Treatment Responsive Relapsing MOG-Ab Associated Demyelination

Objective: To describe the clinical and paraclinical features, treatment response and outcome of children with myelin oligodendrocyte glycoprotein antibodies (MOG)-Ab and relapsing demyelinating syndromes. Methods: Review of a prospective EU multicenter database on 83 children with MOG-Ab associated relapsing disease. All patients were tested for MOG-Ab using cell based assays. Data including demographics, clinical findings and laboratory results were reviewed by an adjudication panel and clinical diagnosis confirmed. Annual relapse rate (ARR) and EDSS before and after treatment were compared in patients receiving immunotherapy for over 1 year. Results: 32(37%) of children were diagnosed with neuromyelitis optica spectrum disorder (NMOSD, median age 9 years, 27 females), 19 (23%) with multiphasic disseminated encephalomyelitis (MDEM, median age 4.5 years, 11 females), 18 (22%) acute disseminated encephalomyelitis (ADEM) followed by recurrent or monophasic optic neuritis (ADEM-ON, median age 6.6 years, 10 females) and 14 (17%) with relapsing idiopathic optic neuritis (RION, median age 14 years, 8 females). Cerebellar symptoms (49%) and seizures (38%) were common amongst the 49 patients with abnormal intracranial MRI at presentation. CSF lymphocytosis was seen in 51%, with only 9% of patients having intrathecal oligoclonal bands. Evidence of remote EBV infection was detected in 22% and ESR was elevated in 53%. Median EDSS at 2 years was 1 with cognitive problems seen in 22%. Forty two patients received treatment. Conventional MS treatment (Interferon-beta and Glatiramer acetate, n = 12) did not change relapses frequency. ARR was reduced by 0.6 with Azathioprine (n = 18, p = 0.0006), 0.9 with Mycophenolate mofetil (n = 12, p = 0.0057), 1.3 with Rituximab (n = 7, p = 0.018) and 2.5 with regular IVIG (n = 9, p = 0.0054). Eight patients continued to relapse despite treatment. Conclusion: Children with MOG-Ab had features atypical for MS and relapsed on conventional MS treatment. B-cells targeted treatment, and particularly IVIG might reduce relapses but there appeared to be a treatment refractory group with poor outcome.