Direct-acting antivirals for the treatment of hepatitis C virus infection: optimizing current IFN-free treatment and future perspectives.

There has been a revolution in the treatment of chronic hepatitis C. Several oral regimens combining direct-acting antivirals (DAAs) from different families [NS5B nucleotide inhibitors, NS5B non-nucleoside inhibitors, NS5A replication complex inhibitors and NS3/4A protease inhibitors (PI)] have been developed. These regimens result in an increase in sustained virological response (SVR) rates to above 90% and reduce the duration of treatment to 12 weeks or less. As of 2016 several regimens will be approved with additive potencies, without cross-resistance and with a good safety profile. Remaining issues will include increasing screening and access to care so that HCV may become the first chronic viral infection eradicated worldwide. This review summarizes results obtained with oral DAA combinations that have been approved and/or have completed phase 3 clinical trials for HCV infection and discusses future perspectives.

Changes in autophagic response in patients with chronic hepatitis C virus infection.

Autophagy is a regulated process that can be involved in the elimination of intracellular microorganisms and in antigen presentation. Some in vitro studies have shown an altered autophagic response in hepatitis C virus infected hepatocytes. The present study aimed at evaluating the autophagic process in the liver of chronic hepatitis C (CHC) patients. Fifty-six CHC patients and 47 control patients (8 with nonalcoholic steatohepatitis or alcoholic liver disease, 18 with chronic heptatitis B virus infection, and 21 with no or mild liver abnormalities at histological examination) were included. Autophagy was assessed by means of electron microscopy and microtubule-associated protein light chain 3 immunoblotting. Using light chain 3 immunoblotting, the form present on autophagic vesicle (light chain 3-II) was significantly higher in CHC patients than in controls (P < 0.05). Using quantitative electron microscopy analysis, the median number of autophagic vesicles observed in hepatocytes from CHC patients was sixfold higher than in overall controls (P < 0.001). In contrast, there was no difference between CHC patients and controls in the number of mature lysosomes with electron-dense contents arguing in favor of a lack of fusion between autophagosome and lysosome. Neither genotype nor viral load influenced the autophagy level. In conclusion, autophagy is altered in hepatocytes from CHC patients, likely due to a blockade of the last step of the autophagic process.

Insulin resistance in chronic hepatitis C: association with genotypes 1 and 4, serum HCV RNA level, and liver fibrosis.

BACKGROUND & AIMS: Our study was designed to test the association between insulin resistance (IR) and hepatitis C virus (HCV) genotypes, serum HCV RNA level and liver fibrosis stage in a large prospective cohort of chronic hepatitis C (CHC) patients. METHODS: Six hundred consecutive patients (CHC, n = 500; chronic hepatitis B (CHB), n = 100) were evaluated on the day of liver biopsy. IR (Homeostasis Model for Assessment of Insulin Resistance) and all components of the metabolic syndrome were assessed. By logistic regression, independent factors associated with IR and those associated with significant fibrosis were assessed in nondiabetic and noncirrhotic CHC, respectively. Parameters of IR were compared between hepatitis B and 240 CHC matched by epidemiologic, metabolic, and histologic features. RESULTS: IR was present in 32.4% of the 462 nondiabetic CHC and associated with the metabolic syndrome, genotypes 1 and 4, significant fibrosis, and severe steatosis. IR was diagnosed in 15% of 145 CHC without metabolic syndrome or significant fibrosis, and associated with genotypes 1 and 4, high serum HCV RNA level, and moderate-severe necroinflammation. Significant fibrosis was present in 51.1% of the 454 noncirrhotic CHC patients and associated with male sex, age >40 years, IR, moderate-severe necroinflammation, and severe steatosis. IR was less frequent in CHB than in matched CHC (5% vs 35%, respectively, P < .001). CONCLUSIONS: IR is a specific feature of CHC, associated with genotypes 1 and 4 and high serum HCV RNA level. Significant fibrosis is associated with IR independent from steatosis.

High predictive value of early viral kinetics in retreatment with peginterferon and ribavirin of chronic hepatitis C patients non-responders to standard combination therapy.

BACKGROUND/AIMS: To evaluate the efficacy of peginterferon alfa-2b and ribavirin in unselected consecutive patients with chronic hepatitis C, treated outside of trials, who were relapsers or non-responders to interferon and ribavirin combination. METHODS: One hundred and fifty-four patients were evaluated. There were 101 non-responders and 53 relapsers to standard combination therapy. Patients were retreated with peginterferon alfa-2b 1.5 microg/kg/wk plus ribavirin 1000-1200 mg/day during 48 weeks. RESULTS: Forty-four patients (28.6%) achieved sustained virological response (SVR). Rapid (week 4) and early (week 12) virological response had high negative predictive values of SVR (94% and 97%, respectively); however positive predictive values were relatively low (52% and 49%, respectively). Relapsers had higher SVR rates (58.5%) than non-responders (13%) p<0.0001. In non-responders, SVR raised to 50% in patients with genotype non-1 and mild or moderate fibrosis. In multivariate analysis, predictors of SVR were: relapse after interferon plus ribavirin combination, mild or moderate fibrosis, genotype non-1 and baseline viral load <2 million copies/ml. CONCLUSIONS: Relapsers to interferon plus ribavirin therapy, and non-responders with genotype non-1 and mild or moderate fibrosis, achieved a relatively high SVR rate following retreatment with peginterferon plus ribavirin. Early viral kinetics had a high negative predictive value of SVR.

Expertise of laboratories in viral load quantification, genotyping, and precore mutant determination for hepatitis B virus in a multicenter study.

A national evaluation study was performed in 14 specialized laboratories with the objective of assessing their capacities to provide (i) hepatitis B virus (HBV) viral loads (VL), (ii) HBV genotypes, and(iii) identification of precore/core mutants. The panel consisted of 12 HBV DNA-positive samples with VLs from 2.8 to 9.1 log(10) copies/ml, different HBV genotypes (A to F), and 3 mutant and 9 wild-type samples at nucleotide 1896. The coefficients of variation of the mean VLs ranged from 2.4% to 10.4% with the Cobas HBV Monitor assay, from 1.8% to 5.5% with the Cobas TaqMan 48, from 1.5 to 26.2% with RealArt HBV PCR, and from 0 to 7% with branched DNA (bDNA). The Cobas Monitor assay underestimated the VLs of genotype F samples, with differences ranging from 1.4 to 2.4 log(10) copies/ml. The accuracies of genotype determinations ranged from 33% to 100%, and those of precore mutant determinations ranged from 25 to 100%. This study showed some drawbacks of two widely used assays: (i) Cobas Monitor has a narrow dynamic range and underestimates genotype F sample VLs and (ii) bDNA shows poor sensitivity and may fail to identify patients with low VLs. With higher performance in terms of analytical sensitivity combined with a larger dynamic range and an ability to quantify the main genotypes equally, real-time PCR methods appear more appropriate for accurate monitoring of HBV DNA quantification. Furthermore, the clinical implications of HBV genotyping and the determination of precore/core mutants need to be clearly stated to justify the standardization of these methods.

Expertise of French laboratories in detection, genotyping, and quantification of hepatitis C virus RNA in serum.

Before initiating new large-scale therapeutic trials for hepatitis C virus (HCV)-infected patients, the French Health Authorities for HCV research decided to organize an evaluation of the expertise of laboratories that could be engaged to undertake molecular biology assays in such trials; 21 experienced laboratories participated in this national evaluation of laboratory expertise, which was performed in two successive rounds. The first round evaluated the laboratories for their abilities to detect HCV RNA in serum, determine genotypes, and quantify HCV RNA loads. The results observed by qualitative assays for HCV RNA detection were 100% sensitivity and 100% specificity for all laboratories. The genotyping results were 100% concordant for 9 laboratories and greater than 90% for 10 laboratories. By contrast, large coefficients of variation were observed for quantitative determination of HCV RNA loads, leading to a second round with standardized quantitative assays only. The dispersion of the results was larger by the AMPLICOR HCV Monitor assay than by the branched-DNA assay (mean coefficients of variation, 57.4 and 16.9%, respectively). In the majority of cases, discrepancies between the results of the two tests were found for samples with high viral loads. These results indicate the usefulness of validating, by controlling for expertise, both the reliabilities of laboratories involved in multicenter work and the standardized assays chosen for use in the evaluation of the biological impacts of new therapies.

Differential expression of perforin and granzyme B in the liver of patients with chronic hepatitis C.

T lymphocytes have been reported to be the predominant inflammatory cells in the liver of patients with chronic hepatitis C. On activation, CD8+ T lymphocytes can exert their cytolytic activity by releasing their granule components, notably perforin and granzyme B. The aim of the present study was to assess whether the granule cytolytic pathway was used by liver-infiltrating CD8+ T lymphocytes. Immunostaining for perforin and granzyme B was performed in 25 patients with chronic hepatitis C, according to the disease activity and their virologic status. Cells stained for perforin and for granzyme B represented 0.15% and 0.10% of the total liver-infiltrating CD8+ T lymphocytes, respectively. Perforin was expressed mainly by activated CD8+ T lymphocytes located in liver lobules. In contrast, granzyme B was expressed mainly by activated CD8+ T lymphocytes located in interface hepatitis and portal tracts. The results were similar in the different groups of patients, whatever the disease activity. In conclusion, this is the first study showing a differential expression of granule components of CD8+ T lymphocytes in the same tissue in vivo. Perforin and granzyme B may be differently expressed by liver-infiltrating CD8+ T lymphocytes, according to their localization in the different specific compartments of the liver, in patients with chronic hepatitis C.