Advantages of the lipoprotein-associated phospholipase A2 activity assay

Leslie J. Donato, Jeffrey W. Meeusen, Heidi Callanan, Amy K. Saenger, Allan S Jaffe

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Objectives: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is increased in circulation in patients at higher risk of coronary heart disease (CHD) events and stroke. Therefore, measurement of Lp-PLA2 can be used as an adjunct to traditional cardiovascular risk factors for identifying individuals at higher risk of cardiovascular events. Recently, a reagent for measuring Lp-PLA2 activity (diaDexus, San Francisco, CA) received FDA approval. Here we evaluate the assay performance of the Lp-PLA2 activity assay.Methods: Lp-PLA2 activity assay reagent performance was evaluated on an open user-defined channel on a Cobas 6000/c501 (Roche Diagnostics, Indianapolis, IN) using a 5-point calibration curve (0-400nmol/min/mL). Analytical performance was established for the following parameters: precision, linearity, accuracy, analytical sensitivity, analytical specificity, reference interval, reagent lot-to-lot comparison, specimen type, on-board reagent stability, and sample stability.Results: Assay limit of detection was determined to be 7.8nmol/min/mL with an average %CV of 2.8%. Precision studies revealed a coefficient of variation ≤1.6% between 79 and 307 nmol/min/mL and accuracy was demonstrated between 4.8-368.7 nmol/min/mL. Comparable results were generated in paired SST serum and EDTA plasma. No age association was found with Lp-PLA2 activity at the 95th percentile however a gender association was identified resulting in gender-specific 95th percentile limits in a healthy reference population. No bias was found when comparing results from several different lots of assay reagent. Lp-PLA2 activity results are extremely stable in both serum and EDTA plasma under refrigerate and frozen storage conditions up to 31days.Conclusions: Lp-PLA2 activity assay displays accurate and precise performance characteristics on the Cobas c501 platform. The assay performance is significantly improved over the predecessor immunoassay allowing for adoption of Lp-PLA2 activity in clinical practice.

Original languageEnglish (US)
Pages (from-to)172-175
Number of pages4
JournalClinical Biochemistry
Volume49
Issue number1
DOIs
StatePublished - Jan 1 2016

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Keywords

  • Assay validation
  • Biomarkers
  • Lipoprotein-associated phospholipase A2
  • Lp-PLA
  • PLAC activity
  • Platelet activating factor acetylhydrolase

ASJC Scopus subject areas

  • Clinical Biochemistry

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