Coexisting neuronal autoantibodies among children with demyelinating syndromes.

OBJECTIVES: To determine the incidence and clinical relevance of neuronal autoantibodies in children with demyelinating syndromes.

METHODS: We conducted a prospective study including 31 consecutive children with demyelinating syndromes. Four patients with N-Methyl-D-aspartate receptor (NMDAR) encephalitis, 32 patients with Guillain-Barre syndrome, 13 children with benign childhood epilepsy, and 28 healthy children were used as controls. Prior to initiating immunomodulatory therapy, serum samples were tested for antibodies against NMDAR, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) 1, AMPAR2, leucine-rich glioma-activated protein 1, contactin-associated protein 2, gamma-aminobutyric acid B receptors, paraneoplastic ma antigen 2 (PNMA2/Ta), Yo, Ri, Hu, CV2, amphiphysin, and aquaporin-4 by indirect immunofluorescence assays.

RESULTS: Three anti-neuronal antibodies were detected; NMDAR antibody in one with multiple sclerosis, PNMA2/Ta antibody in one with multiple sclerosis, and Yo antibody in one with clinically isolated syndrome. The positivity rate of neuronal autoantibodies in demyelinating syndrome was 10%. All seropositive patients were found to be negative for tumor screening. None of these patients exhibited symptoms of encephalitis.

CONCLUSION: Children with demyelinating syndromes without symptoms of encephalitis can be positive for anti-neuronal antibodies.