Homogeneous assay for direct determination of high-density lipoprotein cholesterol evaluated.
We evaluated a new homogeneous assay for quantifying high-density lipoprotein cholesterol (HDL-C). The assay included four reagents: polyethylene glycol for "wrapping" chylomicrons, very-low-density lipoproteins (VLDL), and low-density lipoproteins (LDL); antibodies specific for apolipoprotein (apo) B and apo C-III to produce aggregates of chylomicrons, VLDL, and LDL; enzymes for the enzymatic cholesterol determination of the noncomplexed lipoproteins with 4-aminoantipyrine as the color reagent; and guanidine salt to stop the enzymatic reaction and to solubilize the complexes of apo B-containing lipoproteins, which would otherwise interfere with the reading of absorbance. The total CVs of the new method ranged between 2.4% and 8.4%. The HDL-C values (y) were in good agreement with those by a comparison phosphotungstic acid/MgCl2 method (x): y= 0.987x + 17.2 mg/L (68th percentile of the residuals on the regression line= 21.49, r= 0.970). At triglyceride concentrations of 20 g/L (Intralipid) the homogeneous HDL-C concentrations increased by 2%. Hemoglobin markedly increased the results, whereas bilirubin reduced them. The homogeneous HDL-C assay was easy to handle and allows full automation. This test should considerably facilitate the screening of individuals at an increased risk of cardiovascular disease.
Nauck
M
M
Department of Medicine, Division of Clinical Chemistry, University Hospital of Freiburg, Germany.
März
W
W
Haas
B
B
Wieland
H
H
D016632:Apolipoprotein A-I / Q000032:analysis; D001322:Autoanalysis; D011232:Chemical Precipitation; D008076:Cholesterol, HDL / Q000097:blood*; D002914:Chylomicrons; D005069:Evaluation Studies as Topic; D006801:Humans; D007202:Indicators and Reagents; D015636:Magnesium Chloride; D010772:Phosphotungstic Acid; D011092:Polyethylene Glycols; D011786:Quality Control; D012680:Sensitivity and Specificity; D014280:Triglycerides / Q000097:blood
D016632:Apolipoprotein A-I; D008076:Cholesterol, HDL; D002914:Chylomicrons; D007202:Indicators and Reagents; D014280:Triglycerides; D015636:Magnesium Chloride; D010772:Phosphotungstic Acid; D011092:Polyethylene Glycols