Where does adefovir stand amongst newly developed antivirals: from pharmacology to virology

Comparison of clinical application of the Abbott HBV PCR kit and the VERSANT HBV DNA 3.0 test to measure serum hepatitis B virus DNA in Taiwanese patients

With an estimated 350-400 million people worldwide chronically infected with hepatitis B virus (HBV), and the subsequent serious complications caused by liver damage including cirrhosis, liver failure, and hepatocellular carcinoma, HBV infection remains a global health issue, particularly in Taiwan, an HBV-hyperendemic area. Sensitive and accurate quantification of HBV DNA is necessary to monitor patients with chronic hepatitis B who are receiving antiviral therapy to determine treatment response and adapt therapy. We evaluated and compared the clinical performance of two HBV DNA assays based on different technologies: the RealArt HBV PCR Kit (Abbott HBV DNA PCR kit, real-time polymerase chain reaction assay, detection limit: 27 IU/mL) and the VERSANT bDNA 3.0 assay (Bayer, branched DNA signal amplification assay, detection limit: 357 IU/mL). Serum levels of HBV DNA in 173 chronic HBV carriers were determined using both the RealArt HBV PCR Kit and the VERSANT bDNA 3.0 test. Of the 173 samples analyzed for baseline viral load detection, HBV DNA was quantifiable in 147 patients (82.1%) by the RealArt HBV PCR Kit, which was significantly higher than the 92 (53.2%) samples quantified by the VERSANT bDNA 3.0 assay. A total of 86 (49.7%) samples were quantifiable by both assays, whereas 25 (14.5%) were below the detection limit of both assays. The HBV DNA quantification values measured by the RealArt HBV PCR Kit and the VERSANT bDNA 3.0 assay were positively correlated (Spearman's rank correlation coefficient r = 0.932, p < 0.001). On average, the results derived from the RealArt HBV PCR Kit were 0.67 log lower than those of the VERSANT bDNA 3.0 assay. HBV DNA concentrations were significantly higher in 63 HBV e antigen (HBeAg)-seropositive patients than in 110 HBeAg-seronegative patients (5.42 +/- 2.34 logs vs. 3.21 +/- 2.27 logs, p < 0.001). The RealArt HBV PCR Kit is more sensitive and has a wider dynamic range than the VERSANT bDNA 3.0 assay in the clinical setting of chronic hepatitis B patients. The sensitivity and wide dynamic range of the PCR assay allow optimal monitoring and timely adaptation of antiviral therapy. Nevertheless, the HBV DNA values measured by the RealArt HBV PCR Kit and the VERSANT bDNA 3.0 assay were significantly correlated.

Characterization of a new sensitive PCR assay for quantification of viral DNA isolated from patients with hepatitis B virus infections

Sensitive and accurate quantification of hepatitis B virus (HBV) DNA is necessary for monitoring patients with chronic hepatitis receiving antiviral therapy in order to determine treatment response and to adapt therapy in case of inadequate virologic control. The development of quantitative PCR assays has been crucial in meeting these needs. The objective of this study was to compare the performance of a new real-time PCR assay (Abbott RealTime) for HBV DNA with that of three other commercial assays for the detection of HBV DNA. These were the Versant 3.0 branched-chain DNA assay, the Cobas Amplicor HBV Monitor test, and the Cobas AmpliPrep-Cobas TaqMan hepatitis B virus assay (CAP-CTM). HBV DNA was measured in blood samples taken from two cohorts of patients with chronic hepatitis. HBV DNA levels measured with the Abbott RealTime assay were highly correlated with those measured with the other three tests over their respective dynamic ranges (r, 0.88 to 0.96). The sensitivity (detection limit, 10 IU/ml) and dynamic range of the Abbott RealTime assay (10(1) to 10(9) IU/ml) was superior to that of the Versant assay. The RealTime assay recognized both HBV strains belonging to genotypes A to G and those bearing polymerase gene mutations equivalently. In conclusion, this study demonstrates the utility of the Abbott RealTime assay for monitoring HBV DNA levels in patients with chronic hepatitis B. Its sensitivity and wide dynamic range should allow optimal monitoring of antiviral therapy and timely treatment adaptation.