Antibodies against Wnt receptor of muscle-specific tyrosine kinase in myasthenia gravis

J Neuroimmunol. 2013 Jan 15;254(1-2):183-6. doi: 10.1016/j.jneuroim.2012.09.001. Epub 2012 Sep 18.

Abstract

Muscle-specific tyrosine kinase (MuSK) antibodies are detected in a proportion of myasthenia gravis (MG) patients who are negative for acetylcholine receptor (AChR) antibodies and have prominent bulbar weakness and crises. In the MuSK ectodomains, the immunoglobulin-like 1 and 2 domains (Ig1/2) mediate the agrin-Lrp4-MuSK signaling and the cysteine-rich domain (CRD) mediates the Wnt-MuSK-Dishevelled signaling; both contribute to AChR clustering. Immunoblotting against recombinant proteins showed MuSK Ig1/2 antibodies in 33 anti-AChR-negative MG patients; 10 patients of them (30%) were additionally positive for MuSK CRD antibodies. The result suggests that MuSK antibodies have heterogeneity in their binding to functional domains of MuSK.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies / metabolism
  • Child
  • Electromyography
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myasthenia Gravis / metabolism*
  • Myasthenia Gravis / physiopathology
  • Receptor Protein-Tyrosine Kinases / metabolism*
  • Receptors, Cholinergic / metabolism*
  • Receptors, Wnt / immunology*
  • Young Adult

Substances

  • Antibodies
  • Receptors, Cholinergic
  • Receptors, Wnt
  • MUSK protein, human
  • Receptor Protein-Tyrosine Kinases