Diagnostic accuracy and age-dependent prognostic confounding of kappa free light chain parameters in multiple sclerosis.
BACKGROUND The kappa free light chain (κ-FLC) index is widely recognized as an alternative to oligoclonal bands for demonstrating intrathecal immunoglobulin synthesis in multiple sclerosis (MS). However, its prognostic value remains controversial. We investigated whether physiological age-related changes confound κ-FLC...