AIM: Cryptogenic forms of epileptic encephalopathies (EE) with their well-known features of drug-resistance, mental deterioration and partial response to immunotherapies are ideal candidates for screening for neuronal autoantibodies (NAA). METHOD: Fifty consecutive pediatric patients with a diagnosis of EE of unknown cause were included. Nine NAAs were tested by ELISA, RIA or cell-based assays. Clinical features of seronegative and seropositive patients were compared. RESULTS: NAAs were found in 7/50 (14%) patients. They were N-methyl-d-aspartate receptor in two (4%), glycine receptor in two (4%), contactin-associated protein-like 2 in one (2%), glutamic acid decarboxylase in one (2%) and type A gamma aminobutyric acid receptor in one patient (2%). Furthermore, serum IgGs of two patients negative for well-characterized NAAs, showed strong reactivity with the uncharacterized membrane antigens of live hippocampal neurons. There were no significant differences between seropositive and seronegative patients by means of epilepsy duration, anti-epileptic drug resistance, EE type, types of seizures, seizure frequencies, EEG features or coexisting autoimmune diseases. Some seropositive patients gave good-moderate response to immunotherapy. DISCUSSION: Potential clues for the possible role of autoimmunity in seropositive patients with EE were atypical prognosis of the classical EE type, atypical progression and unusual neurological findings like dyskinesia.
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Epileptic encephalopathy, Immune-mediated epilepsy, Lennox-Gastaut syndrome, Neuronal auto-antibodies, West syndrome, Adolescent, Adult, Autoantibodies, Child, Child, Preschool, Epilepsy, Female, Follow-Up Studies, Humans, Infant, Lennox Gastaut Syndrome, Male, Membrane Proteins, Neurons, Receptors, Neurotransmitter, Spasms, Infantile, Young Adult