Neurol. praxi. 2010;11(2):85-89

Autoantibody-mediated disorders of the neuromuscular junction

doc. MUDr. Peter Špalek, PhD.

Centrum pre neuromuskulárne ochorenia, Neurologická klinika SZU, FN Bratislava-Ružinov

The neuromuscular junction is the most accesible synapse in the nervous system and is very susceptible to circulating factors, notably

neurotoxins and specific autoantibodies. Research advances have shown that key transmembrane proteins at the neuromuscular junction

are vulnerable to antibody-mediated autoimmune attack. Autoantibodies lead to loss of the specific ion channels causing physiological

defects in neuromuscular transmission. Main antigenic targets are acetylcholine receptors (AChRs) and muscle specific kinase (MuSK)

in myasthenia gravis, voltage-gated calcium channels (VGCCs) in the Lambert-Eaton myasthenic syndrome (LEMS), voltage-gated potassium

channels (VGKCs) in neuromyotonia and GQ1b ganglioside in Miller Fisher syndrome (MFS). Autoantibodies can be measured in

patients sera by immunoprecipation of detergent-extracted ion channels radioactivelly-labelled with high affinity 125I-neurotoxins. The

pathogenetic role of the circulating antibodies can be demonstrated by passive transfer to mice, and by the clinical improvement that

follows plasma exchange and other immunotherapies. This paper will briefly discuss the role of circulating autoantibodies in autoimmune

disorders of neuromuscular transmission: seropositive myasthenia gravis, myasthenia gravis with MuSK antibodies, seronegative

myasthenia, transient neonatal myasthenia, arthrogryposis multiplex congenita, LEMS, acquired neuromytonia and MFS.

plasmapheresis.

Keywords: neuromuscular junction, circulating autoantibodies, antigens (AchRs; MuSK; VGCCs; VGKC; GQ1b ganglioside), imunotherapy,

Published: April 1, 2010  Show citation