Advantage of PCR for detecting low amounts of HBV DNA in patients' sera

Abstract Serum hepatitis B virus DNA (HBV DNA) is now the most important and reliable marker for monitoring viral replication. Quantitative detection of HBV DNA in serum is based on a commercial standardized solution hybridization assay (Genostics). In this work, we studied the sensitivity and specificity of this method, in comparison with the polymerase chain reaction (PCR) technique, for low-value HBV DNA serum samples. Fifty-four patients with or without HBV serological markers were divided into 4 groups according to their HBV DNA values. Genomic amplication was found to affect 2 conserved regions of the viral genome, the S and C regions. Samples with an HBV DNA concentration equal to or greater than 1.5 pg/ml were considered positive in the “Genostics” test. A total of 38% of patients considered negative in the quantitative assay ( Our PCR results suggest that the positive limit level of the Genostics test has to be re-evaluated. Indeed, for low values of HBV DNA (under 20 pg/ml and especially under 10 pg/ml), it is not possible to conclude about the positivity from the quantitative assay, and results have to be estimated according to the clinical and serological status of the patients. Moreover, PCR can be falsely negative because of methodological problems. Nevertheless, this study confirms that PCR does enable detection of the viral genome in HBV-seronegative patients and in “old” and “cured” HBV-infection marker carriers.