Antibodies to neural and non-neural autoantigens in Japanese patients with CNS demyelinating disorders

•We enrolled 70 CNS demyelinating disorder patients.•Two of the three anti-NMDAR antibodies (Ab) carriers had anti-AQP4 Ab.•Only one anti-NMDAR Ab carrier had episodes of anti-NMDAR encephalitis.•One of the three anti-CASPR2 Ab carrier had anti-AQP4 Ab.•Multiple autoantibodies can participate in CNS demyelination.

Anti-aquaporin 4 (AQP4) antibodies (Abs) are essential in neuromyelitis optica spectrum disorders (NMOSD), but the relationship between CNS demyelinating disorders (CNSDD) and other neural Abs remains unclear. Here we screened anti-neural Abs in the sera of 70 Japanese CNSDD patients. While two had only demyelinating events among three anti-N-methyl-d-aspartate receptor (NMDAR) Ab-positive subjects, the other subject who also had anti-AQP4 Abs experienced episodes of anti-NMDAR encephalitis and of NMOSD. Major lesions in the three anti-contactin-associated protein 2 Ab-positive subjects were infratentorial, including one co-carrying anti-AQP4 Abs. Thus, autoantibodies can be clinically silent, but multiple autoantibodies may participate in the pathogenesis.