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Introduction: Presence of anti-E1E2 antibodies was previously associated with spontaneous cure of hepatitis C virus (HCV) and predictive before treatment of a sustained virological response (SVR) to bi- or tri-therapy in naïve or experienced patients, regardless of HCV genotype. We investigated the impact of anti-E1E2 seroprevalence at baseline on treatment response in patients receiving direct-acting antiviral (DAA) therapy., Material and Methods: We screened anti-E1E2 antibodies by ELISA in serum samples collected at treatment initiation for two groups of patients: 59 with SVR at the end of DAA treatment and 44 relapsers after DAA treatment. Nineteen patients received a combination of ribavirin (RBV) or PEG-interferon/ribavirin with sofosbuvir or daclatasvir and others received interferon-free treatment with DAA±RBV. HCV viral load was measured at different time points during treatment in a subgroup of patients., Results: A significant association was observed between presence of anti-E1E2 and HCV viral load<6log10 prior treatment. Among patients with anti-E1E2 at baseline, 70% achieved SVR whereas among patients without anti-E1E2, only 45% achieved SVR. Conversely, 66% of patients experiencing DAA-failure were anti-E1E2 negative at baseline. In the multivariate analysis, presence of anti-E1E2 was significantly associated with SVR after adjustment on potential cofounders such as age, sex, fibrosis stage, prior HCV treatment and alanine aminotransferase (ALT) level., Conclusions: The presence of anti-E1E2 at treatment initiation is a predictive factor of SVR among patients treated with DAA and more likely among patients with low initial HCV viral load (<6log10). Absence of anti-E1E2 at baseline could predict DAA-treatment failure., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Background & Aims: Hepatitis B virus (HBV) persistence and the pathobiology of chronic HBV (CHB) infections result from the interplay between viral replication and host immune responses. We aimed to comprehensively analyse the expression of intrahepatic host genes as well as serum and liver HBV markers in a large cohort of untreated CHB patients., Methods: One-hundred and five CHB patients untreated at the time of liver biopsy (34 HBeAg[+] and 71 HBeAg[-]) were analysed for the intrahepatic expression profile of 67 genes belonging to multiple innate immunity pathways. Results were correlated to serological (quantification of HBsAg [qHBsAg] and HBV DNA) and intrahepatic viral markers (total HBV DNA, pre-genomic RNA and covalently closed circular HBV DNA)., Results: Intrahepatic gene expression profiling revealed a strong downregulation of antiviral effectors, interferon stimulated genes, Toll-like and pathogen recognition receptor pathways in CHB patients as compared to non-infected controls, which was not directly correlated to HBV replication. A subset of genes [CXCL10, GBP1, IFITM1, IFNB1, IL10, IL6, ISG15, TLR3, SOCS1, SOCS3] was more repressed in HBeAg(-) respect to HBeAg(+) patients (median of serum HBV DNA 7.9×10 3 vs. 7.9×10 7 IU/ml, respectively). Notably, HBeAg(-) patients with lower qHBsAg (<5×10 3 IU/ml) showed a relief of repression of genes belonging to multiple pathways., Conclusions: Our results show a strong impairment of innate immune responses in the liver of CHB patients. The association of low levels of qHBsAg with gene repression, if confirmed, might prove useful for the identification of patients who would most benefit from immune-modulators and/or HBsAg targeting agents as strategies to restore immune responsiveness., Lay Summary: Chronic hepatitis B virus (HBV) infections represent a major public health problem worldwide. Over 200 million people are chronically infected and at risk of developing chronic hepatitis, liver cirrhosis and cancer. Our work aimed to understand the molecular consequences of chronic hepatitis B in the infected liver. It was conducted in a large cohort of untreated chronically infected HBV patients and analysed the expression of immunity and liver disease-related genes in the liver, with respect to markers of viral replication and persistence. Our results indicate that chronic HBV infection has a suppressive effect on immune responses, which was more pronounced with high levels of hepatitis B virus surface antigen (HBsAg). These data provide novel insight into the mechanisms of HBV persistence in the liver and suggest that approaches aimed at reducing HBsAg levels, may restore immune responsiveness against the virus., (Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background and Aims: We previously showed that pre-treatment serum anti-E1E2 predicted hepatitis C virus (HCV) RNA viral kinetics (VKs) and treatment outcome in patients with chronic hepatitis C receiving pegylated interferon/ribavirin (Peg-IFN/RBV) double therapy. Here, we determined whether baseline anti-E1E2 was correlated with the on-treatment VK and could predict virological outcome in treatment-experienced HCV-infected cirrhotic patients receiving protease inhibitor-based triple therapy., Methods: Sera from 19 patients with HCV genotype 1 infection and compensated cirrhosis who failed to respond to a prior course of Peg-IFN/RBV were selected at time 0 before starting triple therapy with boceprevir or telaprevir. We assessed patients with sustained viral response 12 weeks after the end of triple therapy (SVR12) by analyzing VKs at weeks 4, 12, 24, 36, 48 (end of treatment) and 60., Results: Patients baseline characteristics were similar to the well-defined CUPIC cohort (age, HCV subtype, baseline viremia, and treatment history). Among the 19 patients, 11 achieved an SVR12. Fifteen patients were positive for pre-treatment anti-E1E2 and all of them achieved SVR12. Moreover, anti-E1E2 and SVR12 correlated with prior response to IFN/RBV therapy (relapse, partial or null response)., Conclusions: Baseline anti-E1E2 could be considered as a new biomarker to predict SVR12 after triple therapy in this most difficult-to-treat population. These results warrant further validation on larger cohorts including patients receiving highly effective direct-acting antivirals to explore whether this test could help in better defining treatment duration for these very costly molecules., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Background: Unique serum anti-E1E2 antibodies were shown to be associated with spontaneous recovery or predictive of sustained virological response (SVR) in patients with chronic hepatitis C receiving pegylated interferon/ribavirin (PEG-IFN/RBV) therapy. The objectives were to establish the relationship between pretreatment anti-E1E2 titres and HCV RNA kinetics during PEG-IFN/RBV therapy, and to examine whether the combined determination of interleukin (IL)28B rs12979860 and rs8099917, pretreatment inducible protein (IP)-10 levels and/or anti-E1E2 improved the prediction of SVR., Methods: Sera from 26 treatment-naive consecutive HCV patients treated with PEG-IFN/RBV for 48 weeks were analysed. Serum anti-E1E2 titres and pretreatment IP-10 levels were measured by enzyme-linked immunosorbent assays. The IL28B variants were determined using genotyping real-time polymerase chain reaction method. Viral decline was measured at weeks (W) 4 and 12 and SVR assessed 6 months after the end of therapy., Results: Baseline anti-E1E2 titres were correlated with HCV RNA decline at W4 and W12 and were highly predictive of SVR with 100% of patients negative for anti-E1E2 failing to achieve SVR. Receiver operating characteristic curve analyses indicate that the best prediction of SVR (AUC 0.990) was obtained with the combination of anti-E1E2 and IP-10 levels. Predictive values were better than those obtained with IP-10 alone or in combination with IL28B variants., Conclusions: Pretreatment serum anti-E1E2 response predicts HCV RNA clearance kinetics and treatment outcome. The combination of anti-E1E2 and IP-10 significantly improved the prediction of treatment response. This warrants further investigation and validation on larger cohorts of patients in the context of new therapeutic strategies.

Infection by hepatitis B virus (HBV) and dietary exposure to aflatoxin B(1) (AFB(1)) are the main risk factors for the development of chronic liver disease and hepatocellular carcinoma (HCC). How these factors cooperate is still largely unknown. AFB(1) activation leads to DNA adduction and mutagenesis, with a specific mutation at codon 249 in TP53 (p.R249S). So far, only limited studies have addressed the effects of AFB(1) on HBV replication. We have analysed the effects of both risk factors on p53 induction during HBV infection in HepaRG, a cell line with hepatocyte-like morphology that metabolizes AFB(1) and supports HBV infection. Exposure to AFB(1) up to 5 µM induced a downregulation of HBV replication after 48 h, as measured by a decrease in viral antigens in the culture medium (HBsAg, HBeAg and large envelope protein) and in intracellular levels of HBV transcripts, DNA and HBsAg. Conversely, HBV infection did not significantly modify AFB(1)-DNA adduct formation or repair as assessed by immunodot-blot assay, and the induction of p53 in response to AFB(1) was similar in infected and non-infected HepaRG cells. Overall, our results suggest that AFB(1) exposure decreases HBV replication, whereas DNA damage by AFB(1) and subsequent p53 induction is not affected by the presence of the virus. Thus, in HepaRG cell line, AFB(1) and HBV do not cooperate to increase DNA damage by AFB(1). Further studies on the effects of both factors in a context of chronicity are needed to better understand synergistic effects.

Unlabelled: HepaRG human liver progenitor cells exhibit morphology and functionality of adult hepatocytes. We investigated the susceptibility of HepaRG hepatocytes to in vitro infection with serum-derived hepatitis C virus (HCV) particles (HCVsp) and the potential neutralizing activity of the E1E2-specific monoclonal antibody (mAb) D32.10. The infection was performed using HCVsp when the cells actively divided at day 3 postplating. HCV RNA, E1E2, and core antigens were quantified in HCV particles recovered from culture supernatants of differentiated cells for up to 66 days. The density distributions of particles were analyzed on iodixanol or sucrose gradients. Electron microscopy (EM) and immune-EM studies were performed for ultrastructural analysis of cells and localization of HCV E1E2 proteins in thin sections. HCV infection of HepaRG cells was documented by increasing production of E1E2-core-RNA(+) HCV particles from day 21 to day 63. Infectious particles sedimented between 1.06 and 1.12 g/mL in iodixanol gradients. E1E2 and core antigens were expressed in 50% of HCV-infected cells at day 31. The D32.10 mAb strongly inhibited HCV RNA production in HepaRG culture supernatants. Infected HepaRG cells frozen at day 56 were reseeded at low density. After only 1-3 subcultures and induction of a cell differentiation process the HepaRG cells produced high titer HCV RNA and thus showed to be sustainably infected. Apolipoprotein B-associated empty E1E2 and complete HCV particles were secreted. Characteristic virus-induced intracellular membrane changes and E1E2 protein-association to vesicles were observed., Conclusion: HepaRG progenitor cells permit HCVsp infection. Differentiated HepaRG cells support long-term production of infectious lipoprotein-associated enveloped HCV particles. The E1E2-specific D32.10 mAb neutralizes the infection and this cellular model could be used as a surrogate infection system for the screening of entry inhibitors., (Copyright © 2011 American Association for the Study of Liver Diseases.)

Background & Aims: Fibrosis progression in patients with chronic hepatitis C (CHC) is highly variable. A Cirrhosis Risk Score (CRS) based on seven genetic variants has been recently developed for identifying patients at risk for cirrhosis. The objective of this study was to assess the role of the CRS for the early prediction of fibrosis progression in CHC patients with mild liver fibrosis. In addition, we evaluated the potential benefit, for prediction accuracy, of a recently described non-invasive fibrosis staging assay, the Enhanced Liver Fibrosis (ELF) test., Methods: Two separate cohorts of HCV patients (Brussels, Belgium/Hannover, Germany) were retrospectively analyzed. Only patients with a fibrosis Ishak or METAVIR score of F0-F1 at baseline were included. Patients were classified as progressors if they showed an increase ≥2 fibrosis stages at the second histological evaluation after a follow-up ≥5years. The CRS was calculated locally. Genotyping was performed by PCR and oligonucleotide ligation with the resulting signal detected with a Luminex® 200TM and computer analysis., Results: In Brussels, 12/25 patients progressed (48%); similarly in Hannover, 16/31 (52%) patients progressed. In both sample sets, the CRS was significantly associated with fibrosis progression (p=0.050 in Brussels; p=0.018 in Hannover). The ELF test was only a significant predictor in Hannover (p=0.015). In multivariate analysis the CRS remained the only variable associated with fibrosis progression (odds-ratio=2.23, 95%CI 1.21-4.11 p=0.01)., Conclusions: Although conducted on a limited number of patients, this study in two independent centres confirms that the CRS predicts fibrosis progression in initially mild CHC., (Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Unlabelled: Only 20% of patients with chronic hepatitis C (CHC) will develop cirrhosis, and fibrosis progression remains highly unpredictable. A recent genome-wide association study identified a genetic variant in the patatin-like phospholipase-3 (PNPLA3) gene (rs738409 C>G) associated with steatosis that was further demonstrated to influence severity of fibrosis in nonalcoholic fatty liver disease. The aim of this study was to assess the impact of this polymorphism on histological liver damage and response to antiviral therapy in CHC. We recruited 537 Caucasian CHC patients from three European centers (Brussels, Belgium [n = 229]; Hannover, Germany [n = 171]; Lyon, France [n = 137]); these patients were centrally genotyped for the PNPLA3 (rs738409 C>G) polymorphism. We studied the influence of rs738409 and other variants in the PNPLA3 region on steatosis and fibrosis assessed both in a cross-sectional and longitudinal manner. Seven other variants previously associated with fibrosis progression were included. Finally, we explored the impact of rs738409 on response to standard antiviral therapy using the interferon lambda 3 (IL28B) [rs12979860 C>T] variant both as a comparator and as a positive control. After adjustment for age, sex, body mass index, alcohol consumption, and diabetes, rs738409 mutant G allele homozygote carriers remained at higher risk for steatosis (odds ratio [OR] 2.55, 95% confidence interval [CI] 1.08-6.03, P = 0.034), fibrosis (OR 3.13, 95% CI 1.50-6.51, P = 0.002), and fibrosis progression (OR 2.64, 95% CI 1.22-5.67, P = 0.013). Conversely, rs738409 was not independently associated with treatment failure (OR 1.07, 95% CI 0.46-2.49, P = 0.875) and did not influence clinical or biological variables., Conclusion: The PNPLA3 (rs738409 C>G) polymorphism favors steatosis and fibrosis progression in CHC. This polymorphism may represent a valuable genetic predictor and a potential therapeutic target in CHC liver damage., (Copyright © 2011 American Association for the Study of Liver Diseases.)

Background & Aims: We previously reported the frequent overexpression of the FZD7 membrane receptor in hepatocellular carcinoma (HCC) and its role for controlling cancer phenotype. Herein, this study aimed at assessing the anticancer properties of compounds inhibiting FZD7 activity by disrupting its binding with the cytosolic Dishevelled (DVL) adaptator., Methods: We have designed small interfering peptides (RHPDs) that are able to enter within cells and to competitively antagonize the binding of FZD7 to the PDZ domain of DVL. Their anti-neoplastic properties were assessed in vitro on a panel of human HCC cell lines and in vivo on the SV40-TAg transgenic mouse model of HCC., Results: We have shown that RHPDs decrease cell viability via apoptosis depending on their affinity for PDZ, with a therapeutic index between cancerous and non-cancerous cells. RHPD properties were linked to β-catenin degradation and PKCδ activation. In transgenic mice, intra-tumor injection of RHPDs inhibited HCC progression., Conclusions: We have completed a proof-of-concept showing that in vitro and in vivo the pharmacological inhibition of FZD7 displays anti-cancerous properties against HCC. The mechanisms can involve β-catenin and PKCδ modulations. Further studies are warranted to design protocols showing the compatibility with systemic in vivo applications., (Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background: Case-control studies suggested a moderate, but consistent, association of hepatitis C virus (HCV) infection with lymphoid tissue malignancies, especially non-Hodgkin lymphoma (NHL). More limited data suggested that hepatitis B virus (HBV) infection might also be associated with NHL. However, prospective studies on the topic are few., Methods: A nested case-control study was conducted in eight countries participating in the EPIC prospective study. Seven hundred thirty-nine incident cases of NHL, 238 multiple myeloma (MM), and 46 Hodgkin lymphoma (HL) were matched with 2,028 controls. Seropositivity to anti-HCV, anti-HBc, and HBsAg was evaluated and conditional logistic regression was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) for NHL, MM, or HL, and their combination., Results: Anti-HCV seropositivity among controls in different countries ranged from 0% to 5.3%; HBsAg from 0% to 2.7%; and anti-HBc from 1.9% to 45.9%. Similar nonsignificant associations were found with seropositivity to HBsAg for NHL (OR = 1.78; 95% CI: 0.78-4.04), MM (OR = 4.00; 95% CI: 1.00-16.0), and HL (OR = 2.00; 95% CI: 0.13-32.0). The association between HBsAg and the combination of NHL, MM, and HL (OR = 2.21; 95% CI: 1.12-4.33) was similar for cancer diagnosed less than 3 and 3 or more years after blood collection. No significant association was found between anti-HCV and NHL, MM, or HL risk, but the corresponding CIs were very broad., Conclusions: Chronic HBV infection may increase the risk of lymphoid malignancies among healthy European volunteers., Impact: Treatment directed at control of HBV infection should be evaluated in HBsAg-seropositive patients with lymphoid tissue malignancies., (©2011 AACR.)

Objective: To determine whether liver-derived hepatitis C RNA-containing particles express the E1E2 discontinuous antigenic determinant defined by unique monoclonal antibody (mAb) D32.10 which recognizes three highly conserved segments in E1 (aa297-306) and E2 (aa480-494 and aa613-621) envelope glycoproteins., Methods: Human hepatocytes were isolated from HCV-infected cirrhotic explanted livers. The liver-derived hepatitis C virus (HCV) particles released from three distinct cultures (genotypes 1b and 2b) were characterized. HCV RNA+ was quantified by real-time RT-PCR. The E1E2 antigenic activity was assessed by indirect ELISA and immunoblotting using D32.10. The density distributions of HCV RNA and E1E2 antigen were determined by isopycnic sucrose density gradients. HCV E1E2, E2 and core antigens were detected in the cells by immunochemical staining., Results: Liver-derived HCV particles contained HCV RNA (10⁶-10⁷ copies/mg of protein) and core proteins and expressed the E1E2/D32.10 epitope. HCV RNA and E1E2 cosedimented between 1.15 and 1.25 g/ml in sucrose gradients. Moreover, the mAb D32.10 detected E1E2 by immunostaining in HCV-infected hepatocytes in parallel with E2 and core antigens., Conclusion: Our results provide evidence that the mAb D32.10 recognizes E1E2 envelope complexes expressed in the cell cytoplasm and on the surface of HCV RNA-containing particles released from short-term cultures of in vivo infected hepatocytes., (Copyright © 2010 S. Karger AG, Basel.)

Unlabelled: The monoclonal antibody (mAb) D32.10 recognizes a discontinuous epitope encompassing three regions E1 (amino acids 297-306), E2A (amino acids 480-494), and E2B (amino acids 613-621) juxtaposed on the surface of serum-derived hepatitis C virus (HCV) particles (HCVsp). The mAb D32.10 inhibits efficiently and specifically the binding of HCVsp to human hepatocytes. Therefore, we investigated the clinical relevance of anti-E1E2A,B response in the serum of patients infected with HCV. To this end, an enzyme-linked immunosorbent assay (ELISA) using synthetic E1-, E2A-, and E2B-derived peptides was used. The ELISA was validated in terms of sensitivity, specificity, and test efficiency. The detection of the anti-E1E2 D32.10 epitope-binding antibodies during natural HCV infection in more than 300 HCV-positive sera demonstrated significantly (P < 0.001) higher prevalence of these antibodies: (1) in patients who spontaneously cured HCV infection (46 of 52, 88.5%) showing high titers (70% ≥ 1/1000) compared to never-treated patients with chronic hepatitis C (7 of 50, 14%) who actively replicated the virus, and (2) in complete responders (20 of 52, 38.5%) who cleared virus following treatment and achieved a sustained viral response compared to nonresponders (4 of 40, 10%). Serum anti-E1E2 antibodies were monitored before, during, and after the current standard-of-care therapy (pegylated interferon plus ribavirin) in responder and nonresponder patients. Optimal cutoff values were assessed by receiver operating characteristic curve analysis. One month prior to therapy initiation, the threshold of 1131 (optical density × 1000) gave 100% and 86% positive and negative predictive values, respectively, for achieving or not achieving a sustained viral response., Conclusion: The anti-E1E2 D32.10 epitope-binding antibodies are associated with control of HCV infection and may represent a new relevant prognostic marker in serum. This unique D32.10 mAb may also have immunotherapeutic potential.

Unlabelled: The development of new anti-hepatitis B virus (HBV) therapies, especially immunotherapeutic approaches, has been limited by the lack of a primate model more accessible than chimpanzees. We have previously demonstrated that sylvanus and cynomolgus macaques are susceptible to in vivo HBV infection after intrahepatic HBV DNA inoculation. In this study, we evaluated the susceptibility of primary macaque hepatocytes (PMHs) to HBV infection with a highly efficient HBV genome-mediated transfer system via a recombinant baculovirus (Bac-HBV). Freshly prepared PMHs, isolated from macaque liver tissue by collagenase perfusion, were transduced with Bac-HBV, and intermediates of replication were followed for 9 days post-transduction. Evidence of HBV replication (hepatitis B surface antigen secretion, viral DNA, RNA, and covalently closed circular DNA) was detected from day 1 to day 9 post-transduction. HBV markers were dose-dependent and still detectable at a multiplicity of infection of 10. Importantly, transduced PMHs secreted all typical forms of HBV particles, as evidenced by a cesium chloride gradient as well as transmission electron microscopy. Furthermore, the Toll-like receptor 9 (TLR9) ligand was used to stimulate freshly prepared macaque peripheral blood mononuclear cells to generate TLR9-induced cytokines. We then demonstrated the antiviral effects of both TLR9-induced cytokines and nucleoside analogue (lamivudine) on HBV replication in transduced PMHs., Conclusion: Baculovirus-mediated genome transfer initiated a full HBV replication cycle in PMHs; thus highlighted both the baculovirus efficiency in crossing the species barrier and macaque susceptibility to HBV infection. Moreover, our results demonstrate the relevance of thus system for antiviral compound evaluations with either nucleoside analogues or inhibitory cytokines. Cynomolgus macaques are readily available, are immunologically closely related to humans, and may therefore represent a promising model for the development of new immunotherapeutic strategies.

HCV particles were isolated from the plasma of chronically infected patients. The virus was analysed by sucrose density gradient centrifugation. The fractions were tested for viral RNA, core antigen and envelope proteins by using a monoclonal antibody directed against the natural E1E2 complex (D32.10). Two populations of particles containing RNA plus core antigen were separated: the first with a density of 1.06-1.08 g/ml did not contain the envelope proteins; the second with a density between 1.17 and 1.21 g/ml expressed both E1 and E2 glycoproteins. Electron microscopy of the enveloped population after immunoprecipitation with D32.10 showed spherical particles with a rather featureless surface and with a diameter around 40 nm. Immuno-gold staining gave evidence that the E1E2 complex was indeed positioned at the surface of these particles.

A new quantitative marker of HCV viremia based on the detection of the core antigen of the virus has recently become commercially available in Europe. The usefulness of this test was examined for the management of patients treated with pegylated interferon/ribavirin. One hundred twenty-eight pegylated interferon/ribavirin treated patients were studied. Serum samples were available at baseline, week 4 and week 12 time-points, respectively. Core antigen was quantified using the trak-C assay (Ortho Clinical Diagnostics, Raritan, NJ). For all genotypes at week 4, the positive and negative predictive values of HCV core antigen were 81.4 and 92.9%, respectively, while at week 12 they were 67.9 and 100%, respectively. These predictive values varied substantially according to viral genotype. Among patients with a negative core antigen level (<1.5 pg/ml) at week 12, only 33% of those who were positive at week 4 achieved a sustained virological response whereas 85% of those who were already negative did (P < 0.001). The core antigen assay may be used at week 4 and week 12 to distinguish patients who will achieve a sustained virological response from those who will relapse/breakthrough. This assay is a new reliable alternative for early prediction of virological non-response in patients treated with pegylated interferon/ribavirin., (Copyright 2004 Wiley-Liss, Inc.)

To study the correlation between total Hepatitis C virus (HCV) Core antigen (Ag) and HCV-RNA, and to assess the proficiency of HCV Core Ag testing in monitoring and predicting virologic response during and after pegylated interferon (PEG-IFN) and ribavirin combination therapy. A total of 307 samples from treated and untreated patients were used to assess the correlation between the total HCV Core Ag test and quantitative HCV-RNA assays (Superquant, and Quantiplex branched DNA 2.0 assay). Twenty-four patients received combination therapy for 48 weeks. Blood samples were collected at day 0, and week 2, 4, 12, 24, 48 and 72 for virologic evaluation. A linear relation exists between total HCV Core Ag and HCV-RNA levels. At 3 months the positive predictive value (PPV) of response to therapy was 100% with either HCV Core Ag or HCV-RNA. For HCV Core Ag the negative predictive value (NPV) was 100% whereas for HCV-RNA the NPV was 80% (P > 0.05). At month 1, the PPV was 95% and 100% when determined by HCV Core Ag and HCV-RNA, respectively. The NPV value was 100% for HCV Core Ag and 33% for HCV-RNA (P = 0.005). HCV Core Ag quantification could be useful in clinical practice to predict a sustained virological response early during therapy (4 weeks), reaching an optimal performance at month 3. The determination of total HCV Core Ag levels in serum, constitutes an accurate and reliable alternative to HCV-RNA for monitoring and predicting treatment outcome in patients receiving PEG-IFN/Ribavirin combination therapy.

Background: Our aim was to evaluate the anti-HBV activity of a novel L-nucleoside analog, 2',3'-dideoxy-2',3'-didehydro-beta-L-5-fluorocytidine (beta-L-Fd4C), in study models of HBV infection., Method: Its mechanism of action was evaluated on the in vitro expressed duck HBV (DHBV) reverse transcriptase and in primary hepatocyte cultures of duck and human origin. The capacity of antiviral therapy to clear viral infection was analyzed in vivo in the duck and woodchuck models., Results: beta-L-Fd4C-TP exhibited a more potent inhibitory effect on the RT activity of the DHBV polymerase than other cytidine analogs (lamivudine-TP, ddC-TP, beta-L-FddC-TP). In primary duck hepatocyte cultures, beta-L-Fd4C exhibited a long-lasting inhibitory effect on viral DNA synthesis but could not clear viral cccDNA. In vivo treatment with beta-L-Fd4C in infected ducklings and woodchucks, induced a greater suppression of viremia and intrahepatic viral DNA synthesis than with lamivudine. However, covalently closed circular DNA persistence explained the relapse of viral replication after treatment withdrawal. Viral spread was strongly reduced in the case of early therapeutical intervention, but the number of infected cells did not decline when therapy was started during chronic infection. Liver histology analysis showed a decrease in the inflammatory activity of chronic hepatitis while no ultrastructural modification of liver cells was observed in electron microscopy studies. Furthermore, in human primary hepatocyte cultures, beta-L-Fd4C induced a significant inhibition of HBV DNA synthesis., Conclusion: beta-L-Fd4C is a potent inhibitor of hepadnavirus RT and inhibits viral DNA synthesis in hepatocytes both in vitro and in vivo. These experimental studies allowed as to show that beta-L-Fd4C is a promising anti-HBV agent. Combination therapy should be evaluated to eradicate viral infection., (Copyright 2002 Blackwell Publishing Asia Pty Ltd)

Hepatitis C virus (HCV) is of major social, medical and economic importance. The prevalence of HCV is approximatively 1% in most developed countries, and much higher in developing countries. HCV infection is the second major cause, after hepatitis B virus infection, for the generation of chronic liver disease and hepatocellular carcinoma. To date, the only reliable model for the study of HCV infection is the chimpanzee. Indeed, there is no robust in vitro infection system, yet. There is thus an urgent need for such an in vitro infection system in order to evaluate therapeutic agents. Here, a process is provided for infecting hepatocyte cell lines with hepatitis C virus in vitro. It is strongly suggested that cell-bound lipoproteins are playing a crucial role during the infection process. In order to obtain a robust infection, the cell-bound lipoproteins have first to be removed from their cellular receptor prior to the addition of viral inocula originating from human sera, the latter being made originally of a virus-lipoprotein complex.

Background/aims: An interaction between human schistosomiasis and viral hepatitis B has often been suggested, but never established. The experimental investigation has been hampered by the lack of a suitable model. Only woodchucks are susceptible to both Schistosoma mansoni and a B-like hepatitis virus (WHV) infections. This study explores the relevance of this unique model regarding hepatitis/schistosomiasis interactions., Methods: Woodchucks (Marmota monax and Marmota marmota) were infected with: (a), S. mansoni; (b), WHV; or (c), both S. mansoni and WHV., Results: Following the experimental parasitic infection of woodchucks, with or without WHV, schistosomiasis presented a peculiar and severe course in early infection, involving mostly the intestines. Subsequently, the intestinal and hepatic lesions underwent considerable modulation and the periovular granulomas decreased in size and number, while the parasitic infection tended to self-cure within the 9 months following infection. Nine woodchucks inoculated with the hepatitis virus alone presented with several degrees of acute and chronic hepatitis, with one of them dying of hepatocarcinoma 1 year after inoculation. Four woodchucks with concomitant viral and schistosome infections presented with a simple additive pattern of lesions, without any evidence of modification or aggravation of either one of the two infections. Similarly, no significant impact of schistosomiasis on WHV serum markers could be seen., Conclusions: Schistosomiasis and viral hepatitis in woodchucks run parallel courses, with neither apparent special histological features derived from the association of the two conditions, nor modulation of WHV replication. Schistosomiasis itself, however, was observed to run a peculiar course in the woodchuck. The present data are important for consideration in further experiments exploring the interplay between schistosomiasis and viral hepatitis induced liver damage in this unique experimental host.

Primary human hepatocytes were used to develop a culture model for in vitro propagation of hepatitis C virus (HCV). Production of positive- strand full-length viral RNA in cells and culture supernatants was monitored by PCR methods targeting three regions of the viral genome: the 5' NCR, the 3' X-tail and the envelope glycoprotein E2. De novo synthesis of negative-strand RNA was also demonstrated. Evidence for a gradual increase in viral components over a 3 month period was obtained by two quantitative assays: one for evaluation of genomic titre (quantitative PCR) and one for detection of the core antigen. Production of infectious viral particles was indicated by passage of infection to naive hepatocyte cultures. Reproducibility of the experiments was assessed using cultures from three liver donors and eleven sera. Neither the genotype, nor the genomic titre, nor the anti-HCV antibody content, were reliable predictive factors of serum infectivity, while the liver donor appeared to play a role in the establishment of HCV replication. Quasispecies present in hepatocyte cultures established from three different liver donors were analysed by sequencing hypervariable region 1 of the E2 protein. In all three cases, the complexity of viral quasispecies decreased after in vitro infection, but the major sequences recovered were different. These data strongly suggest that human primary hepatocytes are a valuable model for study of persistent and complete HCV replication in vitro and for identification of the factors (viral and/or cellular) associated with successful infection.

Background: A group of 290 transfusion recipients enrolled in a prospective study of posttransfusion hepatitis was studied to determine the possibility of previously unrecognized hepatitis C virus (HCV) transmission., Study Design and Methods: Before and after transfusion, blood specimens that were negative in first-generation enzyme immunoassay (EIA) were tested by current commercial EIAs, several single-antigen research EIAs, and supplemental tests., Results: Current second- and third-generation EIAs identified five subjects (1.7% of total) who had chronic hepatitis C before transfusion. Twenty additional sera had some reactivity with research EIAs. However, those results were the same before and after transfusion (n = 7), had reverted to partially reactive or nonreactive (n = 8), or could not be confirmed by serologic tests or polymerase chain reaction in follow-up specimens (n = 5)., Conclusions: Transient or restricted reactivity to HCV antigens measured by more sensitive research EIAs does not seem to correspond to recent HCV transmission by transfusion. Whether such reactivity could reflect remote HCV infection, with the potential for chronic or intermittent viremia, remains to be determined.

Aims/methods: PLC/PRF/5 is a continuous human hepatocarcinoma cell line whose genome contains integrated HBV DNA and which secretes two of the hepatitis B virus envelope proteins (HBs and PreS2). This line is also susceptible to infection by hepatitis A virus and was therefore used to compare the effects of interferon on protein synthesis of these two viruses and to assess the interactions which occur between them during infection., Results: Results showed that recombinant interferon alpha 2-a inhibited the expression of the two hepatitis B virus envelope antigens (HBs and PreS2) and of the only hepatitis A virus antigen in a dose-dependent fashion. Comparison of the effect of interferon on antigenic protein production of these two viruses, showed stronger inhibition of hepatitis A virus capsid antigen than of hepatitis B virus envelope antigens. Infection with hepatitis A virus also downregulates the expression of the two hepatitis B virus proteins., Conclusions: Considering the absence of cytotoxic effects from the doses used, this study confirms the relevance of this cellular model for the study of antiviral cytokines in vitro. It also provides a further rationale for the clinical evaluation of the therapeutic potential of interferons in severe hepatitis cases due either to hepatitis A virus alone or to superinfection of hepatitis B virus carriers by hepatitis A virus.

Objectives and Methods: We performed a prospective study to determine the clinical and virological significance of pre-S antigen detection in serum samples from patients with chronic hepatitis B virus infection. Four hundred thirty seven consecutive serum samples from 116 patients were tested for the presence of both pre-S1 and pre-S2 antigens by radioimmunoassay using specific monoclonal antibodies., Results: The pre-S1 antigen/HBs antigen ratio, gave an estimation of the number of pre-S1 epitopes expressed on the surface of circulating viral particles, and was positively correlated with the intensity of viral replication intensity (P < 0.05). Moreover, the pre-S1 antigen/HBs antigen ratio was significantly higher in patients suffering from chronic hepatitis associated with viral replication (24% +/- 13); in anti-HBe positive patients, the pre-S1 antigen/HBs antigen ratio was higher in patients replicating a HBe antigen minus variant of the hepatitis B virus and suffering from chronic hepatitis (17% +/- 9) than in asymptomatic HBs antigen carriers (5% +/- 6) (P < 0.05). The pre-S2 antigen/HBs antigen ratio was not correlated with the level of viral replication or with the patient's clinical status., Conclusion: This study confirms that pre-S1 antigen detection is a reliable marker of hepatitis B virus replication which can be easily performed in chronically infected patients. This assay is especially useful in identifying anti-HBe positive carriers who replicate a minus pre-core mutant and could benefit from antiviral therapy.

The treatment of hepatitis C virus (HCV) infections is essentially known for chronic hepatitis C and is mainly restricted to interferon alpha. Initial trials have indicated that around 50% of the patients with chronic hepatitis C respond to alpha interferon (administered at 3 MU, thrice weekly, during 6 months) by normalizing alanine aminotransferase at the end of therapy, although 25% were found to relapse after therapy. Normalization of biochemical tests is associated with an improvement in liver histological features and with decrease or loss of HCV from serum and liver. Response to therapy is influenced by both duration and dose levels of the treatment. Following studies which showed that higher doses and longer duration were more effective than the current recommendations of 3MU thrice weekly for 6 months have recently conducted to the recent recommendation of a 12 month course of therapy using 3 MU. The outcome of therapy was also shown to be negatively influenced by longer duration of disease and presence of cirrhosis. More recently, the critical role of virological markers has been emphasized with a lower rate of response in patients infected with the genotype 1 b and a high viral load. However, these factors do not certainly predict for an individual patient the quality of the response. Therapeutical goals are: to precisely define pre-treatment scores of response able to give each individual patient the optimal treatment regimen, non responders to interferon alpha and patients with a transient benefit of therapy. Thus, development of new treatments appears critical among which those with other interferons and above all the bitherapy using ribavirin and interferon alpha which may have a marked increase in efficacy in comparison with interferon alpha used as monotherapy.

We have previously identified the two major hepatitis C virus (HCV) genotypes prevalent in France (type I and type II). We report here the identification and partial characterization of a new HCV genotype with a highly divergent 5' noncoding (NC) region and a structural protein region. This genotype showed only 93-94% sequence identity with either type I or type II HCV in the 5' NC region. Sequence analysis of the structural protein region revealed extremely low sequence homology with all the four major HCV genotypes: 86-89% for the core protein and 56-69% for the envelope protein. However, further analysis revealed that this new genotype was very similar to the genotype 3a described most recently. Screening of 150 clinical samples with genotype-specific oligoprobes revealed prevalence of this genotype in 12% of the French samples with a significant association with drug addiction and a good response to interferon therapy. These results may have implications for the diagnosis of HCV infection and the design of HCV vaccines.

The synthesis of new potential PFA-BCH-189 conjugate analogues is described and their molecular structure clearly identified through NMR and mass spectra techniques. The anti-HIV-1 activity was determined according to the inhibition of syncytium formation in MT-4 cells, while the anti-HBV activity was determined in infected duck hepatocytes. Both antiviral activities of the PFA-BCH-189 conjugates were much lower than those of the parent BCH-189 (2',3'-dideoxy-3'-thiacytidine) (1). Whereas a prodrug effect, following cleavage and release of the free BCH-189 and PFA, cannot be ruled out, poor cellular permeation of the drug seems to be the most likely reason for the reduced activities against HIV and DHBV. The presence of the PFA moiety appears to be detrimental for both the anti-HIV and anti-DHBV activity of PFA-BCH-189 cases.

Initial trials indicated that around 50% of patients respond to recombinant alpha interferon by normalizing alanine aminotransferase (ALT) at the end of therapy and that half of these relapsed within 6 months following cessation of treatment. Both dose and duration of treatment are critical in the response to therapy. Higher doses and longer duration have been suggested to be more effective than the current recommendations of 3 MUI thrice weekly for 6 months based on results of these initial studies which used ALT and histological scores to evaluate the efficacy of interferon therapy. Following studies using virological markers have shown that improvements in clinical features of disease are associated with decrease or loss of hepatitis C virus (HCV) from serum and liver. The heterogeneity of the response rates between clinical centers using identical protocol emphasizes that the selection of the patients treated was as important for the outcome that the therapy regimen itself with better responses in cases without cirrhosis and with low levels of HCV RNA. Furthermore, the genotype of HCV seems to be also critical for the response rate. Virological evaluations appears therefore crucial to assess not only HCV infection but also for the indication and monitoring of therapy.

The relation between preS1 antigen/antibody system and different phases of hepatitis B virus infection were studied in 425 serum samples from 50 hepatitis B patients before, during and after antiviral therapy using interferon alone or in combination with corticosteroid withdrawal. A typical profile of self-limited acute hepatitis B was characterized by hepatitis B virus-DNA clearance using polymerase chain reaction and preS antigens using monoclonal radioimmunoassays and by antibody responses to the middle and the large HBs proteins (gp33/gp36 and p39/gp42) using immunoblotting quantitative analysis. After interferon therapy in patients with protracted hepatitis B, complete eradication of the virus was observed in 70% of patients, and antibody response directed to middle HBs and large HBs proteins could be induced. Conversely, this antibody response was never detected in follow-up studies of chronic active hepatitis B patients who responded well to antiviral therapy and lost HBs, preS2 and preS1 antigens. Most interesting, in 50% of patients with HBeAg-positive chronic active hepatitis B who received combination therapy and in 67% of patients with anti-HBe-positive chronic active hepatitis B given interferon alone, the elevated serum preS1Ag/HBsAg ratio persisted after treatment was discontinued and even increased until the end of the follow-up when hepatitis B virus DNA was undetectable in serum by the conventional hybridization technique. This rebound of preS1 antigen expression following antiviral therapy in patients with chronic active hepatitis B may indicate virus persistence, suggesting the possibility of relapse through wild-type hepatitis B virus or the emergence of hepatitis B virus mutants.

Duck hepatitis B virus (DHBV) was found in the serum of 1-6% of Pekin ducklings originated from French commercial flocks. The viremia was followed in the serum of 5 ducklings over a span of 3 mth by monitoring the levels of DHBV DNA and the endogenous DNA polymerase (DNAp) activity. The DHBV DNA levels in serum were quantified either by the DNA dot hybridization technique including counting of retained radioactivity, or by successive dilutions of each serum sample followed by DNA hybridization. The counting of the retained radioactivity was plotted on a curve and its evolution compared with that of viral DNAp activity. DHBV DNA levels in serum, estimated by both methods paralleled those of the DNAp activity, which peaked at the 4th or 5th week posthatch to decrease and fluctuate thereafter. Occasional discordance between DHBV DNA levels and the endogenous DNAp activity was observed, which could be correlated with the degree of repair of the single stranded gap of serum DHBV DNA. Parallel follow up studies comparing quantitative estimations of serum viral DNA and of DNAp activity, as presented here, may provide some clues for the understanding of the mechanisms involved in the establishment of the HEPA DNA virus carrier state. Such comparative studies may also be crucial for optimal monitoring of antiviral drugs in both human clinical trials and animal experimental studies.