Clinical utility of anti-MOG antibody testing in a Danish cohort

Background: Anti-myelin oligodendrocyte glycoprotein (MOG) antibody (Ab) can be found in different immunemediated inflammatory CNS disorders. The full range of clinical manifestations may not have been fully discovered yet. Methods: In a cross-sectional study 184 adults (age 16) were tested for anti-MOG antibody (Ab) with a cell-based assay. To define the relevant target population for anti-MOG antibody testing in a neurology clinic, we divided the entire study population based on the presenting symptoms and classified cases followed for multiple sclerosis (MS) according to the clinical features and response to disease-modifying therapy. Results: We identified eight (4.4%) MOG-Ab positive cases in the whole cohort. All eight cases had first manifestations suggestive of neuromyelitis optica spectrum disorder (NMOSD), but had highly variable disease courses and responses to therapy. This included a patient with chronic relapsing inflammatory optic neuropathy (CRION) responding only to therapy with infliximab. Four (3%) out of 134 cases followed for MS who tested positive for anti-MOG Ab showed atypical features and had poor response to therapy. Conclusion: A broad range of clinical and radiological features of anti-MOG associated disorder was observed in a single centre. MOG-Ab testing should be considered in patients with an NMOSD phenotype and in MS patients presenting atypical features. The potential use of infliximab therapy for MOG-Ab disease should be further investigated.