[Myasthenia gravis: current status of antibody diagnostics and aspects on refractory myasthenia gravis]

Acquired myasthenia gravis (MG) is an autoimmune disease that leads to fluctuating muscle weakness and fatigue, caused by circulating antibodies against different structures of the neuromuscular junction. In most patients, antibodies against acetylcholine receptor (AChR) can be detected. In a smaller proportion of patients with and without AChR antibodies, antibodies to muscle-specific kinase (MuSK), or related proteins such as agrin, cortactin and low-density lipoprotein receptor-related protein 4 (LRP4), are present. With current therapy, most patients achieve a stable condition with good quality of life and normal life expectancy. Nevertheless, 10 to 15 % of patients fail to respond ad equately to current therapies and are defined as refractory myasthenia gravis. Their clinical course is characterized by recurrent episodes of severe, acute deterioration, which sometimes appear life threatening. This article gives an overview of the current state of myasthenic antibody diagnostics and recommended treatment of refractory myasthenia gravis.