Evaluation of the Polyethylene Glycol Precipitation Method for the Estimation of High-Density Lipoprotein Cholesterol

Author(s):  
Catherine J Briggs ◽  
Deborah Anderson ◽  
P Johnson ◽  
T Deegan

Treatment of fresh sera with polyethylene glycol 6000 at a final concentration of 100 g/l produced selective precipitation of low-density lipoproteins with only traces of contamination with high-density lipoproteins, as determined by electroimmunoassay using antisera to human α1-lipoprotein and human β-lipoprotein. Supernatants collected for high-density lipoprotein-cholesterol estimation were free from low-density lipoproteins. Precipitates sedimented readily from specimens with high triglyceride contents, and secondary precipitation during enzymatic cholesterol determinations was absent. Values obtained by this method correlated well with those obtained by precipitation of low-density lipoproteins with heparin and manganous ions at concentrations optimal for discrete separation of lipoprotein classes (r = 0·975; P<0·001).

1978 ◽  
Vol 24 (6) ◽  
pp. 900-904 ◽  
Author(s):  
G R Warnick ◽  
J J Albers

Abstract We describe a modified heparin--Mn2+ procedure for high-density-lipoprotein cholesterol quantitation, especially in lipemic samples. High-density-lipoproteins may be estimated as cholesterol remaining in plasma supernates after precipitation of other lipoproteins by heparin and Mn2+ treatment. However, in lipemic samples or those from non-fasting individuals, the lower density of the precipitated chylomicrons, very-low-, and low-density-lipoproteins frequently prevents their sedimentation by the usual low-speed centrifugation, and high-density-lipoprotein cholesterol thus is overestimated in the resulting turbid supernates. Sedimentation is improved by a twofold increase in Mn2+ concentration to 92 mmol/liter. The procedure reported here produced clear supernates in more than 95% of samples tested. Any remaining turbid supernates can be cleared by a simple, convenient ultrafiltration technique. The filtration removed essentially all of the very-low- and low-density-lipoproteins without removing appreciable amounts of high-density-lipoproteins.


1979 ◽  
Vol 25 (7) ◽  
pp. 1309-1313 ◽  
Author(s):  
C Mayfield ◽  
G R Warnick ◽  
J J Albers

Abstract Commercial heparin preparations (18 lots) from seven manufacturers were compared in the heparin-Mn2+ procedure for high-density-lipoprotein cholesterol quantitation. With normotriglyceridemic samples, 16 heparin lots, isolated from porcine intestinal mucosa, gave mean values for supernatant cholesterol that did not differ statistically; all were within 7 mg/L. Two heparin preparations from bovine lung gave results that were slightly (16 mg/L, average) but significantly (p less than 0.005) lower. With hypertriglyceridemic samples, we observed greater variation in supernatant cholesterol among the heparin preparations, which was ascribable to variable sedimentation by centrifugation of very-low-density and low-density lipoproteins precipitated by heparin-Mn2+ treatment. If the precipitated lipoproteins were completely removed by an ultrafiltration procedure, we saw no significant difference among the heparin preparations for results with hypertriglyceridemic samples.


1996 ◽  
Vol 42 (3) ◽  
pp. 424-429 ◽  
Author(s):  
M Nauck ◽  
W März ◽  
B Haas ◽  
H Wieland

Abstract 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.


1981 ◽  
Vol 27 (3) ◽  
pp. 371-374 ◽  
Author(s):  
C Izzo ◽  
F Grillo ◽  
E Murador

Abstract We describe a modified method of precipitating low- and very-low-density lipoproteins with polyethylene glycol, for quantitation of high-density lipoprotein cholesterol. A 100 g/L concentration of polyethylene glycol 6000 in a buffered (pH 10) solution is used. Under these conditions precipitation of beta-lipoproteins is complete. Values for HDL cholesterol as measured with this method fully correspond to those obtained on separating the lipoproteins by ultracentrifugation or with heparin-Mn2+, 46 mmol/L; are slightly higher than those obtained with heparin-Mn2+, 92 mmol/L; and are significantly higher than those determined after precipitation with polyethylene glycol, 100 g/L at pH 8.0. Comparison with results by the ultracentrifugation method showed excellent correlation (r = 0.957) with a good correspondence of results (slope 1.065 and y-intercept -22.231); comparison with the heparin-Mn2+, 46 mmol/L, method gave r = 0.998 with slope of 0.985 and y-intercept 2.963. The method is unaffected by precipitation and centrifugation time and temperature (up to 24 h with 4-22 degrees C temperature for precipitation and between 10 and 30 min with 4-22 degrees C temperature for centrifugation). This extremely simple method is particularly suitable for routine analyses of many samples, even in small laboratories.


1978 ◽  
Vol 24 (6) ◽  
pp. 931-933 ◽  
Author(s):  
P R Finley ◽  
R B Schifman ◽  
R J Williams ◽  
D A Lichti

Abstract We describe a method for measuring high-density lipoprotein cholesterol. MgCl2 and dextran sulfate are used to precipitate all low-density and very-low-density lipoproteins. The supernate contains only high-density lipoproteins, the cholesterol concentration of which is estimated by an enzymic method, with a discrete analyzer (Abbott Bichromatic Analyzer). Concentration and instrument response are linearly related to 50 mg/liter. The precision of the method is excellent in the range of clinical interest (100 to 1000 mg of cholesterol per liter). The precision and efficiency of the precipitation are shown at various concentrations of high-density lipoprotein cholesterol. The method was compared to that of two laboratories in the Cooperative Lipoprotein Phenotyping Study group by testing a number of split samples, and agreement was good.


1980 ◽  
Vol 26 (13) ◽  
pp. 1775-1779 ◽  
Author(s):  
P N Demacker ◽  
A G Hijmans ◽  
H E Vos-Janssen ◽  
A van't Laar ◽  
A P Jansen

Abstract We studied polyethylene glycol 6000 precipitation of lipoproteins other than high-density lipoproteins, before cholesterol is estimated in the supernate. Other lipoproteins in the supernatant fractions were detected by using rocket immunoelectrophoresis. A polyethylene glycol concentration of 75 g/L in the final mixture appeared to be optimal, and results agreed with those obtained by ultracentrifugation. Differences in serum pH, use of polyethylene glycol from different suppliers, or the presence of ethylenediaminetetraacetate resulted in values that differed significantly (by 40 to 60 mumol/L) from the reference values. Polyethylene glycol did not interfere in four different methods for determination of cholesterol. In combination with an enzymic cholesterol method, the polyethylene glycol method appeared to be very precise, even when lipemic sera (triglycerides up to 5.5 mmol/L) were analyzed that had diminished high-density lipoprotein cholesterol values. We consider this method a method of choice, especially when lipemic sera are tested and enzymic cholesterol analysis is used.


1979 ◽  
Vol 25 (2) ◽  
pp. 325-327 ◽  
Author(s):  
J K Allen ◽  
W J Hensley ◽  
A V Nicholls ◽  
J B Whitfield

Abstract Enzymic measurement of high-density lipoprotein cholesterol with a centrifugal analyzer is described. We used polyethylene glycol (Mr 6000), final concentration 100 g/L, to precipitate low-density and very-low-density lipoproteins, thereby eliminating the difficulties of the commonly used heparin/Mn2+ precipitation method and facilitating the use of ethylenediaminetetraacetate-stabilized plasma. As measured by rocket immunoelectrophoresis, this final concentration of polyethylene glycol completely precipitates beta-lipoproteins, leaving the alpha-lipoproteins in solution. Between-run reproducibility (CV) was 3.6%, within-run reproducibility (CV) 0.8%. Reagent costs currently are $US 0.13 per test and large numbers of samples can be handled conveniently. Normal ranges were compiled for 539 men and 444 women. The high-density lipoprotein cholesterol for men was 1.20 +/- 0.31 (SD) mmol/L and for women 1.52 +/- 0.38 (SD) mmol/L.


1997 ◽  
Vol 92 (5) ◽  
pp. 473-479 ◽  
Author(s):  
Gregory D. Sloop ◽  
David W. Garber

1. Increased blood or plasma viscosity has been observed in almost all conditions associated with accelerated atherosclerosis. Cognizant of the enlarging body of evidence implicating increased viscosity in atherogenesis, we hypothesize that the effects of low-density lipoprotein and high-density lipoprotein on blood viscosity correlate with their association with risk of atherosclerosis. 2. Blood viscometry was performed on samples from 28 healthy, non-fasting adult volunteers using a capillary viscometer. Data were correlated with haematocrit, fibrinogen, serum viscosity, total cholesterol, high-density lipoprotein-cholesterol, triglycerides and calculated low-density lipoprotein-cholesterol. 3. Low-density lipoprotein-cholesterol was more strongly correlated with blood viscosity than was total cholesterol (r = 0.4149, P = 0.0281, compared with r = 0.2790, P = 0.1505). High-density lipoprotein-cholesterol levels were inversely associated with blood viscosity (r = −0.4018, P = 0.0341). 4. To confirm these effects, viscometry was performed on erythrocytes, suspended in saline, which had been incubated in plasma of various low-density lipoprotein/high-density lipoprotein ratios. Viscosity correlated directly with low-density lipoprotein/high-density lipoprotein ratio (n = 23, r = 0.8561, P < 0.01). 5. Low-density lipoprotein receptor occupancy data suggests that these effects on viscosity are mediated by erythrocyte aggregation. 6. These results demonstrate that the effects of low-density lipoprotein and high-density lipoprotein on blood viscosity in healthy subjects correlate with their association with risk of atherosclerosis. These effects on viscosity may play a role in atherogenesis by modulating the dwell or residence time of atherogenic particles in the vicinity of the endothelium.


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