OBJECTIVETo evaluate the clinical efficacy of two kinds homogenous assays for direct determination of high-density lipoprotein cholesterol (HDL-C) based on the principle of polyanion polymer/detergent (PPD method) and polyethylene glycol-modified enzyme (PEGME) method.

METHODSThe two homogenous methods were compared with the precipitation method (PTA-Mg2+ method), their precision, accuracy, specificity and interference were also analyzed.

RESULTSBoth homogenous HDL-C assays were precise, having a within-run CV < 3%, day-to-day CV < 3% and total CV < 4%. The HDL-C values measured by the two homogenous methods correlated well with those by PTA-Mg2+ method (X): Y = 0.9316 X + 0.1063, r = 0.9762 for PPD method (Y); and Y = 0.9106 X + 0.1368, r = 0.9894 for PEGME method (Y). The linearity studies showed the two homogenous methods to be linear up to 4.14 mmol/L. The lowest detectable concentration of the two methods was apparently 0.08 mmol/L. Recoveries of the two methods were 94.1%-106.2%. Hemoglobin did not interfere with the HDL-C results in the two homogenous methods, whereas icteric samples with total bilirubin > 200 mg/L showed discrepancies. Lipemia up to triglyceride concentration of 17.0 mmol/L did not interfere with the two homogenous HDL-C assays.

CONCLUSIONSThe two new homogenous HDL-C assays meet the requirements for accuracy, precision, ease of handling with massive sample, allow full automation, and are clinically useful.