Evaluation of the VITROS® chemistry products dHDL slides for direct measurement of high density lipoprotein cholesterol

BackgroundWe evaluated the new VITROS direct high density lipoprotein cholesterol (dHDL) slide assay, based on the precipitation of apolipoprotein B-containing lipoproteins by phosphotungstic acid/magnesium chloride (PTA/MgCl2).MethodsWe determined linearity, within-run and between-run imprecision for the VITROS dHDL slide assay, and compared it to the RANDOX two-step PTA/MgCl2 method for 300 fresh sera. Moreover, triglyceride and cholesterol interference were tested.ResultsThe VITROS dHDL slide assay was linear from 0 to 3.13 mmol/l. Within-run and between-run imprecision were 1.6%, 1.8%, 3.3% and 3.2% for target values at 1.00 and 1.40 mmol/l, respectively. For 300 fresh serum samples, the linear regression equation between the VITROS dHDL slide assay (y) and the RANDOX PTA/MgCl2 2 method (x) was: y (mmol/l) = 0.934 x + 0.043 (CI = 0.916–0.952 for slope and 0.017–0.069 for intercept) . The bias of the VITROS assay compared to the RANDOX PTA/MgCl2 method was less than 5% for HDL cholesterol concentrations used for medical decision (1.04 and 1.50 mmol/l). Total error remained below 13% for triglyceride and LDL cholesterol concentrations below 6.6 mmol/l.ConclusionThe VITROS dHDL slide assay is rapid, linear over a broad range of concentrations, and satisfies the National Cholesterol Education Program goals for precision and accuracy.