Rituximab in Refractory Myasthenia Gravis - Challenges and Lessons Learnt.

Abstract

Nearly 10%-15% patients with generalized myasthenia gravis (MG) have refractory disease and are candidates for newer nonconventional immunotherapies. Rituximab has emerged as an attractive option in them. We describe the efficacy and safety of rituximab in 12 patients with refractory MG treated over a period of 4 years in a tertiary care center. We had a female-predominant cohort (10 females) in the age range 10-67 years. There were eight seropositive patients (acetylcholine receptor, muscle-specific kinase, or both antibodies) and eight had undergone thymectomy. Median number of crises was 2 before treatment with rituximab. Sustained improvement at 12 months was seen in seven patients and steroid dose could be reduced in them. Four worsened on therapy (including one death following prolonged ventilation and septicemia). One patient who had no response to therapy was re-evaluated and diagnosed with congenital myasthenic syndrome related to biallelic CHRNE mutation. In summary, nearly two-thirds (7/11, 63.6%) of autoimmune refractory MG in this cohort showed a good response to rituximab.