Possible clinical role of MOG antibody testing in children presenting with acute neurological symptoms.

The differential diagnosis between acquired inflammatory demyelinating syndromes of the central nervous system (CNS), such as multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD) and acute disseminated encephalomyelitis (ADEM) can be very challenging at onset. Apart from cerebrospinal fluid oligoclonal bands and anti-aquaporin-4 antibodies (AQP4-Ab), definite diagnostic biomarkers are lacking. Anti-myelin oligodendrocyte glycoprotein antibodies (MOG-Abs) have been increasingly described in children with AQP4-seronegative NMOSD, ADEM and other inflammatory demyelinating CND syndromes; despite partial overlaps with AQP4-Ab disease, a novel "MOG-Ab-disorder" phenotype has been suggested. In this study, we tested the presence of MOG-Ab and AQP4-Ab in 57 children at first onset of acute neurological symptoms; three clinical subgroups were identified: 12 patients had acquired inflammatory demyelinating CNS syndromes, 11 had other autoimmune/immune-mediated disorders of the central and peripheral nervous system and 34 had non-immune-mediated CNS disorders. MOG-Abs were found positive only in a subset of cases in the subgroup with acquired inflammatory demyelinating CNS syndromes (in 2/12 patients, both with non-MS phenotype) and in none of the patients with other autoimmune and immune-mediated disorders of the central and peripheral nervous system or with non-immune-mediated disorders of the CNS.Data from the literature review support clinical and analytical observations.