Purpose of review: The clinical interest for auto-antibodies against myelin oligodendrocyte glycoprotein (MOG) has recently reemerged, with the use of more specific detection methods. Large national cohorts have allowed characterizing a more precise clinical spectrum delineated by the presence of human MOG-antibodies.
Recent findings: In adults with MOG-antibodies, optic neuritis is the most frequent clinical presentation, with features different from multiple sclerosis (MS), including bilateral involvement and predilection for the anterior part of the optic nerve. Myelitis and brainstem syndrome are also frequent, and may clinically mimic neuromyelitis optica spectrum disorders (NMOSD). Despite the frequently severe clinical presentation, most of patients recover quickly after steroids initiation. Other less typical presentations include encephalitis with seizures, cranial nerve involvement, and chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids-like. Although the majority of adult patients follow a relapsing course, long-term prognosis differs from aquaporin-4-antibodies NMOSD, with only a small proportion of patients with a poor outcome.
Summary: MOG-antibodies-associated disease is a new entity in the spectrum of inflammatory demyelinating diseases, distinct from both MS and NMOSD. There is a crucial need to identify factors associated to the risk of relapse or poor outcome, to seek patient subgroups in which immunoactive treatments could be beneficial.