Pathophysiology of myasthenia gravis.
Myasthenia gravis (MG) is arguably the best understood autoimmune disease, and its study has also led to fundamental appreciation of mechanisms of neuromuscular transmission. MG is caused by antibodies against the acetylcholine receptor (AChR), which produce a compromise in the end-plate potential, reducing the safety factor for effective synaptic transmission. It is clear that AChR antibody destruction of the postsynaptic surface is dependent on complement activation. A muscle-specific kinase has been recently found to be an antigenic target in MG patients without antibodies against the AChR. Autoantibody production in MG is a T-cell-dependent process, but how a breakdown in tolerance occurs is not known. In MG there is an interesting differential involvement of muscle groups, in particular, the extraocular muscles. This article reviews normal neuromuscular transmission, mechanisms of the autoimmune process of MG, and differential susceptibility of eye muscles to MG.
Hughes
Benjamin W
BW
Department of Neurology, Case Western Reserve University, Louis Stokes Cleveland DVA Medical Center, University Hospitals of Cleveland, Cleveland, Ohio 44106, USA.
Moro De Casillas
Maria Luisa
ML
Kaminski
Henry J
HJ
D001323:Autoantibodies / Q000276:immunology*; D006801:Humans; D009157:Myasthenia Gravis / Q000276:immunology / Q000503:physiopathology*; D009469:Neuromuscular Junction / Q000276:immunology / Q000503:physiopathology*; D009801:Oculomotor Muscles / Q000276:immunology; D011978:Receptors, Nicotinic / Q000276:immunology*; D013570:Synaptic Membranes / Q000276:immunology; D009435:Synaptic Transmission / Q000276:immunology
D001323:Autoantibodies; D011978:Receptors, Nicotinic