Significance of hepatitis B viremia levels determined by a quantitative polymerase chain reaction assay in patients with hepatitis B e antigen-negative chronic hepatitis B virus infection

OBJECTIVES: In hepatitis B e antigen (HBeAg)-negative chronic hepatitis B virus (HBV) infection, the clinical relevance of low viremia levels remains unclear. We evaluated the clinical significance of a single baseline serum HBV DNA measurement by a quantitative polymerase chain reaction (PCR) assay in this setting. METHODS: In total, 196 patients with HBeAg-negative chronic HBV infection (62 inactive carriers, 134 with chronic hepatitis B) were studied. ALT activity was normal at baseline in 25/134 HBeAg-negative chronic hepatitis B patients (18.7%), whereas it remained normal throughout follow-up in all inactive carriers. RESULTS: HBV DNA was <30,000 copies/ml in 14 (10.5%) and <100,000 copies/ml in 17 (12.9%) HBeAg-negative chronic hepatitis B patients, whereas it was <30,000 copies/ml in all inactive carriers (undetectable in 14). In particular, HBV DNA levels were <100,000 copies/ml in eight (32%) and <30,000 copies/ml in five (20%) of the 25 patients with HBeAg-negative chronic hepatitis B and normal baseline ALT values. HBV DNA levels with a cut-off at 30,000 or 100,000 copies/ml could correctly classify 92.9% or 91.3% of patients with HBeAg-negative chronic HBV infection, whereas ALT or IgM anti-HBc (IgM class antibody to HBV core antigen) index > 0.200 could correctly classify only 87.2% and 82.1% of patients, respectively. A combined HBV DNA and IgM anti-HBc index performed better by correctly classifying 94.4% of cases. CONCLUSIONS: Serum HBV DNA levels evaluated by sensitive quantitative PCR assays can be used for differentiation between HBeAg-negative chronic hepatitis B and inactive hepatitis B surface antigen carrier state, but the cut-off level should be set at approximately 30,000 copies/ml and certainly lower than the recently suggested level of 100,000 copies/ml.