical relapse in all patients Conclusions: These findings suggest that MuSK-Ab concentrations may be a useful biomarker for the long-term monitoring of MuSK myasthenia gravis, particularly while in clinical remission. This may allow preemptive escalation of therapy to prevent clinical relapse, and conversely permitting greater weaning of unnecessary immunosuppression. Muscle Nerve, 2019.