Analytical and Clinical Evaluation of Two Homogeneous Assays for LDL-Cholesterol in Hyperlipidemic Patients

作者：Margarita Esteban-Salán, Amada Guimón-Bardesi, Jesús María de la Viuda-Unzueta, María Nerea Azcarate-Ania, Pilar Pascual-Usandizaga, Eduardo Amoroto-Del-Río · 发表于：Clinical Chemistry · 年份：2000 · DOI：10.1093/clinchem/46.8.1121 · 被引用次数：63 · 研究领域：Diabetes, Cardiovascular Risks, and Lipoproteins、Lipoproteins and Cardiovascular Health、Pharmacology and Obesity Treatment

BACKGROUND: LDL-cholesterol (LDL-C) concentrations are the primary basis for treatment guidelines established for hyperlipidemic patients. LDL-C concentrations are commonly monitored by means of the Friedewald formula, which provides a relative estimation of LDL-C concentration when the triglyceride concentration is <2000 mg/L and there are no abnormal lipids. The Friedewald formula has several limitations and may not meet the current total error requirement of <12% in LDL-C measurements. METHODS: We evaluated the analytical and clinical performance of two direct methods (Roche and Wako) by analyzing 313 fresh serum samples obtained from dyslipidemic patients in a lipid clinic and comparing them with modified beta-quantification. RESULTS: Both homogeneous assays displayed excellent precision (CV <2%). The Roche method showed a mean total error of 7.72%, and the Wako method showed a mean total error of 4.46% over a wide range of LDL-C concentrations. The Roche method correlated highly with the modified beta-quantification assay (r = 0.929; y = 1.052x - 168 mg/L; n = 166) and showed a bias of -4. 5% as a result of the assigned standard value. The Wako method also correlated highly with beta-quantification (r = 0.966; y = 0.9125x + 104.8 mg/L; n = 145) without significant bias. The Roche method correctly classified 97% of patients with triglycerides <2000 mg/L, 75% of patients with type IIb hyperlipemia (HPL), and 84% of patients with type IV HPL based on the cutpoints of 1300 a...