Kflc Index Evaluation to Assess Immunoglobulin Intrathecal Synthesis

Abstract

Multiple sclerosis (MS), where intrathecal synthesis is present, is one of the most common neurological diseases of the young adults in CNS, and it often causes deficits since its early stage. Clinically isolated syndrome (CIS) is a central nervous system demyelinating event isolated in time and it is compatible with the possible future development of multiple sclerosis (MS). Early risk stratification for conversion to MS helps with treatment decisions [3]. Currently it is possible to identify the presence of antibodies by the detection of oligoclonal immunoglobulin bands (OCBs) in cerebrospinal fluid (CSF) [4,5]. It is necessary to differentiate the origin of immunoglobulin (Ig) in the CSF before intrathecal immunoglobulin synthesis can be diagnosed [6]. Immunoglobulin light chains that are circulating in serum in a free state are called Free Light Chains (FLCs). These can be both kappa (kFLCs) and lambda type (λFLCs). We examined 80 CSF/serum pairs from patients of the neurological clinic who underwent analysis of OCBs during their diagnostic workup. We analysed the correlation between OCBs test and the FLCs nephelometric assay [1] and we assessed the diagnostic accuracy of a nephelometric assay for k free light chain determination in cerebrospinal fluid and serum. The correlation between the two methods was very good, but the method to determine OCBs is timeconsuming, not quantitative, and also relatively insensitive and operator depending. [1,2,7-9]. On the contrary, the nephelometric determination of FLCs in serum and CSF is a quantitative method and it might be a sensitive alternative to the above-mentioned approach.