Methods

A retrospective study was performed of generalised MuSK+ MG patients referred to our neuromuscular clinic from 2003 to 2011. Nine MuSK+ patients were identified with refractory disease and treated with rituximab. The group consisted of eight females and one male with a median age of 40. Patients were defined as refractory when they:(1) could not lower their immunotherapy without clinical relapse,(2) were not clinically controlled on their immunotherapy regimen or (3) had intolerable side effects from treatment. We examined immunotherapy regimens, time to taper off these therapies, clinical exams, MG Foundation of America Clinical Classification scores, Post-Intervention Status (PIS), 8 duration since first and last rituximab cycle and qualitative MuSK antibody status (table 1). MuSK antibody testing was performed at Athena Diagnostics (Worcester, Massachusetts, USA). Safety evaluation during treatment consisted of clinical observation during infusions and monitoring of complete blood cell counts and liver function test profiles.