title: Automated measurement of lipoprotein(a) by immunoturbidimetric analysis.
abstract: Immunoturbidimetric analysis of lipoprotein(a) in plasma or serum was developed for use on the Roche COBAS FARA II and COBAS MIRA clinical chemistry analyzers. The components of the assay are: (1) buffer consisting of 2.25% polyethylene glycol in phosphate-buffered saline, 0.2% gelatin, and a surfactant; (2) fractionated goat anti-human lipoprotein(a) IgG; (3) five standards with lipoprotein(a) concentrations ranging from 0.05 to 1.0 g/l; (4) two controls with concentrations of approximately 0.2 and 0.5 g/l. The analyzer delivers sample and buffer, incubates the reaction mixture at 37 degrees C for 5 min, delivers neat lipoprotein(a) antibody, and incubates for an additional 10 min. The lipoprotein(a) concentration of samples is calculated by the COBAS DENS (Data Evaluation for Non-linear Standard Curves) option by fitting the standard curve values to a four-parameter logit-log curve model. Total imprecision results (CV%) for the FARA II and MIRA were under 11% (NCCLS protocol EP5-T). The assay is linear beyond the highest calibrator to 2.6 g/l. No interference was observed for plasminogen up to 2.3 g/l, apolipoprotein B up to 4.36 g/l, hemoglobin up to 10 g/l, bilirubin up to 4.0 g/l, and triglycerides up to 4.36 g/l. Comparison with a double monoclonal ELISA used at the Northwest Lipid Research Laboratories yielded: R = 0.970, slope = 1.013, and y-intercept = 0.00009 (n = 37). Comparison with a commercially available ELISA kit for lipoprotein(a) yielded: r = 0.987, slope = 1.243, and y-intercept = 0.024 (n = 40). This assay provides rapid, accurate, and precise screening of lipoprotein(a) in serum or plasma.
authors.affiliation: Rogosin Institute, New York Hospital, Cornell Medical Center, NY 10021.
authors.forename: D M
authors.initials: DM
authors.lastname: Levine
authors.forename: B J
authors.initials: BJ
authors.lastname: Sloan
authors.forename: J E
authors.initials: JE
authors.lastname: Donner
authors.forename: J D
authors.initials: JD
authors.lastname: Lorenz
authors.forename: R H
authors.initials: RH
authors.lastname: Heinzerling
mesh_terms: D000917:Antibody Formation / Q000276:immunology; D000941:Antigens / Q000096:biosynthesis; D001331:Automation; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D017270:Lipoprotein(a); D008074:Lipoproteins / Q000032:analysis*; D008297:Male; D009391:Nephelometry and Turbidimetry; D010641:Phenotype
chemical_list: D000941:Antigens; D017270:Lipoprotein(a); D008074:Lipoproteins