Evaluation of the Abbott RealTime HBV DNA Assay and Comparison to the Cobas AmpliPrep/Cobas TaqMan 48 Assay in Monitoring Patients with Chronic Cases of Hepatitis B

Abstract

The new Abbott RealTime hepatitis B virus (HBV) assay was compared to the Cobas AmpliPrep/CobasTaqMan assay with 128 serum samples from patients with chronic hepatitis B. There was an excellent correlation (r ‫؍‬ 0.961) between the two assays, with the Abbott RealTime test showing at least equivalent sensitivity and a slightly wider dynamic range than the Cobas TaqMan assay. By coupling high sensitivity with a large dynamic range, the Abbott RealTime HBV assay is useful in monitoring the response to antiviral therapy.Hepatitis B virus (HBV) is a small partially double-stranded virus belonging to the family of the Hepadnaviridae that can cause acute or chronic hepatitis (2). Millions of people around the world are infected by HBV, and it is estimated that about 350 million people worldwide have developed a persistent infection (6). Measurement of HBV levels in serum is a reliable marker for prognosis of acute and chronic infection and plays an important role in the management of patients receiving antiviral drugs (7,8). Therefore, diagnostic assays for the accurate quantitation of HBV DNA are essential for optimal patient management. Monitoring of HBV DNA allows to predict the success of antiviral therapy and to identify the development of drug resistance. Real-time PCR is a new molecular tool that is progressively replacing endpoint PCR systems for monitoring patients with chronic hepatitis B since it allows for high sensitivity, a broad dynamic range, accuracy, and rapid results (1, 9).Quantification by real-time PCR is based on the determination of the threshold cycle (C T ) when the amplified product is detected for the first time (4) and the PCR is still in the exponential phase. In this case the quantification of the viral load is much more accurate and reliable than that measured with endpoint PCR systems (3).The aim of our study was to evaluate the Abbott RealTime HBV assay for the detection and quantification of HBV-DNA in serum samples and to compare these results with those obtained using the Cobas AmpliPrep/Cobas TaqMan HBV test (Roche Diagnostics). The study was carried out on 128 serum samples collected from patients with chronic HBV infections attending our hepatology clinic at the University Hospital Tor Vergata, Rome, Italy.Blood samples were collected in a BD Vacutainer tube containing a separation gel. After centrifugation, the serum was divided into two aliquots of 1 ml each and tested by the Abbott and Cobas TaqMan Real-time PCR assays, respectively. Both systems use a hybridization probe with a fluorescent moiety covalently linked to the 5Ј end of the probe (reporter) and a quenching moiety bound to the 3Ј end of the probe (quencher). In the presence of target, probe hybridization and primer extension occur simultaneously. The fluorescent signal is generated by removing the reporter through the 5Ј33Ј exonuclease activity of a thermostable Taq DNA polymerase (4, 5). In the TaqMan and Abbott RealTime PCR assays an additional probe is used to detect genotype G or C, respectively. While the Coba...

The human polyomaviruses KI and WU: virological background and clinical implications

“…Quantitative real-time PCR is routinely used to monitor antiviral therapy in patients with chronic infection (for instance, chronic hepatitis B or C; HIV-1 positive patients) (32)(33)(34) or viral reactivation (CMV, EBV, BKPyV, AdV, etc.) in transplant patients (35).…”

Multilaboratory Evaluation of Real-Time PCR Tests for Hepatitis B Virus DNA Quantification

“…Reported studies of real-time assays have mainly focused on the performance of individual tests compared to signal amplification tests rather than the comparative performance of multiple real-time PCR tests (2,3,6,9). The present study assessed the limit of detection, linear range, reproducibility, and agreement among four commercially available real-time PCR HBV viral load tests: the Abbott RealTime HBV IUO, the Roche Cobas AmpliPrep/Cobas TaqMan HBV test, the Roche Cobas TaqMan HBV test with HighPure system, and the Qiagen artus HBV TM ASR.…”

“…A number of antiviral drugs have been introduced recently for the treatment of chronic HBV infection, and viremia is an important component in the decision to initiate treatment and in monitoring therapeutic response (5, 7). Reported studies of real-time assays have mainly focused on the performance of individual tests compared to signal amplification tests rather than the comparative performance of multiple real-time PCR tests (2,3,6,9). …”

Usefulness of in-house PCR methods for hepatitis B virus DNA detection

“…These assays are based on the amplification of DNA targets using HBV-specific primers (COBAS Amplicor HBV Monitor); branched-DNA signal amplification, such as the VERSANT HBV DNA 3.0 assay; the hybridization of a chemiluminescent probe as hybrid capture; or a specific fluorescent probe in real-time PCR (Abbott Real-time HBV or Cobas TaqMan HBV test) (Ciotti et al, 2008;Morris et al, 2013;Shi et al, 2008;Yao et al, 2004;Yuan et al, 2004). In Brazil, HBV DNA testing is commonly conducted to monitor HBV treatment, but commercial assays are generally used.…”