Antibodies to glutamate receptor subtype 3 (GluR3) are found in some patients suffering from epilepsy as the main disease, but not in patients whose epilepsy accompanies antiphospholipid syndrome or Sneddon's syndrome.

[sneddon syndrome]

Autoantibodies (Ab 's ) to the "B " peptide (amino acids 372 -395 ) of glutamate /AMPA receptor subtype 3 (GluR 3 ) are found in serum and cerebrospinal fluid of some patients with different types of epilepsy . Since such anti-GluR 3 B Ab 's can activate and /or kill neurons in vitro and in vivo , they may contribute to epilepsy . To investigate whether anti-GluR 3 B Ab 's may also be relevant to epilepsy when it accompanies some autoimmune -diseases , we tested for these Ab 's in patients suffering from epilepsy that accompanies anti-phospholipid syndrome (APS ) or Sneddon 's syndrome (SNS ), both being autoimmune -diseases with frequent neurological complications . We tested 77 pediatric patients whose epilepsy is their main disease ; 31 adult patients whose epilepsy accompanies APS (primary or SLE-associated ) or SNS ; 45 epilepsy -free APS and SNS patients ; and 90 healthy controls . Compared to the controls , significantly elevated anti-GluR 3 B Ab 's were found in 22 /77 (29 %) patients whose epilepsy is their main disease , but in none of the patients whose seizures accompany APS or SNS . Yet , all the APS and SNS patients harbored the characteristic anti-phospholipid Ab 's (aPL ), directed against cardiolipin and beta 2 -glycoprotein I , and had lupus anti-coagulant . Thus , anti-GluR 3 B Ab 's are not crossreactive with aPL , and not produced as a non-specific consequence of seizures on the one hand , or autoimmune -diseases on the other . Taken together with new findings accumulated recently in our lab , we suggest that anti-GluR 3 B Ab 's are produced primarily in the periphery due to specific /non-specific "irritation " of the immune system , and that once they reach the brain via a leaky blood -brain barrier they may cause neuronal /glial damage and facilitate the outburst of epilepsy and additional neurological abnormalities . In contrast , the presence of anti-GluR 3 B Ab 's does not seem to increase the probability of developing APS , SNS or the seizures that often accompany these autoimmune -diseases . These findings may have important diagnostic and therapeutic implications .

Diseases
Validation

Diseases presenting "epilepsy" symptom

22q11.2 deletion syndrome

adrenomyeloneuropathy

alexander disease

canavan disease

classical phenylketonuria

cohen syndrome

cowden syndrome

familial hypocalciuric hypercalcemia

gm1 gangliosidosis

hereditary cerebral hemorrhage with amyloidosis

hirschsprung disease

homocystinuria without methylmalonic aciduria

kabuki syndrome

locked-in syndrome

lymphangioleiomyomatosis

monosomy 21

neonatal adrenoleukodystrophy

pendred syndrome

phenylketonuria

proteus syndrome

pyruvate dehydrogenase deficiency

sneddon syndrome

wolf-hirschhorn syndrome

zellweger syndrome

This symptom has already been validated