Hepatitis B virus and hepatitis C virus affect mitochondrial function through different metabolic pathways, explaining virus-specific clinical features of chronic hepatitis

BACKGROUND

Hepatitis C virus (HCV) and hepatitis B virus (HBV) cause chronic hepatitis with important clinical differences. HCV causes hepatic steatosis and insulin resistance, while HBV confers increased risk of liver cancer. We hypothesised these differences may be due to virus-specific effects on mitochondrial function.

METHODS

Seahorse technology was utilised to investigate effects of virus infection on mitochondrial function. Cell based assays were used to measure mitochondrial membrane potential and quantify pyruvate and lactate. Mass spectrometry was performed on mitochondria isolated from HBV expressing, HCV infected and control cells cultured with isotope-labelled amino acids, to identify proteins with different abundance. Altered expression of key mitochondrial proteins was confirmed by real time PCR and western blot.

RESULTS

Reduced mitochondrial function and ATP production were observed with HCV infection and HBV expression. HCV impairs glycolysis and reduces expression of genes regulating fatty acid oxidation, promoting lipid accumulation. HBV causes lactate accumulation by increasing expression of lactate dehydrogenase A, which converts pyruvate to lactate. In HBV expressing cells there was marked enrichment of pyruvate dehydrogenase kinase, inhibiting conversion of pyruvate to acetyl-CoA and thereby reducing its availability for mitochondrial oxidative phosphorylation.

CONCLUSIONS

HCV and HBV impair mitochondrial function and reduce ATP production. HCV reduces acetyl-CoA availability for energy production by impairing fatty acid oxidation, causing lipid accumulation and hepatic steatosis. HBV has no effect on fatty oxidation but reduces acetyl-CoA availability by disrupting pyruvate metabolism. This promotes lactic acidosis and oxidative stress, increasing the risk of disease progression and liver cancer.

Hepatitis C Virus Antiviral Drug Resistance and Salvage Therapy Outcomes Across Australia

Background

Hepatitis C virus (HCV) infection can now be cured with well-tolerated direct-acting antiviral (DAA) therapy. However, a potential barrier to HCV elimination is the emergence of resistance-associated substitutions (RASs) that reduce the efficacy of antiviral drugs, but real-world studies assessing the clinical impact of RASs are limited. Here, an analysis of the impact of RASs on retreatment outcomes for different salvage regimens in patients nationally who failed first-line DAA therapy is reported.

Methods

We collected data from 363 Australian patients who failed first-line DAA therapy, including: age, sex, fibrosis stage, HCV genotype, NS3/NS5A/NS5B RASs, details of failed first-line regimen, subsequent salvage regimens, and treatment outcome.

Results

Of 240 patients who were initially retreated as per protocol, 210 (87.5%) achieved sustained virologic response (SVR) and 30 (12.5%) relapsed or did not respond. The SVR rate for salvage regimens that included sofosbuvir/velpatasvir/voxilaprevir was 94.3% (n = 140), sofosbuvir/velpatasvir 75.0% (n = 52), elbasvir/grazoprevir 81.6% (n = 38), and glecaprevir/pibrentasvir 84.6% (n = 13). NS5A RASs were present in 71.0% (n = 210) of patients who achieved SVR and in 66.7% (n = 30) of patients who subsequently relapsed. NS3 RASs were detected in 20 patients (20%) in the SVR group and 1 patient in the relapse group. NS5B RASs were observed in only 3 patients. Cirrhosis was a predictor of relapse after retreatment, as was previous treatment with sofosbuvir/velpatasvir.

Conclusions

In our cohort, the SVR rate for sofosbuvir/velpatasvir/voxilaprevir was higher than with other salvage regimens. The presence of NS5A, NS5B, or NS3 RASs did not appear to negatively influence retreatment outcomes.

Inhibition of cellular factor TM6SF2 suppresses secretion pathways of Hepatitis B, Hepatitis C and Hepatitis D viruses

Chronic viral hepatitis is caused by hepatitis B virus, hepatitis C virus or hepatitis D virus (HBV, HCV, and HDV). Despite different replication strategies, all these viruses rely on secretion through the host endoplasmic reticulum-Golgi pathway, providing potential host targets for antiviral therapy. Knockdown of transmembrane 6 superfamily member 2 (TM6SF2) in virus cell culture models reduced secretion of infectious HCV virions, HDV virions and HBV subviral particles. Moreover, in a cohort of people with hepatitis B a TM6SF2 polymorphism (rs58542926 CT/TT, which causes protein misfolding and reduced TM6SF2 in the liver) correlated with lower concentrations of subviral particles in blood, complementing our previous work showing decreased HCV viral load in people with this polymorphism. In conclusion, the host protein TM6SF2 plays a key role in secretion of HBV, HCV and HDV, providing the potential for novel pan-viral agents to treat people with chronic viral hepatitis.

Polo-like kinase-1 mediates hepatitis C virus-induced cell migration, a drug target for liver cancer

Polo-like kinase 1 (PLK1) is a regulator of cell mitosis and cytoskeletal dynamics. PLK1 overexpression in liver cancer is associated with tumour progression, metastasis, and vascular invasion. Hepatitis C virus (HCV) NS5A protein stimulates PLK1-mediated phosphorylation of host proteins, so we hypothesised that HCV-PLK1 interactions might be a mechanism for HCV-induced liver cancer. We used a HCV cell-culture model (Jc1) to investigate the effects of virus infection on the cytoskeleton. In HCV-infected cells, a novel posttranslational modification in β-actin was observed with phosphorylation at Ser239. Using in silico and in vitro approaches, we identified PLK1 as the mediating kinase. In functional experiments with a phosphomimetic mutant form of β-actin, Ser239 phosphorylation influences β-actin polymerization and distribution, resulting in increased cell motility. The changes were prevented by treating cells with the PLK1 inhibitor volasertib. In HCV-infected hepatocytes, increased cell motility contributes to cancer cell migration, invasion, and metastasis. PLK1 is an important mediator of these effects and early treatment with PLK1 inhibitors may prevent or reduce HCC progression, particularly in people with HCV-induced HCC.

Special Issue "Hepatitis B Virus: New Breakthroughs to Conquer an Ancient Disease"

Chronic hepatitis B affects >300 million people worldwide and is a major cause of liver disease, causing ~800,000 deaths each year [...].

Bacillus Calmette-Guérin vaccination for protection against recurrent herpes labialis: a nested randomised controlled trial

Background

Recurrences of herpes simplex virus (HSV) in the orofacial region (herpes labialis or cold sores) impact quality-of-life. We aimed to study whether the bacille Calmette-Guérin (BCG) vaccine can attenuate cold sore recurrences through off-target immunomodulatory effects.

Methods

In this nested randomised controlled trial within the multicentre, phase 3 BRACE trial, 6828 healthcare workers were randomised in 36 sites in Australia, the Netherlands, Spain, the United Kingdom and Brazil, to receive BCG-Denmark or no BCG (1:1 ratio using a web-based procedure) and followed for 12 months with 3-monthly questionnaires. Exclusion criteria included contraindication to BCG vaccine or previous vaccination with BCG within the past year, any other live-attenuated vaccine within the last month, or any COVID-specific vaccine. The intervention group received one intradermal dose of 0.1 mL of BCG-Denmark corresponding to 2-8 x 105 colony forming units of Mycobacterium bovis, Danish strain 1331. The primary outcome was the difference in restricted mean survival time (i.e., time to first cold-sore recurrence), in participants with frequent recurrent herpes labialis (≥4 recurrences/year), analysed by intention-to-treat. Secondary outcomes addressed additional questions, including analyses in other sub-populations. Adverse events were monitored closely during the first 3 months and were reported in all participants who received one dose of study drug according to intervention received. The BRACE trial is registered with ClinicalTrials.gov, NCT04327206.

Findings

Between March 30, 2020 and February 18, 2021, 84 individuals with frequent recurrent cold sores were randomly assigned to BCG (n = 38) or control (n = 46). The average time to first cold-sore recurrence was 1.55 months longer in the BCG group (95% CI 0.27-2.82, p = 0.02) than the control group (hazard ratio 0.54, 95% CI 0.32-0.91; intention-to-treat). The beneficial effect of BCG was greater in the as-treated population (difference 1.91 months, 95% CI 0.69-3.12, p = 0.003; hazard ratio 0.45, 95% CI 0.26-0.76). In prespecified subgroup analyses, only sex modified the treatment effect (interaction p = 0.007), with benefit restricted to males. Over 12 months, a greater proportion of participants in the BCG group compared with the control group reported a decrease in duration (61% vs 21%), severity (74% vs 21%), frequency (55% vs 21%), and impact on quality of life (42% vs 15%) of cold sore recurrences. In participants who had ever had a cold sore, there was also a decrease in self-reported burden of recurrences in the BCG group. In participants who had never had a cold sore, there was an increased risk of a first episode in the BCG group (risk difference 1.4%; 95% CI 0.3-2.6%, p = 0.02). There were no safety concerns.

Interpretation

BCG-Denmark vaccination had a beneficial effect on herpes labialis, particularly in males with frequent recurrences, but may increase the risk of a first cold sore.

Funding

Bill & Melinda Gates Foundation, the Minderoo Foundation, Sarah and Lachlan Murdoch, the Royal Children's Hospital Foundation, Health Services Union NSW, the Peter Sowerby Foundation, SA Health, the Insurance Advisernet Foundation, the NAB Foundation, the Calvert-Jones Foundation, the Modara Pines Charitable Foundation, the UHG Foundation Pty Ltd, Epworth Healthcare, and individual donors.

PEMT Mediates Hepatitis C Virus-Induced Steatosis, Explains Genotype-Specific Phenotypes and Supports Virus Replication

The hepatitis C virus (HCV) relies on cellular lipid pathways for virus replication and also induces liver steatosis, but the mechanisms involved are not clear. We performed a quantitative lipidomics analysis of virus-infected cells by combining high-performance thin-layer chromatography (HPTLC) and mass spectrometry, using an established HCV cell culture model and subcellular fractionation. Neutral lipid and phospholipids were increased in the HCV-infected cells; in the endoplasmic reticulum there was an ~four-fold increase in free cholesterol and an ~three-fold increase in phosphatidyl choline (p < 0.05). The increase in phosphatidyl choline was due to the induction of a non-canonical synthesis pathway involving phosphatidyl ethanolamine transferase (PEMT). An HCV infection induced expression of PEMT while knocking down PEMT with siRNA inhibited virus replication. As well as supporting virus replication, PEMT mediates steatosis. Consistently, HCV induced the expression of the pro-lipogenic genes SREBP 1c and DGAT1 while inhibiting the expression of MTP, promoting lipid accumulation. Knocking down PEMT reversed these changes and reduced the lipid content in virus-infected cells. Interestingly, PEMT expression was over 50% higher in liver biopsies from people infected with the HCV genotype 3 than 1, and three times higher than in people with chronic hepatitis B, suggesting that this may account for genotype-dependent differences in the prevalence of hepatic steatosis. PEMT is a key enzyme for promoting the accumulation of lipids in HCV-infected cells and supports virus replication. The induction of PEMT may account for virus genotype specific differences in hepatic steatosis.

Viral Biomarkers for Hepatitis B Virus-Related Hepatocellular Carcinoma Occurrence and Recurrence

Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide and the fourth leading cause of cancer-related death. The most common risk factor for developing HCC is chronic infection with hepatitis B virus (HBV). Early stages of HBV-related HCC (HBV-HCC) are generally asymptomatic. Moreover, while serum alpha-fetoprotein (AFP) and abdominal ultrasound are widely used to screen for HCC, they have poor sensitivity. Thus, HBV-HCC is frequently diagnosed at an advanced stage, in which there are limited treatment options and high mortality rates. Serum biomarkers with high sensitivity and specificity are crucial for earlier diagnosis of HCC and improving survival rates. As viral-host interactions are key determinants of pathogenesis, viral biomarkers may add greater diagnostic power for HCC than host biomarkers alone. In this review, we summarize recent research on using virus-derived biomarkers for predicting HCC occurrence and recurrence; including circulating viral DNA, RNA transcripts, and viral proteins. Combining these viral biomarkers with AFP and abdominal ultrasound could improve sensitivity and specificity of early diagnosis, increasing the survival of patients with HBV-HCC. In the future, as the mechanisms that drive HBV-HCC to become clearer, new biomarkers may be identified which can further improve early diagnosis of HBV-HCC.

Expansion of dysfunctional CD56-CD16+ NK cells in chronic hepatitis B patients

BACKGROUND & AIMS

Natural killer (NK) cells are primary innate effector cells that play an important role in the control of human viral infections. During chronic viral infection, NK cells undergo significant changes in phenotype, function and subset distribution, including the appearance of CD56-CD16+ (CD56-) NK cells, previously identified in chronic human immunodeficiency virus (HIV) and hepatitis C virus infection. However, the presence of CD56- NK cells in the pathogenesis of chronic hepatitis B (CHB) remains unknown.

METHODS

Phenotype and function of CD56- NK cells from patients with CHB (n = 28) were assessed using flow cytometry and in vitro stimulation with HBV antigen.

RESULTS

CHB patients had a higher frequency of CD56- NK cells compared to healthy controls in peripheral blood (6.2% vs 1.4%, P < .0001). Compared to CD56+ NK cells, CD56- NK cells had increased expression of inhibitory receptors, and reduced expression of activating receptors, as measured by MFI and qPCR. CD56- NK cells were less responsive to target cell and cytokine stimulation compared to their CD56+ counterparts. In addition, CD56- NK cells demonstrated defective dendritic cells (DCs) interactions resulting in reduced DCs maturation, lower expression of NK CD69 and impaired capacity of NK cells to eliminate immature DCs in co-culture studies. Finally, frequency of CD56- NK cells was positively correlated with serum HBV DNA levels.

CONCLUSION

Chronic HBV infection induces the expansion of highly dysfunctional of CD56- NK cells that likely contribute to inefficient innate and adaptive antiviral immune response in chronic HBV infection.

HBV vaccination and HBV infection induces HBV-specific natural killer cell memory

OBJECTIVE

Vaccination against hepatitis B virus (HBV) confers protection from subsequent infection through immunological memory that is traditionally considered the domain of the adaptive immune system. This view has been challenged following the identification of antigen-specific memory natural killer cells (mNKs) in mice and non-human primates. While the presence of mNKs has been suggested in humans based on the expansion of NK cells following pathogen exposure, evidence regarding antigen-specificity is lacking. Here, we demonstrate the existence of HBV-specific mNKs in humans after vaccination and in chronic HBV infection.

DESIGN

NK cell responses were evaluated by flow cytometry and ELISA following challenge with HBV antigens in HBV vaccinated, non-vaccinated and chronic HBV-infected individuals.

RESULTS

NK cells from vaccinated subjects demonstrated higher cytotoxic and proliferative responses against autologous hepatitis B surface antigen (HBsAg)-pulsed monocyte-derived dendritic cells (moDCs) compared with unvaccinated subjects. Moreover, NK cell lysis of HBsAg-pulsed moDCs was significantly higher than that of hepatitis B core antigen (HBcAg)-pulsed moDCs (non-vaccine antigen) or tumour necrosis factor α-activated moDCs in a NKG2D-dependent manner. The mNKs response was mediated by CD56^dim NK cells coexpressing CD57, CD69 and KLRG1. Further, mNKs from chronic hepatitis B patients exhibited greater degranulation against HBcAg-pulsed moDCs compared with unvaccinated or vaccinated patients. Notably, mNK activity was negatively correlated with HBV DNA levels.

CONCLUSIONS

Our data support the presence of a mature mNKs following HBV antigen exposure either through vaccination or infection. Harnessing these antigen specific, functionally active mNKs provides an opportunity to develop novel treatments targeting HBV in chronic infection.

Hepatitis C Virus (HCV) Eradication With Interferon-Free Direct-Acting Antiviral-Based Therapy Results in KLRG1+ HCV-Specific Memory Natural Killer Cells

Direct acting antiviral therapies rapidly clear chronic hepatitis C virus (HCV) infection and restore natural killer (NK) cell function. We investigated NK-cell memory formation following HCV clearance by examining NK-cell phenotype and responses from control and chronic HCV patients before and after therapy following sustained virologic response at 12 weeks post therapy (SVR12). NK-cell phenotype at SVR12 differed significantly from paired pretreatment samples, with an increase in maturation markers CD16, CD57, and KLRG1. HCV patients possessed stronger cytotoxic responses against HCV-infected cells as compared to healthy controls; a response that further increased following SVR12. The antigen-specific response was mediated by KLRG1+ NK cells, as demonstrated by increased degranulation and proliferation in response to HCV antigen only. Our data suggest that KLRG1+ HCV-specific memory NK cells develop following viral infection, providing insight into their role in HCV clearance and relevance with regard to vaccine design.

COVID-19: The Immune Responses and Clinical Therapy Candidates

The pandemic of coronavirus disease 2019 (COVID-19), with rising numbers of patients worldwide, presents an urgent need for effective treatments. To date, there are no therapies or vaccines that are proven to be effective against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several potential candidates or repurposed drugs are under investigation, including drugs that inhibit SARS-CoV-2 replication and block infection. The most promising therapy to date is remdesivir, which is US Food and Drug Administration (FDA) approved for emergency use in adults and children hospitalized with severe suspected or laboratory-confirmed COVID-19. Herein we summarize the general features of SARS-CoV-2's molecular and immune pathogenesis and discuss available pharmacological strategies, based on our present understanding of SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV) infections. Finally, we outline clinical trials currently in progress to investigate the efficacy of potential therapies for COVID-19.

Pre-treatment antiviral resistance in Australians with chronic hepatitis C: prevalence of NS3 and NS5A resistance data in the state of New South Wales

BACKGROUND

Direct-acting antivirals (DAAs) have revolutionized HCV treatment, but the impact of antiviral resistance at a population level is still not clear. The majority of patients who fail DAA therapy develop resistance-associated substitutions (RASs), which can impact re-treatment. There is potential for resistance prevalence to rise in the community with treatment scale up, due to transmission of resistant virus. Monitoring for increasing antiviral resistance requires a reliable baseline, yet there are few published data on the prevalence of HCV resistance in Australia. The aim of this study was to determine the prevalence of RASs among untreated Australians with HCV genotype-1a infection, to inform ongoing surveillance.

METHODS

A cross-sectional study was performed at a single large university hospital pathology laboratory in Australia. Archived blood samples referred for HCV genotype testing were analysed. All patients were naive to DAAs. The prevalence of RASs in the HCV NS3 and NS5A regions was determined using Sanger based population sequencing.

RESULTS

Of 379 samples tested, 34% contained DAA-resistant virus: 24% had resistance to NS3 protease inhibitors, 12% had NS5A inhibitor resistance and 4% of patients had resistance to both drug classes. Clinically relevant RASs conferring resistance against NS5A inhibitors ledipasvir, daclatasvir and elbasvir were detected in 5.8% of samples.

CONCLUSIONS

This is the largest study of HCV antiviral drug resistance in Australia, which differs from resistance prevalence in the USA. The results provide valuable data on the baseline prevalence of HCV resistance, which can be used in the future to monitor for increasing antiviral resistance.

Epidemiology of Coronavirus Disease in Gansu Province, China, 2020

To determine the epidemiology of coronavirus disease (COVID-19) in a remote region of China, far from Wuhan, we analyzed the epidemiology of COVID-19 in Gansu Province. From January 23 through February 3, 2020, a total of 35 (64.8%) of 54 reported cases were imported from COVID-19-epidemic areas. Characteristics that differed significantly during the first and second waves of illness in Gansu Province were mean patient age, occupation, having visited epidemic areas, and mode of transportation. Time from infection to illness onset for family clusters was shorter in Gansu Province than in Wuhan, consistent with shortened durations from onset to first medical visit or hospitalization. Spatial distribution pattern analysis indicated hot spots and spatial outliers in Gansu Province. As a result of adequate interventions, transmission of the COVID-19 virus in Gansu Province is decreasing.

Impact of an Open Access Nationwide Treatment Model on Hepatitis C Virus Antiviral Drug Resistance

Direct acting antivirals (DAAs) have revolutionized hepatitis C virus (HCV) treatment, but drug resistance could undermine proposed global elimination targets. Real‐world studies are needed to inform the impact of widespread DAA treatment on antiviral resistance in the community. The prevalence and range of posttreatment resistance‐associated substitutions (RASs) was determined in Australian patients with open access to DAAs through a wide range of prescribers. NS3, NS5A, and NS5B regions were amplified by polymerase chain reaction and analyzed by population sequencing. Clinically relevant RASs were identified using online databases (ReCALL and Geno2Pheno[hcv]). Of 572 samples, 60% were from genotype 3 and 27% from genotype 1a. Ninety‐two percent of people failed a DAA regimen containing an NS5A inhibitor, including 10% with a pangenotype regimen. NS5A RASs were detected in 72% of people with genotype 1 and 80% with genotype 3. For genotype 1, there was a range of RASs across the NS5A region, while for genotype 3, the Y93H RAS predominated (72%). The prevalence of NS3 RASs was higher in people exposed to an NS3 inhibitor (35% vs. 3.9%; P < 0.0001). NS5B resistance was rare, with a single case of sofosbuvir resistance. Multiclass drug resistance was found in 33% of people exposed to both NS3 and NS5A inhibitors. Conclusion: The high prevalence of NS5A RASs among people failing DAA therapy reinforces the importance of specific retreatment regimens, ideally guided by resistance testing. The impact of multiclass drug resistance on retreatment in people exposed to both NS3 and NS5A inhibitors needs to be assessed in real‐world studies. Surveillance for increasing antiviral resistance during treatment scale‐up is essential to maintain the efficacy of current DAA regimens.

Macrophage Coordination of the Interferon Lambda Immune Response

Lambda interferons (IFN-λs) are a major component of the innate immune defense to viruses, bacteria, and fungi. In human liver, IFN-λ not only drives antiviral responses, but also promotes inflammation and fibrosis in viral and non-viral diseases. Here we demonstrate that macrophages are primary responders to IFN-λ, uniquely positioned to bridge the gap between IFN-λ producing cells and lymphocyte populations that are not intrinsically responsive to IFN-λ. While CD14⁺ monocytes do not express the IFN-λ receptor, IFNLR1, sensitivity is quickly gained upon differentiation to macrophages in vitro. IFN-λ stimulates macrophage cytotoxicity and phagocytosis as well as the secretion of pro-inflammatory cytokines and interferon stimulated genes that mediate immune cell chemotaxis and effector functions. In particular, IFN-λ induced CCR5 and CXCR3 chemokines, stimulating T and NK cell migration, as well as subsequent NK cell cytotoxicity. Using immunofluorescence and cell sorting techniques, we confirmed that human liver macrophages expressing CD14 and CD68 are highly responsive to IFN-λ ex vivo. Together, these data highlight a novel role for macrophages in shaping IFN-λ dependent immune responses both directly through pro-inflammatory activity and indirectly by recruiting and activating IFN-λ unresponsive lymphocytes.

A STAT4 variant increases liver fibrosis risk in Caucasian patients with chronic hepatitis B

BACKGROUND

Host genetic modifiers of the natural history of chronic hepatitis B (CHB) remain poorly understood. Recently, a genome-wide association study (GWAS)-identified polymorphism in the STAT4 gene that contributes to the risk for hepatocellular carcinoma (HCC) was shown to be associated with the full spectrum of hepatitis B virus (HBV) outcomes in Asian patients. However, the functional mechanisms for this effect are unknown and the role of the variant in modulating HBV disease in Caucasians has not been investigated.

AIMS

To determine whether STAT4 genetic variation is associated with liver injury in Caucasian patients with CHB and to investigate potential mechanisms mediating this effect.

METHODS

STAT4 rs7574865 was genotyped in 1085 subjects (830 with CHB and 255 healthy controls). STAT4 expression in liver, PBMCs and NK cells, STAT4 phosphorylation and secretion of interferon-gamma (IFN-γ) according to STAT4 genetic variation was examined.

RESULTS

STAT4 rs7574865 genotype was independently associated with hepatic inflammation (OR: 1.42, 95% CI: 1.07-2.06, P = 0.02) and advanced fibrosis (OR: 1.83, 95% CI: 1.19-2.83, P = 0.006). The minor allele frequency of rs7574865 was significantly lower than that in healthy controls. rs7574865 GG risk carriers expressed lower levels of STAT4 in liver, PBMCs and in NK cells, while NK cells from patients with the risk genotype had impaired STAT4 phosphorylation following stimulation with IL-12/IL-18 and a reduction in secretion of IFN-γ.

CONCLUSION

Genetic susceptibility to HBV persistence, hepatic inflammation and fibrosis in Caucasians associates with STAT4 rs7574865 variant. Downstream effects on NK cell function through STAT4 phosphorylation-dependent IFN-γ production likely contribute to these effects.

Rapid and persistent decline in soluble CD163 with successful direct-acting antiviral therapy and associations with chronic hepatitis C histology

BACKGROUND AND AIM

Soluble CD 163 (sCD163) is released from activated liver macrophages in chronic viral hepatitis C (HCV) and serum levels reflect liver disease severity. The impact of direct-acting antiviral (DAA)-therapy on sCD163-levels and the ability of sCD163 to predict the presence of liver fibrosis remain unclear. In a combined observational and prospective study, we aimed to investigate changes in sCD163 with DAA-treatment, to investigate associations between sCD163 and histopathological activity and fibrosis and to validate the sCD163-based fibrosis score in HCV-patients.

METHODS

We examined three groups of patients: an Australian (n = 28) treated with pegylated-interferon and a first-generation DAA, a Danish (n = 38) treated with sofosbuvir-based DAA-regimens and a Japanese (n = 562) assessed for activity and fibrosis (Metavir scoring system) in liver biopsies. Serum sCD163-levels were quantified by ELISA.

RESULTS

Thirteen (46%) of the Australian patients achieved sustained virological response (SVR) and only these patients had significant decreases in sCD163-levels (2.7 (95%CI:1.9-3.6) vs. 4.1(2.9-5.7) mg L ^- 1, p = .008). In the Danish group, 37 (97%) patients achieved SVR at 12-weeks post-treatment with 32% reduction in sCD163-levels (5.0 (4.3-5.8) vs. 7.4 (6.3-8.7), p < .001). The decline was rapid and persisted 12 months after treatment cessation (p < .007). sCD163 levels increased in parallel with inflammatory activity and fibrosis (p < .001). The sCD163-based fibrosis score outperformed established fibrosis scores for significant fibrosis (areas under the receiver operating characteristics curves (AUROCs): 0.79 (0.75-0.83) vs. aspartate aminotransferase to platelet ratio index (APRI) 0.73 (0.69-0.77), Fibrosis-4 (FIB-4) 0.74 (0.70-0.78), p < .001).

CONCLUSION

sCD163-levels decline rapidly with successful DAA therapy and are associated with histological inflammatory activity and fibrosis, confirming a key role for macrophages in HCV inflammation and fibrosis and supporting sCD163 as a biomarker of treatment response.

The antiviral role of zinc and metallothioneins in hepatitis C infection

Metallothioneins (MTs) are small, cysteine-rich proteins characterized by a high affinity for monovalent and divalent cations, such as copper and zinc. Of the four known MT isoforms, only, members of the MT 1 and 2 subfamilies are widely expressed, acting as metal chaperones whose primary role is to mediate intracellular zinc homoeostasis. Metallothioneins are potently induced by heavy metals and other sources of oxidative stress where they facilitate metal binding and detoxification as well as free radical scavenging. Metallothionein expression is well documented in the context of viral infection; however, it remains uncertain whether MTs possess specific antiviral roles or whether induction is merely a consequence of cellular stress. To better understand the role of MTs following hepatitis C virus (HCV) infection, we examined MT expression and localization in vitro and in vivo and used a siRNA knockdown approach to ascertain their antiviral efficacy. We confirmed HCV-driven MT induction in vitro and demonstrated MT accumulation in the nucleus of HCV-infected hepatocytes by immunofluorescence. Using a pan-MT siRNA to knock down all members of the MT1 and MT2 subfamilies, we demonstrate that they are mildly antiviral against the JFH1 strain of HCV in vitro (~1.4 fold increase in viral RNA, P < .05). Furthermore, the antiviral effect of zinc treatment against HCV in vitro was mediated through MT induction (P < .05). Our data suggest a potential benefit of using zinc as a low-cost adjunct to current HCV antiviral therapies and suggest that zinc may facilitate the antiviral role of MTs against other viruses.

The paradox of HBV evolution as revealed from a 16th century mummy

Hepatitis B virus (HBV) is a ubiquitous viral pathogen associated with large-scale morbidity and mortality in humans. However, there is considerable uncertainty over the time-scale of its origin and evolution. Initial shotgun data from a mid-16^th century Italian child mummy, that was previously paleopathologically identified as having been infected with Variola virus (VARV, the agent of smallpox), showed no DNA reads for VARV yet did for hepatitis B virus (HBV). Previously, electron microscopy provided evidence for the presence of VARV in this sample, although similar analyses conducted here did not reveal any VARV particles. We attempted to enrich and sequence for both VARV and HBV DNA. Although we did not recover any reads identified as VARV, we were successful in reconstructing an HBV genome at 163.8X coverage. Strikingly, both the HBV sequence and that of the associated host mitochondrial DNA displayed a nearly identical cytosine deamination pattern near the termini of DNA fragments, characteristic of an ancient origin. In contrast, phylogenetic analyses revealed a close relationship between the putative ancient virus and contemporary HBV strains (of genotype D), at first suggesting contamination. In addressing this paradox we demonstrate that HBV evolution is characterized by a marked lack of temporal structure. This confounds attempts to use molecular clock-based methods to date the origin of this virus over the time-frame sampled so far, and means that phylogenetic measures alone cannot yet be used to determine HBV sequence authenticity. If genuine, this phylogenetic pattern indicates that the genotypes of HBV diversified long before the 16^th century, and enables comparison of potential pathogenic similarities between modern and ancient HBV. These results have important implications for our understanding of the emergence and evolution of this common viral pathogen.

Hepatitis B virus (HBV) exerts formidable morbidity and mortality in humans. We used ancient DNA techniques to recover the complete genome sequence of an HBV from the mummified remains of a child discovered in the 16^th century from Naples, Italy. Strikingly, our analysis of this specimen resulted in two contrasting findings: while the damage patterns lend credence to this HBV sequence being authentically 16^th century, phylogenetic analysis revealed a close relationship to recently sampled viruses as expected if the sequence were a modern contaminant. We reconcile these two observations by showing that HBV evolution over the last ~450 years is characterized by a marked lack of temporal structure that hinders attempts to resolve the evolutionary time-scale of this important human pathogen.

Sequencing of hepatitis C virus for detection of resistance to direct-acting antiviral therapy: A systematic review

The significance of the clinical impact of direct‐acting antiviral (DAA) resistance‐associated substitutions (RASs) in hepatitis C virus (HCV) on treatment failure is unclear. No standardized methods or guidelines for detection of DAA RASs in HCV exist. To facilitate further evaluations of the impact of DAA RASs in HCV, we conducted a systematic review of RAS sequencing protocols, compiled a comprehensive public library of sequencing primers, and provided expert guidance on the most appropriate methods to screen and identify RASs. The development of standardized RAS sequencing protocols is complicated due to a high genetic variability and the need for genotype‐ and subtype‐specific protocols for multiple regions. We have identified several limitations of the available methods and have highlighted areas requiring further research and development. The development, validation, and sharing of standardized methods for all genotypes and subtypes should be a priority. (Hepatology Communications 2017;1:379–390)

Zinc is a potent and specific inhibitor of IFN-λ3 signalling

Lambda interferons (IFNL, IFN-λ) are pro-inflammatory cytokines important in acute and chronic viral infection. Single-nucleotide polymorphisms rs12979860 and rs8099917 within the IFNL gene locus predict hepatitis C virus (HCV) clearance, as well as inflammation and fibrosis progression in viral and non-viral liver disease. The underlying mechanism, however, is not defined. Here we show that the rs12979860 CC genotype correlates with increased hepatic metallothionein expression through increased systemic zinc levels. Zinc interferes with IFN-λ3 binding to IFNL receptor 1 (IFNLR1), resulting in decreased antiviral activity and increased viral replication (HCV, influenza) in vitro. HCV patients with high zinc levels have low hepatocyte antiviral and inflammatory gene expression and high viral loads, confirming the inhibitory role of zinc in vivo. We provide the first evidence that zinc can act as a potent and specific inhibitor of IFN-λ3 signalling and highlight its potential as a target of therapeutic intervention for IFN-λ3-mediated chronic disease.

IFN-λ3, not IFN-λ4, likely mediates IFNL3-IFNL4 haplotype-dependent hepatic inflammation and fibrosis

Genetic variation in the IFNL3-IFNL4 (interferon-λ3-interferon-λ4) region is associated with hepatic inflammation and fibrosis. Whether IFN-λ3 or IFN-λ4 protein drives this association is not known. We demonstrate that hepatic inflammation, fibrosis stage, fibrosis progression rate, hepatic infiltration of immune cells, IFN-λ3 expression, and serum sCD163 levels (a marker of activated macrophages) are greater in individuals with the IFNL3-IFNL4 risk haplotype that does not produce IFN-λ4, but produces IFN-λ3. No difference in these features was observed according to genotype at rs117648444, which encodes a substitution at position 70 of the IFN-λ4 protein and reduces IFN-λ4 activity, or between patients encoding functionally defective IFN-λ4 (IFN-λ4-Ser70) and those encoding fully active IFN-λ4-Pro70. The two proposed functional variants (rs368234815 and rs4803217) were not superior to the discovery SNP rs12979860 with respect to liver inflammation or fibrosis phenotype. IFN-λ3 rather than IFN-λ4 likely mediates IFNL3-IFNL4 haplotype-dependent hepatic inflammation and fibrosis.

Listening to both sides: A qualitative comparison between patients with hepatitis C and their healthcare professionals' perceptions of the facilitators and barriers to hepatitis C treatment adherence and completion

This qualitative study compares and contrasts the perspectives of healthcare professionals who treat hepatitis C with those of patients in treatment. Comparative analysis of semi-structured interviews with 20 healthcare professionals and 20 patients undergoing treatment for hepatitis C concluded that patients and healthcare professionals disagreed on the source of communication breakdowns, but both felt that individualised clinical information improved adherence. Stigma was recognised as a barrier to treatment adherence by both patients and healthcare professionals. Limitations of the healthcare system, such as patients receiving inconsistent information and long wait times, negatively impacted both patients and providers.

IFNL3/4 genotype is associated with altered immune cell populations in peripheral blood in chronic hepatitis C infection

Single-nucleotide polymorphisms near the interferon lambda 3 (IFNL3) gene predict outcomes to infection and anti-viral treatment in hepatitis C virus (HCV) infection. To identify IFNL3 genotype effects on peripheral blood, we collected phenotype data on 400 patients with genotype 1 chronic hepatitis C (CHC). The IFNL3 responder genotype predicted significantly lower white blood cells (WBCs), as well as lower absolute numbers of monocytes, neutrophils and lymphocytes for both rs8099917 and rs12979860. We sought to define the WBC subsets driving this association using flow cytometry of 67 untreated CHC individuals. Genotype-associated differences were seen in the ratio of CD4CD45RO+ to CD4CD45RO-; CD8CD45RO+ to CD8CD45RO-, NK CD56 dim to bright and monocyte numbers and percentages. Whole blood expression levels of IFNL3, IFNLR1 (interferon lambda receptor 1), IFNLR1-mem (a membrane-associated receptor), IFNLR1-sol (a truncated soluble receptor), MxA and T- and NK (natural killer) cell transcription factors TBX21, GATA3, RORC, FOXP3 and EOMES in two subjects were also determined. CHC patients demonstrated endogenous IFN activation with higher levels of MxA, IFNLR1, IFNLR1-mem and IFNLR1-sol, and IFNL3 genotype-associated differences in transcription factors. Taken together, these data provide evidence of an IFNL3 genotype association with differences in monocyte, T- and NK cell levels in the peripheral blood of patients with CHC. This could underpin genotype associations with spontaneous and treatment-induced HCV clearance and hepatic necroinflammation.

Diverse impacts of the rs58542926 E167K variant in TM6SF2 on viral and metabolic liver disease phenotypes

A genome-wide exome association study has identified the transmembrane 6 superfamily member 2 (TM6SF2) rs58542926 variant encoding an E167K substitution as a genetic determinant of hepatic steatosis in nonalcoholic fatty liver disease (NAFLD). The roles of this variant across a spectrum of liver diseases and pathologies and on serum lipids comparing viral hepatitis to NAFLD and viral load in chronic viral hepatitis, as well as its intrahepatic molecular signature, have not been well characterized. We undertook detailed analyses in 3260 subjects with viral and nonviral liver diseases and in healthy controls. Serum inflammatory markers and hepatic expression of TM6SF2 and genes regulating lipid metabolism were assessed in a subset with chronic hepatitis C (CHC). The rs58542926 T allele was more prevalent in 502 NAFLD patients than controls (P = 0.02) but not different in cohorts with CHC (n = 2023) and chronic hepatitis B (n = 507). The T allele was associated with alterations in serum lipids and hepatic steatosis in all diseases and with reduced hepatic TM6SF2 and microsomal triglyceride transfer protein expression. Interestingly, the substitution was associated with reduced CHC viral load but increased hepatitis B virus DNA. The rs58542926 T allele had no effect on inflammation, impacted ≥F2 fibrosis in CHC and NAFLD assessed cross-sectionally (odds ratio = 1.39, 95% confidence interval 1.04-1.87, and odds ratio = 1.62, 95% confidence interval 1.03-2.52, respectively; P < 0.03 for both), but had no effect on fibrosis progression in 1174 patients with CHC and a known duration of infection.

CONCLUSION

The TM6SF2 E167K substitution promotes steatosis and lipid abnormalities in part by altering TM6SF2 and microsomal triglyceride transfer protein expression and differentially impacts CHC and chronic hepatitis B viral load, while effects on fibrosis are marginal. (Hepatology 2016;64:34-46).

Calsyntenin-1 mediates hepatitis C virus replication

The hepatitis C virus (HCV) RNA genome of 9.6 kb encodes only 10 proteins, and so is highly dependent on host hepatocyte factors to facilitate replication. We aimed to identify host factors involved in the egress of viral particles. By screening the supernatant of HCV-infected Huh7 cells using SILAC-based proteomics, we identified the transmembrane protein calsyntenin-1 as a factor specifically secreted by infected cells. Calsyntenin-1 has previously been shown to mediate transport of endosomes along microtubules in neurons, through interactions with kinesin light chain-1. Here we demonstrate for the first time, we believe, a similar role for calsyntenin-1 in Huh7 cells, mediating intracellular transport of endosomes. In HCV-infected cells we show that calsyntenin-1 contributes to the early stages of the viral replication cycle and the formation of the replication complex. Importantly, we demonstrate in our model that silencing calsyntenin-1 disrupts the viral replication cycle, confirming the reliance of HCV on this protein as a host factor. Characterizing the function of calsyntenin-1 will increase our understanding of the HCV replication cycle and pathogenesis, with potential application to other viruses sharing common pathways.

Listening to both sides: A qualitative comparison between patients with hepatitis C and their healthcare professionals' perceptions of the facilitators and barriers to hepatitis C treatment adherence and completion

This qualitative study compares and contrasts the perspectives of healthcare professionals who treat hepatitis C with those of patients in treatment. Comparative analysis of semi-structured interviews with 20 healthcare professionals and 20 patients undergoing treatment for hepatitis C concluded that patients and healthcare professionals disagreed on the source of communication breakdowns, but both felt that individualised clinical information improved adherence. Stigma was recognised as a barrier to treatment adherence by both patients and healthcare professionals. Limitations of the healthcare system, such as patients receiving inconsistent information and long wait times, negatively impacted both patients and providers.

Role of fibrogenic and inflammatory cytokines in HCV-induced fibrosis

HCV is one of the main causative agents of liver fibrosis and hepatocellular carcinoma. Liver inflammation resulting from HCV infection triggers fibrosis. In HCV-related fibrosis, differentiated hepatic stellate cells (HSCs) known as myofibroblasts participate in the fibrogenic and inflammatory response. TGF-β1 and CTGF, released from these HSCs, have been implicated as master cytokines mediating HCV induced hepatic fibrosis. PDGF is another potent mitogen, which facilitates the progression of liver fibrosis by enhancing the proliferation and migration of HSCs. In addition to these major cytokines, the release of TNF-α, IL-6, IL-1b and IL-10 by immune cells also promotes the effect of HCV induced fibrosis. Targeting these cytokines may offer the potential for treatments to prevent or cure fibrosis.

Hepatitis C Virus Driven AXL Expression Suppresses the Hepatic Type I Interferon Response

Treatment of chronic hepatitis C virus (HCV) infection is evolving rapidly with the development of novel direct acting antivirals (DAAs), however viral clearance remains intimately linked to the hepatic innate immune system. Patients demonstrating a high baseline activation of interferon stimulated genes (ISGs), termed interferon refractoriness, are less likely to mount a strong antiviral response and achieve viral clearance when placed on treatment. As a result, suppressor of cytokine signalling (SOCS) 3 and other regulators of the IFN response have been identified as key candidates for the IFN refractory phenotype due to their regulatory role on the IFN response. AXL is a receptor tyrosine kinase that has been identified as a key regulator of interferon (IFN) signalling in myeloid cells of the immune system, but has not been examined in the context of chronic HCV infection. Here, we show that AXL is up-regulated following HCV infection, both in vitro and in vivo and is likely induced by type I/III IFNs and inflammatory signalling pathways. AXL inhibited type IFNα mediated ISG expression resulting in a decrease in its antiviral efficacy against HCV in vitro. Furthermore, patients possessing the favourable IFNL3 rs12979860 genotype associated with treatment response, showed lower AXL expression in the liver and a stronger induction of AXL in the blood, following their first dose of IFN. Together, these data suggest that elevated AXL expression in the liver may mediate an IFN-refractory phenotype characteristic of patients possessing the unfavourable rs12979860 genotype, which is associated with lower rates of viral clearance.

The Mechanism of Interferon Refractoriness During Hepatitis C Virus Infection and Its Reversal with a Peroxisome Proliferator-Activated Receptor α Agonist

Patients who respond poorly to therapies for hepatitis C virus (HCV) infection display a characteristic phenotype with high basal hepatic interferon-stimulated gene (ISG) expression, but limited induction following interferon (IFN) treatment. The molecular pathways that mediate this refractory state are not known. We examined whether the AMPK activator metformin, the PPARγ agonist pioglitazone, or the PPARα agonist WY-14643 could potentiate IFN responses, reverse IFN refractoriness, and enhance viral eradication in hepatocytes. WY-14643 demonstrated the strongest antiviral synergy with IFN-α and so was tested in the context of chronic IFN activation. Cells rendered refractory to IFN by IFN-α pretreatment were resensitized by WY-14643, as demonstrated by improved STAT1 phosphorylation, promoter activation, and ISG expression. WY-14643 treatment reduced the expression of key negative regulators of IFN signaling: the AXL receptor tyrosine kinase, suppressor of cytokine signaling (SOCS) 1 and 3, which are upregulated in the IFN-refractory state. AXL is a novel regulator of IFN-α signaling that is induced by HCV infection in vitro and which may drive SOCS3 expression. Our data suggests that PPARα agonists could be a useful adjunct treatment for chronic HCV infection by reducing the expression of AXL/SOCS and increasing the sensitivity to IFN.

The Hepatitis C treatment experience: Patients' perceptions of the facilitators of and barriers to uptake, adherence and completion

OBJECTIVE

This study explores the perceptions of patients receiving treatment for Hepatitis C to determine what factors influence their decision to commence treatment, ability to maintain adherence and complete their treatment program.

DESIGN

Semi-structured interview techniques were used in a qualitative study of 20 patients undergoing treatment for Chronic Hepatitis C (CHC).

MAIN OUTCOME MEASURES

To explore patients' perceived barriers and facilitators of Hepatitis C treatment adherence and completion.

RESULTS

Analysis of patient interviews identified four key themes: (1) motivations for commencing CHC treatment - fear of death and ridding themselves of stigma and shame; (2) the influential role of provider communication - patients reported that information and feedback that was personalised to their needs and lifestyles was the most effective for improving adherence to treatment; (3) facilitators of treatment adherence and completion - social, emotional and practical support improved adherence and completion, as did temporarily ceasing employment; (4) barriers to treatment adherence and completion - these included side effects, stigma, a complicated dosing schedule and limitations of the public healthcare system.

CONCLUSION

To increase treatment adherence and completion rates, a patient-centred approach is required that addresses patients' social, practical, and emotional support needs and adaptive coping strategies.

Hepatitis C virus infection mediates cholesteryl ester synthesis to facilitate infectious particle production

Cholesterol is a critical component of the hepatitis C virus (HCV) life cycle, as demonstrated by its accumulation within infected hepatocytes and lipoviral particles. To cope with excess cholesterol, hepatic enzymes ACAT1 and ACAT2 produce cholesteryl esters (CEs), which are destined for storage in lipid droplets or for secretion as apolipoproteins. Here we demonstrate in vitro that cholesterol accumulation following HCV infection induces upregulation of the ACAT genes and increases CE synthesis. Analysis of human liver biopsy tissue showed increased ACAT2 mRNA expression in liver infected with HCV genotype 3, compared with genotype 1. Inhibiting cholesterol esterification using the potent ACAT inhibitor TMP-153 significantly reduced production of infectious virus, but did not inhibit virus RNA replication. Density gradient analysis showed that TMP-153 treatment caused a significant increase in lipoviral particle density, suggesting reduced lipidation. These data suggest that cholesterol accumulation following HCV infection stimulates the production of CE, a major component of lipoviral particles. Inhibition of CE synthesis reduces HCV particle density and infectivity, suggesting that CEs are required for optimal infection of hepatocytes.

IFNL3 mediates interaction between innate immune cells: Implications for hepatitis C virus pathogenesis

Common IFN lambda 3 (IFNL3) variants have been demonstrated to affect spontaneous and treatment-induced clearance of hepatitis C virus (HCV) infection. The functional basis of these genetic variants has yet to be determined. Data examining the effect of IFNL3, specifically, in innate immune cells is lacking. Here, we determined the expression of IFNL3 and its receptor IFNLR1 in blood immune cell subsets and in HCV-infected livers. Next we assessed their sensitivity to IFNL3. All participants were genotyped for the IFNL3 SNPs rs8099917 and rs12979860. Importantly, unstimulated blood immune cells express significantly higher levels of IFNL3 than HCV liver biopsies. Plasmacytoid dendritic cells (pDCs) are the predominant producers of IFNLR1, especially in response to IFN-α. PBMCs, monocytes and pDCs all respond to IFNL3 based on MxA up-regulation. No differences in IFNL3 expression levels between rs8099917 or rs12979860 genotypes were detected. This is the first study to show peripheral blood pDCs to be the main producers of IFNL3, especially compared with HCV-infected livers. This makes innate immune cells the key players in determining the functional significance of INFL3 polymorphisms in patients with HCV.

Endocannabinoid CB1 antagonists inhibit hepatitis C virus production, providing a novel class of antiviral host-targeting agents

Direct-acting antivirals have significantly improved treatment outcomes in chronic hepatitis C (CHC), but side effects, drug resistance and cost mean that better treatments are still needed. Lipid metabolism is closely linked with hepatitis C virus (HCV) replication, and endocannabinoids are major regulators of lipid homeostasis. The cannabinoid 1 (CB1) receptor mediates these effects in the liver. We have previously shown upregulation of CB1 receptors in the livers of patients with CHC, and in a HCV cell-culture model. Here, we investigated whether CB1 blockade inhibited HCV replication. The antiviral effect of a CB1 antagonist, N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251), was examined in HCV strain JFH1 cell-culture and subgenomic replicon models. The effects on the expression of genes involved in lipid metabolism were also measured. CB1 short hairpin RNA (shRNA) was used to confirm that the effects were specific for the cannabinoid receptor. Treatment with AM251 strongly inhibited HCV RNA (~70 %), viral protein (~80 %), the production of new virus particles (~70 %) and virus infectivity (~90 %). As expected, AM251 reduced the expression of pro-lipogenic genes (SREBP-1c, FASN, SCD1 and ACC1) and stimulated genes promoting lipid oxidation (CPT1 and PPARα). This effect was mediated by AMP-activated protein kinase (AMPK). Stable CB1 knockdown of cells infected with HCV showed reduced levels of HCV RNA compared with controls. Thus, reduced CB1 signalling inhibits HCV replication using either pharmacological inhibitors or CB1 shRNA. This may be due, at least in part, to reduced lipogenesis, mediated by AMPK activation. We suggest that CB1 antagonists may represent an entirely new class of drug with activity against HCV.

Instrumental support to facilitate hepatitis C treatment adherence: working around shortfalls in shared-care

Adherence to treatment for hepatitis C virus (HCV) infection is associated with the successful eradication of infection. However, patients often have difficulty adhering to HCV treatment because of factors such as the psychiatric side effects of regimens and social disadvantage. Commonly, health professionals including specialist physicians, nurses, social workers and psychologists work together under a multidisciplinary model of shared-care to support patients' adherence to HCV treatment. In some HCV treatment clinics, shared-care is not always available, or only partially implemented and this has implications for patient adherence. To explore the facilitators of adherence, an interview-based study was conducted in 2012 with a purposive sample of Australian physicians and nurses (N = 20). The findings reveal that when comprehensive shared-care was limited or unavailable, physicians and nurses filled in the gaps by assuming roles outside of their expertise to help patients adhere to HCV treatment. Physicians and nurses applied instrumental support strategies based on psychosocial interventions, namely patient advocacy, pragmatic problem-solving, treatment engagement and emotional support. These strategies were provided by dedicated physicians and nurses to address shortfalls in multidisciplinary shared-care. Although these interventions were reported to assist adherence, there is an increased risk of complications when physicians and nurses move beyond the bounds of their disciplinary training, for example, to assess and manage patients' psychiatric side effects or advocate on their behalf for social services. Future research should measure the effectiveness of instrumental support strategies on HCV treatment adherence, and explore the costs associated with physicians and nurses providing instrumental support in the absence of comprehensive multidisciplinary shared-care.

Hepatic metallothionein expression in chronic hepatitis C virus infection is IFNL3 genotype-dependent

The IFNL3 genotype predicts the clearance of hepatitis C virus (HCV), spontaneously and with interferon (IFN)-based therapy. The responder genotype is associated with lower expression of interferon stimulated genes (ISGs) in liver biopsies from chronic hepatitis C patients. However, ISGs represent many interacting molecular pathways, and we hypothesised that the IFNL3 genotype may produce a characteristic pattern of ISG expression explaining the effect of genotype on viral clearance. For the first time, we identified an association between a cluster of ISGs, the metallothioneins (MTs) and IFNL3 genotype. Importantly, MTs were significantly upregulated (in contrast to most other ISGs) in HCV-infected liver biopsies of rs8099917 responders. An association between lower fibrosis scores and higher MT levels was demonstrated underlying clinical relevance of this association. As expected, overall ISGs were significantly downregulated in biopsies from subjects with the IFNL3 rs8099917 responder genotype (P=2.38 × 10(-7)). Peripheral blood analysis revealed paradoxical and not previously described findings with upregulation of ISGs seen in the responder genotype (P=1.00 × 10(-4)). The higher MT expression in responders may contribute to their improved viral clearance and MT-inducing agents may be useful adjuncts to therapy for HCV. Upregulation of immune cell ISGs in responders may also contribute to the IFNL3 genotype effect.

Virus induced inflammation and cancer development

Chronic inflammation as a result of viral infection significantly increases the likelihood of cancer development. A handful of diverse viruses have confirmed roles in cancer development and progression, but the list of suspected oncogenic viruses is continually growing. Viruses induce cancer directly and indirectly, by activating inflammatory signalling pathways and cytokines, stimulating growth of infected cells and inhibiting apoptosis. Although oncogenic viruses induce inflammation by various mechanisms, it is generally mediated by the MAPK, NFκB and STAT3 signalling pathways. This review will explore the unique mechanisms by which different oncogenic viruses induce inflammation to promote cancer initiation and progression.

Psychological, lifestyle and social predictors of hepatitis C treatment response: a systematic review

BACKGROUND

To increase cure rates for Hepatitis C, barriers to treatment adherence and completion must be identified and overcome.

AIMS

This study systematically reviewed evidence on the psychological, lifestyle and social determinants of achieving viral eradication with antiviral therapy.

METHODS

An electronic search strategy was used to identify relevant studies that examined psychological, lifestyle and social factors related to achieving a sustained virological response (SVR).

RESULTS

Thirty-four studies that matched our criteria were identified. Of the factors that predict response to treatment, Asian ethnicity was an independent predictor of SVR. We found an indirect relationship between diet and SVR, with non-responders to treatment consuming more polyunsaturated fatty acids, fats and carbohydrates than those who attained SVR. The effect of alcohol consumption relied on the amount consumed; fewer than 30 grams daily had no effect on SVR, whereas >70 grams daily had an adverse impact on a patient's ability to achieve SVR, with termination rates up to 44% in those who drank >2 drinks a day. Patients with psychiatric illnesses had comparable SVR rates to controls if they continued psychological therapy (average 42%), although discontinuation rates were high with 11 studies reporting rates from 14 to 48%.

CONCLUSIONS

There are major gaps in current knowledge of the impact of variables such as diet, exercise, attitudes and coping skills on cure rates in chronic Hepatitis C. Those who drink limited amounts of alcohol or have psychiatric disorders should be offered treatment for their disease, with adjunctive education and support to improve treatment completion.

Australian tertiary care outcomes of entecavir monotherapy in treatment naive patients with chronic hepatitis B

AIM: To evaluate the long-term treatment outcomes of entecavir monotherapy in treatment naive patients in an Australian tertiary care setting.

METHODS: A retrospective analysis of treatment naive patients receiving entecavir monotherapy through Westmead Hospital was performed. Patients were excluded if they had received previous treatment with another nucleoside or nucleotide analogue, were pregnant or less than 18 years old.

RESULTS: Out of 336 patients, 163 patients fulfilled the selection criteria. Range of follow up was 3-46 mo (mean 26 mo). 134 patients (82.2%) had pre-treatment biopsies, with 26 patients (16.0 %) demonstrating F3-4 fibrosis. In total, 153 patients (93.9%) achieved at least Partial Virological Suppression (PVS), with 134 patients (82.2%) achieving complete virological suppression. The cumulative CVS and PVS rates at 36 mo were 92.2% and 97.3%, respectively. 3 patients (1.8%) failed to achieve PVS, while 5 patients (3.0%) developed virological rebound. 128 patients (78.5%) maintained CVS throughout follow up. Predictors of CVS included lower baseline DNA level (P = 0.001), hepatitis B virus e antigen negative status (P = 0.001) and increasing age at treatment (log rank 0.001). No significant adverse effects were reported necessitating cessation of entecavir.

CONCLUSION: Entecavir monotherapy is efficacious and safe in an Australian tertiary care setting. Resistance and rebound rates are very low. This is similar to data from controlled and uncontrolled trials around the world.

Organelle dysfunction in hepatitis C virus-associated steatosis: anything to learn from nonalcoholic steatohepatitis?

Nonalcoholic fatty liver disease (NAFLD) spans a pathological spectrum from nonalcoholic steatosis to steatohepatitis. The pathophysiology of this disorder is complex, but includes insulin resistance and disrupted lipid and carbohydrate homeostasis, which at a subcellular level results in oxidative stress, free fatty acid-mediated lipotoxicity, defects in mitochondrial function, endoplasmic reticulum stress and cytokine-mediated toxicity. In chronic hepatitis C (CHC), systemic metabolic derangements similar to NAFLD may be operative, but in addition, virus-specific factors contribute to steatosis. The mechanisms for steatosis in CHC appear to share common pathways with those observed in NAFLD. This article outlines our current understanding of the subcellular mechanisms of steatosis in NAFLD and CHC, including their similarities and differences.

Lipid metabolism and HCV infection

Chronic infection by hepatitis C virus (HCV) can lead to severe liver disease and is a global healthcare problem. The liver is highly metabolically active and one of its key functions is to control the balance of lipid throughout the body. A number of pathologies have been linked to the impact of HCV infection on liver metabolism. However, there is also growing evidence that hepatic metabolic processes contribute to the HCV life cycle. This review summarizes the relationship between lipid metabolism and key stages in the production of infectious HCV.