Neuronal voltage-gated potassium channel complex autoimmunity in children

Pediatr Neurol. 2011 Apr;44(4):275-81. doi: 10.1016/j.pediatrneurol.2010.10.015.


Autoimmunity targeting voltage-gated potassium channel complexes have not been systematically documented in children. Identified in the Neuroimmunology Laboratory records of Mayo Clinic were 12 seropositive children, 7 among 252 Mayo Clinic pediatric patients tested on a service basis for serologic evidence of neurologic autoimmunity (June 2008-April 2010), 4 during the assay's preimplementation validation (before June 2008) and 1 non-Mayo patient with available clinical information. Neurologic manifestations were subacute and multifocal. Three had global developmental regression, 6 movement disorders, 4 dysarthria, 3 seizures, 1 Satoyoshi syndrome, 1 painful red feet, 2 insomnia, 2 gastrointestinal dysmotility, and 2 small fiber neuropathy. Neoplasia was found in 1 child. Treating physicians recorded improvement in all 7 children who received immunotherapy. Neurologic symptom relapse occurred in 3 of 6 children after ceasing immunotherapy. These findings highlight a diverse clinical spectrum of neuronal potassium channel complex autoimmunity in children, and they illustrate benefit from early initiated immunotherapy, with a tendency to relapse when therapy ceases. Diagnosis is generally delayed in the process of eliminating neurodegenerative causes. Currently 2.7% of pediatric sera evaluated for neurologic autoimmunity are positive for neuronal potassium channel complex-reactive immunoglobulin G. The frequency and full spectrum of neurologic accompaniments remains to be determined.

MeSH terms

  • Adolescent
  • Autoantibodies / blood*
  • Autoimmune Diseases / blood*
  • Autoimmune Diseases / immunology
  • Autoimmune Diseases / therapy*
  • Autoimmunity / immunology*
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Immunoglobulin G / blood
  • Immunoprecipitation / methods
  • Immunosuppressive Agents / therapeutic use
  • Magnetic Resonance Imaging
  • Male
  • Neoplasms / etiology
  • Plasma Exchange / methods
  • Potassium Channels, Voltage-Gated / immunology*


  • Autoantibodies
  • Immunoglobulin G
  • Immunosuppressive Agents
  • Potassium Channels, Voltage-Gated