Phenotypic Characteristics and Recurrence Factors of MOG-IgG Associated Disorders in Children

Abstract

Background The prevalence of anti-myelin oligodendrocyte glycoprotein (MOG) -IgG associated disorders (MOGAD) is significantly higher in children than that in adults. The characteristics and associations of phenotypes and recurrence risk in children are still unclear. Objective To examine the phenotypic features and recurrence factors of MOG-IgG positivity in central nervous system inflammatory demyelinating diseases in children. Methods A follow-up study on 54 children with MOGAD diagnosed in Children's Hospital of Hebei Province from December 2017 to December 2021 was performed. Phenotypic features at each demyelinating attack, laboratory tests, imaging characteristics, MOG-IgG titers in serum/cerebrospinal fluid (CSF), efficacy, and high risk factors for recurrence were analyzed. The MOG-IgG was tested using cell-based immunofluorescence assay. All patients were followed up until March 31, 2022. Results In our study, the median age of onset was 6.0 (4.0, 8.0) years and the male to female ratio was 1∶1.07. Serum MOG-IgG titers were 1∶10-1∶320. Acute disseminated encephalomyelitis (ADEM) was the most common phenotype (44.4%, 24/54), followed by optic neuritis (ON) (25.9%, 14/54) and non-ADEM-like meninges /encephalitis (20.4%, 11/54). Ten cases (18.5%) were positive for MOG-IgG in serum and CSF, and 2 (3.7%) were positive for both NMDAR-IgG in CSF and MOG-IgG in serum. Brain MRI showed new lesions during the 76.9% (60/78) of the 78 attacks in total, and the most common locations were cortical white matter (66.7%, 40/60) and optic nerve (35.0%, 21/60). Forty patients (74.1%, 40/54) experienced one episode, the main phenotypes were ADEM (57.5%, 23/40) and non-ADEM-like meninges/encephalitis (25.0%, 10/40). Fourteen patients (25.9%, 14/54) had two or more episodes, and the initial phenotype of them was ADEM with ON (57.1%, 8/14) or ON (21.4%, 3/14). Compared with recrudescent cases, non-recrudescent cases had much lower prevalence of ON or ADEM with ON as the primary phenotype (P<0.05). All the children received first-line immunoregulation therapy at the time of the initial attack. Of the 14 relapsed cases, 2 (14.3%) were improved after mycophenolate mofetil treatment, one (7.1%) was better after rituximab treatment, and the other 11 (78.6%) had improved symptoms and imaging manifestations after being treated with methylprednisone pulse therapy combined with gamma globulin again. MOG-IgG titers were not increased in the recurrent children. After treatment, 28 (51.9%) children were completely improved, while 11 (20.4%) children had various neurological sequelae, among which visual dysfunction〔54.5% (6/11) 〕 was the most common. Conclusion The clinical phenotypes of MOGAD in children are diverse, among which the common phenotypes are ADEM, ON and non-ADEM-like meninges/encephalitis. Brain damages detected by MRI are extensive. The initial phenotypes of ADEM with ON and ON are prone to relapse. Most children have a good prognosis, but some may be accompanied by neurological after effects.

Keywords

• demyelinating autoimmune diseases, cns|myelin oligodendrocyte glycoprotein|child|clinical phenotype|recurrence