[Immunopathogenesis of myasthenia gravis and the Lambert-Eaton myasthenic syndrome]

Myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS) are autoimmune diseases manifestant a disorder of neuromuscular transmission. In MG, the autoimmune process is directed against the postsynaptic part whereas in LEMS, it is focused at the presynaptic part of this connection. Current immunological studies have confirmed the polyclonal and heterogenous characters of the autoimmune process. In patient with MG, the presence of antibodies against various epitopes of acetylcholine receptor, as well as against other muscular fiber protein (e.g. ryanodine receptor, titin, myosin, etc.) were confirmed. Patients with LEMS yielded antibodies against the proteins of various types of voltage-dependent calcium channels located in the presynaptic part of the motor nerve ending, as well as those against synaptotagmin. These findings indicate the necessity of a more complex immunological examination of patients in order to clarify both variability of clinical picture and prospective planning of specific immunotherapy. (Tab. 4, Fig. 3, Ref. 25.)