Pre- and postsynaptic neuromuscular junction abnormalities in musk myasthenia.
Autoantibodies to muscle-specific kinase (MuSK) can cause myasthenia gravis (MG). The pathophysiological mechanism remains unknown. We report in vitro electrophysiological and histological studies of the neuromuscular junction in a MuSK MG patient. Low levels of presynaptic acetylcholine release and small miniature endplate potentials were found. This combination of pre- and postsynaptic abnormalities was supported by histology, revealing partially denervated postsynaptic areas, and some degeneration of postsynaptic folds. Results suggest that anti-MuSK antibodies reduce the stability of muscle-nerve contact.
Niks
Erik H
EH
Department of Neurology, Leiden University Medical Center, K5Q-114, P.O. Box 9600, 2300 RC Leiden, The Netherlands. ehniks@lumc.nl
Kuks
Jan B M
JB
Wokke
John H J
JH
Veldman
Henk
H
Bakker
Egbert
E
Verschuuren
Jan J G M
JJ
Plomp
Jaap J
JJ
D000328:Adult; D001323:Autoantibodies / Q000276:immunology; D004594:Electrophysiology; D005260:Female; D006801:Humans; D009045:Motor Endplate / Q000276:immunology / Q000503:physiopathology; D018908:Muscle Weakness / Q000276:immunology / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000276:immunology / Q000503:physiopathology; D009157:Myasthenia Gravis / Q000276:immunology / Q000503:physiopathology*; D009469:Neuromuscular Junction / Q000276:immunology / Q000503:physiopathology*; D020794:Receptor Protein-Tyrosine Kinases / Q000276:immunology*; D011950:Receptors, Cholinergic / Q000276:immunology*
D001323:Autoantibodies; D011950:Receptors, Cholinergic; C095714:MUSK protein, human; D020794:Receptor Protein-Tyrosine Kinases