ABSTRACT

This chapter describes the methods for detecting anti-Acetylcholine receptor (AChR) antibodies by two different assay systems that use labeled neurotoxin. It has been confirmed that the AChR antibody is polyclonal in most patients. In the study of heterogeneity of AChR antibodies, the authors undertook an IgG subclass analysis of AChR antibodies in sera from 38 MG patients. Venoms of several snakes have been known to cause muscular paralysis. Subsequently, several neurotoxin components that inhibit neuromuscular transmission by attacking different targets were isolated from the venom. Later, neurotoxins have been utilized in biochemical and immunological studies to detect nicotinic acetylcholine receptors (nAChRs) or their antibodies in research related to pathogenesis of myasthenia gravis (MG). Neurotoxins in the venoms of elapid and sea snakes can be easily purified by a combination of gel filtration and ion-exchange cellulose chromatography. Histological abnormalities, such as hyperplasia and epithelial thymoma of the thymus gland, have been found in almost all MG patients.