Analytical and Clinical Performance of a Detergent-based Homogeneous LDL-Cholesterol Assay: A Multicenter Evaluation

Abstract

Abstract Background: LDL-cholesterol (LDL-C) concentrations currently are determined in most clinical laboratories using the Friedewald calculation. This approach has several limitations and may not always meet the current total error recommendation in LDL-C measurement of ≤12% established by the National Cholesterol Education Program. Methods: In a multicenter study, we evaluated the analytical and clinical performance of a homogeneous LDL-C assay (LDL-CRoche; Roche Diagnostics, Indianapolis, IN) in a comparison with a β-quantification method. Results: This direct assay correlated highly with a β-quantification method (r = 0.968; y = 1.037x − 95.8 mg/L; n = 355; 95% confidence intervals, 1.011–1.063 for the slope and −129.5 to 62.0 mg/L for the y-intercept) and met the current total error requirement. The assay was not affected significantly by concentrations of hemoglobin up to 6000 mg/L or bilirubin up to 500 mg/L. However, a negative bias of 10% was seen when triglyceride concentrations exceeded 10 000 mg/L. At the medical decision cut-point range, the LDL-CRoche assay showed positive predictive values of 91–100% and negative predictive values of 80–99%. Furthermore, the clinical utility of the assay seemed unaffected in samples obtained postprandially. Conclusions: The homogeneous LDL-CRoche assay meets the currently established analytical performance goals and may be useful for the diagnosis and management of hyperlipidemic patients.