Dominance of hepatitis C virus (HCV) is associated with lower quantitative hepatitis B surface antigen and higher serum interferon-γ-induced protein 10 levels in HBV/HCV-coinfected patients.

Different viral dominance patterns have been documented in coinfection with hepatitis B virus (HBV) and hepatitis C virus (HCV) based on HBV DNA and HCV RNA quantification. In most cases, HCV is dominant and suppresses HBV replication. In vitro studies revealed that there is most probably no direct interference between HBV and HCV replication. We hypothesized that indirect mechanisms mediated by host immune responses might be responsible for the different dominance patterns. In this study we analysed quantitative hepatitis B surface antigen (HBsAg) as a marker for immune control of HBV and interferon γ-induced protein 10 (IP-10) as host marker for the endogenous interferon in 85 patients with HBV/HCV coinfection. Levels of HBsAg were closely associated with viral dominance patterns in 85 HBV/HCV-coinfected patients. HBsAg levels were lowest in patients with HCV dominance, even lower compared with HBV-monoinfected patients undergoing treatment with nucleos(t)ide analogues (NA) but comparable to low replicative HBsAg carriers. An increase in HCV RNA during follow up was associated with HBsAg decline. Patients with HCV dominance had significantly higher serum IP-10 levels compared with HBV-dominant patients or HBV-monoinfected patients treated with NA. Lower HBsAg and higher IP-10 levels in HCV-dominant HBV/HCV-coinfected patients suggest that HCV suppresses HBV DNA replication and also HBsAg production by immune mechanisms.

Hepatitis B core-related antigen (HBcrAg) levels in the natural history of hepatitis B virus infection in a large European cohort predominantly infected with genotypes A and D.

Hepatitis B core-related antigen (HBcrAg) has been suggested as an additional marker of hepatitis B virus (HBV) infection. HBcrAg combines the antigenic reactivity resulting from denatured hepatitis B e antigen (HBeAg), HBV core antigen and an artificial core-related protein (p22cr). In Asian patients, high levels of HBcrAg have been suggested to be an independent risk factor for hepatocellular carcinoma, while low levels could guide safe cessation of treatment with nucleos(t)ide analogues. We here studied HBcrAg levels in different phases of HBV infection in a large European cohort predominantly infected with genotypes A and D: HBeAg-positive immune tolerance (n = 30), HBeAg-positive immune clearance (IC) (n = 60), HBeAg-negative hepatitis (ENH) (n = 50), HBeAg-negative inactive/quiescent carrier phase (c) (n = 109) and acute hepatitis B (n = 8). Median HBcrAg levels were high in the immune tolerance and immune clearance phases (8.41 and 8.11 log U/mL, respectively), lower in ENH subjects (4.82 log U/mL) but only 2.00 log U/mL in ENQ subjects. Correlation between HBcrAg and HBV DNA varied among the different phases of HBV infection, while HBcrAg moderately correlated with hepatitis B surface antigen in all phases. ENQ patients had HBcrAg levels <3 log U/mL in 79%, in contrast to only 12% in the ENH group. HBcrAg levels vary significantly during the different phases of HBV infection. HBcrAg may serve as valuable marker for virus replication and reflect the transcriptional activity of intrahepatic cccDNA. In HBeAg-negative patients, HBcrAg may help to distinguish between inactive carriers (ENQ) and those with active disease (ENH).