Myelin oligodendrocyte glycoprotein (MOG) antibodies (ab) are detected in approximately 1/3 of children with demyelinating disease at onset; presentations commonly overlap with optic neuritis, neuromyelitis optica spectrum disorder (NMOSD) or acute disseminated encephalomyelitis. Serum MOG-ab titers have unclear relevance to disease course, and optimal treatment strategy is unknown.
We aimed to characterize children with CNS demyelinating disorders who tested positive for MOG-ab. We also aimed to evaluate the relevance of serum MOG-ab titers for diagnosis, risk and severity of subsequent demyelinating events. Finally, we aimed to evaluate treatment strategies for MOG-ab positive children.
This retrospective study evaluated children with demyelinating disorders with onset before 18 years of age seen at the University of California, San Francisco who tested positive for MOG-ab (tested by live cell-based fluorescent activated cell sorting assay at Mayo Clinic) between October 2006-June 2020. Demographic information, clinical presentation at onset, MRI, CSF, brain biopsy, and treatment data were collected by chart review.
Sixty children were included (mean onset age 8.2 years; 53% female; 72% white; 40% Hispanic or Latino). The most common clinical localization at onset included optic nerve (ON) (53%) and/or brainstem/cerebellum (42%). 83% of initial events were severe. Median EDSS assessed within 6 months of onset was 1.5 (range 0-4). 81% of initial brain MRIs had T2 bright lesions and 61% had gadolinium-enhancing lesions; T2 bright lesions were most commonly seen in subcortical areas (50%) and/or brainstem/cerebellum (33%). Oligoclonal bands were positive in 17% of initial CSF. 57% had initial serum MOG-ab titers ≥1:100 (median time from onset to first titer 15.4 months). Titers ≥1:320 were only observed within 2 months of an event (disease onset or relapse). While 38% had no relapses (mean follow-up 1.42 years), those who did had a median of 2 relapses (mean follow-up 3.83 years). The most commonly used treatments were interferon beta (28%) and rituximab (27%). Brain biopsy was performed in 2 patients and showed overt demyelination and prominent infiltration of monocyte lineage and polymorphonuclear cells.
The most common clinical onset localizations in MOG-ab positive children were ON and brainstem/cerebellum. Higher MOG-ab titers were only observed close to a clinical event.