A genotype-independent real-time PCR assay for quantification of hepatitis B virus DNA

Abstract

Accurate quantification of hepatitis B virus (HBV) DNA levels is important for monitoring patients with chronic HBV infection and for assessing their responses to antiviral therapy. This study aimed to develop a real-time PCR assay that is sensitive and can accurately quantify a wide range of HBV DNA levels across the known HBV genotypes. An in-house real-time PCR assay using primers and a TaqMan probe in a highly conserved region of the HBV surface gene was designed. The assay was standardized against a WHO standard and validated against plasmids of HBV genotypes A through H. The linear quantification range was approximately 5 × 100 to 2.0 × 109 IU/ml. Results of samples from patients infected with HBV genotypes A through H tested using our real-time in-house PCR assay showed an excellent correlation with those of the Cobas Amplicor HBV Monitor (R2 = 0.9435) and the Cobas TaqMan HBV (R2 = 0.9873) tests. We have established a real-time PCR assay that is genotype independent and can accurately quantify a wide range of HBV DNA levels. Further studies of additional samples are ongoing to validate the genotype independence of our assay. Copyright © 2007, American Society for Microbiology. All Rights Reserved.