Myasthenia gravis and myasthenic syndromes

AbstractMore than a decade ago myasthenic symptoms were observed in rabbits immunized with acetylcholine receptor (AChR) {119} and AChR deficiency was found at the neuromuscular junction in human myasthenia gravis (MG) {36}. By 1977 the autoimmune character of MG and the pathogenic role of AChR antibodies had been established by several measures. These included the demonstration of circulating AChR antibodies in nearly 90% of patients with MG {87}, passive transfer with IgG of several features of the disease from human to mouse {149}, localization of immune complexes (IgG and complement) on the postsynaptic membrane {30}, and the beneficial effects of plasmapheresis {20, 123}. Substantial subsequent progress has occurred in understanding the structure and function of AChR and its interaction with AChR antibodies. The relationships of the concentration, specificities, and functional properties of the antibodies to the clinical state in MG have been carefully analyzed, and the mechanisms by which AChR antibodies impair neuromuscular transmission have been further investigated. The clinical classification of MG has been refined, the role of the thymus gland in the disease has been fur