Serum antibodies in epilepsy and seizure-associated disorders

Neurology. 2005 Dec 13;65(11):1730-6. doi: 10.1212/01.wnl.0000187129.66353.13.


Objective: To investigate whether autoantibodies to ion channels and other neural antigens are present in the sera of patients with epilepsy and seizure-related diseases.

Methods: Sera were obtained from 139 patients, including 26 with preexisting autoimmune disease, 46 in whom an autoimmune basis was suspected, and 67 with drug-resistant epilepsy. The sera were assayed for antibodies to voltage-gated potassium (VGKC) and calcium (VGCC) channels, glutamic acid decarboxylase (GAD), gangliosides, glutamate receptor type 3, cardiolipins, DNA, and nuclear antigens; the results were compared with results from a large cohort of healthy and disease controls.

Results: Increased titers of VGKC antibodies (>100 pM) were detected in 16 of 139 (11%) patients with seizures but only 1 control (0.5%). Eight VGKC-positive patients presented with an acute/subacute illness, and 5 of these had the highest VGKC antibodies; 3 patients improved spontaneously, another 5 patients responded well to immunomodulatory therapy. The other VGKC-positive patients had longer disease duration (>6 years) and intermediate levels of antibodies; immunotherapies have not been tested in this group. Very high levels of GAD antibodies (>1,000 U) were found in an additional 3 patients (2.1%) with long-standing drug-resistant epilepsy.

Conclusions: The presence of autoantibodies to voltage-gated potassium channels and glutamic acid decarboxylase suggests that the immune system may contribute to certain forms of epilepsy or seizure-associated disorders. Further studies are needed to determine whether the antibodies are pathogenic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antigens / blood
  • Antigens / immunology
  • Autoantibodies / analysis
  • Autoantibodies / blood*
  • Autoimmune Diseases / blood
  • Autoimmune Diseases / immunology*
  • Brain / immunology*
  • Brain / physiopathology
  • Epilepsy / blood*
  • Epilepsy / diagnosis
  • Epilepsy / immunology*
  • Female
  • Glutamate Decarboxylase / deficiency
  • Glutamate Decarboxylase / immunology*
  • Humans
  • Immunologic Factors / therapeutic use
  • Male
  • Nerve Tissue Proteins / immunology
  • Neural Inhibition / immunology
  • Potassium Channels, Voltage-Gated / immunology*
  • Predictive Value of Tests
  • gamma-Aminobutyric Acid / biosynthesis
  • gamma-Aminobutyric Acid / deficiency


  • Antigens
  • Autoantibodies
  • Immunologic Factors
  • Nerve Tissue Proteins
  • Potassium Channels, Voltage-Gated
  • gamma-Aminobutyric Acid
  • Glutamate Decarboxylase