Kappa free light chain index as a diagnostic biomarker in multiple sclerosis: a real ‐world investigation

AbstractKappa free light chain (KFLC)-index, a measure for intrathecal production of free kappa chains, has been increasingly recognized for its diagnostic potential in multiple sclerosis (MS) as a quantitative alternative to IgG oligoclonal-bands (OCBs). Our objective was to investigate the sensitivity, specificity, and overall diagnostic accuracy of KFLC-index in MS. KFLC-index was prospectively determined as part of the diagnostic workup in patients with suspected MS (n=327) between May 2013 and February 2020. Patients with clinically isolated syndrome (CIS), radiologically isolated syndrome (RIS), and MS had markedly higher KFLC-index (44.6, IQR 16-128) compared with subjects with other neuro-inflammatory disorders (ONID) and symptomatic controls (SC) (2.19, IQR 1.68-2.98, p<0.001). KFLC-index had a sensitivity of 0.93 (95% CI 0.88-0.95) and specificity of 0.87 (95% CI 0.8-0.92) to discriminate CIS/RIS/MS from ONID and SC (AUC 0.94, 95% CI 0.91-0.97, p<0.001). KFLC-index and intrathecal fraction (IF) KFLC  had similar accuracies to detect MS. Treatment with disease-modifying therapy (DMT) did not influence the level of KFLC-index and it was not affected by demographic factors or associated with degenerative or inflammatory biomarkers in cerebrospinal fluid (CSF). KFLC-index in MS diagnostics has met hodological advantages compared to OCB and is independent to subjective interpretation. Moreover, it is an attractive diagnostic tool since the diagnostic specificity a...
Source: Journal of Neurochemistry - Category: Neuroscience Authors: Tags: ORIGINAL ARTICLE Source Type: research