Combined Analysis of Inflammatory Biomarkers for CNS Autoimmune Diseases Diagnostic

Project rationale: Since 2017, multiple sclerosis diagnosis should match the new McDonald criteria in which a "no better explanation than MS" should be fulfilled. However, many patients present with red flags that lead to a complex diagnostic work-up. There are no available biomarkers that permit to confirm or roll out MS diagnosis in such cases. Therefore, we lack biological markers that can help in the diagnosis of patients presenting with suspected MS. Many studies have found that serum and cerebrospinal fluid (CSF) cytokines could help to differentiate MS from other diseases such as neuromyelitis optica spectrum disorders (i.e., IL-6) or neurosarcoidosis (i.e., sIL-2R). Serum and CSF kappa free light chains have also shown good diagnosis performance in MS. In daily practice, our MS tertiary center already perform the analysis of CSF concentrations of IL-1β, sIL-2R, IL-6, IL-10, and serum and CSF kappa and lambda free light chains to roll out other central nervous system (CNS) autoimmune diseases in patients presenting with white matter hyperintensities (WMH). Objective: To correlate CSF IL-1β, sIL-2R, IL-6, IL-10, serum and CSF kappa and lambda free light chains with the final diagnosis in patients presenting to our MS tertiary center with suspected MS to identify a specific inflammatory biomarker profil involved in MS and other CNS autoimmune diseases. The methodology: This is an observational study. All patients ongoing a routine diagnostic work-up for suspected MS from june 2020 to june 2022 in our MS tertiary center will be analyzed. Cerebrospinal fluid IL-1β, sIL-2R, IL-6, IL-10, serum and CSF kappa and lambda free light chains will be correlated with the final diagnosis to ultimately find MS associated biomarkers.