Myelin oligodendrocyte glycoprotein (MOG) antibody-mediated disease: The difficulty of predicting relapses

Background: While many patients with myelin oligodendrocyte glycoprotein antibody-mediated disease (MOG-AD) will have a monophasic course, 30-80% of patients will relapse after the initial attack. It is not known which factors predict relapse. Here we describe our clinical experience with MOG-AD and evaluate for factors that correlate with relapsing disease. Methods: This was a retrospective, multi-institutional study of 54 patients with MOG-AD, including 17 children and 37 adults. Mann-Whitney U and Fischer's Exact tests were used for comparisons and logistic regression for correlations. Results: Incident attack phenotype included acute disseminated encephalomyelitis (15%), unilateral optic neuritis (ON; 39%), bilateral ON (24%), transverse myelitis (TM; 11%) and ON with TM (11%). Pediatric patients were more likely than adults to present with ADEM (p =.009) and less likely to present with unilateral ON (p =.04). 31 patients (57%) had a relapsing disease course, with time to first relapse of 8.2 months and median annualized relapse rate of 0.97 months. In 40% of patients (n = 22) the first relapse occurred following the withdrawal of treatment for the incident attack. 5 patients converted to seronegative at follow up, 2 of whom later relapsed. Logistic regression revealed no significant relationship between age, gender, race, presentation phenotype, antibody titer, or cerebrospinal fluid results with risk of relapse. For patients who started disease modifying therapy (DMT) prior to the first relapse (n = 11), 64% remained monophasic. 50% (n = 15) of patients on DMT continued to have disease activity, requiring treatment adjustment. Conclusions: It is difficult to predict which patients with MOG-AD will relapse. Research is needed to determine the optimal timing and choice of treatment.