Complement inhibition in seropositive generalized myasthenia gravis as rescue therapy in impending and effective treatment in frequently recurring impending myasthenic crisis-a case series.

In seropositive myasthenia gravis (MG), complement inhibition has been shown to be an effective and a fast-acting therapeutic option. Myasthenic crisis (MC), usually preceded by impending MC, is a life-threatening complication requiring highly effective treatments with rapid onset of action. Currently used treatment options of MC are limited, consisting mainly of symptomatic and immune therapies, that is, intravenous immunoglobulins and plasma exchange/immunoadsorption. So far, there is only very limited data on complement inhibitors in impending or manifest MC or termination of frequently recurring impending crises. Here, we report three cases of acetylcholine receptor antibody positive MG, two with impending and one case suffering from high-frequency impending MC, where complement inhibition with eculizumab or ravulizumab resulted in a rapid and sustained remission. Meningococcal vaccination, mandatory when using complement inhibitors, did not result in symptom-worsening or manifest MC.