Kappa Free Light Chains (KFLC) in Multiple Sclerosis (MS) and Clinically Isolated Syndrome (CIS)

The goal of this observational study is to learn about the role of kappa free light chains (KFLC) in cerebrospinal fluid (CSF) in the diagnosis of multiple sclerosis (MS) and clinically isolated syndrome (CIS). The main question it aims to answer is: Are KFLC superior, inferior or equally useful in the diagnostic work-up of CSF of patients with MS and CIS? In CSF and serum sample pairs of patients diagnosed with MS or CIS, KFLC are measured using a nephelometric assay and are compared with the gold standard, of CSF diagnostics, oligoclonal bands.