title: Analytical and clinical performance of two homogeneous assays for measuring of LDL-cholesterol.
abstract: A clinical laboratory currently estimates LDL-Cholesterol (LDL-C) concentration using the Friedewald calculation, which requires fasting specimens and is subject to error with increasing triglycerides levels. We evaluated the analytical and clinical performance of the direct LDL-C assay from two companies, Roche Diagnostics (LDL-C(Roche)) and Wako Pure Chemical (LDL-C(Wako)). Both methods meet current guidelines for precision with within-run coefficients of variation less than 3 per cent. The LDL-C(Roche) assay correlated well with the LDL-C from the Friedewald equation (LDL-C(Fried), r = 0.958, y = 0.85x + 17.08 mg/dL, n = 422). The LDL-C(Wako) assay also correlated with the LDL-C(Fried) (r = 0.946, y = 0.86x + 7.81 mg/dL, n = 422). In addition, at the medical decision cutoff points, LDL-C(Roche) assay and LDL-C(Wako) showed positive predictive values of 87.44 per cent and 69.67 per cent respectively. We conclude that the LDL-C(Roche) assay meets the currently established analytical and clinical performance, but LDL-C(Wako) assay meets only analytical performance. Clinical performance needs further evaluation.
authors.affiliation: Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: W
authors.initials: W
authors.lastname: Leowattana
authors.forename: S
authors.initials: S
authors.lastname: Narkrung
authors.forename: S
authors.initials: S
authors.lastname: Pokum
authors.forename: S
authors.initials: S
authors.lastname: Kiartivich
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods; D008078:Cholesterol, LDL / Q000032:analysis*; D006801:Humans; D016014:Linear Models
chemical_list: D008078:Cholesterol, LDL