[Pathogenic mechanisms of myasthenia gravis induced by antibodies against muscle-specific kinase].

Antibodies to acetylcholine receptor (AChR) are major cause of the human autoimmune disease, myasthenia gravis (MG). Additionally, autoantibodies against Muscle-specific kinase (MuSK) were found in a proportion of patients with generalized MG. After the identification of MuSK antibodies in MG patients, laboratory test for measuring antibodies to MuSK is now required to confirm the diagnosis of MG and the clinical treatment as well as AChR antibodies. MuSK is critical to the clustering of AChR and plays multiple roles at neuromuscular junctions (NMJ). However, it has been dispute concerning the pathogenicity of MuSK antibodies in muscle weakness of MG, as the experimental autoimmune MG caused by MuSK antibodies was absent. Here we describe the recent progress to understand the pathogenic roles of MuSK antibodies in muscle weakness of experimental animals induced by MuSK protein.