Lipemic interference of ceruloplasmin assays – An evaluation of lipid removal methods

Abstract

BackgroundThe present studies were conducted to characterize lipemic interference across three FDA-cleared ceruloplasmin (CERU) assays and to evaluate procedures designed to remove lipemic interference. MethodsCERU assays on the Abbott ARCHITECT ci8200, Beckman AU5800, and Roche cobas Integra 400 Plus were evaluated. Precision, linearity with dilution, lipemic interference, and three methods for removing lipemia were assessed on each platform: ultracentrifugation (UC), lipemia-clearing reagent LipoClear (LC), and 1:5 dilution (DIL). Lipemia-index (L-index) thresholds were established using endogenously lipemic specimens and sera spiked with human-derived triglyceride-rich lipoproteins. ResultsThe ci8200 showed greater susceptibility to endogenous lipemic interference than would be expected based on vendor-derived limits established with Intralipid. Endogenous lipemia causes a negative interference on the ci8200 and a positive interference on the Integra. UC was generally the most reliable method of removing lipemic interference without impacting baseline CERU results. ConclusionsCERU assays on different platforms have varying susceptibility to lipemic interference. L-index thresholds derived using Intralipid may not accurately represent interference caused by endogenous lipemia.