Multiple Sclerosis-like Features in Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease: Red Flag, Red Herring, or Regular Occurrence?

Background: MOG antibody-associated disease (MOGAD) is an inflammatory demyelinating disorder characterized by IgG antibodies against myelin oligodendrocyte glycoprotein (MOG). Distinct from both multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD), MOGAD classically presents with recurrent optic neuritis and longitudinally extensive transverse myelitis (LETM). Recent recommendations discourage testing for MOG-IgG in patients with clinical or paraclinical findings more typical of MS, such as periventricular Dawson’s finger-type or juxtacortical lesions, CSF-restricted oligoclonal bands (OCBs), or a progressive clinical course.

Objectives: To understand the clinical spectrum of MOGAD, with a focus on MS-like features.

Methods: Records of all patients in the neuroimmunology clinic at the University of Cincinnati who had serum MOG-IgG testing were identified through a query of the electronic medical record. All patients with a titer of at least 1:20, as measured by fluorescence-activated cell sorting (FACS), were included in the series. Records were reviewed retrospectively for clinical, laboratory, and imaging data. Imaging classifications were verified by at least two independent neurologists.

Results: Serum MOG-IgG was positive in 24 patients (titers 1:20-1:1000). There was a female predominance of 1.4:1, with a mean age of onset of 34 years (range 5-58). Demyelinating lesions characteristic of MS were observed in multiple cases, including periventricular lesions (58.3%) and juxtacortical lesions (25.0%). Short segment myelitis was seen in 71% of patients; only one had longitudinally extensive myelitis. Three patients had a progressive course. Another patient presented with tumefactive demyelination. Of those tested (n=19), 32% had CSF-restricted OCBs. Twelve cases met both the 2017 McDonald criteria and the 2016 Magnetic Resonance Imaging in MS (MAGNIMS) criteria. In addition, two cases met only the MAGNIMS criteria, with optic neuritis contributing to dissemination in space. Among those with an MS-like presentation (n=14), titers ranged from 1:40-1:1000.

Conclusions: MOGAD may present with features more typical of MS, and these features should not deter testing for MOG-IgG, particularly since treatment differs for the two disorders. Conversely, testing should be considered in MS patients with atypical features.