3 GENERATIONS OF HIGH-DENSITY-LIPOPROTEIN CHOLESTEROL ASSAYS COMPAREDWITH ULTRACENTRIFUGATION DEXTRAN SULFATE-MG2+ METHOD/

We report on the analytical performance of three generations of HDL-ch olesterol assays: phosphotungstic acid/Mg2+, Spinpro(R), and a homogen eous method, N-geneous(TM). The run-to-run imprecision (CV) of all ass ays was less than or equal to 4.9%, and all results correlated highly with those of a modified reference procedure (r greater than or equal to 0.96). At triglycerides concentrations <4000 mg/L, these field meth ods showed an acceptable systematic error (y = 1.12x - 47, 1.05x - 23, and 0.96x + 8 for the phosphotungstate, Spinpro, and N-geneous assays , respectively), and the total error of the field methods met the curr ent National Cholesterol Education Program (NCEP) performance goal of less than or equal to 22%. Regression analyses of results for samples with triglycerides >4000 mg/L produced the following results for the a bove respective assays: y = 1.08x - 4.2, 1.02x + 3.6, and 0.85x + 108. In this hypertriglyceridemic group, only the N-geneous assay (at an H DL-cholesterol content of 240 mg/L) had a total error (35%) that excee ded the NCEP limit. Bilirubin and ascorbate produced a negative interf erence with the phosphotungstate and Spinpro assays but had little eff ect on the N-geneous assay.