Clinical course, treatment responses and outcomes in Chinese paediatric neuromyelitis optica spectrum disorder

Background Few data exists on paediatric neuromyelitis optica spectrum disorder (NMOSD). Here, we investigated the clinical presentation, treatment responses and long-term prognoses in a large cohort of patients with NMOSD and compared between children and adults with aquaporin-4 antibody (AQP4-IgG). Methods A retrospective chart review of patients followed in multiple centres identified 127 patients with NMOSD (31 children; 96 adults). Data were collected through medical records and structured questionnaire. Results In the paediatric cohort, median age at onset was 14 (range 7–17) years; 87% were female. AQP4 and myelin oligodendrocyte glycoprotein antibodies were detected in 82% and 16%, respectively. During a median disease duration of 48 months, 23% developed visual acuity of <6/60 Snellen, 3% were wheelchair-dependent. The frequency of brain/brainstem phenotype (18% vs 9%, p = 0.018) was more common in AQP4-IgG-positive children, while AQP4-IgG-positive adults were more likely to present transverse myelitis (TM) (44% vs 29%, p = 0.005) of all 452 episodes. Multivariable analyses showed that sustained disability was independently associated with the presence of TM (p = 0.030), brain/brainstem symptoms (p = 0.010), annualized relapse rate (p < 0.001) and possibly age of onset (p = 0.069). The reduction of ARR after azathioprine was more prominent in adults (79%) than in children (48%). Mycophenolate mofetil and rituximab decreased the relapse frequency of children, with a reduction of 94% and 100%, respectively. Conclusions paediatric NMOSD is a severely disabling disorder characterized by repeated brain attacks and early disability accrual. Prompt therapy including mycophenolate mofetil and rituximab should be considered to improve paediatric care.