COVID-19 susceptibility and outcomes among patients with neuromyelitis optica spectrum disorder (NMOSD): A systematic review and meta-analysis

Background: We conducted this systematic review and meta-analysis to assess the risk of coronavirus disease (COVID-19), clinical features and outcome among patients with neuromyelitis optica spectrum disorder (NMOSD). Methods: We systematically searched PubMed, Scopus, Web of Science, and Embase from December 1, 2019, to July 2, 2021. The gray literature including the references of original studies, review studies, conference abstracts, and WHO COVID-19 database was also searched. We included any type of studies that reported NMOSD patients with COVID-19, prevalence of COVID-19 among NMOSD patients or the infection outcome (hospitalization, intensive care unit [ICU] admission, or mortality). Results: Out of 540 records, a total of 23 studies (19 published articles and 4 conference abstracts) including 112 NMOSD patients with COVID-19 met the inclusion criteria. Nine studies reporting risk of COVID-19 and nine studies on outcome were included in a quantitative synthesis. The pooled prevalence of COVID-19 was 1.2% (95% CI: 0.001%–0.030%; I² = 92%, p< 0.001), with hospitalization of 33.7% (95% CI: 23.3–44.8%; I² = 9.1%, p = 0.360) with 52.9% on rituximab treatment. ICU admission was 15.4% (95% CI: 7.6%-24.7%; I² = 20.7%, p = 0.272) and mortality was 3.3% (95% CI: 0–9.7%; I² = 21.3%, p = 0.253). Thirty-eight patients (48.7%) reported at least one comorbidity. The mean age of the included patients was 40.8 (10.63) years, female/male ratio was 3.35:1. The most common COVID-19 symptom was fever (54.5%), followed by fatigue/asthenia (42.9%), headache (41.6%), and cough (40.3%). Four patients developed neurological worsening. The Begg's and Egger's tests showed no evidence of publication bias. Conclusion: The analysis suggests that comorbidity and treatment with rituximab may be risk factors for COVID-19 infection in NMOSD patients.