High sensitivity and specificity of elevated cerebrospinal fluid kappa free light chains in suspected multiple sclerosis

Abstract

Cerebrospinal fluid (CSF) analysis is routinely used in the diagnostic work-up of multiple sclerosis (MS), by detecting CSF-specific oligoclonal bands (OCB). More recently, several studies have reported CSF free light chains (FLC) as an alternative. We show that absolute CSF κFLC concentrations were highly sensitive - more than OCB testing - and specific for clinically isolated syndrome, relapsing remitting and primary progressive MS. Measurement of κFLC alone was sufficient. Our results suggest that CSF κFLC levels measured by nephelometry, if validated in a larger series, are a preferred test to OCB analysis in the diagnostic work-up of patients suspected of having MS.

Assessment of Intrathecal Free Light Chain Synthesis: Comparison of Different Quantitative Methods with the Detection of Oligoclonal Free Light Chains by Isoelectric Focusing and Affinity-Mediated Immunoblotting

“…However, from the immunological point of view, the analysis of both fLC might be useful as widely different fLLC values were seen in MS patients by our group [39] as well as by the others [3,4]. It is plausible to suggest that the fKLC/fLLC ratio may provide important additional information on the intrathecal humoral immune response and might even be of prognostic significance.…”

“…In the context of MS diagnosis, o-IgG seems to be more specific than fKLC tests. We therefore conclude that it is too early to recommend abandoning the o-IgG test as suggested in some recent reports [3, 8] until more data have been gathered from various laboratories and different fKLC assay methods have been used. The diagnostic performance of qualitative as well as quantitative fLLC tests is inferior to that of o-IgG and fKLC tests, but enormous variability in the CSF fLLC concentration observed among individual MS patients warrants further studies including prospective evaluation of the possible significance of intrathecal fLLC synthesis in MS.…”

Free light chains of immunoglobulins in patients with systemic sclerosis: correlations with lung involvement and inflammatory milieu

“…In the majority of autoimmune diseases,16–19 32 33 a significantly higher concentration of FLC has been reported. In multiple sclerosis, κ-FLC fraction of cerebrospinal fluid has a role as diagnostic36 and prognostic35 tool. The real role of increased κ fraction in SSc is unknown.…”

Quantitation of free light chains in the cerebrospinal fluid reliably predicts their intrathecal synthesis

“…[1][2][3][4] Up to now, CSF fLC measurements have only been compared to o-IgG as a gold standard. This approach, however, does not compare exactly like with like.…”