title: Autoantibodies to glutamic acid decarboxylase in patients with therapy-resistant epilepsy.
abstract: BACKGROUND
  Autoantibodies to glutamic acid decarboxylase (GAD-A) are present in type 1 diabetes and stiff man syndrome (SMS), and have also been reported in cerebellar ataxia. Epilepsy was present in 4 of 19 patients with SMS and GAD-A, implying that epilepsy sometimes is associated with anti-GAD autoimmunity.
  
  
  METHODS
  The authors investigated the prevalence of GAD-A in patients with therapy-resistant localization-related epilepsy (n = 51) and generalized epilepsy (n = 49) by a radiobinding assay. The positive samples were confirmed by immunohistochemistry and immunoblotting of recombinant human GAD65.
  
  
  RESULTS
  GAD-A were found in eight patients with localization-related epilepsy, whereas none of the patients with generalized epilepsy, other neurologic disorders (n = 38), or the control subjects (n = 48) had GAD-A. Two patients had high levels of GAD-A, similar to SMS, whereas six patients had significantly lower titers, characteristic of type 1 diabetes. The two patients with high levels of GAD-A had GAD-A both in serum and CSF by immunohistochemistry and immunoblotting. Both of them had longstanding therapy-resistant temporal lobe epilepsy but did not have diabetes. One had a history of autoimmune disease, whereas the other had serologic evidence of multiple autoantibodies without any clinical signs of autoimmune disease.
  
  
  CONCLUSIONS
  GAD autoimmunity may be associated with refractory localization-related epilepsy.
authors.affiliation: Department of Neurology, Tampere University Hospital, Finland. lljupe@uta.fi
authors.forename: J
authors.initials: J
authors.lastname: Peltola
authors.forename: P
authors.initials: P
authors.lastname: Kulmala
authors.forename: J
authors.initials: J
authors.lastname: Isojärvi
authors.forename: A
authors.initials: A
authors.lastname: Saiz
authors.forename: K
authors.initials: K
authors.lastname: Latvala
authors.forename: J
authors.initials: J
authors.lastname: Palmio
authors.forename: K
authors.initials: K
authors.lastname: Savola
authors.forename: M
authors.initials: M
authors.lastname: Knip
authors.forename: T
authors.initials: T
authors.lastname: Keränen
authors.forename: F
authors.initials: F
authors.lastname: Graus
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D002531:Cerebellum / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D004351:Drug Resistance / Q000276:immunology*; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology*; D005260:Female; D005968:Glutamate Decarboxylase / Q000097:blood / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011869:Radioligand Assay
chemical_list: D001323:Autoantibodies; D005968:Glutamate Decarboxylase