OP67 – 2451: Antibodies against neuronal surface antigens in children with inflammatory demyelinating diseases of the CNS

Objective To study if neuronal surface autoantibodies are present in children with a first demyelinating event. Methods Serum samples from 79 children with and without MOG antibodies were selected from an ongoing prospective study. All serum samples were evaluated for the presence of NMDAR-, GABA-A, B, Glycin-R, DR2 antibodies using cell-based assays and screened for the presence of cell surface and intracellular antibodies using different screening methods. Results Serum samples from 79 children with a complete data set, MRI, MOG, AQP4 antibody status were selected including 16 children with ADEM/MOGpos; 16 children with ADEM/MOGneg, 12 children with ON/MOGpos; 9 children with ON/MOGneg, 8 children with MS/MOGneg in addition to 8 children with acute cerebellits and 10 children with other inflammatory neurological disease (OIND). 4/79 children showed GlyR antibodies, 3/79 children had serum antibodies against DR2. No antibodies against GABA-A,B or NMDA-R were detected. Serum of 1/79 children revealed a neuropil staining pattern using rat hippocampal PFA-fixed section, but staining of rat hippocampal neuronal cell cultures did not reveal a single case with a moderate or intense positive staining pattern. Conclusion In children with a first demyelinating event with or without MOG antibodies only rarely autoantibodies against neuronal surface antigens are detected.