Kappa free light chains: Diagnostic performance in multiple sclerosis and utility in a clinical laboratory.

Background: Automated, technically simple analytical methods offering objective results are highly valued in clinical laboratories. Kappa free light chains (KFLC) in cerebrospinal fluid (CSF) are promising multiple sclerosis (MS) biomarkers, particularly kappa (K) index.

Methods: KFLC were determined in CSF and serum samples of patients diagnosed with MS, clinically/radiologically isolated syndrome (N, 39), and controls (N, 152; inflammatory and non-inflammatory neurological disorders).