Clinically Isolated Demyelinating Syndrome Associated with Anti-MOG Antibody (P1.2-081)

Objective: To describe cases of clinically isolated demyelinating syndrome (CIS) in patients with positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody. Background: Demyelinating disease associated with anti-MOG antibody is increasingly recognized. Some patients develop severe impairment similar to aquaporin-4 antibody-positive neuromyelitis optica. However, several reports suggest lower relapse rates in patients with anti-MOG antibody. There are no prospective studies to guide treatment decisions in patients with CIS and anti-MOG antibody. Design/Methods: Medical records and imaging of patients from the author’s practice found to have anti-MOG antibody after an initial demyelinating syndrome and prior to second relapse were reviewed. Results: Four patients meeting inclusion criteria were seen from November 2017 to October 2018. Median age was 37 years (range 17–57); sex was female in 3. Initial presentations included bilateral optic neuritis (2), longitudinally extensive transverse myelitis (1), and multifocal active CNS demyelination (1). All cases were initially treated with corticosteroids and rescue plasmapheresis was used in one. None had aquaporin-4 antibodies or MRI findings fulfilling the International Panel diagnostic criteria for multiple sclerosis. After detection of anti-MOG antibody, options including empiric immune therapy and watchful-waiting strategy were discussed. Fifty percent (2/4) declined treatment. In patients electing immune therapy, options used included rituximab (2), corticosteroids (1), and mycophenolate (1). After median follow-up of 11 months (range 4–24 months), one patient had a single clinical relapse (unilateral optic neuritis) on immune therapy with mycophenolate and was switched to rituximab. Remaining patients were relapse-free at last follow up, and none required support for ambulation or had unilateral visual acuity worse than 20/40. Conclusions: The spectrum of outcomes in patients with CIS and anti-MOG antibody varied, ranging from recurrent disease despite immune therapy to stable disease on no treatment. A prospective, multicenter study of outcomes in this patient population would be valuable to guide clinical decision making. Disclosure: Dr. Schmalstieg has nothing to disclose.