Free light chain UV quantification compared with immunochemical measurement: How dimers and monomers may influence the results.

Autor: Caponi L; Department of Translational Research, University of Pisa, Pisa, Italy. Electronic address: laura.caponi@med.unipi.it., Koni E; Department of Translational Research, University of Pisa, Pisa, Italy., Romiti N; Department of Translational Research, University of Pisa, Pisa, Italy., Paolicchi A; Department of Translational Research, University of Pisa, Pisa, Italy., Franzini M; Department of Translational Research, University of Pisa, Pisa, Italy.
Jazyk: angličtina
Zdroj: Clinica chimica acta; international journal of clinical chemistry [Clin Chim Acta] 2020 Nov; Vol. 510, pp. 278-284. Date of Electronic Publication: 2020 Jul 21.
DOI: 10.1016/j.cca.2020.07.027
Abstrakt: Serum κ and λ free light chain (FLC) levels are important for the management of plasma cell disorders. Immunochemical measurements on automated platforms with different reagents occasionally return different results that make them not interchangeable. The reasons for this behaviour are not clear and it is not known which result is the most accurate. The aim of the study is to quantify naturally occurring FLCs with a reference method (UV absorbance) in a sample devoid of other sources of UV absorbance. This was possible on a particular urine sample containing only lambda FLC proteins, dialyzed to clear it from low molecular weight UV absorbing compounds. The sample was submitted to Fast Protein Liquid Chromatography separation with a size-exclusion column in order to separate the FLC monomers and dimers. FLCs were also measured with the Freelite and N Latex FLC methods and the results were compared. The results demonstrated that the amount of FLC calculated on the basis of UV absorbance was overestimated by both immunochemical methods, and that the amount measured by the two reagents was affected by the different proportions of dimers or monomers. The present findings may be useful for the comprehension of the immunochemical measurement of FLC.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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