Abstracts

Rationale: Immune mechanisms are thought to be involved in the pathological disease process in a significant number of childhood and adult epileptic syndromes, and in other seizure related disorders (e.g. encephalitis). Of particular interest is the occurrence of highly specific autoantibodies to important neuronal proteins (VGKC-complex proteins, NMDAR, AMPAR, GABAbRs) in the blood and spinal fluid in some of these patients. The aim of this study is to examine the sera of newly diagnosed paediatric epilepsy patients for the presence of specific neuronal autoantibodies. Methods: This Dutch cohort consists of 178 paediatric patients aged between 1 month and 16 years with newly diagnosed epilepsy. The sera are being tested for antibodies to the NMDA receptor, VGKC-complex and associated proteins (LGI1, CASPR2, contactin-2), GAD and glycine receptor. The presence of antibodies are detected visually using antigen specific cell-based assays (NMDAR, LGI1, CASPR2, contactin-2, glycine receptor), and the levels of antibodies against the VGKC-complex and GAD are quantitated by radioimmunoprecipitation assays. Results: In total, 25/178 patients (14%) have been found to have a positive antibody test so far. The most commonly found antibody is to the VGKC-complex. Conclusions: Preliminary testing of a newly diagnosed paediatric epilepsy cohort has revealed a significant number of patients with potentially pathogenic neuronal autoantibodies in the serum. Further work will include completion of testing for antibodies to the CNS antigens described, a coded comparison with age-matched controls, a search for novel antigenic targets and the correlation of patient clinical features with the presence of a positive antibody.