Comparison of 2 Serum Free Light Chain Assays with Creatinine Normal and Abnormal Populations Demonstrates the Need for Standardization.

Autor:	Griffiths M; Diazyme Laboratories Inc., Poway, CA, United States., Cheng PL; Division of Clinical Biochemistry, University Health Network, Toronto, Canada., Wang XY; Division of Clinical Biochemistry, University Health Network, Toronto, Canada., Schneider R; Abbott Laboratories, Abbott Park, IL, United States., Kulasingam V; Division of Clinical Biochemistry, University Health Network, Toronto, Canada.; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.
Jazyk:	angličtina
Zdroj:	The journal of applied laboratory medicine [J Appl Lab Med] 2024 Sep 03; Vol. 9 (5), pp. 978-988.
DOI:	10.1093/jalm/jfae065
Abstrakt:	Background: The objective of this study was to compare The Binding Site's Freelite on Optilite and Diazyme's Kappa/Lambda free light chains (K/L FLC) on Abbott Architect c8000 with healthy and renal insufficient populations and to evaluate their respective reference intervals for serum free light chains (sFLCs). Methods: Two hundred sixty serum samples were measured for creatinine and sFLCs by both assays and a subset by immunofixation electrophoresis. Verification of manufacturer-defined reference intervals was assessed. Results: Kappa free light chains (KFLC) showed excellent correlation of 0.998 R2 with a slope of 0.73. For Lambda free light chains (LFLC), an acceptable correlation of 0.953 R2 was found with a slope of 1.50 as well as a skewness-based difference with a -12.70 intercept. Healthy estimated glomerular filtration rate (eGFR) ≥60 reference interval verification of central 95% could not be confirmed for either Freelite or Diazyme although LFLC was much closer than KFLC for both assays with Freelite KFLC recovering only 37% of values within reference interval claims. The K/L FLC ratio did not meet 100% claim for both Freelite (91%) and Diazyme (95%) among those with eGFR ≥60. Samples with eGFR ≤59 had increasingly higher levels of KFLC and LFLC for both assays. When comparing worsening eGFR status, Freelite recovered increasingly higher ratios while Diazyme recovered increasingly lower ratios. Conclusions: Healthy reference intervals could not be verified for either Freelite or Diazyme. Renal reference intervals for Freelite are currently warranted while they are not recommended for Diazyme. The differences between these 2 assays can be minimized by standardization efforts such as recalibration. (© Association for Diagnostics & Laboratory Medicine 2024. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
Databáze:	MEDLINE
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