HCV core antigen testing in HIV- and HBV-coinfected patients, and in HCV-infected patients on hemodialysis.

BACKGROUND: A quantitative HCV core antigen (HCVcoreAg) immunoassay has been developed for the confirmation of viremia in patients with hepatitis C. OBJECTIVES: We evaluated the correlation of HCV RNA and HCVcoreAg in different patient populations without HCV-specific treatment: HIV/HCV-coinfection, HBV/HCV-coinfection, and patients with end-stage renal disease. STUDY DESIGN: HCVcoreAg was quantified by a fully-automated immunoassay. Correlation of HCVcoreAg with HCV RNA was studied cross-sectionally in HIV/HCV- and HBV/HCV-coinfected patients, as well as before and after hemodialysis in patients with end-stage renal disease. RESULTS: A concordant positive or negative test result for both HCV RNA and HCVcoreAg was observed in 68 of 71 (96%), 55 of 57 (96%), and in 109 of 109 (100%) samples of patients with HIV- or HBV/HCV-coinfection, and patients undergoing hemodialysis, respectively. HCVcoreAg showed high correlation with HCV RNA in samples from HIV/HCV-coinfected patients and HCV-infected patients undergoing hemodialysis (r=0.97 and r=0.94, p<0.001). There was no overall correlation between HCVcoreAg and HCV RNA in HBV/HCV-coinfected individuals (r=0.04, p=0.822). Excluding patients with HCV RNA to HCVcoreAg ratios below 100 and above 10,000kIU/fmol led to improved correlation (r=0.53; p=0.02), but remained worse than for the other cohorts. Overall, HCV RNA to HCVcoreAg ratios did not differ significantly between the different patient populations, though variation tended to be higher in HBV/HCV-coinfected patients. Patients with lower HCV RNA levels tend to have lower HCV RNA/HCVcoreAg ratios. CONCLUSIONS: HCVcoreAg represents a reliable marker of viral replication showing a good correlation with HCV RNA in various patient populations, with some limitations in HBV/HCV-coinfection.

Rapid early HDV RNA decline in the peripheral blood but prolonged intrahepatic hepatitis delta antigen persistence after liver transplantation.

BACKGROUND & AIMS: Chronic HDV infection is an inflammatory liver disease and liver transplantation (LTX) remains the only curative treatment option for most patients. The hepatitis D virus (HDV) uses HBsAg as its surface protein, however, it is controversial to what extend HDV may be detected independently of HBsAg in blood and liver after LTX. The aims of this study were to investigate kinetics of HDV RNA and HBsAg early after LTX, to apply the data to a mathematical model and to study long-term persistence of HDV after LTX. METHODS: We retrospectively analyzed 26 patients with chronic hepatitis delta who underwent LTX between 1994 and 2009. Blood samples were obtained every 1-3 days during the first 14 days after LTX. Data were applied to a mathematical model to study viral kinetics. Available liver biopsy samples were stained for HBV and HDV viral antigens and tested for HBV DNA/cccDNA. RESULTS: HBsAg and HDV RNA became negative after a median of 5 days (range 1-13) and 4 days (range 1-10), respectively. Early HDV RNA and HBsAg decline paralleled almost exactly in all patients; however the mathematical model showed a high variability of virion death. HDAg stained positive in transplanted livers in six patients in the absence of liver HBV DNA/cccDNA, serum-HBsAg, and HDV RNA for up to 19 months after LTX. CONCLUSIONS: HDV RNA and HBsAg decline follow almost identical kinetic patterns within the first days after LTX. Nevertheless, intrahepatic latency of HDAg has to be considered when exploring novel concepts to withdraw HBIG.

Performance and clinical utility of a novel fully automated quantitative HCV-core antigen assay.

BACKGROUND: Recently, a novel quantitative HCVcoreAg immunoassay developed for commercialisation by Abbott has become available in Europe and Asia. OBJECTIVES: We evaluated the correlation of HCV-RNA and HCVcoreAg and investigated the stability of HCVcoreAg and HCV-RNA. STUDY DESIGN: HCVcoreAg was quantified by a novel fully automated immunoassay (Architect HCVAg, Abbott, Germany). HCV-RNA quantification was performed either using the Cobas-TaqMan assay or Amplicor-HCV-Monitor (Roche-Diagnostics, Germany). Correlation of HCVcoreAg with HCV-RNA was studied cross-sectionally and longitudinally in untreated patients followed for up to 8 years. Stability of HCVcoreAg and HCV-RNA was evaluated in plasma and whole blood stored for up to 96 h at different conditions. RESULTS: HCVcoreAg showed good correlation with HCV-RNA in all 118 cross-sectional tested samples irrespective of the HCV genotype (r=0.75). In the majority but not all of the 10 longitudinally studied patients HCVcoreAg also demonstrated a good correlation with HCV-RNA. HCVcoreAg was stable in plasma at 4, 20, and 37 degrees C for up to 96 h, whereas HCV-RNA significantly declined at 37 degrees C. In whole blood, HCVcoreAg and HCV-RNA levels declined at all conditions with exception of HCVcoreAg at 37 degrees C. HCVcoreAg was stable after 1-5 freezing/thawing cycles and not light-sensitive. CONCLUSIONS: HCVcoreAg represents a stable and reliable marker of viral replication showing a good correlation with HCV-RNA irrespective of the HCV genotype. HCVcoreAg determination can be used to confirm viral replication and monitor viral load or acquisition of HCV over time.

The treatment of chronic hepatitis B: Focus on adefovir-like antivirals.

SEVERAL OPTIONS FOR THE TREATMENT OF HEPATITIS B HAVE BEEN LICENSED IN THE LAST YEARS: interferon, pegylated interferon, lamivudine, adefovir, entecavir, and telbivudine. In addition tenofovir has been licensed in the EU and is expected to be licensed in the USA in 2008. The antivirals can be divided into "lamivudine-like" and "adefovir-like", which clinically differ in their capacity to induce "YMDD" mutants, which are the hallmark of lamivudine resistance. The differing resistance profile makes them good combination partners, even in the absence of synergy in antiviral potency.

Progression to cirrhosis in hepatitis C patients: an age-dependent process.

BACKGROUND: Age at infection is known to be associated with disease progression rate in hepatitis C virus (HCV) infected patients. The aim of this study was to assess when cirrhosis is expected to occur according to host and viral factors. METHODS: Fibrosis progression was studied in 247 naive HCV patients using multiple regression analysis. The expected age at cirrhosis was calculated for each patient. RESULTS: Progression rate was 0.13, 0.14, 0.27, and 0.36 U of fibrosis/year for patients with age at infection or=37 years, respectively. Age at infection above 37 years was independently associated with fast progression (rate>0.13; P=0.001). Body mass index >25 kg/m2 and alanine aminotransferase>3 x ULN are also possibly associated with faster progression. Based on progression rates, the expected age at cirrhosis is 65.4, 64.6, 64.8 and 69.4 years for age at infection or=37 years, respectively. CONCLUSION: Most HCV patients, if untreated, are expected to develop cirrhosis at about 65 years, irrespective of the age at infection. Thus, age itself seems even more important than age at infection for predicting the occurrence of liver cirrhosis. A specific active monitoring and therapeutic approach should be adopted in older patients to prevent progression to cirrhosis and its complications.

Caspase 8 small interfering RNA prevents acute liver failure in mice.

A major concern in therapy of acute liver failure is protection of hepatocytes to prevent apoptosis and maintain liver function. Small interfering RNA (siRNA) is a powerful tool to silence gene expression in mammalian cells. To evaluate the therapeutic efficacy of siRNA in vivo we used different mouse models of acute liver failure. We directed 21-nt siRNAs against caspase 8, which is a key enzyme in death receptor-mediated apoptosis. Systemic application of caspase 8 siRNA results in inhibition of caspase 8 gene expression in the liver, thereby preventing Fas (CD95)-mediated apoptosis. Protection of hepatocytes by caspase 8 siRNA significantly attenuated acute liver damage induced by agonistic Fas (CD95) antibody (Jo2) or by adenovirus expressing Fas ligand (AdFasL). However, in a clinical situation the siRNAs most likely would be applied after the onset of acute liver failure. Therefore we injected caspase 8 siRNA at a time point during AdFasL- and adenovirus wild type (Adwt)-mediated liver failure with already elevated liver transaminases. Improvement of survival due to RNA interference was significant even when caspase 8 siRNA was applied during ongoing acute liver failure. In addition, it is of particular interest that caspase 8 siRNA treatment was successful not only in acute liver failure mediated by specific Fas agonistic agents (Jo2 and AdFasL) but also in acute liver failure mediated by Adwt, which is an animal model reflecting multiple molecular mechanisms involved in human acute viral hepatitis. Consequently, our data raise hope for future successful application of siRNA in patients with acute liver failure.