Spectrum of anti-myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated diseases: an Indian perspective.

Myelin oligodendrocyte glycoprotein antibody (MOG-Ab) is involved in the pathogenesis of central nervous system (CNS) demyelination disorders. We aimed to explore the spectrum of MOG-Ab-associated diseases in eastern India. A single-center, prospective observational study was done over a period of 2 years in a tertiary care hospital of eastern India. Patients with CNS demyelination disorders who tested positive for MOG-Ab using live cell-based assay were included in the study; while, those with age less than 1 year, documented preexisting CNS structural lesions, developmental delays or diagnosed multiple sclerosis were excluded. Demographic profile, clinical spectrum, disease course, radiological features as well as response to treatment were analyzed among included patients. Twenty MOG-Ab-positive patients were included (M:F 1:1.85). The median age of symptom onset was 10.5 years. The median follow-up of patients was 13 months. Acute disseminated encephalomyelitis (ADEM) was the commonest presentation at first attack (55%), followed by optic neuritis (ON) (45%). Patients with ADEM had a significantly lower age at first attack (p = 0.025). Monophasic and relapsing disease courses were seen in 45% and 55% patients, respectively. While all patients with only ADEM had a monophasic course, 77.8% with ON had a relapsing course. Among patients who presented with isolated transverse myelitis, 75% had a monophasic course and all had disease confined to the spinal cord. Good response to corticosteroids was seen in majority of participants. Second-line drugs were needed in 55% patients, rituximab being the commonest second-line agent used. 35% patients had significant disability (EDSS > 4) at last follow-up. MOG-Ab-associated diseases have diverse clinical phenotypes characterized by age-dependent pattern-specific courses.