2022 年 39 巻 3 号 p. 282-288
MOG (Myelin oligodendrocyte glycoprotein) is a myelin protein expressed exclusively in the central nervous system (CNS). MOG has long been studied as a target antigen for autoimmune inflammatory demyelinating diseases of the CNS because of its distribution in the outermost layer of the myelin sheath and its structural features as a member of the immunoglobulin superfamily. Recently, the detection of conformation–sensitive MOG antibodies has led to the establishment of the clinical concept of MOG–antibody associated disease (MOGAD) as an independent autoimmune demyelinating disease. The clinical phenotypes include acute/multiphasic disseminated encephalomyelitis, optic neuritis, myelitis and brain stem and cerebral cortical encphalitis, whereas MOG antibodies are rarely detected in typical multiple sclerosis.
The treatment of MOGAD is divided into acute and chronic phases. The acute treatment is mainly provided by high dose methylprednisolone. The response to the treatment is generally good, and most cases recover without severe sequelae. On the other hand, there is still no established treatment to relapse prevention. The currently accepted approach is to treat the acute phase of the disease followed by 3–6 months of oral steroid therapy, reassessment of MOG antibodies, and continued maintenance treatment in patients with persistent positive MOG antibodies. For patients who become negative for MOG antibodies, it may be appropriate to discontinue maintenance therapy and follow–up. However, the pathogenesis of MOGAD is complex, with variability in response to B–cell removal therapy between cases. We hoped that the pathophysiology of MOGAD will be further elucidated in the future.
