Development of a Second Version of the Cobas AmpliPrep/Cobas TaqMan Hepatitis C Virus Quantitative Test with Improved Genotype Inclusivity

Vermehren, Johannes; Colucci, Giuseppe; Gohl, Peter; Hamdi, Nabila; Abdelaziz, Ahmed Ihab; Karey, U.; Thamke, Diana; Zitzer, Heike; Zeuzem, Stefan; Sarrazin, Christoph

doi:10.1128/jcm.00602-11

Cited by 30 publications

(22 citation statements)

References 21 publications

(23 reference statements)

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“…1]), although discrepancies for values generated by these two assays have been reported for strains of genotypes 1, 2, and 4 (5,6,34). In Japan, the prevalent genotypes are 1b, 2a, and 2b (11); no genotype 4 sample was included in our reference panel (Table 1).…”

Section: Discussionmentioning

confidence: 99%

“…Although core Ag levels are thought to be related closely to HCV RNA titers, the correlation and linearity of core Ag levels have not yet been fully evaluated. In addition, these quantitative parameters are known to be affected by nucleotide and amino acid sequences at the target regions of the assays (5,6,28,34), and this sequence variation depends on genotypes or predominant strains in specific geographical regions.…”

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confidence: 99%

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Japanese Reference Panel of Blood Specimens for Evaluation of Hepatitis C Virus RNA and Core Antigen Quantitative Assays

et al. 2012

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An accurate and reliable quantitative assay for hepatitis C virus (HCV) is essential for measuring viral propagation and the efficacy of antiviral therapy. There is a growing need for domestic reference panels for evaluation of clinical assay kits because the performance of these kits may vary with region-specific genotypes or polymorphisms. In this study, we established a reference panel by selecting 80 donated blood specimens in Japan that tested positive for HCV. Using this panel, we quantified HCV viral loads using two HCV RNA kits and five core antigen (Ag) kits currently available in Japan. The data from the two HCV RNA assay kits showed excellent correlation. All RNA titers were distributed evenly across a range from 3 to 7 log IU/ml. Although the data from the five core Ag kits also correlated with RNA titers, the sensitivities of individual kits were not sufficient to quantify viral load in all samples. As calculated by the correlation with RNA titers, the theoretical lower limits of detection by these core Ag assays were higher than those for the detection of RNA. Moreover, in several samples in our panel, core Ag levels were underestimated compared to RNA titers. Sequence analysis in the HCV core region suggested that polymorphisms at amino acids 47 to 49 of the core Ag were responsible for this underestimation. The panel established in this study will be useful for estimating the quality of currently available and upcoming HCV assay kits; such quality control is essential for clinical usage of these kits.

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Japanese Reference Panel of Blood Specimens for Evaluation of Hepatitis C Virus RNA and Core Antigen Quantitative Assays

et al. 2012

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“…Since our study was completed, a new version (2.0) of the CAP-CTM assay has been described, in order to remedy a problem with underestimation of the VL for certain HCV genotypes (8,21); however, the CAP-CTM version 2.0 assay is not yet FDA approved, and so laboratories in the United States are still using version 1.0. The linearity, precision, and sensitivity portion of this study was performed only with the ART assay, making direct comparisons to the CAP-CTM assay difficult.…”

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confidence: 99%

Performance of the Abbott RealTime and Roche Cobas TaqMan Hepatitis C Virus (HCV) Assays for Quantification of HCV Genotypes

et al. 2012

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We evaluated the Abbott RealTime (ART) and Roche Cobas TaqMan Hepatitis C virus (HCV) viral load assays for quantification of HCV genotypes in patient specimens. The ART HCV assay was a more sensitive and precise tool for accurate HCV viral load quantification across the HCV genotypes tested, especially genotype 1b. Hepatitis C virus (HCV) infection is associated with significant liver-related morbidity and mortality around the world. The World Health Organization estimates that 3% of the global population is infected with HCV and that there are approximately 170 million people at risk of developing cirrhosis or hepatocarcinoma (23,24). Treatment of HCV infection typically consists of pegylated interferon plus ribavirin or pegylated interferon, ribavirin, and a direct-acting antiviral (DAA) protease inhibitor (triple therapy) for non-genotype 1 and genotype 1, respectively (11,12,13). Depending on the particular treatment regimen and the genotype of HCV, treatment success as measured by failure to detect viral replication 24 weeks after cessation of treatment can be achieved in 50 to 80% of patients (12).Measurement of HCV viral load (VL) for the different HCV genotypes is crucial to clinical management of HCV-infected patients, both treated and not, for disease staging, decisions regarding treatment initiation, and individualization of treatment strategy (i.e., dosage and duration based on response kinetics) (1,6,7,13). Furthermore, with the advent of DAAs, VL monitoring may help prevent protease inhibitor resistance development by allowing for switching or stopping therapy if VL does not decrease or returns while on treatment.There are currently several commercially available HCV VL assays; real-time PCR assays are generally preferred because of their wide dynamic ranges and good sensitivities (1, 3). Two commercial real-time PCR platforms are available, the Cobas AmpliPrep/Cobas TaqMan HCV assay version 1.0 (CAP-CTM; Roche Molecular Systems, Pleasanton, CA) and the Abbott RealTime HCV assay (ART; Abbott Molecular, Des Plaines, IL). We characterized the performance of the ART assay and compared results obtained with both assays using clinical specimens of diverse HCV genotypes in a university hospital central testing laboratory.HCV VL was determined with the ART and the CAP-CTM as per the manufacturers' recommendations. A serum specimen volume of 500 l was required for ART, compared to 850 l for CAP-CTM. Sample preparation for the ART assay was performed using the Abbott m2000sp instrument. HCV genotypes were identified using the Versant Inno-LIPA HCV Genotype 2.0 assay (Siemens Healthcare Diagnostics, Deerfield, IL); specimens with indeterminate results were tested with the RealTime Genotyping II RUO assay (Abbott Molecular, Des Plaines, IL) or by direct sequencing and phylogenetic analysis of NS5B (performed by Siemens Clinical Laboratories, Berkeley, CA). Statistical tests were performed using Prism 5.0 (GraphPad Software, La Jolla, CA).To evaluate the sensitivity, linearity, and intra-and interrun precisio...

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“…Even more challenging was the identifi- cation of clinical samples in which the first-generation Cobas TaqMan assays did not detect HCV RNA, whereas high virus titers were found with other assays, including real-time PCR assays (11,13). We identified single nucleotide polymorphisms in the 5=UTR of HCV genome that are not rare in genotype 4 sequences and were responsible for mismatches with the probe used for quantification in the first-generation Cobas TaqMan assays (14,20). Since accurate quantification regardless of the HCV genotype is required in clinical practice, the manufacturer developed a new version (v2.0) of its TaqMan assay.…”

Section: Discussionmentioning

confidence: 99%

The Cobas AmpliPrep/Cobas TaqMan HCV Test, Version 2.0, Real-Time PCR Assay Accurately Quantifies Hepatitis C Virus Genotype 4 RNA

et al. 2013

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Development of a Second Version of the Cobas AmpliPrep/Cobas TaqMan Hepatitis C Virus Quantitative Test with Improved Genotype Inclusivity

Cited by 30 publications

References 21 publications

Japanese Reference Panel of Blood Specimens for Evaluation of Hepatitis C Virus RNA and Core Antigen Quantitative Assays

Japanese Reference Panel of Blood Specimens for Evaluation of Hepatitis C Virus RNA and Core Antigen Quantitative Assays

Performance of the Abbott RealTime and Roche Cobas TaqMan Hepatitis C Virus (HCV) Assays for Quantification of HCV Genotypes

The Cobas AmpliPrep/Cobas TaqMan HCV Test, Version 2.0, Real-Time PCR Assay Accurately Quantifies Hepatitis C Virus Genotype 4 RNA

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