Comparison of 2 Serum-Free Light-Chain Assays in CKD Patients.

ABSTRACT: Introduction:Quantification of serum-free light chains (FLCs) is important in the diagnosis and monitoring of paraprotein-related diseases. There are currently 2 FLC assays available: the Freelite assay (Binding Site) and the N Latex assay (Siemens). There is emerging evidence that these assays give different results, but it is not established how kidney dysfunction affects these assays differently. Methods:In this study, we measured and compared serum FLCs in patients with mild-to-moderate chronic kidney disease (CKD) using both assays. Results:Although ? FLCs are higher by Freelite, ? FLCs are higher by N Latex. Both ? and ? FLCs correlate inversely with estimated glomerular filtration rate (eGFR) in the 2 assays, but this effect is more pronounced in ?-free light-chain measurement by N Latex. Consequently, although the ?/? ratio by Freelite is inversely correlated by eGFR, the ?/? ratio by N Latex is positively correlated with eGFR. Conclusion:Our results clearly demonstrate that the 2 available FLC assays cannot be used interchangeably in patients with CKD.

SUBMITTER: Sprangers B 

PROVIDER: S-EPMC7210599 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature