Publications (3)12.74 Total impact

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    ABSTRACT: The COBAS(®) AmpliPrep(®)/COBAS(®) TaqMan(®) HCV Test, v2.0 (CAP/CTM2) is used for HCV RNA viral load monitoring. The performance of the CAP/CTM2 was compared to other widely used tests, including a manual version of the assay (the COBAS(®) TaqMan(®) HCV Test, v2.0 for use with the High Pure System, HPS/CTM2) predominantly used during phase III clinical trials for the new direct acting antiviral therapies. Low HCV RNA level comparisons were performed across tests (Abbott Realtime HCV Test, ART; COBAS(®) AmpliPrep(®)/COBAS(®) TaqMan(®) HCV Test, v1.0, CAP/CTM1; CAP/CTM2; and HPS/CTM2) using dilutions of the 2nd HCV WHO International Standard. Additionally, the clinical performance of the CAP/CTM2 was evaluated with 421 leftover HCV RNA-positive routine clinical samples. All quantifiable WHO dilutions were within ±0.3log10IU/mL of the expected results across tests and the analytical sensitivity resulted in a limit of detection of 12IU/mL (95% confidence interval, 10, 15). When clinical samples were tested the results for 87% (367 of 421) of all sample comparisons were within ±0.5log10IU/mL. When low viral load results (25-3500IU/mL) were compared, values obtained by the ART assay were significantly lower (p<0.0001) than those obtained with the CAP/CTM2. The new CAP/CTM2 showed good accuracy with comparable sensitivity to comparator assays. The new kit is well-suited for use in the routine diagnostic laboratory, especially for accurate monitoring of patients receiving triple therapy or interferone-free regimens. Copyright © 2015 Elsevier B.V. All rights reserved.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 06/2015; 67. DOI:10.1016/j.jcv.2015.03.023 · 3.02 Impact Factor
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    ABSTRACT: Early on-treatment virological response is one of the most important predictors for sustained virological response (SVR) to treatment of chronic hepatitis C virus (HCV) genotype 1 infection with triple therapy including HCV protease inhibitors (PI). Treatment duration (24 vs. 48 weeks) is based on HCV RNA results at weeks 4 and 12 of PI therapy when HCV RNA must be 'undetectable' to allow shorter therapy. To analyse the reliability of HCV RNA measurements at key decision time points (weeks 4 and 12) and the predictive value of concordant or discordant assay results for SVR. Weeks 4 and 12 samples of patients receiving telaprevir-containing triple therapy were initially tested with the AmpliPrep/COBAS-TaqMan_HCV-Test-v1.0 (limit of detection; LOD = 15IU/mL) and retested with the AmpliPrep/COBAS-TaqMan_HCV-Test-v2.0 (LOD = 15IU/mL) and the High_Pure/COBAS-TaqMan_HCV-Test-v2.0 (LOD = 20IU/mL). Concordance among the three test results in classifying samples as HCV RNA 'undetectable' or 'detectable' was only 55% at week 4, but 85% at week 12. Retesting of 'undetectable' week 4 samples with the respective other assays revealed positive HCV RNA results in 32-50%. In 30%, HCV RNA was 'undetectable' by all three tests at week 4 and all of these patients achieved SVR. In contrast, treatment failure occurred in 62% of patients with at least one 'detectable' result, including cases with one or two other 'undetectable' tests at week 4. A single 'undetectable' HCV RNA result at week 4 is not always associated with achieving SVR. Repeated testing in difficult-to-treat patients may identify those at risk for treatment failure.
    Alimentary Pharmacology & Therapeutics 11/2013; 39(1). DOI:10.1111/apt.12544 · 5.73 Impact Factor
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    ABSTRACT: Two FDA-approved (in vitro diagnostic [IVD]) hepatitis B virus (HBV) viral load assays, the manual Cobas TaqMan HBV Test for use with the High Pure System (HP) and the automated Cobas AmpliPrep/Cobas TaqMan HBV Test v2.0 (CAP/CTM), were compared to a modified (not FDA-approved) version of the HP assay by automating the DNA extraction using the Total Nucleic Acid Isolation (TNAI) kit on the Cobas AmpliPrep. On average, CAP/CTM measurements were 0.08 log IU/ml higher than HP results (n = 206), and TNAI results were 0.17 log IU/ml higher than HP results (n = 166). The limit of detection (LOD), as determined by probit analysis using dilutions of the 2nd HBV international standard, was 10.2 IU/ml for CAP/CTM. The data sets for HP and TNAI were insufficient for probit analysis; however, there was 100% detection at ≥ 5 or ≥ 10 IU/ml for TNAI and HP, respectively. Linearity was demonstrated between 60 and 2,000,000 IU/ml, with slopes between 0.95 and 0.99 and R(2) values of >0.99 for all assays. Total precision (log percent coefficient of variance [CV]) was between 0.8% and 2.1% at 4.3 log IU/ml and between 1.4% and 4.9% at 2.3 log IU/ml. Correlation of samples, reproducibility, linearity, and LOD were acceptable and similar in all assays. The CAP/CTM assay and, to a lesser extent, the TNAI assay reduced hands-on time due to automation. There were no instances of contamination detected in negative samples during the course of the study, despite testing several samples up to 9.6 log IU/ml. The incidence of false-positive negative controls in HP and CAP/CTM clinical testing was <0.5% over 6 to 7 months of testing.
    Journal of clinical microbiology 04/2012; 50(7):2337-42. DOI:10.1128/JCM.00746-12 · 3.99 Impact Factor

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