[Myasthenic syndromes: retrospective analysis of two patient cohorts].

Myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS) are rare autoimmune-mediated neuromuscular diseases characterized by muscle weakness. Although various treatment options are available for MG, a subset of patients may be considered treatment-refractory, with differing definitions of this status present in the scientific literature. This monocentric, retrospective cohort study investigated 200 patients with MG and 15 patients with LEMS. Data on clinical characteristics, antibody status, treatment response, and concomitant diseases were collected. MG patients who received at least three different immunosuppressants during their disease history were categorized as treatment-refractory. Statistical analyses were conducted using SPSS.11.5% of MG patients (n=23) were classified as treatment-refractory. According to the MGFA classification, these patients were more likely to exhibit severe disease, have a higher prevalence of MuSK antibodies, and experience increased cardiovascular comorbidities. The results indicate that patients in the treatment-refractory group exhibited severe disease progression more frequently according to the MGFA classification and required escalation therapies more often. However, a standardized definition of therapy-refractory MG is not yet available.