Cryptogenic partial epilepsies with anti-GM1 antibodies: a new form of immune-mediated epilepsy?
OBJECTIVE
We wished to study immune system dysfunction which has been proposed as a potential cause of epilepsy. Epileptogenic action of antibodies directed against GM1 gangliosides was demonstrated in rats, but the potential role of anti-GM1 antibodies in human epilepsy has not yet been studied.


METHODS
We investigated the presence of IgG or IgM anti-GM1 antibodies in the sera of 64 patients with various types of epileptic syndromes: idiopathic generalized epilepsy (IGE) (n = 6), symptomatic or cryptogenic generalized epilepsy (SCGE) (n = 7), symptomatic partial epilepsy (SPE) (n = 26), and cryptogenic partial epilepsy (CPE) (n = 25).


RESULTS
Two patients had elevated titers of IgM anti-GM1 antibodies, one patient had elevated titers of both IgM and IgG anti-GM1 antibodies, and 1 patient had elevated titers of IgG anti-GM1 antibodies. All 4 patients had complex partial seizures (CPS) secondarily generalized, drug resistance, psychiatric disorders, and normal brain imaging. Anti-GM1 antibodies were never associated with IGE, SCGE, or SPE. We compared the reactivity of sera from these patients with the sera from 5 patients with motor neuropathies with conduction block (MNCB) against different gangliosides and concluded that epilepsy sera did not react with the Gal(beta 1-3)GalNAc epitope. Two anti-GM1-positive patients were treated successfully with high-dose intravenous immunoglobulins (IgIV).


CONCLUSIONS
Our findings suggest that detection of anti-GM1 antibodies could allow identification of a subgroup of patients with partial epilepsy associated with an autoimmune response. If anti-GM1 antibodies prove pathogenic, they could be an important prognostic factor for drug resistance and worsening of seizures.
Bartolomei
F
F
Department of Neurology, Hôpital Sainte-Marguerite, Marseille, France.
Boucraut
J
J
Barrié
M
M
Kok
J
J
Dravet
C
C
Viallat
D
D
Bernard
D
D
Gastaut
J L
JL
D000328:Adult; D017668:Age of Onset; D000368:Aged; D000818:Animals; D000918:Antibody Specificity / Q000276:immunology; D000927:Anticonvulsants / Q000627:therapeutic use; D001323:Autoantibodies / Q000032:analysis* / Q000276:immunology / Q000502:physiology; D004351:Drug Resistance; D004828:Epilepsies, Partial / Q000188:drug therapy / Q000276:immunology / Q000503:physiopathology; D004827:Epilepsy / Q000188:drug therapy / Q000276:immunology* / Q000503:physiopathology; D005260:Female; D005677:G(M1) Ganglioside / Q000276:immunology*; D005732:Gangliosides / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D051381:Rats
D000927:Anticonvulsants; D001323:Autoantibodies; D005732:Gangliosides; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016756:Immunoglobulins, Intravenous; D005677:G(M1) Ganglioside