Clinical and neuroimaging characteristics of MOG autoimmunity in children with acquired demyelinating syndromes

Background Myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) have been recently reevaluated as a biomarker of acquired demyelinating syndromes (ADS) of the central nervous system (CNS). Here, we describe the clinical and neuroimaging features, and the long-term outcome of children with ADS of the CNS associated with MOG-IgG. Methods All patients underwent brain and spinal cord magnetic resonance imaging (MRI), lumbar puncture for cerebrospinal fluid (CSF) analysis and MOG-IgG and aquaporin-4 IgG (AQP4-IgG) testing. Results Forty-eight pediatric patients were recruited. MOG-IgG were detected in 11/48 (25%) patients with the following clinical presentations: encephalomyelitis (EM), 8/11 (73%); optic neuritis (ON), 2/11 (18%); transverse myelitis (TM), 1/11 (9%). Patients negative for MOG-IgG were diagnosed with Multiple Sclerosis (MS) (n=15), EM (n=7), ON (n=7), neuromyelitis optica spectrum disorders (NMOSD) (n=5), TM (n=2) and encephalitis (n=1). MOG-IgG positive patients were younger at disease onset and they more frequently experienced encephalopathy and epileptic seizures compared with negative patients. EM and inflammatory lesions involving optic nerves on MRI imaging were more frequent in MOG-IgG positive patients. None of the patients with MOG-IgG became persistently seronegative during the follow-up, although a decrease in MOG-IgG titer was observed. Patients with MOG-IgG showed a good response to therapy and only two patients presented relapses during follow-up. Conclusion This study supports the distinction of MOG autoimmune oligodendrocytopathy as a unique disease entity, with clinical features different from those of MS and AQP4-IgG-positive NMOSD.