Pathogenesis and detection methods of anti-acetylcholine receptor antibodies in myasthenia gravis

Myasthenia gravis (MG), which affects the endplate region of the postsynaptic neuromuscular junction, is the best-understood autoimmune disease. MG is driven by anti-acetylcholine receptor (AChR) or muscle-specific receptor tyrosine kinase, and 65% of MG patients have anti-AChR-positive generalized MG. Experimental autoimmune MG is a useful model to investigate the pathogenic mechanisms of anti-AChR antibodies and to evaluate the efficacy of new immunotherapies. Since long-term drug treatment is usually necessary for MG patients, the selection of immunotherapy must be chosen based on an understanding of the pathophysiology, including the roles of the thymus, T cells, B cells, autoantibodies, and neuromuscular junction. The main pathogenic mechanism of MG is the activation of the complement system caused by the attack of anti-AChR antibodies. Molecular technology using the neonatal Fc receptor (FcRn) is currently being applied to the development of new MG therapies. Many biological drugs targeting B cells, interleukin-6, FcRn and complement show promise as potential therapeutics for anti-AChR-positive generalized MG. With regard to anti-AChR antibody detection, the overall agreement rate between radioimmunoassay and enzyme linked immunosorbent assay is 91%, with positive agreement of 87% and negative agreement of 99%.