• Berin Inan, Irem Gul Orhan, Can Ebru Bekircan-Kurt, Sevim Erdem-Ozdamar, and Ersin Tan.
• Department of Neurology, Hacettepe University Faculty of Medicine, Ankara, Turkey.
• Ir J Med Sci. 2024 Aug 1.

BackgroundIncreasing data are available on the use and efficacy of rituximab (RTX) in patients with anti-muscle-specific tyrosine kinase (MuSK)-positive myasthenia gravis (MG), especially those steroid-dependent or unresponsive to traditional immunotherapies.AimsWe aimed to evaluate the clinical characteristics and treatment responses of adult patients with generalized anti-MuSK-positive MG treated with RTX.MethodsWe retrospectively recruited 16 patients who were on RTX, between January 2010 and September 2023. RTX was given 1000 mg/day intravenously twice, two weeks apart. Maintenance treatment was administered at intervals of 3-6 months based on clinical evaluation. The outcome was assessed by Myasthenia Gravis Foundation of America (MGFA) and Myasthenia Gravis Status and Treatment Intensity (MGSTI) scores. Additionally, anti-MuSK antibody levels were retested after treatment in all patients except one.ResultsTwelve patients were female. The mean age at disease onset was 35.3 ± 17.3 years. The median duration between disease onset and RTX administration was 2.4 years (min-max: 0.5-36.5 years). The worst MGFA class before RTX was between IIIb-V. After RTX treatment, 81.3% of patients achieved MGFA minimal manifestations or better and MGSTI level 1 or better. Anti-MuSK antibodies became negative in 12 patients, while they remained positive in three. The changes in antibody levels seemed associated with clinical outcomes.ConclusionsRTX is an effective treatment in anti-MuSK-positive MG. Furthermore, our results support the inhibition of antibody production by RTX and we recommend monitoring anti-MuSK antibody titers to follow disease progression and treatment response.© 2024. The Author(s).

4 keywords...

hide…