ADEM-like presentation, anti-MOG antibodies, and MS pathology: TWO case reports

Acute disseminated encephalomyelitis (ADEM) mostly occurs in children and can be triggered by infections and vaccinations. Recently, 40% of patients with ADEM were found to be seropositive for myelin oligodendrocyte glycoprotein antibodies (MOGabs). Furthermore, a subgroup of adult patients negative for aquaporin-4 antibody fulfilling diagnostic clinical and radiologic criteria for neuromyelitis optica spectrum disorder (NMOSD) harbor high-titer serum MOG-abs. We present clinical, serologic, and histopathologic features of 2 adult patients with a clinical diagnosis of ADEM according to the diagnostic criteria associated with intrathecal MOG-abs synthesis. MOG-abs were determined by live-cell immunofluorescence on HEK293T cells expressing full-length human MOG-enhanced green fluorescent protein at a starting dilution of 1:20 in serum and 1:2 in CSF using an epifluorescence microscope and endpoint titration as previously described.