The new criteria increase the estimates, but NMOSD remains as a rare disease. The differences in age- and sex-specific estimates highlight the importance of the serologic classification.

Objective:To investigate glial and neuronal biomarkers in cerebrospinal fluid (CSF) samples from patients with relapsing–remitting multiple sclerosis (RRMS) and clinically isolated syndrome (CIS) suggestive of multiple sclerosis (MS), and to evaluate their ability to predict conversion from CIS to clinically definite MS (CDMS) and also disability progression in MS.Methods:CSF levels of neurofilament light protein (NFL), t-tau, p-tau, glial fibrillary acidic protein (GFAP), S-100B, human chitinase 3-like 1 protein (YKL-40), monocyte chemoattractant protein-1 (MCP-1), α-sAPP and β-sAPP; and Aβ38, Aβ40 and Aβ42, were analyzed in 109 CIS patients and 192 RRMS patients. The mean follow-up time of these 301 patients was 11.7 ± 6.4 years.Results:High levels of NFL were associated with early conversion from CIS to CDMS (hazard ratio (HR) with 95% confidence interval (CI): 2.69 (1.75 – 4.15); p < 0.0001). High levels of YKL-40 and GFAP were associated with earlier progression in the Expanded Disability Status Scale (EDSS), score 3: YKL-40 (HR (95% CI): 2.78 (1.48 – 5.23); p = 0.001) and GFAP (HR (95% CI): 1.83 (1.01 – 3.35); p = 0.04). High levels of YKL-40 were associated with earlier progression to EDSS 6 (HR (95% CI): 4.57 (1.01 – 20.83); p = 0.05).Conclusions:CSF levels of NFL in CIS patients are an independent prognostic marker for conversion to CDMS. Whereas, CSF levels of YKL-40 and GFAP are independent prognostic markers for disability progression in MS.

In the present study, CSF concentrations of NFL, t-tau, p-tau, GFAP, S-100B, YKL-40, MCP-1, α-sAPP, β-sAPP, and Aβ38, Aβ40, Aβ42 were measured in 324 MS patients to test whether a correlation among the biomarkers exists and whether the profile of CSF biomarkers varies among the different types of MS. The CSF concentrations of NFL were significantly higher in RRMS while CSF concentrations of GFAP were higher in PPMS. CSF concentrations of NFL correlated with YKL-40 in CIS patients while CSF concentrations of GFAP correlated with YKL-40 in RRMS patients.