Myelin oligodendrocyte glycoprotein immunoglobulin G‐associated disease

Abstract

AbstractMyelin oligodendrocyte glycoprotein (MOG) is a minor myelin protein localized at the outermost layer of the myelin sheath. Cell‐based assays to detect conformation‐sensitive MOG‐immunoglobulin G (IgG) have identified a unique group of patients with optic neuritis, acute/multiphasic disseminated encephalomyelitis, encephalitides (brainstem and cerebral cortical), myelitis and aquaporin‐4 IgG‐negative neuromyelitis optica spectrum disorders. MOG‐IgG‐associated disease affects both children and adults, and the female : male ratio is almost 1:1. Cerebrospinal fluid (CSF) examination shows pleocytosis of mononuclear or polymorphonuclear cells during acute exacerbation, but oligoclonal IgG bands are usually negative. CSF‐myelin basic protein levels are high, but CSF‐glial fibrillary acidic protein is not elevated, suggesting demyelination. CSF‐cytokines related to T helper cell‐17, B cells and neutrophils are remarkably upregulated, which is similar to aquaporin‐4 IgG‐positive neuromyelitis optica spectrum disorders, but distinct from multiple sclerosis. As for treatment of MOG‐IgG‐associated disease, high‐dose intravenous methylprednisolone is commonly used in the acute phase, but it has not been established which patients require long‐term immunosuppression and which drugs should be chosen to prevent relapse. There have been some recent studies to support the pathogenicity of MOG‐IgG in vitro and in vivo. Taken together, MOG‐IgG‐associated disease seems to be a unique inflammatory demyelinating disease of the central nervous system, but further research is required to clarify the clinical and epidemiological features, treatment strategy, and the underlying pathology.