Myelin oligodendrocyte glycoprotein (MOG)-associated disease (MOGAD) is a rare, antibody-mediated inflammatory
demyelinating disorder of the central nervous system (CNS) with various phenotypes starting from
optic neuritis, via
transverse myelitis to acute demyelinating
encephalomyelitis (ADEM) and cortical
encephalitis. Even though sometimes the clinical picture of this condition is similar to the presentation of
neuromyelitis optica spectrum disorder (NMOSD), most experts consider MOGAD as a distinct entity with different immune system pathology. MOG is a molecule detected on the outer membrane of myelin sheaths and expressed primarily within the brain, spinal cord and also the optic nerves. Its function is not fully understood but this
glycoprotein may act as a
cell surface receptor or
cell adhesion molecule. The specific outmost location of myelin makes it a potential target for autoimmune
antibodies and cell-mediated responses in demyelinating processes.
Optic neuritis seems to be the most frequent presenting phenotype in adults and ADEM in children. In adults, the disease course is multiphasic and subsequent relapses increase disability. In children ADEM usually presents as a one-time incident. Luckily, acute
immunotherapy is very effective and severe disability (ambulatory and visual) is less frequent than in NMOSD. A critical
element of reliable diagnosis is detection of pathogenic serum
antibodies MOG with accurate, specific and sensitive methods, preferably with optimized cell-based assay (CBA). MRI imaging can also help in differentiating MOGAD from other neuro-inflammatory disorders. Reports on randomised control trials are limited, but observational open-label experience suggests a role for high-dose
steroids and
plasma exchange in the treatment of acute attacks, and for immunosuppressive therapies, such as
steroids, oral
immunosuppressants and
rituximab as maintenance treatment. In this review, we present up-to-date clinical, immunological, radiographic, histopathological data concerning MOGAD and summarize the practical aspects of diagnosing and managing patients with this disease.