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- Lindahl, Bertil, et al.
(författare)
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Evaluation of four sensitive troponin assays for risk assessment in acute coronary syndromes using a new clinically oriented approach for comparison of assays
- 2013
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1434-6621 .- 1437-4331. ; 51:9, s. 1859-1864
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Tidskriftsartikel (refereegranskat)abstract
- Background:Measurement of cardiac troponin T or I (cTnT; cTnI) is useful for risk prediction in acute coronary syndromes. The objective of the present study was to compare the prognostic capacity of four sensitive cardiac troponin assays using a new method for comparison.Methods:Cardiac troponin was analyzed in serum samples from 1335 patients with acute coronary syndrome using the Elecsys high sensitivity TnT (hs-cTnT), ARCHITECT STAT high sensitivity TnI (hs-cTnI), Access AccuTnI (Acc-cTnI) and Architect cTnI (Arc-cTnI) assays. All patients were followed for 30 days regarding death and acute myocardial infarction (AMI), and for 1 year regarding mortality.Results:By receiver operating characteristic (ROC) curve analyses, there were only minor differences in the area under the curves (AUC) between the assays. At a given sensitivity of 85% the hs-cTnT, Arc-cTnI and Acc-cTnI assays showed comparable specificities, while 90% or higher sensitivity was only possible to achieve with the hs-cTnT, hs-cTnI and Acc-cTnI assays. The highest odds ratios for death/AMI at 30 days and death at 1 year, respectively, were reached by cut-off levels yielding 95% sensitivity; these cut-off levels were below the respective 99th percentile levels.Conclusions:By the adoption of a new method for the comparison of cardiac troponin assays we showed that the hs-cTnT, hs-cTnI and Acc-cTnI assays had comparable prognostic properties, while the Arc-cTnI assay had inferior prognostic sensitivity.
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| 2. |
- Savukoski, Tanja, et al.
(författare)
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Novel sensitive cardiac troponin I immunoassay free from troponin I-specific autoantibody interference
- 2014
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1434-6621 .- 1437-4331. ; 52:7, s. 1041-1048
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cardiac troponins (cTnI and cTnT) are the recommended biomarkers of myocardial infarction. As cTn-specific autoantibodies (cTnAAb) can interfere with the cTn detection by state-of-the-art cTnI assays, our objective was to develop a sensitive cTnI immunoassay free from this analytical interference. Methods: The assay used antibody-coated spots containing three capture Mabs/Fabs directed against the N-terminus, midfragment and C-terminus of cTnI and a europium chelate-labeled tracer Mab against the C-terminus. Following a 3-h sample incubation and washing, cTnI was quantified by time-resolved fluorometry. Results: The limit of detection (LoD) was 2.9 ng/L and the assay was linear up to 50,000 ng/L. The total precision of 10% CV was not reached, but 20% CV was reached at 10 ng/L. Mean cTnI (10-50,000 ng/L) recoveries were 100% and 119% in three cTnAAb-positive and two cTnAAb-negative individuals, respectively, verifying the interference resistance of the antibody design used. On average, Architect hs-cTnI assay gave seven-fold higher cTnI concentrations than the new assay but the correlation between the assays was good (r=0.958). Of apparently healthy individuals (n=159), 18% had measurable cTnI values (>LoD) and 10% were cTnAAb-positive. The proportion of measurable cTnI values, however, was significantly higher in cTnAAb-positive individuals (13/16, median cTnI 8.5 ng/L) than in cTnAAb-negative individuals (15/143, median cTnI
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