Is genotype 3 of the hepatitis C virus the new villain?

Role of IL-28B genetic variants in HCV-related liver disease severity in patients with different viral genotypes

Reports of the role of host interleukin 28B (IL-28B) genetic variants in liver disease severity in patients with chronic hepatitis C (CHC) have obtained conflicting results. The impact of IL-28B in Asian patients with different viral genotypes remains elusive.We try to elucidate the effect of IL-28B genetic variants in a large Asian cohort with different viral genotypes.The association between the IL-28B rs8099917 genotype and liver fibrosis was investigated in 1288 patients with biopsy-proven CHC.Patients with hepatitis C virus genotype 1 (HCV-1) infection comprised 59.4% of the population. The remaining 40.6% (518 patients) did not have HCV-1 infection. Of the 1084 patients with the IL-28 genotype, 85.6% (928 patients) had the TT genotype. Univariate analysis revealed that, compared to patients without advanced liver fibrosis, patients with advanced liver fibrosis (Metavir fibrosis score 3-4) had an older age, a lower platelet count, a higher α-fetoprotein level, a higher alanine aminotransferase level, a higher incidence of diabetes, and a higher frequency of rs8099917 non-TT genotype carriage.Logistic regression analysis revealed that factors significantly associated with advanced liver fibrosis included age (odds ratio [OR]/95% confidence interval [CI]: 1.023/1.009-1.037, P = .001), diabetes (OR/CI: 1.736/1.187-2.539, P = .004), α-fetoprotein (OR/CI: 1.007/1.002-1.012, P = .009), platelet count (OR/CI: 0.991/0.988-0.993, P < .001), and carriage of the rs8099917 non-TT genotype (OR/CI: 0.585/0.400-0.856, P = .006). When patients were classified by viral genotype, factors that had significant independent associations with advanced liver fibrosis in patients with HCV-1 infection included diabetes (OR/CI: 2.379/1.452-3.896, P = .001), α-fetoprotein (OR/CI: 1.023/1.012-1.035, P < .001), platelet count (OR/CI: 0.99/0.987-0.994, P < .001), and carriage of the rs8099917 non-TT genotype (OR/CI: 0.529/0.328-0.854, P = .009). In patients who had advanced liver fibrosis but not HCV-1 infection, factors that had significant independent associations with advanced liver fibrosis included age (OR/CI: 1.039/1.016-1.063, P = .001) and platelet count (OR/CI: 0.99/0.986-0.995, P < .001); additionally, IL-28B genetic variants were not associated with liver disease severity.Unfavorable IL-28B genetic variants were associated with advanced liver disease. The genetic effect is limited to patients with HCV-1 infection.

Hepatitis C virus: Morphogenesis, infection and therapy

Hepatitis C virus (HCV) is a major cause of liver diseases including liver cirrhosis and hepatocellular carcinoma. Approximately 3% of the world population is infected with HCV. Thus, HCV infection is considered a public healthy challenge. It is worth mentioning, that the HCV prevalence is dependent on the countries with infection rates around 20% in high endemic countries. The review summarizes recent data on HCV molecular biology, the physiopathology of infection (immune-mediated liver damage, liver fibrosis and lipid metabolism), virus diagnostic and treatment. In addition, currently available in vitro, ex vivo and animal models to study the virus life cycle, virus pathogenesis and therapy are described. Understanding of both host and viral factors may in the future lead to creation of new approaches in generation of an efficient therapeutic vaccine.

Lysophosphatidylcholine acyltransferase 1 is downregulated by hepatitis C virus: impact on production of lipo-viro-particles

OBJECTIVE

HCV is intimately linked with the liver lipid metabolism, devoted to the efflux of triacylglycerols stored in lipid droplets (LDs) in the form of triacylglycerol-rich very-low-density lipoproteins (VLDLs): (i) the most infectious HCV particles are those of lowest density due to association with triacylglycerol-rich lipoproteins and (ii) HCV-infected patients frequently develop hepatic steatosis (increased triacylglycerol storage). The recent identification of lysophosphatidylcholine acyltransferase 1 (LPCAT1) as an LD phospholipid-remodelling enzyme prompted us to investigate its role in liver lipid metabolism and HCV infectious cycle.

DESIGN

Huh-7.5.1 cells and primary human hepatocytes (PHHs) were infected with JFH1-HCV. LPCAT1 depletion was achieved by RNA interference. Cells were monitored for LPCAT1 expression, lipid metabolism and HCV production and infectivity. The density of viral particles was assessed by isopycnic ultracentrifugation.

RESULTS

Upon HCV infection, both Huh-7.5.1 cells and PHH had decreased levels of LPCAT1 transcript and protein, consistent with transcriptional downregulation. LPCAT1 depletion in either naive or infected Huh-7.5.1 cells resulted in altered lipid metabolism characterised by LD remodelling, increased triacylglycerol storage and increased secretion of VLDL. In infected Huh-7.5.1 cells or PHH, LPCAT1 depletion increased production of the viral particles of lowest density and highest infectivity.

CONCLUSIONS

We have identified LPCAT1 as a modulator of liver lipid metabolism downregulated by HCV, which appears as a viral strategy to increase the triacylglycerol content and hence infectivity of viral particles. Targeting this metabolic pathway may represent an attractive therapeutic approach to reduce both the viral titre and hepatic steatosis.

A systematic review and meta-analysis of HCV clearance

While hepatitis C exemplifies the role of host genetics in infectious diseases outcomes, there is no comprehensive overview of polymorphisms influencing spontaneous and/or treatment-induced hepatitis C virus clearance. We performed a systematic review and meta-analysis of host polymorphisms associated with these phenotypes. Literature search was conducted using combinations of keywords in three databases. Studies were reviewed and relevant data systematically extracted for subsequent meta-analyses. Polymorphisms from candidate gene studies were tested in two cohorts of HCV-infected patients with available genomic data. The literature search yielded 8'294 citations, among which 262 studies were selected. In the meta-analysis of 27 HLA studies, the most significant associations with spontaneous hepatitis C virus clearance included DQB1*02, DQB1*03, DRB1*04 and DRB1*11. In the meta-analysis of 16 studies of KIR genes and their HLA-ligands, KIR2DS3 was associated with both spontaneous and treatment-induced clearance, and the HLA-C2 ligand with failure to spontaneously clear the virus. In a pooled analysis of 105 candidate genes and two genome-wide association studies, we observed associations of single nucleotide polymorphisms from nine genes (EIF2AK2, IFNAR2, ITPA, MBL2, MX1, OASL, SPP1, TGFB1, TNK2) with response to interferon-based therapy. Meta-analysis of 141 studies confirmed the association of IFNL3/4 polymorphisms with spontaneous and treatment-induced hepatitis C virus clearance, even in previously underpowered groups, such as hepatitis C virus genotypes 2/3-infected patients. This study may contribute to a better understanding of hepatitis C virus immunopathogenesis and highlights the complex role of host genetics in hepatitis C virus clearance.

Immunogenetic studies of the hepatitis C virus infection in an era of pan-genotype antiviral therapies - Effective treatment is coming

What are the factors that influence human hepatitis C virus (HCV) infection, hepatitis status establishment, and disease progression? Firstly, one has to consider the genetic background of the host and HCV genotypes. The immunogenetic host profile will reflect how each infected individual deals with infection. Secondly, there are environmental factors that drive susceptibility or resistance to certain viral strains. These will dictate (I) the susceptibility to infection; (II) whether or not an infected person will promote viral clearance; (III) the immune response and the response profile to therapy; and (IV) whether and how long it would take to the development of HCV-associated diseases, as well as their severity. Looking at this scenario, this review addresses clinical aspects of HCV infection, following by an update of molecular and cellular features of the immune response against the virus. The evasion mechanisms used by HCV are presented, considering the potential role of exosomes in infection. Genetic factors influencing HCV infection and pathogenesis are the main topics of the article. Shortly, HLAs, MBLs, TLRs, ILs, and IFNLs genes have relevant roles in the susceptibility to HCV infection. In addition, ILs, IFNLs, as well as TLRs genes are important modulators of HCV-associated diseases. The viral aspects that influence HCV infection are presented, followed by a discussion about evolutionary aspects of host and HCV interaction. HCV and HIV infections are close related. Thus, we also present a discussion about HIV/HCV co-infection, focusing on cellular and molecular aspects of this interaction. Pharmacogenetics and treatment of HCV infection are the last topics of this review. The understanding of how the host genetics interacts with viral and environmental factors is crucial for the development of new strategies to prevent HCV infection, even in an era of potential development of pan-genotypic antivirals.

Cardiovascular Manifestations of Hepatitis C Virus

Hepatitis C virus (HCV) infection is a prevalent condition associated with numerous extrahepatic manifestations. Epidemiologic studies have found that HCV is associated with increased cardiovascular morbidity and mortality, in particular with carotid atherosclerosis, cerebrovascular events, and coronary heart disease. The mechanisms involved encompass a chronic systemic inflammatory state, insulin resistance, and a potential, direct infection of the vascular endothelium. Sustained virologic response with interferon-based regimens is associated with reduced cardiovascular events, although this must be validated with newer direct-acting antivirals. This clear association between HCV and cardiovascular events may have significant economical and public health implications.

Hepatitis C Virus-Genotype 3: Update on Current and Emergent Therapeutic Interventions

PURPOSE OF REVIEW

Direct-acting antiviral agents (DAAs) have markedly improved the prognosis of hepatitis C virus (HCV)-genotype 3 (GT3), a highly prevalent infection worldwide. However, in patients with hepatic fibrosis, cirrhosis, or hepatocellular carcinoma (HCC), GT3 infection presents a treatment challenge compared with other genotypes. The dependence of the HCV life cycle on host lipid metabolism suggests the possible utility of targeting host cellular factors for combination anti-HCV therapy. We discuss current and emergent DAA regimens for HCV-GT3 treatment. We then summarize recent research findings on the reliance of HCV entry, replication, and virion assembly on host lipid metabolism.

RECENT FINDINGS

Current HCV treatment guidelines recommend the use of daclatasvir plus sofosbuvir (DCV/SOF) or sofosbuvir plus velpatasvir (SOF/VEL) for the management of GT3 based upon clinical efficacy [≥88% overall sustained virological response (SVR)] and tolerability. Potential future DAA options, such as SOF/VEL co-formulated with GS-9857, also look promising in treating cirrhotic GT3 patients. However, HCV resistance to DAAs will likely continue to impact the therapeutic efficacy of interferon-free treatment regimens. Disruption of HCV entry by targeting required host cellular receptors shows potential in minimizing HCV resistance and broadening therapeutic options for certain subpopulations of GT3 patients. The use of cholesterol biosynthesis and transport inhibitors may also improve health outcomes for GT3 patients when used synergistically with DAAs. Due to the morbidity and mortality associated with HCV-GT3 infection compared to other genotypes, efforts should be made to address current limitations in the therapeutic prevention and management of HCV-GT3 infection.

The Role of Direct-acting Antivirals in the Treatment of Children with Chronic Hepatitis C

In the United States, chronic infection with the hepatitis C virus (HCV) affects an estimated 0.1-2% of the pediatric population, who are consequently at risk for major complications, including cirrhosis, hepatocellular carcinoma, and death. The current standard of treatment for chronic hepatitis C (CHC) in children is pegylated-interferon-alpha (PEG-IFN) in combination with ribavirin. PEG-IFN/ribavirin therapy is approved for children ages 3 and older; however, it is often held from use until adulthood because of its extensive list of potential side effects and high likelihood of causing adverse symptoms. While CHC is usually indolent in children and adolescents, immediately treating and curbing the spread of HCV before adulthood is important, as there can be transmission to other individuals via sexual activity and infected females can later vertically transmit the infection during pregnancy, the latter representing the most common means of transmission for children in the United States. The recent development of direct-acting antivirals has shown promising results in clinical trials for use in children and has dramatically increased the rates of sustained virological response in adults while improving side effect profiles as compared to interferon-based treatments. Given the usually indolent course of CHC in children, significant side effects of the currently-approved PEG-IFN/ribavirin therapy, and likely availability of all-oral interferon-free regimens for children within a few years, deferring treatment in clinically-stable children with CHC in anticipation of upcoming superior treatment modalities may be justified.

Real-world use, effectiveness and safety of anti-viral treatment in chronic hepatitis C genotype 3 infection

BACKGROUND

Treatment of chronic hepatitis C genotype 3 (GT3) is more challenging compared with other genotypes. Since 2014, several new treatment regimens have been approved but sometimes based on limited data.

AIM

To validate the use, effectiveness and safety of anti-viral treatment in chronic hepatitis C genotype 3 infection under real-word conditions.

METHODS

The German Hepatitis C-Registry is a large national non-interventional real-world study for patients with chronic hepatitis C. A total of 1322 GT3 patients were enrolled (211 untreated and 1111 treated patients).

RESULTS

Between February 2014 and September 2015, five different treatment strategies have been used (PegIFN+RBV, PegIFN+RBV+SOF, SOF+RBV, DCV+SOF±RBV, LDV/SOF±RBV). Treatment uptake and use of treatment concepts changed markedly and rapidly during the study influenced by new approvals, guideline recommendations, and label updates. PegIFN-based therapies constantly declined while DCV-based therapies increased with one interruption after the approval of LDV/SOF, which was frequently used until new guidelines recommended not using this combination for GT3. Per-protocol SVR ranged from 80.9% in the PegIFN+RBV group to 96.1% in PegIFN+RBV+SOF treated patients. Treatment-experienced patients with cirrhosis showed a suboptimal SVR of 68% for SOF+RBV but a high SVR of 90-95% for DCV+SOF±RBV. The safety analysis showed more adverse events and a stronger decline of haemoglobin for RBV containing regimens.

CONCLUSIONS

Real-world data can validate the effectiveness and safety for treatment regimens that had previously been approved with limited data, in particular for specific subgroups of patients. The present study demonstrates how rapid new scientific data, new treatment guidelines, new drug approvals and label changes are implemented into routine clinical practice today.

Infection With Hepatitis C Virus Genotype 3 Is an Independent Risk Factor for End-Stage Liver Disease, Hepatocellular Carcinoma, and Liver-Related Death

BACKGROUND & AIMS

Few studies have examined factors associated with disease progression in hepatitis C virus (HCV) infection. We examined the association of 11 risk factors with adverse outcomes in a population-based prospective cohort observational study of Alaska Native/American Indian persons with chronic HCV infection.

METHODS

We collected data from a population-based cohort study of liver-related adverse outcomes of infection in American Indian/Alaska Native persons with chronic HCV living in Alaska, recruited from 1995 through 2012. We calculated adjusted hazard ratios (aHR) and 95% confidence intervals (CIs) for end-stage liver disease (ESLD; presence of ascites, esophageal varices, hepatic encephalopathy, or coagulopathy), hepatocellular carcinoma (HCC), and liver-related death using a Cox proportional hazards model.

RESULTS

We enrolled 1080 participants followed up for 11,171 person-years (mean, 10.3 person-years); 66%, 19%, and 14% were infected with HCV genotypes 1, 2, and 3, respectively. On multivariate analysis, persons infected with HCV genotype 3 had a significantly increased risk of developing all 3 adverse outcomes. Their aHR for ESLD was 2.1 (95% CI, 1.5-3.0), their aHR for HCC was 3.1 (95% CI, 1.4-6.6), and their aHR for liver-related death was 2.4 (95% CI, 1.5-4.0) compared with genotype 1. Heavy alcohol use was an age-adjusted risk factor for ESLD (aHR, 2.2; 95% CI, 1.6-3.2), and liver-related death (aHR, 2.9; 95% CI, 1.8-4.6). Obesity was a risk factor for ESLD (aHR, 1.4; 95% CI, 1.0-1.9), and diabetes was a risk factor for ESLD (aHR, 1.5; 95% CI, 1.1-2.2). Male sex was a risk factor for HCC (aHR, 3.6; 95% CI, 1.6-8.2).

CONCLUSIONS

In a population-based cohort study of American Indian/Alaska Native persons with chronic HCV infection, we found those infected with HCV genotype 3 to be at high risk for ESLD, HCC, and liver-related death.

Week 4 response predicts sustained virological response to all-oral direct-acting antiviral-based therapy in cirrhotic patients with hepatitis C virus genotype 3 infection

OBJECTIVE

The aim of this study was to determine the predictive capacity of response at treatment week (TW) 4 for the achievement of sustained virological response 12 weeks after the scheduled end of therapy date (SVR₁₂) to treatment against hepatitis C virus (HCV) genotype 3 (GT3) infection with all-oral direct-acting antiviral (DAA) -based regimens.

PATIENTS AND METHODS

From a prospective multicohort study, HCV GT3-infected patients who completed a course of currently recommended DAA-based therapy at 33 Spanish hospitals and who had reached the SVR₁₂ evaluation time-point were selected. TW4 HCV-RNA levels were categorized as target-not-detected (TND), below the lower limit of quantification (LLOQ_TD) and ≥LLOQ.

RESULTS

A total of 123 patients were included, 86 (70%) received sofosbuvir/ daclatasvir±ribavirin, 27 (22%) received sofosbuvir/ ledipasvir/ ribavirin and 10 (8.1%) received sofosbuvir/ ribavirin, respectively. In all, 114 (92.7%) of the 123 patients presented SVR₁₂ in an on-treatment approach, but nine (7.3%) patients relapsed, all of them had presented cirrhosis at baseline. In those who achieved TND, LLOQ_TD and ≥LLOQ, SVR₁₂ was observed in 81/83 (98%; 95% CI 91.5%-99.7%), 24/28 (85.7%; 95% CI 67.3%-96%) and 9/12 (75%; 95% CI 42.8%-94.5%), respectively; p_{(linear association)} 0.001. Corresponding numbers for subjects with cirrhosis were: 52/54 (96.3%; 95% CI 87.3%-95.5%), 14/18 (77.8%; 95% CI 52.4%-93.6%) and 7/10 (70%; 95% CI 34.8%-93.3%); p 0.004.

CONCLUSIONS

TW4-response indicates the probability of achieving SVR₁₂ to currently used DAA-based therapy in HCV genotype 3-infected individuals with cirrhosis. This finding may be useful to tailor treatment strategy in this setting.

Silymarin/Silybin and Chronic Liver Disease: A Marriage of Many Years

Silymarin is the extract of Silybum marianum, or milk thistle, and its major active compound is silybin, which has a remarkable biological effect. It is used in different liver disorders, particularly chronic liver diseases, cirrhosis and hepatocellular carcinoma, because of its antioxidant, anti-inflammatory and antifibrotic power. Indeed, the anti-oxidant and anti-inflammatory effect of silymarin is oriented towards the reduction of virus-related liver damages through inflammatory cascade softening and immune system modulation. It also has a direct antiviral effect associated with its intravenous administration in hepatitis C virus infection. With respect to alcohol abuse, silymarin is able to increase cellular vitality and to reduce both lipid peroxidation and cellular necrosis. Furthermore, silymarin/silybin use has important biological effects in non-alcoholic fatty liver disease. These substances antagonize the progression of non-alcoholic fatty liver disease, by intervening in various therapeutic targets: oxidative stress, insulin resistance, liver fat accumulation and mitochondrial dysfunction. Silymarin is also used in liver cirrhosis and hepatocellular carcinoma that represent common end stages of different hepatopathies by modulating different molecular patterns. Therefore, the aim of this review is to examine scientific studies concerning the effects derived from silymarin/silybin use in chronic liver diseases, cirrhosis and hepatocellular carcinoma.

Robust HCV Genotype 3a Infectious Cell Culture System Permits Identification of Escape Variants With Resistance to Sofosbuvir

BACKGROUND & AIMS

Direct-acting antivirals (DAAs) effectively eradicate chronic hepatitis C virus (HCV) infection, although HCV genotype 3a is less responsive to these drugs. We aimed to develop genotype 3a infectious cultures and study the effects of inhibitors of NS5A and NS5B and resistance to sofosbuvir-the only nucleotide analog approved for treatment of chronic HCV infection.

METHODS

The developed HCV genotype 3a full-length genome (DBN3a), with a strain-DBN coding sequence, modified NS5B consensus sequence, pS52 untranslated regions, and coding mutations from a culture-efficient JFH1-based core-NS5A (DBN) recombinant, was transfected into Huh7.5 cells. The efficacy of selected DAAs was determined in dose-response assays, in which the number of HCV-infected cells was measured after incubation with different concentrations of the specific DAA. Long-term culture of infected Huh7.5 cells with increasing concentrations of sofosbuvir was used to promote selection of HCV-resistant variants.

RESULTS

We engineered a DBN3a variant with 17 substitutions (DBN3a_cc) that had replication and propagation kinetics in Huh7.5 cells comparable with prototype J6/JFH1. The adaptive mutations also produced culture-efficient DBN-based recombinants with NS5B from HCV genotype 3a strains S52 and DH11. Compared with genotype 1a, genotype 3a was less sensitive to daclatasvir, ledipasvir, and elbasvir, but equally sensitive to ombitasvir, velpatasvir, beclabuvir, dasabuvir, MK-3682, and sofosbuvir. Exposure of Huh7.5 cells infected with DBN3a to sofosbuvir led to identification of an escape variant with substitutions in NS5B, including the resistance-associated substitution S282T. This variant showed increased infectivity of Huh7.5 cells, compared with DBN3a, and was genetically stable in cell cultures without sofosbuvir. Sofosbuvir, MK-3682, dasabuvir, or combinations of sofosbuvir and ledipasvir or sofosbuvir and velpatasvir had decreased efficacy against infection with the DBN3a sofosbuvir escape variant.

CONCLUSIONS

We developed a system for highly efficient culture of HCV genotype 3a. Genotype 1a has a high genetic barrier to resistance for sofosbuvir, whereas resistance to this DAA can be induced in genotype 3a. We therefore isolated HCV genotype 3a variants with reduced sensitivity to sofosbuvir, with increased fitness and with cross-resistance to other NS5B inhibitors. These findings indicate that sofosbuvir escape variants could compromise the effectiveness of nucleotide analogs against HCV. GenBank accession numbers: KX280712-KX280716.

SOCS3 mRNA expression and polymorphisms as pretreatment predictor of response to HCV genotype 3a IFN-based treatment

Aim

Suppressor of Cytokine Signaling 3 (SOCS3) gene belongs to SOCS family as one of the negative regulators of cytokine signaling and IFN response that function via the JAK-STAT pathway in antiviral response. SOCS3 expression and genetic polymorphism influences the pathogenesis and outcome of antiviral treatment in hepatitis C virus (HCV) infected patients. This study was designed for analysis of SOCS3 gene expression and polymorphism in Pakistani HCV patients.

Methods

This descriptive study was conducted on 250 diagnosed HCV genotype 3a infected subjects. The study population was divided into two major groups on the basis of therapeutic response i.e. sustained virological response (SVR) and non-responders/relapsers (NR). SOCS3 gene mRNA expression analysis was done by using Real time PCR technique, whereas ARMS PCR technique was used for analysis of SOCS3 gene polymorphisms i.e. 8464 A/C (rs12952093), −4874 A/G (rs4969170) and −1383 A/G, (rs4969168).

Results

Gene expression analysis of SOCS3 showed that there was statistically significant increase of 2.275-fold and 3.72-fold in relative gene expression for SVR and NR as compared to normal healthy samples (p < 0.001). The distribution of rs4969168, rs4969170 and rs12952093 genotype frequencies between SVR versus NR group were not statistically significant, only the allelic frequency of rs4969170 was statistically significant (p ≤ 0.0001) with therapeutic response.

Conclusion

The gene expression analysis of SOCS3 showed a clear difference in mRNA expression of SOCS3 as a possible indicator of therapeutic response rather than polymorphism of SOCS3 gene in our studied population.

Diagnostics in hepatitis C: The end of response-guided therapy?

On-treatment hepatitis C virus (HCV) RNA has been used to predict response to interferon (IFN)-based therapy. The concept of response-guided treatment (RGT) was established to determine optimal treatment duration and to early identify patients not responding to futile therapies. RGT helped to improve sustained virologic response (SVR) rates and lower the rates of adverse effects. RGT was of particular importance for telaprevir- and boceprevir-based triple therapies. RGT strategies are dependent on highly sensitive and reproducible HCV RNA quantification. However, different HCV RNA assays are used in routine clinical practice and these differ significantly in their performance characteristics. The development of IFN-free therapies has fundamentally changed the role of on-treatment HCV RNA for SVR prediction. Given the high efficacy and excellent tolerability of IFN-free regimens, the interest in treatment individualization has decreased. However, shorter treatment durations may still be desirable, particularly with respect to the high costs of current IFN-free direct-acting antiviral agents (DAAs). Moreover, some difficult-to-treat patients remain, e.g., those infected with HCV genotype 3 in whom the current standard of care may not always be sufficient to achieve SVR, especially in treatment-experienced patients with cirrhosis. Here, a RGT extension may be feasible. However, current data on the predictive value of on-treatment HCV RNA are limited and have shown conflicting results. As more potent DAAs become available, the role of response prediction may diminish further. Currently, shorter treatment duration is only based on baseline HCV RNA whereas no RGT strategy is recommended for any of the approved DAA regimens available.

The history of hepatitis C virus (HCV): Basic research reveals unique features in phylogeny, evolution and the viral life cycle with new perspectives for epidemic control

The discovery of hepatitis C virus (HCV) in 1989 permitted basic research to unravel critical components of a complex life cycle for this important human pathogen. HCV is a highly divergent group of viruses classified in 7 major genotypes and a great number of subtypes, and circulating in infected individuals as a continuously evolving quasispecies destined to escape host immune responses and applied antivirals. Despite the inability to culture patient viruses directly in the laboratory, efforts to define the infectious genome of HCV resulted in development of experimental recombinant in vivo and in vitro systems, including replicons and infectious cultures in human hepatoma cell lines. And HCV has become a model virus defining new paradigms in virology, immunology and biology. For example, HCV research discovered that a virus could be completely dependent on microRNA for its replication since microRNA-122 is critical for the HCV life cycle. A number of other host molecules critical for HCV entry and replication have been identified. Thus, basic HCV research revealed important molecules for development of host targeting agents (HTA). The identification and characterization of HCV encoded proteins and their functional units contributed to the development of highly effective direct acting antivirals (DAA) against the NS3 protease, NS5A and the NS5B polymerase. In combination, these inhibitors have since 2014 permitted interferon-free therapy with cure rates above 90% among patients with chronic HCV infection; however, viral resistance represents a challenge. Worldwide control of HCV will most likely require the development of a prophylactic vaccine, and numerous candidates have been pursued. Research characterizing features critical for antibody-based virus neutralization and T cell based virus elimination from infected cells is essential for this effort. If the world community promotes an ambitious approach by applying current DAA broadly, continues to develop alternative viral- and host- targeted antivirals to combat resistant variants, and invests in the development of a vaccine, it would be possible to eradicate HCV. This would prevent about 500 thousand deaths annually. However, given the nature of HCV, the millions of new infections annually, a high chronicity rate, and with over 150 million individuals with chronic infection (which are frequently unidentified), this effort remains a major challenge for basic researchers, clinicians and communities.

Getting the Skinny on CD4(+) T Cell Survival in Fatty Livers

Non-alcoholic fatty liver disease is associated with hepatocellular carcinoma. In the March 10 issue of Nature, Greten and colleagues report that this metabolic disruption affects tumor surveillance by depleting CD4+ T helper cells through lipotoxic mechanisms associated with NAFLD.

High antiviral activity of NS5A inhibitor ABT-530 with paritaprevir/ritonavir and ribavirin against hepatitis C virus genotype 3 infection

BACKGROUND & AIMS

ABT-530 is a next-generation hepatitis C virus (HCV) NS5A inhibitor with potent pangenotypic antiviral activity in vitro. Paritaprevir is an NS3/4A protease inhibitor codosed with ritonavir that displays in vitro activity against HCV genotypes 1-4 and 6.

METHODS

Efficacy, pharmacokinetics and safety of ABT-530 with paritaprevir/ritonavir and ribavirin were evaluated in this phase 2, open-label, multicentre study in treatment-naïve non-cirrhotic patients with genotype 3 infection. Ten patients, all genotype 3a, received 120 mg ABT-530 and 150/100 mg paritaprevir/ritonavir once daily with ribavirin for 12 weeks.

RESULTS

Nine (90%) patients achieved a sustained virological response at post-treatment weeks 12 and 24. One patient experienced virological failure at treatment week 6. Sequence analyses for HCV variants in samples from this patient identified A166S in NS3 at baseline and after breakthrough, as well as A30K at baseline and linked S24F+M28K+A30K variants in NS5A after breakthrough. Neither genotype 3 NS3 A166S nor NS5A A30K variant confers any resistance to paritaprevir or ABT-530 respectively. However, genotype 3 NS5A S24F+M28K+A30K-linked variant confers a >5000-fold increase in ABT-530 EC50 relative to that of the wild-type replicon. This patient's ABT-530 exposure was comparable to the cohort, while paritaprevir and ritonavir exposures were the lowest of all patients. No serious or severe adverse events and adverse events leading to early discontinuation were reported.

CONCLUSIONS

Results from this study show that ABT-530 holds promise as part of a direct-acting antiviral treatment regimen for HCV genotype 3 infection.

Impact of HCV genotype on treatment regimens and drug resistance: a snapshot in time

The introduction of highly potent direct-acting antivirals (DAAs) has revolutionized hepatitis C virus treatment. Nevertheless, viral eradication worldwide remains a challenge also in the era of DAA treatment, because of the high associated costs, high numbers of undiagnosed patients, high re-infection rates in some risk groups and suboptimal drug efficacies associated with host and viral factors as well as advanced stages of liver disease. A correct determination of the HCV genotype allows administration of the most appropriate antiviral regimen. Additionally, HCV genetic sequencing improves our understanding of resistance-associated variants, either naturally occurring before treatment, acquired by transmission at HCV infection, or emerging after virological failure. Because treatment response rates, and the prevalence and development of drug resistance variants differ for each DAA regimen and HCV genotype, this review summarizes treatment opportunities per HCV genotype, and focuses on viral genetic sequencing to guide clinical decision making. Although approval of the first pan-genotypic DAA-only regimen is expected soon, HCV genetic sequencing will remain important because when DAA therapies fail, genotyping and resistance testing to select a new active DAA combination will be essential. Copyright © 2016 John Wiley & Sons, Ltd.

Hepatitis C virus relies on lipoproteins for its life cycle

Hepatitis C virus (HCV) infects over 150 million people worldwide. In most cases, HCV infection becomes chronic causing liver disease ranging from fibrosis to cirrhosis and hepatocellular carcinoma. Viral persistence and pathogenesis are due to the ability of HCV to deregulate specific host processes, mainly lipid metabolism and innate immunity. In particular, HCV exploits the lipoprotein machineries for almost all steps of its life cycle. The aim of this review is to summarize current knowledge concerning the interplay between HCV and lipoprotein metabolism. We discuss the role played by members of lipoproteins in HCV entry, replication and virion production.

Significance of hepatitis virus infection in the oncogenic initiation of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related death worldwide. Chronic infection of hepatitis B virus (HBV) and/or hepatitis C virus (HCV) is a major risk factor in the development of the HCC, independently from excessive alcohol abuse and metabolic disease. Since the biology of HBV and HCV is different, their oncogenic effect may go through different mechanisms, direct and/or indirect. Viral hepatitis infection is associated with cellular inflammation, oxidative stress, and DNA damage, that may lead to subsequent hepatic injuries such as chronic hepatitis, fibrosis, cirrhosis, and finally HCC. Direct oncogenic properties of these viruses are related with their genotypic characteristics and the ability of viral proteins to interact with host proteins, thus altering the molecular pathways balance of the cells. In addition, the integration of HBV DNA, especially the gene S and X, in a particular site of the host genome can disrupt chromosomal stability and may activate various oncogenic mechanisms, including those in hematopoietic cells. Recently, several studies also had demonstrated that viral hepatitis could trigger the population of hepatic cancer stem cells. This review summarize available pre-clinical and clinical data in literature regarding oncogenic properties of HBV and HCV in the early initiation of HCC.

The broad assessment of HCV genotypes 1 and 3 antigenic targets reveals limited cross-reactivity with implications for vaccine design

OBJECTIVE

Developing a vaccine that is cross-reactive between HCV genotypes requires data on T cell antigenic targets that extends beyond genotype-1. We characterised T cell immune responses against HCV genotype-3, the most common infecting genotype in the UK and Asia, and assessed within genotype and between genotype cross-reactivity.

DESIGN

T cell targets were identified in 140 subjects with either acute, chronic or spontaneously resolved HCV genotype-3 infection using (1) overlapping peptides and (2) putative human leucocyte antigens (HLA)-class-I wild type and variant epitopes through the prior assessment of polymorphic HCV genomic sites associated with host HLA, in IFNγ-ELISpot assays. CD4+/CD8+ T cell subsets were defined and viral variability at T cell targets was determined through population analysis and viral sequencing. T cell cross-reactivity between genotype-1 and genotype-3 variants was assessed.

RESULTS

In resolved genotype-3 infection, T cells preferentially targeted non-structural proteins at a high magnitude, whereas in chronic disease T cells were absent or skewed to target structural proteins. Additional responses to wild type but not variant HLA predicted peptides were defined. Major sequence viral variability was observed within genotype-3 and between genotypes 1 and 3 HCV at T cell targets in resolved infection and at dominant epitopes, with limited T cell cross-reactivity between viral variants. Overall 41 CD4/CD8+ genotype-3 T cell targets were identified with minimal overlap with those described for HCV genotype-1.

CONCLUSIONS

HCV T cell specificity is distinct between genotypes with limited T cell cross-reactivity in resolved and chronic disease. Therefore, viral regions targeted in natural HCV infection may not serve as attractive targets for a vaccine that aims to protect against multiple HCV genotypes.

Sofosbuvir and Velpatasvir for HCV Genotype 2 and 3 Infection

BACKGROUND

In phase 2 trials, treatment with the combination of the nucleotide polymerase inhibitor sofosbuvir and the NS5A inhibitor velpatasvir resulted in high rates of sustained virologic response in patients chronically infected with hepatitis C virus (HCV) genotype 2 or 3.

METHODS

We conducted two randomized, phase 3, open-label studies involving patients who had received previous treatment for HCV genotype 2 or 3 and those who had not received such treatment, including patients with compensated cirrhosis. In one trial, patients with HCV genotype 2 were randomly assigned in a 1:1 ratio to receive sofosbuvir-velpatasvir, in a once-daily, fixed-dose combination tablet (134 patients), or sofosbuvir plus weight-based ribavirin (132 patients) for 12 weeks. In a second trial, patients with HCV genotype 3 were randomly assigned in a 1:1 ratio to receive sofosbuvir-velpatasvir for 12 weeks (277 patients) or sofosbuvir-ribavirin for 24 weeks (275 patients). The primary end point for the two trials was a sustained virologic response at 12 weeks after the end of therapy.

RESULTS

Among patients with HCV genotype 2, the rate of sustained virologic response in the sofosbuvir-velpatasvir group was 99% (95% confidence interval [CI], 96 to 100), which was superior to the rate of 94% (95% CI, 88 to 97) in the sofosbuvir-ribavirin group (P=0.02). Among patients with HCV genotype 3, the rate of sustained virologic response in the sofosbuvir-velpatasvir group was 95% (95% CI, 92 to 98), which was superior to the rate of 80% (95% CI, 75 to 85) in the sofosbuvir-ribavirin group (P<0.001). The most common adverse events in the two studies were fatigue, headache, nausea, and insomnia.

CONCLUSIONS

Among patients with HCV genotype 2 or 3 with or without previous treatment, including those with compensated cirrhosis, 12 weeks of treatment with sofosbuvir-velpatasvir resulted in rates of sustained virologic response that were superior to those with standard treatment with sofosbuvir-ribavirin. (Funded by Gilead Sciences; ASTRAL-2 ClinicalTrials.gov number, NCT02220998; and ASTRAL-3, NCT02201953.).

Transcriptomic Analysis of Chronic Hepatitis B and C and Liver Cancer Reveals MicroRNA-Mediated Control of Cholesterol Synthesis Programs

Chronic hepatitis B (CHB), chronic hepatitis C (CHC), and associated hepatocellular carcinoma (HCC) are characterized by cholesterol imbalance and dyslipidemia; however, the key regulatory drivers of these phenotypes are incompletely understood. Using gene expression microarrays and high-throughput sequencing of small RNAs, we performed integrative analysis of microRNA (miRNA) and gene expression in nonmalignant and matched cancer tissue samples from human subjects with CHB or CHC and HCC. We also carried out follow-up functional studies of specific miRNAs in a cell-based system. These studies led to four major findings. First, pathways affecting cholesterol homeostasis were among the most significantly overrepresented among genes dysregulated in chronic viral hepatitis and especially in tumor tissue. Second, for each disease state, specific miRNA signatures that included miRNAs not previously associated with chronic viral hepatitis, such as miR-1307 in CHC, were identified. Notably, a few miRNAs, including miR-27 and miR-224, were components of the miRNA signatures of all four disease states: CHB, CHC, CHB-associated HCC, and CHC-associated HCC. Third, using a statistical simulation method (miRHub) applied to the gene expression data, we identified candidate master miRNA regulators of pathways controlling cholesterol homeostasis in chronic viral hepatitis and HCC, including miR-21, miR-27, and miR-33. Last, we validated in human hepatoma cells that both miR-21 and miR-27 significantly repress cholesterol synthesis and that miR-27 does so in part through regulation of the gene that codes for the rate-limiting enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase (HMGCR).

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are phylogenetically unrelated hepatotropic viruses that persistently infect hundreds of millions of people world-wide, often leading to chronic liver disease and hepatocellular carcinoma (HCC). Chronic hepatitis B (CHB), chronic hepatitis C (CHC), and associated HCC often lead to cholesterol imbalance and dyslipidemia. However, the regulatory mechanisms underlying the dysregulation of lipid pathways in these disease states are incompletely understood. MicroRNAs (miRNAs) have emerged as critical modulators of lipid homeostasis. Here we use a blend of genomic, molecular, and biochemical strategies to identify key miRNAs that drive the lipid phenotypes of chronic viral hepatitis and HCC. These findings provide a panoramic view of the miRNA landscape in chronic viral hepatitis, which could contribute to the development of novel and more-effective miRNA-based therapeutic strategies.

HEPATOCELLULAR CARCINOMA IN A NON-CIRRHOTIC PATIENT WITH SUSTAINED VIROLOGICAL RESPONSE AFTER HEPATITIS C TREATMENT

Chronic infection by hepatitis C virus (HCV) is one of the main risk factors for the development of liver cirrhosis and hepatocellular carcinoma. However, the emergence of hepatocellular carcinoma (HCC) in non-cirrhotic HCV patients, especially after sustained virological response (SVR) is an unusual event. Recently, it has been suggested that HCV genotype 3 may have a particular oncogenic mechanism, but the factors involved in these cases as well as the profile of these patients are still not fully understood. Thus, we present the case of a non-cirrhotic fifty-year-old male with HCV infection, genotype 3a, who developed HCC two years after treatment with pegylated-interferon and ribavirin, with SVR, in Brazil.

Sofosbuvir With Velpatasvir in Treatment-Naive Noncirrhotic Patients With Genotype 1 to 6 Hepatitis C Virus Infection: A Randomized Trial

BACKGROUND

Effective, pangenotypic treatments for hepatitis C virus (HCV) infection are needed.

OBJECTIVE

To assess the safety and efficacy of sofosbuvir with velpatasvir in patients infected with HCV genotypes 1 to 6.

DESIGN

Randomized, phase 2, open-label study. (ClinicalTrials.gov: NCT01858766).

SETTING

48 U.S. sites.

PATIENTS

377 treatment-naive noncirrhotic patients. In part A, patients infected with HCV genotypes 1 to 6 were randomly assigned to sofosbuvir, 400 mg, with velpatasvir, 25 or 100 mg, for 12 weeks. In part B, patients with genotype 1 or 2 HCV infection were randomly assigned to sofosbuvir, 400 mg, and velpatasvir, 25 or 100 mg, with or without ribavirin for 8 weeks.

MEASUREMENTS

Sustained virologic response at 12 weeks (SVR12).

RESULTS

In part A, SVR12 rates were 96% (26 of 27) with velpatasvir, 25 mg, and 100% (28 of 28) with velpatasvir, 100 mg, for genotype 1; 93% (25 of 27) in both groups for genotype 3; and 96% (22 of 23) with velpatasvir, 25 mg, and 95% (21 of 22) with velpatasvir, 100 mg, for genotypes 2, 4, 5, and 6. In part B, for genotype 1, SVR12 rates were 87% (26 of 30) with velpatasvir, 25 mg; 83% (25 of 30) with velpatasvir, 25 mg, plus ribavirin; 90% (26 of 29) with velpatasvir, 100 mg; and 81% (25 of 31) with velpatasvir, 100 mg, plus ribavirin. For genotype 2, SVR12 rates were 77% (20 of 26) with velpatasvir, 25 mg; 88% (22 of 25) with velpatasvir, 25 mg, plus ribavirin; 88% (23 of 26) with velpatasvir, 100 mg; and 88% (23 of 26) with velpatasvir, 100 mg, plus ribavirin. Adverse events included fatigue (21%), headache (20%), and nausea (12%). One patient committed suicide.

LIMITATION

The study was open-label, no inferential statistics were planned, and sample sizes were small.

CONCLUSION

Twelve weeks of sofosbuvir, 400 mg, and velpatasvir, 100 mg, was well-tolerated and resulted in high SVR in patients infected with HCV genotypes 1 to 6.

PRIMARY FUNDING SOURCE

Gilead Sciences.

Sofosbuvir Plus Velpatasvir Combination Therapy for Treatment-Experienced Patients With Genotype 1 or 3 Hepatitis C Virus Infection: A Randomized Trial

BACKGROUND

Effective treatment options are needed for patients with genotype 1 or 3 hepatitis C virus (HCV) infection in whom previous therapy has failed.

OBJECTIVE

To assess the efficacy and safety of sofosbuvir plus velpatasvir, with and without ribavirin, in treatment-experienced patients.

DESIGN

Randomized, phase 2, open-label study. (ClinicalTrials.gov: NCT01909804).

SETTING

58 sites in Australia, New Zealand, and the United States.

PATIENTS

Treatment-experienced adults with genotype 3 HCV infection without cirrhosis (cohort 1) and with compensated cirrhosis (cohort 2) and patients with genotype 1 HCV infection that was unsuccessfully treated with a protease inhibitor with peginterferon and ribavirin (50% could have compensated cirrhosis) (cohort 3).

INTERVENTION

All patients received 12 weeks of treatment that included 400 mg of sofosbuvir once daily. Patients in each cohort were randomly assigned to 25 mg of velpatasvir once daily with or without ribavirin or 100 mg of velpatasvir once daily with or without ribavirin.

MEASUREMENTS

Proportion of patients with sustained virologic response at week 12 after treatment (SVR12).

RESULTS

In cohort 1, SVR12 rates were 85% with 25 mg of velpatasvir, 96% with 25 mg of velpatasvir plus ribavirin, 100% with 100 mg of velpatasvir, and 100% with 100 mg of velpatasvir plus ribavirin. In cohort 2, SVR12 rates were 58% with 25 mg of velpatasvir, 84% with 25 mg of velpatasvir plus ribavirin, 88% with 100 mg of velpatasvir, and 96% with 100 mg of velpatasvir plus ribavirin. In cohort 3, SVR12 rates were 100% with 25 mg of velpatasvir, 97% with 25 mg of velpatasvir plus ribavirin, 100% with 100 mg of velpatasvir, and 96% with 100 mg of velpatasvir plus ribavirin. The most common adverse events were headache, fatigue, and nausea.

LIMITATION

Treatment assignments were not blinded, and no inferential statistics were planned.

CONCLUSION

Treatment with 400 mg of sofosbuvir plus 100 mg of velpatasvir for 12 weeks was well-tolerated and highly effective in treatment-experienced patients with genotype 1 or 3 HCV infection.

PRIMARY FUNDING SOURCE

Gilead Sciences.

Hepatitis C virus infection: Are there still specific problems with genotype 3?

Hepatitis C virus (HCV) infection is one of the most common causes of chronic liver disease and the main indication for liver transplantation worldwide. As promising specific treatments have been introduced for genotype 1, clinicians and researchers are now focusing on patients infected by non-genotype 1 HCV, particularly genotype 3. Indeed, in the golden era of direct-acting antiviral drugs, genotype 3 infections are no longer considered as easy to treat and are associated with higher risk of developing severe liver injuries, such as cirrhosis and hepatocellular carcinoma. Moreover, HCV genotype 3 accounts for 40% of all HCV infections in Asia and is the most frequent genotype among HCV-positive injecting drug users in several countries. Here, we review recent data on HCV genotype 3 infection/treatment, including clinical aspects and the underlying genotype-specific molecular mechanisms.

Efficacy of sofosbuvir plus ribavirin with or without peginterferon-alfa in patients with hepatitis C virus genotype 3 infection and treatment-experienced patients with cirrhosis and hepatitis C virus genotype 2 infection

BACKGROUND & AIMS

We conducted an open-label, randomized, phase 3 trial to determine the efficacy and safety of sofosbuvir and ribavirin, with and without peginterferon-alfa, in treatment-experienced patients with cirrhosis and hepatitis C virus (HCV) genotype 2 infection and treatment-naïve or treatment-experienced patients with HCV genotype 3 infection.

METHODS

The study was conducted at 80 sites in Europe, North America, Australia, and New Zealand Patients were randomly assigned (1:1:1) to groups given sofosbuvir and ribavirin for 16 weeks (n = 196); sofosbuvir and ribavirin for 24 weeks (n = 199); or sofosbuvir, peginterferon-alfa, and ribavirin for 12 weeks (n = 197). The primary end point was the percentage of patients with HCV RNA <15 IU/mL 12 weeks after stopping therapy (sustained virologic response [SVR12]). From October 2013 until April 2014, we enrolled and treated 592 patients-48 with genotype 2 HCV and compensated cirrhosis who had not achieved SVR with previous treatments and 544 with genotype 3 HCV (279 treatment-naïve and 265 previously treated). Overall, 219 patients (37%) had compensated cirrhosis. The last post-treatment week 12 patient visit was in January 2015.

RESULTS

Rates of SVR12 among patients with genotype 2 HCV were 87% and 100%, for those receiving 16 and 24 weeks of sofosbuvir and ribavirin, respectively, and 94% for those receiving sofosbuvir, peginterferon, and ribavirin for 12 weeks. Rates of SVR12 among patients with genotype 3 HCV were 71% and 84% in those receiving 16 and 24 weeks of sofosbuvir and ribavirin, respectively, and 93% in those receiving sofosbuvir, peginterferon, and ribavirin. On-treatment virologic failure occurred in 3 patients with HCV genotype 3a receiving sofosbuvir and ribavirin for 24 weeks. The most common adverse events were fatigue, headache, insomnia, and nausea. Overall, 1% of patients discontinued treatment due to adverse events.

CONCLUSIONS

Among patients with genotype 3 HCV infection, including a large proportion of treatment-experienced patients with cirrhosis, the combination of sofosbuvir, peginterferon, and ribavirin for 12 weeks produces high rates of SVR. Treatment-experienced patients with cirrhosis and genotype 2 HCV infection had high rates of SVR in all groups. EudraCT ID 2013-002641-11.

Viral hepatitis: A new HCV cell culture model for the next clinical challenges

Despite advances in hepatitis C treatment, substantial clinical hurdles remain to achieve universal cure and global control of infection. Saeed et al. identified SEC14L2 as a host factor permitting replication of clinical HCV isolates in cell culture, providing a novel system to model infection of patient-derived viruses.

Modulation of host lipid metabolism by hepatitis C virus: Role of new therapies

It is well established that hepatitis C virus (HCV) infection and replication relies on host lipid metabolism. HCV proteins interact and associate with lipid droplets to facilitate virion assembly and production. Besides, circulating infective particles are associated with very low-density lipoprotein. On the other hand, higher serum lipid levels have been associated with sustained viral response to pegylated interferon and ribavirin therapy in chronic HCV infection, suggesting a relevant role in viral clearance for host proteins. Host and viral genetic factors play an essential role in chronic infection. Lipid metabolism is hijacked by viral infection and could determine the success of viral replication. Recently development of direct acting antiviral agents has shown a very high efficacy (> 90%) in sustained viral response rates even for cirrhotic patients and most of the viral genotypes. HCV RNA clearance induced by Sofosbuvir has been associated with an increased concentration and size of the low-density lipoprotein particles. In this review, host genetic factors, viral factors and the interaction between them will be depicted to clarify the major issues involved in viral infection and lipid metabolism.

Alisporivir plus ribavirin, interferon free or in combination with pegylated interferon, for hepatitis C virus genotype 2 or 3 infection

Alisporivir is a cyclophilin inhibitor with pan-genotypic anti-hepatitis C virus (HCV) activity and a high barrier to viral resistance. The VITAL-1 study assessed alisporivir as interferon (IFN)-free therapy in treatment-naïve patients infected with HCV genotype 2 or 3. Three hundred forty patients without cirrhosis were randomized to: arm 1, alisporivir (ALV) 1,000 mg once-daily (QD); arm 2, ALV 600 mg QD and ribavirin (RBV); arm 3, ALV 800 mg QD and RBV; arm 4, ALV 600 mg QD and pegylated IFN (Peg-IFN); or arm 5, Peg-IFN and RBV. Patients receiving IFN-free ALV regimens who achieved rapid virological response (RVR) continued the same treatment throughout, whereas those with detectable HCV RNA at week 4 received ALV, RBV, and Peg-IFN from weeks 6 to 24. Overall, 300 patients received ALV-based regimens. In arm 1 to arm 4, the intent-to-treat rates of sustained virological response (SVR) 24 weeks after treatment (SVR24) were from 80% to 85%, compared with 58% (n = 23 of 40) with Peg-IFN/RBV. Per-protocol analysis showed higher SVR24 rates in patients who received ALV/RBV, IFN-free after RVR (92%; n = 56 of 61) than with ALV alone after RVR (72%; n = 13 of 18) or with Peg-IFN/RBV (70%; n = 23 of 33). Both RVRs and SVRs to ALV IFN-free regimens were numerically higher in genotype 3- than in genotype 2-infected patients. Viral breakthrough was infrequent (3%; n = 7 of 258). IFN-free ALV treatment showed markedly better safety/tolerability than IFN-containing regimens.

CONCLUSIONS

ALV plus RBV represents an effective IFN-free option for a proportion of patients with HCV genotype 2 or 3 infections, with high SVR rates for patients with early viral clearance. Further investigations of ALV in IFN-free combination regimens with direct-acting antiviral drugs deserve exploration in future trials.

HCV genotype 3 and squamous cell carcinoma antigen (SCCA)-IgM are independently associated with histological features of NASH in HCV-infected patients

Nonalcoholic steatohepatitis (NASH) enhances the risk of progressive liver disease. In chronic hepatitis C (CHC), liver steatosis is frequent, especially in genotype 3, but its clinical significance is debated. As squamous cell carcinoma antigen (SCCA)-IgM has been associated with advanced liver disease and risk of tumour development, we evaluated its occurrence in CHC and the possible relation with NASH at liver biopsy. Using a validated ELISA, serum SCCA-IgM was measured in 91 patients with CHC at the time of liver biopsy performed before antiviral treatment, at the end of treatment and 6 months thereafter, and in 93 HCV-negative patients with histological diagnosis of nonalcoholic fatty liver disease, as controls. SCCA-IgM was detected in 33% of CHC patients and in 4% of controls. This biomarker was found more elevated in CHC patients with histological NASH, and at multivariate analysis, SCCA-IgM and HCV genotype 3 were independently associated with NASH [OR (95% CI): 6.94 (1.21-40) and 27.02 (4.44-166.6)]. As predictors of NASH, HCV genotype 3 and SCCA-IgM had a specificity and a sensitivity of 97% and 44%, and of 95% and 27%, respectively. PPV and NPV were 80% and 86% for HCV genotype 3 vs 73% and 72% for SCCA-IgM. In patients with sustained virologic response to therapy, SCCA-IgM levels decreased significantly, while these remained unchanged in nonresponders. In conclusion, SCCA-IgM is detectable in one-third of patients with CHC and significantly correlates with histological NASH.

Impact of common risk factors of fibrosis progression in chronic hepatitis C

OBJECTIVE

The natural course of chronic hepatitis C varies widely. To improve the profiling of patients at risk of developing advanced liver disease, we assessed the relative contribution of factors for liver fibrosis progression in hepatitis C.

DESIGN

We analysed 1461 patients with chronic hepatitis C with an estimated date of infection and at least one liver biopsy. Risk factors for accelerated fibrosis progression rate (FPR), defined as ≥ 0.13 Metavir fibrosis units per year, were identified by logistic regression. Examined factors included age at infection, sex, route of infection, HCV genotype, body mass index (BMI), significant alcohol drinking (≥ 20 g/day for ≥ 5 years), HIV coinfection and diabetes. In a subgroup of 575 patients, we assessed the impact of single nucleotide polymorphisms previously associated with fibrosis progression in genome-wide association studies. Results were expressed as attributable fraction (AF) of risk for accelerated FPR.

RESULTS

Age at infection (AF 28.7%), sex (AF 8.2%), route of infection (AF 16.5%) and HCV genotype (AF 7.9%) contributed to accelerated FPR in the Swiss Hepatitis C Cohort Study, whereas significant alcohol drinking, anti-HIV, diabetes and BMI did not. In genotyped patients, variants at rs9380516 (TULP1), rs738409 (PNPLA3), rs4374383 (MERTK) (AF 19.2%) and rs910049 (major histocompatibility complex region) significantly added to the risk of accelerated FPR. Results were replicated in three additional independent cohorts, and a meta-analysis confirmed the role of age at infection, sex, route of infection, HCV genotype, rs738409, rs4374383 and rs910049 in accelerating FPR.

CONCLUSIONS

Most factors accelerating liver fibrosis progression in chronic hepatitis C are unmodifiable.

Hepatitis C Virus Deletion Mutants Are Found in Individuals Chronically Infected with Genotype 1 Hepatitis C Virus in Association with Age, High Viral Load and Liver Inflammatory Activity

Hepatitis C virus (HCV) variants characterized by genomic deletions in the structural protein region have been sporadically detected in liver and serum of hepatitis C patients. These defective genomes are capable of autonomous RNA replication and are packaged into infectious viral particles in cells co-infected with the wild-type virus. The prevalence of such forms in the chronically HCV-infected population and the impact on the severity of liver disease or treatment outcome are currently unknown. In order to determine the prevalence of HCV defective variants and to study their association with clinical characteristics, a screening campaign was performed on pre-therapy serum samples from a well-characterized cohort of previously untreated genotype 1 HCV-infected patients who received treatment with PEG-IFNα and RBV. 132 subjects were successfully analyzed for the presence of defective species exploiting a long-distance nested PCR assay. HCV forms with deletions predominantly affecting E1, E2 and p7 proteins were found in a surprising high fraction of the subjects (25/132, 19%). Their presence was associated with patient older age, higher viral load and increased necroinflammatory activity in the liver. While the presence of circulating HCV carrying deletions in the E1-p7 region did not appear to significantly influence sustained virological response rates to PEG-IFNα/RBV, our study indicates that the presence of these subgenomic HCV mutants could be associated with virological relapse in patients who did not have detectable viremia at the end of the treatment.

Serum aminotransferase ratio is independently correlated with hepatosteatosis in patients with HCV: a cross-sectional observational study

OBJECTIVES

The incidence of non-alcoholic fatty liver disease (NAFLD) is significant in hepatitis C virus (HCV) carriers due to multiple mechanisms, and this worsens the progression of chronic liver diseases, such as cirrhosis and hepatocellular carcinoma, and death. The purpose of this study was to examine whether the alanine aminotransferase/aspartate aminotransferase (ALT/AST) ratio correlates with the status of hepatosteatosis.

DESIGN

A cross-sectional observational study.

SETTING

Community-based annual examination in northern Taiwan.

PARTICIPANTS

A total of 1354 participants (age 20 years or over) were enrolled after excluding participants with HCV seronegative, laboratory or questionnaires loss, moderate alcohol consumption, liver cirrhosis, tumours and postlobectomy.

OUTCOME MEASURES

Fatty liver was diagnosed according to echogenic findings. NAFLD included grades 1-3 fatty liver and high-degree NAFLD defined grades 2-3 fatty liver.

RESULTS

580 males and 774 females with a mean age of 47.2 (SD=16.1) years were cross-sectionally studied. The participants with NAFLD have significantly higher levels of ALT/AST ratio, fasting glucose, triglyceride and systolic/diastolic blood pressure than non-NAFLD participants. The association between NAFLD and ALT/AST was significant even when adjusting for the metabolic syndrome (aOR 1.90; 95% CI 1.37 to 2.65; p<0.001). In patients with a high degree of NAFLD, the ALT/AST ratio was still a significant predictor for hepatosteatosis (aOR 2.44; 95% CI 1.58 to 3.77; p<0.001).

CONCLUSIONS

The ALT/AST ratio could be a strong risk of hepatosteatosis in patients with chronic HCV infection.

Concurrent Obesity, Diabetes, and Steatosis Increase Risk of Advanced Fibrosis Among HCV Patients: A Systematic Review

BACKGROUND

Rising rates of obesity, diabetes mellitus (DM), and nonalcoholic fatty liver disease among patients with chronic hepatitis C virus infection (HCV) may contribute to more rapid disease progression.

AIM

To evaluate the impact of concurrent obesity, DM, and steatosis on disease progression among HCV patients.

METHODS

A systematic review using structured keyword search of MEDLINE and EMBASE from January 1, 2001, to July 1, 2014, was performed to identify original articles evaluating the association of obesity, DM, and steatosis with advanced fibrosis (AF) among adults with chronic HCV. Studies involving HCV patients coinfected with human immunodeficiency virus, hepatitis B virus, hepatocellular carcinoma, or other chronic liver diseases were excluded. Quality assessment utilized Newcastle-Ottawa Scale.

RESULTS

Twenty cohort studies met inclusion criteria for analyses. Obesity was associated with increased risk of AF in seven studies with effect size ranging from OR 1.08 to 7.69. However, four studies did not demonstrate a significant association between obesity and AF. The presence of advanced steatosis among HCV patients was associated with increased risk of AF in 12 studies (OR 1.80-14.3). Concurrent DM was associated with increased risk of AF in six studies (OR 2.25-9.24). Thirteen studies were good quality, and seven studies were fair quality.

CONCLUSION

Concurrent DM and steatosis are associated with increased risk of AF among chronic HCV patients. The majority of studies demonstrated significant associations of obesity with AF. Targeted interventions to optimize management of obesity-related diseases among HCV patients may help mitigate HCV disease progression.

Factors Associated with Failure to Achieve SVR in Hepatitis C Genotype 3 Patients Within an Integrated Care Delivery System

BACKGROUND

Achievement of sustained virologic response (SVR) and factors associated with treatment failure in hepatitis C virus (HCV) genotype 3 have been described in tertiary and referral care settings, with rates of SVR reported to range between 72% and 89%. Fewer data exist on SVR outside of these settings.

OBJECTIVE

To describe rates of SVR and characterize factors associated with achievement of SVR within an integrated health care delivery system.

METHODS

A retrospective cohort study of genotype 3 HCV patients treated with dual therapy (pegylated interferon-alpha plus ribavirin) was conducted at Kaiser Permanente Southern California. Adult patients diagnosed with HCV and testing positive for HCV-RNA genotype 3 were identified from electronic medical records. Data were collected on patient demographics, baseline health status, and comorbid conditions. A multivariate logistic regression model was used to determine the association between baseline patient factors and SVR.

RESULTS

A total of 484 HCV genotype 3 patients met the eligibility criteria. The median age was 49 years, and 65.7% were male. Overall, 252 (52.1%) achieved SVR. Aged ≥ 45 years and male gender were associated with lower rates of SVR; cirrhosis and chronic diseases (diabetes and chronic obstructive pulmonary disease) were also associated with lower rates of SVR.

CONCLUSIONS

SVR was lower in patients within an integrated care delivery system than in those in tertiary and referral centers. Males and older patients had lower rates of SVR, as well as patients with cirrhosis, diabetes, and chronic obstructive pulmonary disease.

Development of sofosbuvir for the treatment of hepatitis C virus infection

The nucleotide analog NS5B polymerase inhibitor sofosbuvir was approved by the U.S. Food and Drug Administration (FDA) in December 2013 for the treatment of chronic hepatitis C virus (HCV) infection in combination with ribavirin or peginterferon and ribavirin. Sofosbuvir was developed to meet an urgent medical need for shorter, safer, simplified, more effective HCV treatment regimens and to reduce or eliminate the need for peginterferon. New treatment regimens were especially required for patient populations with limited treatment options, including patients who had failed prior HCV therapy, those with compensated and decompensated cirrhosis, and those who were either intolerant of or had contraindications to interferon. Sofosbuvir plus ribavirin for patients with genotype 2 or 3 HCV infection was the first approved all-oral treatment option. Sofosbuvir is also the backbone of the first regimen available for patients awaiting liver transplantation to prevent HCV recurrence, as well as the first oral interferon-free regimen for patients coinfected with HCV and HIV. This paper describes the development of sofosbuvir up to its original FDA approval.

Hepatitis C virus-induced hepatocellular carcinoma

Hepatitis C virus (HCV) is a leading etiology of hepatocellular carcinoma (HCC). The interaction of HCV with its human host is complex and multilayered; stemming in part from the fact that HCV is a RNA virus with no ability to integrate in the host's genome. Direct and indirect mechanisms of HCV-induced HCC include activation of multiple host pathways such as liver fibrogenic pathways, cellular and survival pathways, interaction with the immune and metabolic systems. Host factors also play a major role in HCV-induced HCC as evidenced by genomic studies identifying polymorphisms in immune, metabolic, and growth signaling systems associated with increased risk of HCC. Despite highly effective direct-acting antiviral agents, the morbidity and incidence of liver-related complications of HCV, including HCC, is likely to persist in the near future. Clinical markers to selectively identify HCV subjects at higher risk of developing HCC have been reported however they require further validation, especially in subjects who have experienced sustained virological response. Molecular biomarkers allowing further refinement of HCC risk are starting to be implemented in clinical platforms, allowing objective stratification of risk and leading to individualized therapy and surveillance for HCV individuals. Another role for molecular biomarker-based stratification could be enrichment of HCC chemoprevention clinical trials leading to smaller sample size, shorter trial duration, and reduced costs.

Should NS5A inhibitors serve as the scaffold for all-oral anti-HCV combination therapies?

Chronic hepatitis C virus (HCV) infection represents a global health problem that affects up to 130–150 million people worldwide. The HCV treatment landscape has been transformed recently by the introduction of direct-acting antiviral (DAA) agents that target viral proteins, including the NS3 protease, the NS5B polymerase, and the NS5A protein. Treatment with multiple DAAs in combination has been shown to result in high rates of sustained virologic response, without the need for pegylated interferon, and a shorter duration of therapy compared with interferon-based regimens; however, the optimal combination of DAAs has yet to be determined. The class of NS5A inhibitors has picomolar potency with pangenotypic activity, and recent clinical studies have shown these inhibitors to be an important component of DAA combination regimens. This review discusses the rational design of an optimal anti-HCV DAA cocktail, with a focus on the role of NS5A in the HCV life cycle, the attributes of the NS5A class of inhibitors, and the potential for NS5A inhibitors to act as a scaffold for DAA-only treatment regimens.

PCSK9, apolipoprotein E and lipoviral particles in chronic hepatitis C genotype 3: evidence for genotype-specific regulation of lipoprotein metabolism

BACKGROUND & AIMS

Hepatitis C virus (HCV) associates with lipoproteins to form "lipoviral particles" (LVPs) that can facilitate viral entry into hepatocytes. Initial attachment occurs via heparan sulphate proteoglycans and low-density lipoprotein receptor (LDLR); CD81 then mediates a post-attachment event. Proprotein convertase subtilisin kexin type 9 (PCSK9) enhances the degradation of the LDLR and modulates liver CD81 levels. We measured LVP and PCSK9 in patients chronically infected with HCV genotype (G)3. PCSK9 concentrations were also measured in HCV-G1 to indirectly examine the role of LDLR in LVP clearance.

METHODS

HCV RNA, LVP (d<1.07g/ml) and non-LVP (d>1.07g/ml) fractions, were quantified in patients with HCV-G3 (n=39) by real time RT-PCR and LVP ratios (LVPr; LVP/(LVP+non-LVP)) were calculated. Insulin resistance (IR) was assessed using the homeostasis model assessment of IR (HOMA-IR). Plasma PCSK9 concentrations were measured by ELISA in HCV-G3 and HCV-G1 (n=51).

RESULTS

In HCV-G3 LVP load correlated inversely with HDL-C (r=-0.421; p=0.008), and apoE (r=-0.428; p=0.013). The LVPr varied more than 35-fold (median 0.286; range 0.027 to 0.969); PCSK9 was the strongest negative predictor of LVPr (R(2)=16.2%; p=0.012). HOMA-IR was not associated with LVP load or LVPr. PCSK9 concentrations were significantly lower in HCV-G3 compared to HCV-G1 (p<0.001). PCSK9 did not correlate with LDL-C in HCV-G3 or G1.

CONCLUSIONS

The inverse correlation of LVP with apoE in HCV-G3, compared to the reverse in HCV-G1 suggests HCV genotype-specific differences in apoE mediated viral entry. Lower PCSK9 and LDL concentrations imply upregulated LDLR activity in HCV-G3.

Impairment of type I but not type III IFN signaling by hepatitis C virus infection influences antiviral responses in primary human hepatocytes

Peginterferon lambda-1a (Lambda), a type III interferon (IFN), acts through a unique receptor complex with limited cellular expression outside the liver which may result in a differentiated tolerability profile compared to peginterferon alfa (alfa). In Phase 2b clinical studies, Lambda administered in combination with ribavirin (RBV) was efficacious in patients with hepatitis C virus (HCV) infection representing genotypes 1 through 4, and was associated with more rapid declines in HCV RNA compared to alfa plus RBV. To gain insights into potential mechanisms for this finding, we investigated the effects of HCV replication on IFN signaling in primary human hepatocytes (PHH) and in induced hepatocyte-like cells (iHLCs). HCV infection resulted in rapid down-regulation of the type I IFN-α receptor subunit 1 (IFNAR1) transcript in hepatocytes while the transcriptional level of the unique IFN-λ receptor subunit IL28RA was transiently increased. In line with this observation, IFN signaling was selectively impaired in infected cells upon stimulation with alfa but not in response to Lambda. Importantly, in contrast to alfa, Lambda was able to induce IFN-stimulated gene (ISG) expression in HCV-infected hepatocytes, reflecting the onset of innate responses. Moreover, global transcriptome analysis in hepatocytes indicated that Lambda stimulation prolonged the expression of various ISGs that are potentially beneficial to antiviral defense mechanisms. Collectively, these observed effects of HCV infection on IFN receptor expression and signaling within infected hepatocytes provide a possible explanation for the more pronounced early virologic responses observed in patients treated with Lambda compared to alfa.

Sofosbuvir with peginterferon-ribavirin for 12 weeks in previously treated patients with hepatitis C genotype 2 or 3 and cirrhosis

Sofosbuvir (SOF) in combination with ribavirin (RBV) for 12 or 24 weeks is the current standard of care for patients infected with hepatitis C virus (HCV) genotypes 2 and 3, respectively. However, in clinical trials treatment-experienced patients, particularly those with cirrhosis, had suboptimal sustained virological response (SVR) rates. We assessed the efficacy and safety of sofosbuvir plus peginterferon and ribavirin (SOF+Peg-IFN+RBV) administered for 12 weeks to treatment-experienced patients with HCV genotypes 2 and 3, with and without cirrhosis. We enrolled 47 patients in this open-label, nonrandomized, uncontrolled phase 2 study. The primary endpoint was the proportion of patients with SVR at 12 weeks after cessation of study treatment (SVR12). The overall rate of SVR12 was 89% (95% confidence interval [CI]: 77-97). Rates of SVR12 were higher in patients with genotype 2 than in those with genotype 3, 96% (95% CI: 78-100) and 83% (95% CI: 62-95), respectively. Rates of SVR12 were similar in patients with and without cirrhosis: for genotype 2, 93% of patients with cirrhosis and 100% of patients without cirrhosis achieved SVR12, and for genotype 3, the SVR12 rate was 83% in patients both with and without cirrhosis. One patient discontinued study treatment because of an adverse event and four patients experienced serious adverse events. The most common adverse events were influenza-like illness, fatigue, anemia, and neutropenia.

CONCLUSION

In treatment-experienced patients with HCV genotypes 2 and 3, 12-week administration of SOF+Peg-IFN+RBV provided high SVR rates, irrespective of cirrhosis status. No safety concerns were identified.

Effect of sofosbuvir and ribavirin treatment on peripheral and hepatic lipid metabolism in chronic hepatitis C virus, genotype 1-infected patients

Hepatitis C virus (HCV) modulates intrahepatic cholesterol biosynthetic pathways to promote viral replication. Chronic HCV infection is associated with altered metabolism, including dyslipidemia and insulin resistance (IR), which contributes to disease progression and influences response to therapy. To further understand the impact of HCV infection on host metabolism, we examined changes in serum lipid profiles and intrahepatic expression of lipid-related genes during interferon (IFN)-free treatment of chronic HCV, genotype 1 infection with sofosbuvir and ribavirin (RBV), and explored associations with treatment outcome. Serum lipids (total cholesterol, low-density lipoprotein [LDL], high-density lipoprotein [HDL], and triglycerides [TGs]) and hemoglobin A1C (HbA1C) were measured during treatment, while gene expression of lipid-related genes was assessed using paired pre- and end-of-treatment (EOT) liver biopsies from 8 patients (n=7 sustained virologic response [SVR]; n=1 relapse) and unpaired EOT liver biopsies from 25 patients (n=17 SVR; n=8 relapse). Serum LDL concentration and particle size increased early in therapy, whereas TG concentration and very-low-density lipoprotein particle size decreased concomitantly, irrespective of treatment outcome. Whereas LDL increased in patients regardless of treatment outcome, average LDL concentration was lower at baseline and post-treatment in patients who relapsed. Analysis of paired liver biopsies revealed altered expression of genes associated with lipid transport, assembly, and signaling. In unpaired EOT liver biopsies, intrahepatic expression of fatty acid metabolism and lipid transport genes was lower in patients who experienced treatment relapse.

CONCLUSION

Clearance of HCV using an IFN-free antiviral regimen results in rapid changes in peripheral and intrahepatic metabolic pathways, implicating a direct effect of HCV replication on lipid homeostasis.

MicroRNAs: Role in Hepatitis C Virus pathogenesis

Hepatitis C virus (HCV) is a global health burden with an estimated 170-200 million peoples chronically infected worldwide. HCV infection remains as an independent risk factor for chronic hepatitis, liver cirrhosis, hepatocellular carcinoma, and a major reason for liver transplantation. Discovery of direct acting antiviral (DAA) drugs have shown promising results with more than 90% success rate in clearing the HCV RNA in patients, although long-term consequences remain to be evaluated. microRNAs (miRNAs) are important players in establishment of HCV infection and target crucial host cellular factors needed for productive HCV replication and augmented cell growth. Altered expression of miRNAs is involved in the pathogenesis associated with HCV infection by controlling signaling pathways such as immune response, proliferation and apoptosis. miRNA is emerging as a means of communication between various cell types inside the liver. There is likely possibility of developing circulating miRNAs as biomarkers of disease progression and can also serve as diagnostic tool with potential of early therapeutic intervention in HCV associated end stage liver disease. This review focuses on recent studies highlighting the contribution of miRNAs in HCV life cycle and their coordinated regulation in HCV mediated liver disease progression.