Myelin Oligodendrocyte Glycoprotein Antibody-Associated Bilateral Optic Neuritis (Mogad) in a Five Year Old Girl

Introduction

MOGAD (+=+myelin oligodendrocyte glycoprotein antibody-associated disease) is a rare inflammatory disease of the central nervous system (incidence 0.16/100,000/year), which is predominantly associated with demyelination of the optic nerve and spinal cord, and disseminated encephalitis (De Mol Cl et al., Mult Scler 2020; 26: 806–814). It is estimated that about 30% of demyelinating events in children are caused by MOGAD (Hennes E et al. Neuropediatrics 2017; 49, 3–11).

Diagnostic criteria include clinical symptoms, a clearly elevated MOG IgG antibody level, and exclusion of another cause (e. g., multiple sclerosis (MS) or aqua-porin-4 associated encephalitis) (Banwell et al., The Lancet Neurol 2023; 22: 268–282).

Myelin oligodendrocyte glycoprotein is expressed on the surface of oligodendrocytes and is highly immunogenic. Its exact function is still the subject of research, but it is thought to function primarily as an adhesion molecule. By being located at the cell surface, it provides a strong target for antibodies (Johns G et al., Journal of Neurochemistry 1999; 72: 1–9).

Relatively little data are yet available on the epidemiology regarding MOGAD, as MOG-Ab IgG was first discovered in 2007 and available testing methods were not established until years later. In cohorts to date, the most common form in children is acute disseminating encephalitis (ADEM) and in adults optic neuritis (Stiebel-Kalish H et al., Neurol Neuroimmunol Neuroinflamm 2019; 6: e572).

Differential diagnoses include multiple sclerosis (MS) and anti-AQP4 myelitis. These three entities are best differentiated by simultaneous determination of MOG-Abs, AQP4-Abs or oligoclonal bands and the clinical course. However these antibodies do not discriminate perfectly (Flanagan EP. Neuromyelitis Optica Spectrum Disorder and Other Non-Multiple Sclerosis Central Nervous System Inflammatory Diseases. Continuum (Minneap Minn) 2019; 25: 815). Typically, in recurrent disease – in contrast to aquaporin-4 associated encephalomyelitis and similar to MS – the first relapses are followed by an almost complete remission. Only later, residual defects occur. Recurrences are also more common in adults than in children (Stiebel-Kalish H et al., Neurol Neuroimmunol Neuroinflamm 2019; 6; e572). 53% of children have a relapsing course, with 2/3 of children having a new relapse in the first 2 years. However, in isolated MOGAD optic neuritis (ON) the relapse rate may only be app. 13%, and all of these patient had ongoing MOG abs titers (Wendel et al., Eur J Paediatr Neurol 2020; 27, 86–93). The overall relapse rate in adults is 40% and therefore higher than in children (Cobo-Calvo a et al., Ann Neurol 2021; 89: 30–41). According to current international guideline recommendations MOGAD should be treated with i. v. Methylprednisolon as first line treatment and high dose i. v. polyvalent immunoglobulins or plasmapheresis als second line options (Bruijsters et al. Eur J Paediatr Neurol 2020; 29: 41–53).

Publication History

Accepted Manuscript online:
07 May 2024

Article published online:
31 May 2024