Objective We systematically reviewed the literature on COVID-19 in patients with multiple sclerosis (MS). Methods We searched PubMed, Scopus, EMBASE, CINAHL, Web of Science, Google Scholar, and World Health Organization database from December 1, 2019, to December 18, 2020. Three conference abstract databases were also searched. We included any types of studies that reported characteristics of patients with MS with COVID-19. Results From an initial 2,679 publications and 3,138 conference abstracts, 87 studies (67 published articles and 20 abstracts) consisting of 4,310 patients with suspected/confirmed COVID-19 with MS met the inclusion criteria. The female/male ratio was 2.53:1, the mean (SD) age was 44.91 (4.31) years, the mean disease duration was 12.46 (2.27), the mean Expanded Disability Status Scale score was 2.54 (0.81), the relapsing/progressive ratio was 4.75:1, and 32.9% of patients had at least 1 comorbidity. The most common symptoms were fever (68.8%), followed by cough (63.9%), fatigue/asthenia (51.2%), and shortness of breath (39.5%). In total, 837 of 4,043 patients with MS with suspected/confirmed COVID-19 (20.7%) required hospitalization, and 130 of 4,310 (3.0%) died of COVID-19. Among suspected/confirmed patients, the highest hospitalization and mortality rates were in patients with no disease-modifying therapies (42.9% and 8.4%), followed by B cell–depleting agents (29.2% and 2.5%). Conclusion Our study suggested that MS did not significantly increase the mortality rate from COVID-19. These data should be interpreted with caution as patients with MS are more likely female and younger compared with the general population where age and male sex seem to be risk factors for worse disease outcome.

There is debate on the role of glial fibrillary acidic protein (GFAP) as a reliable biomarker in multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD), and its potential to reflect disease progression. This review aimed to investigate the role of GFAP in MS and NMOSD. A systematic search of electronic databases, including PubMed, Embase, Scopus, and Web of Sciences, was conducted up to 20 December 2023 to identify studies that measured GFAP levels in people with MS (PwMS) and people with NMOSD (PwNMOSD). R software version 4.3.3. with the random-effect model was used to pool the effect size with its 95% confidence interval (CI). Of 4109 studies, 49 studies met our inclusion criteria encompassing 3491 PwMS, 849 PwNMOSD, and 1046 healthy controls (HCs). The analyses indicated that the cerebrospinal fluid level of GFAP (cGFAP) and serum level of GFAP (sGFAP) were significantly higher in PwMS than HCs (SMD = 0.7, 95% CI: 0.54 to 0.86, p < 0.001, I² = 29%, and SMD = 0.54, 95% CI: 0.1 to 0.99, p = 0.02, I² = 90%, respectively). The sGFAP was significantly higher in PwNMOSD than in HCs (SMD = 0.9, 95% CI: 0.73 to 1.07, p < 0.001, I² = 10%). Among PwMS, the Expanded Disability Status Scale (EDSS) exhibited significant correlations with cGFAP (r = 0.43, 95% CI: 0.26 to 0.59, p < 0.001, I² = 91%) and sGFAP (r = 0.36, 95% CI: 0.23 to 0.49, p < 0.001, I² = 78%). Regarding that GFAP is increased in MS and NMOSD and has correlations with disease features, it can be a potential biomarker in MS and NMOSD and indicate the disease progression and disability in these disorders.