Analytical validation of new ELISAs for the quantitation of polyclonal free light chains and comparison to existing assays for healthy and patient samples.

Autor: Heaney JLJ; Clinical Immunology Service, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK. Electronic address: j.l.j.heaney@bham.ac.uk., Campbell JP; Department for Health, University of Bath, Bath, UK., Goodall M; Clinical Immunology Service, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK., Plant T; Clinical Immunology Service, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK., Shemar M; Department for Health, University of Bath, Bath, UK., Hand C; Abingdon Health Ltd., York, UK., Drayson MT; Clinical Immunology Service, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK.
Jazyk: angličtina
Zdroj: Journal of immunological methods [J Immunol Methods] 2020 Mar; Vol. 478, pp. 112713. Date of Electronic Publication: 2019 Nov 26.
DOI: 10.1016/j.jim.2019.112713
Abstrakt: Background: Polyclonal FLCs can be used as a biomarker of inflammation and immune activation in a range of diseases. This study evaluated the performance of new FLC ELISAs (Seralite FLC ELISA) for the quantitation of polyclonal κ and λ FLC, including comparisons to existing assays.
Methods: Technical performance was assessed for the ELISA and reference ranges were generated using healthy donor serum (N = 91). Patients with a range of conditions associated with polyclonal FLC dysregulation (N = 164) were measured across platforms.
Results: The ELISAs generated references ranges of: 8.72-23.0 mg/L κ FLC, and 8.52-25.24 mg/L for λ FLC. ELISAs demonstrated linearity across the calibration range and intra-assay (≤ 8.7%) and inter-assay (≤ 12.3%) imprecision was low. The limit of detection was 0.63 mg/L for κ and 0.57 mg/L for λ FLC. Minimal cross-reactivity was observed for interference agents, alternate FLC and whole immunoglobulin (median change ≤3.6 mg/L). Assays showed good batch-to-batch consistency. For patient samples, methods generated different κ and λ FLC concentrations and differences were seen between methods for the number of patients classified as below, with and above references ranges for κ and λ FLC. There was no significant difference in the FLC sum between the different techniques.
Conclusions: The ELISAs displayed good analytical and technical performance. The quantification of individual κ and λ FLC appears inherently different between platforms. These differences are attenuated if using the FLC sum, which was similar between methods and provided agreement in relation to patients having normal or elevated FLCs.
Competing Interests: Declaration of Competing Interest MS is an employee of Abingdon Health Ltd. MD has an advisory role with Abingdon Health Ltd. and reports personal fees from Abingdon Health Ltd. JC, MG, and TP own shares in Abingdon Health Ltd. CH is Chairman of Scientific & Medical Advisory Board of Abingdon Health Ltd.
(Copyright © 2019 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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