Sequence Conservation of the Region Targeted by the Abbott RealTime HBV Viral Load Assay in Clinical Specimens

Cloherty, Gavin; Rhoads, James; Young, Thomas P.; Parkin, Neil; Holzmayer, Vera; Yuen, Lilly; Mullen, Carolyn

doi:10.1128/jcm.03003-12

Cited by 6 publications

(3 citation statements)

References 23 publications

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“…Accurate and reproducible HBV DNA level measurements in blood specimens are crucial to diagnose HBV infection, establish the prognosis of HBV-related liver disease, and guide the treatment decision to treat and monitor the virological response to antiviral treatment and the emergence of resistance [ 3 , 7 , 8 , 9 , 10 , 11 , 12 ]. In the present study based on a large number of clinical specimens, including specimens with different genotypes found in HBV-infected patients, the new real-time PCR-based Xpert HBV Viral Load assay accurately quantified HBV DNA levels in plasma and serum.…”

Section: Discussionmentioning

confidence: 99%

Multicenter Evaluation of the Cepheid Xpert® HBV Viral Load Test

et al. 2021

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Accurate measurement of the hepatitis B virus (HBV) DNA is important for the management of patients with chronic HBV infection. Here, the performance of the Xpert® HBV Viral Load test (Xpert HBV Viral Load) versus the Roche COBAS® Ampliprep/COBAS® TaqMan® system (CAP/CTM HBV) HBV test v2.0 was evaluated. From September 2017 to December 2017, a total of 876 prospectively collected or archived serum or EDTA plasma specimens from subjects chronically infected with HBV were tested using the Xpert HBV Viral Load and the CAP/CTM HBV v2.0 assays. Of the 876 specimens tested, 560 were within the quantitative range of both assays. The agreement between the two methods was 90.0%. No difference in plasma or serum samples was observed. Deming regression analysis showed a good correlation of the Xpert HBV Viral Load assay with the CAP/CTM HBV v2.0 assay. The Bland–Altman analysis showed a good agreement between the results of the Xpert HBV Viral Load assay and the CAP/CTM HBV assay, with a mean difference (±1.96 standard deviation) of 0.0091 ± 0.3852 Log IU/mL. Comparing the two assays, only nineteen specimens (2.1%) had a difference greater than 1.96 times the standard deviation. The Xpert® HBV Viral Load test is suitable for monitoring patients with HBV infection and is useful in diagnostic settings.

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Section: Discussionmentioning

confidence: 99%

Multicenter Evaluation of the Cepheid Xpert® HBV Viral Load Test

et al. 2021

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“…All blood samples collected were submitted and processed at the central, microbiology, and immunology laboratories at KCMH. HBV DNA level was measured with real-time PCR technique for quantification of HBV using the Abbott RealTime HBV Viral Load Assay (Abbott Diagnostics Inc., Abbott Park, IL, USA) [ 13 ]. A chemiluminescent microparticle immunoassay (CMIA) was used for the determination of HBeAg status using the Architect i2000 analyzer (Abbott Diagnostics, Inc.) [ 14 ].…”

Section: Methodsmentioning

confidence: 99%

Use of Hepatitis B-e Antigen to Identify Pregnant Women With Hepatitis B Virus Infection Who Need Antiviral Therapy for Prevention of Mother-to-child Transmission

Jiragraivutidej

Tangkijvanich

Chaithongwongwatthana

2021

Cureus

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To evaluate the performance of hepatitis B-e antigen (HBeAg) for identifying pregnant women infected with hepatitis B virus (HBV) who are having a high viral load. MethodsA cross-sectional study was conducted at the tertiary care hospital in Bangkok, Thailand between August 2017 and August 2018. Ninety-six pregnant women having positive hepatitis B-s antigen (HBsAg) results were invited to participate into the study. Clinical data and blood samples were collected and tested for HBeAg and HBV DNA levels. Data were reported as percentage and 95% confidence interval (CI). ResultsHigh viral load was found in 25 women (26.0%, 95% CI: 18.3% to 35.6%) and HBeAg showed positive results in 33 women (34.4%, 95% CI: 25.6% to 44.3%). Among antiviral-naïve women, 24 of 30 cases having positive HBeAg results had high viral load (80.0%, 95% CI: 62.7% to 90.5%) while only 1 of 62 negative HBeAg women had high viral load (1.6%, 95% CI: 0.3% to 8.6%). ConclusionAbout one-fourth of HBV-infected pregnant women were at high risk for mother-to-child transmission (MTCT) of the virus and needed antiviral drugs for reducing MTCT. HBeAg may be used to identify women at high risk for MTCT of HBV in a low-resource setting where HBV DNA level test is not available.

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“…These sequences may not be representative of every variant present in the field, and continuous studies both in silico and in vitro are required to monitor the impact this evolving pandemic may have on molecular diagnostic assays. This type of sequence-based study has been performed for HIV-1 and hepatitis B virus (15,16), but this study represents the first such analysis for the Abbott RealTime HCV viral load assay. Based on the sequence data analyzed here, there is a high degree of sequence conservation within the primer and probe sites of the RealTime HCV viral load assay, and the naturally occurring polymorphisms observed are not anticipated to have a discernible impact on the performance of the assay.…”

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confidence: 99%

Sequence Conservation of the Region Targeted by the Abbott RealTi m e HCV Viral Load Assay

et al. 2014

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dThe Abbott RealTime (RT) HCV assay targets the 5= untranslated region (UTR) of the HCV genome. Here, we analyzed the sequence variability of the assay target regions from 1,092 specimens. Thermodynamic modeling of the percentage of primers/ probes bound at the assay annealing temperature was performed to assess the potential effect of sequence variability. An analysis of this large data set revealed that the primer and probe binding sites of the RealTime HCV viral load assay are highly conserved and that naturally occurring sequence polymorphisms are not expected to discernibly impact assay performance. Hepatitis C Virus (HCV) is one of the most common bloodborne pathogens in the world and a major source of morbidity globally (1). Worldwide, it is estimated that 130 to 170 million people are chronically infected with HCV, with 3 to 4 million new infections and Ͼ350,000 deaths due to HCV-related liver disease per year (2). HCV is highly genetically variable, with six major genotypes described, which share 70 to 80% nucleotide identity with one another, along with Ͼ80 subtypes, which share 80 to 90% nucleotide identities within these genotypes (3). In infected individuals, HCV circulates as a population of closely related yet distinguishable variants with Ͻ10% differences at the nucleotide level (4). The isolates within each subtype are also extremely variable, with 8 to 12% divergence between the isolates from independent patients (5).Monitoring on-treatment viral kinetics with an accurate, precise, and sensitive RNA viral load (VL) test in order to inform treatment decisions, known as response-guided therapy (RGT), is an essential component in the successful treatment of patients with HCV. With the approval of protease inhibitors (PI) in combination with peginterferon alfa-2a and ribavirin (triple therapy) for the treatment of HCV genotype 1 infection (6), complex new futility rules have been introduced to avoid unnecessary drug exposure and prevent the potential evolution or enrichment of drug-resistant HCV variants among patients unlikely to achieve sustained virologic response (SVR) (6-8). The application of RGT rules for triple therapy also allows for the truncation or extension of treatment based on HCV RNA concentrations being above or below the lower limit of quantification (LLOQ) or detection (LOD) of the VL test at weeks 4 and 12 (telaprevir) or 8 and 24 (boceprevir) (7,8). Considering the central role that VL plays in the clinical management of patients with HCV and the high degree of genetic variability that is characteristic of the virus, it is critical that manufacturers of molecular diagnostic assays monitor the performances of their tests against the ever-changing genetic landscape of the HCV epidemic.All molecular diagnostic tests, including real-time PCR, require target-specific primers and probes. Natural polymorphisms occurring within the primer and/or probe sites have the potential to abolish or reduce the efficacy of hybridization, resulting in reduced analytical sensitivity and accuracy (9...

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Sequence Conservation of the Region Targeted by the Abbott RealTime HBV Viral Load Assay in Clinical Specimens

Cited by 6 publications

References 23 publications

Multicenter Evaluation of the Cepheid Xpert® HBV Viral Load Test

Multicenter Evaluation of the Cepheid Xpert® HBV Viral Load Test

Use of Hepatitis B-e Antigen to Identify Pregnant Women With Hepatitis B Virus Infection Who Need Antiviral Therapy for Prevention of Mother-to-child Transmission

Sequence Conservation of the Region Targeted by the Abbott RealTi m e HCV Viral Load Assay

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