Myelin oligodendrocyte glycoprotein antibodies in neuromyelitis optica spectrum disorder.

Purpose of review: Neuromyelitis optica spectrum disorder (NMOSD) is a severe inflammatory disease of the central nervous system, particularly characterized by disabling episodes of optic neuritis and longitudinally extensive transverse myelitis. The pathogenic characteristic is the presence of antiaquaporin 4 antibodies (AQP4-Abs) in the cerebrospinal fluid and serum of most of the affected patients. However, a proportion of the patients (around 20-30%) that have a typical phenotype of NMO are seronegative for AQP4-Abs. Recent findings: A proportion of these seronegative patients (20%) can express antibodies to myelin oligodendrocyte glycoprotein (MOG-Abs). The presence of MOG-Abs in the sera of seronegative NMO patients is associated with typical features of NMO in several patients but in some of them with relapsing episodes of optic neuritis or transverse myelitis. Summary: In this article, we review the clinical and therapeutic aspects of MOG-Ab-positive NMOSD, with a specific focus on optic neuritis.