The presence of hepatitis C virus (HCV) negative strand RNA in extrahepatic compartments based on PCR detection assays has been suggested in many reports with a very heterologous detection rate (from 0 to 100%). In this study, we have analyzed the presence of HCV negative strand in hepatic (liver biopsies, n ϭ 20) and extrahepatic (sera, n ϭ 32; PBMC, n ϭ 26 and fresh bone marrow cells, n ϭ 8) compartments from infected patients with three different reverse transcriptase (RT)-PCR-based assays using primers located in the 5 Ј noncoding region, with or without a tag sequence, or in the nucleocapsid (CAP). Samples were selected to display different viral loads (10 5 -3 ϫ 10 7 genomic equivalent/ml or gram) and viral genotypes ( n ϭ 5). Using synthetic as well as biological templates, we could document extensive artifactual detection of negative strand RNA, due to self priming and mispriming events, when either 5 Ј noncoding region primer pair was used, whereas both artifacts were dramatically reduced (

Ribavirin is the most common treatment for chronic hepatitis E and is mostly effective, although some cases of ribavirin treatment failure have been described. Here, we report on a particular case of ribavirin resistance and investigate the underlying causes of treatment failure. Mutations in the viral polymerase, an essential enzyme for viral replication, appear to be responsible.

Occult hepatitis B virus (HBV) infection is common in chronic hepatitis C patient. However, its significance and consequences are still unclear. The aim of this study was to evaluate the prevalence of occult HBV among HCV chronic carriers in France and to assess its impact on liver histology and response to antiviral therapy. To this end a cohort of 203 patients with chronic hepatitis C without hepatitis B surface antigen (HBsAg) has been examined. Serum HBV-DNA was detected using a highly sensitive PCR with primers located in the S and X genes. HBV viraemia levels were further determined by real-time PCR. Results showed that 47 of 203 (23%) patients had occult HBV infection with a low HBV load (10(2)-10(4) copies/ml) but significantly higher HCV-RNA titers (P < 0.05). No significant difference in age, gender, serum ALT level, HCV genotypes, and the presence of anti-HBc was observed between patients with or without HBV-DNA. When compared histologically, patients with occult HBV infection had higher activity (A2-A3 in 53% vs. 38%, P < 0.01) and more advanced fibrosis (60% vs. 33%, P < 0.001) than HBV-DNA negative cases. Sustained response to combination therapy against Chronic hepatitis C was achieved in 11 (28%) of 40 HBV-DNA positive cases, compared with 65 (45%) of the 144 HBV-DNA negative cases (P < 0.05). Among the 144 HBV-DNA negative HCV patients those with genotype 1 responded less frequently to therapy as compared to other genotypes infected patients (38% vs. 55%, P < 0.05). Surprisingly, when considering all patients studied, irrespective to the HBV-DNA status no significant difference was observed in response to combination therapy regarding HCV genotypes (39% vs. 44%, P > 0.05). In conclusion, HBV-DNA is found in 1/4 of French chronic hepatitis C patients regardless of the presence of anti-HBc. Such an occult HBV co-infection is associated with more severe liver disease, higher HCV viral load and decreased response to antiviral therapy irrespective of HCV genotypes.

Hepatitis B virus (HBV) core promoter activity is positively and negatively regulated by nuclear receptors, a superfamily of ligand-activated transcription factors, via cis-acting sequences located in the viral genome. In this study, we investigated the role of farnesoid X receptor alpha (FXR␣) in modulating transcription from the HBV core promoter. FXR␣ is a liver-enriched nuclear receptor activated by bile acids recognizing hormone response elements by forming heterodimers with retinoid X receptor alpha (RXR␣). Electrophoretic mobility shift assays demonstrated that FXR␣-RXR␣ heterodimers can bind two motifs on the HBV enhancer II and core promoter regions, presenting high homology to the consensus (AGGTCA) inverted repeat FXR␣ response elements. In transient transfection of the human hepatoma cell line Huh-7, bile acids enhanced the activity of a luciferase reporter containing the HBV enhancer II and core promoter sequences through FXR␣. Moreover, using a greater-than-genome-length HBV construct, we showed that FXR␣ also increased synthesis of the viral pregenomic RNA and DNA replication intermediates. The data strongly suggest that FXR␣ is another member of the nuclear receptor superfamily implicated in the regulation of HBV core promoter activity and that bile acids could play an important role in the natural history of HBV infection.Hepatitis B virus (HBV) infection is limited to hepatocytes of humans and primates and is associated with chronic hepatitis, cirrhosis, and hepatocellular carcinoma (10,19). HBV is an enveloped virus containing a 3.2-kb partially doublestranded DNA genome with four open reading frames. These open reading frames encode the reverse transcriptase, precore, and core proteins; three surface antigen proteins (pre-S1, pre-S2, and S); and the X protein. Regulation of HBV transcription is under the control of four promoters (the core, pre-S1, pre-S2/S, and X promoters) and two enhancer regions (EN1 and EN2). For some authors, the core promoter corresponds to two distinct promoters, namely the precore and pregenomic promoters (44,46). The core promoter activity, modulated by the EN2 region, plays a critical role in the virus life cycle. It initiates the synthesis of the precore and pregenomic 3.5-kb RNAs. The precore RNA encodes the precore protein, also called HBe antigen. The pregenomic RNA encodes both the polymerase and the core protein and serves as the template for viral DNA synthesis (24, 34).Multiple cellular transcription factor binding sites have been identified on these regulatory sequences (26,29,31,40,48,51), in particular for several nuclear receptors (NR) belonging to the superfamily of ligand-activated transcription factors (1,11,13,14,22,23). Two important NR response elements (NRRE), situated in the EN2 (NRRE enhII ) and the core promoter (NRRE pre-C ) regions, are recognized by hepatocyte nuclear factor 4 alpha (HNF4␣) and RXR␣-peroxisome proliferatoractivated receptor alpha (PPAR␣) heterodimers (13,30,44).In hepatoma cell lines, HNF4␣ and PPAR␣-RXR␣ upregulate synthes...