New approaches in the treatment of hepatitis C

Undetectable Hepatitis C Viral Load Is Associated With Improved Outcomes Following Total Joint Arthroplasty

BACKGROUND

Previous reports establish that infection with hepatitis C virus (HCV) predisposes total joint arthroplasty (TJA) recipients to poor postoperative outcomes. The purpose of the present study is to assess whether variation in HCV VL influences perioperative outcomes following TJA.

METHODS

A multicenter retrospective review of all patients diagnosed with HCV who underwent primary TJA between January 2005 and April 2018 was conducted. Patients were stratified into 2 cohorts: (1) patients with an undetectable VL (U-VL) and (2) patients with a detectable VL (D-VL). Kaplan-Meier survivorship analysis was calculated with revision TJA as the end point. Subanalysis on the VL profile was done.

RESULTS

A total of 289 TJAs were included (U-VL:118 TJAs; D-VL:171 TJAs). Patients in the D-VL cohort had longer operative times (133.9 vs 109.2 minutes), higher intraoperative blood loss (298.4 vs 219.5 mL), longer inpatient hospital stays (4.0 vs 2.9 days), more postoperative infections (11.7% vs 4.2%), and an increased risk for revision TJA (12.9% vs 5.1%). Kaplan-Meier demonstrated that the U-VL cohort trended toward better survivorship (P = .17). On subanalysis of low and high VL, no difference in outcomes was appreciated.

CONCLUSION

TJA recipients with a detectable HCV VL have longer operative times, experience more intraoperative blood loss, have longer hospital length of stay, and are more likely to experience infection and require revision TJA. The blood loss, hospital length of stay, and revision rate findings should be interpreted with caution, however, as there are confounding factors. Our findings suggest that HCV VL is a modifiable risk factor that, can reduce the risk of infection and revision surgery. Additionally, serum HCV VL was not correlated with outcomes.

Real life efficacy and safety of direct-acting antiviral therapy for treatment of patients infected with hepatitis C virus genotypes 1, 2 and 3 in northwest China

BACKGROUND

Regimens involving direct-acting antiviral agents (DAAs) are recommended for the treatment of infection with hepatitis C virus (HCV) genotypes 1, 2 and 3. But real-world data is still not enough, especially in Asia.

AIM

To investigate the efficacy and safety of DAA-based regimens in a real-life setting in China.

METHODS

This study included 366 patients infected with HCV genotypes 1, 2 and 3, with or without cirrhosis, who were observed between May 2015 and December 2018. They were treated with ledipasvir and sofosbuvir (SOF) (genotype 1) with or without ribavirin (RBV), SOF and RBV (genotype 2), or SOF and daclatasvir (genotype 3), with or without RBV, for 12 or more wk. The participants’ sustained virological responses (SVR) at post-treatment week 12 (SVR12) was the primary endpoint. The occurrence of adverse events and drug-drug interactions were recorded.

RESULTS

In the 366 patients, genotype 1 (59.0%) was the most common genotype, followed by genotypes 2 (34.4%) and 3 (6.6%). Liver cirrhosis was diagnosed in 154 (42.1%) patients. Fifty (13.7%) patients were treatment-experienced. Intention-to-treat analysis revealed that SVR12 was 86.3% (316/366). For modified intention-to-treat analysis, SVR12 was achieved in 96.6% of overall patients (316/327), 96.3% in patients with genotype 1, 97.5% in those with genotype 2, and 95.0% in those with genotype 3. Most of the treatment failures were due to lack of follow-up (3 cases had non-responses, 1 had virological breakthrough, 11 relapsed and 36 did not participate in the follow-up). There was no significant difference in SVR between different genotypes and liver statuses (P < 0.05). Patients with lower alanine aminotransferase levels at baseline who achieved an end of treatment response were more likely to achieve SVR12 (P < 0.05). High SVR was observed regardless of age, gender, liver status, alpha-fetoprotein, HCV RNA levels or history of antiviral therapy (P > 0.05 for all). The cumulative hepatocellular carcinoma occurrence and recurrence rate after using the DAAs was 0.9%. Most of the adverse events were mild. We found two cases of special adverse events. One case involved facial and bilateral lower extremity edema, and the other case showed an interesting change in lipid levels while on medication. No severe adverse events were noted.

CONCLUSION

The DAA-based regimens tested in this study have excellent effectiveness and safety in all patients infected with HCV genotypes 1, 2 and 3, including those with cirrhosis.

Molecular dynamics and docking reveal the potency of novel GTP derivatives against RNA dependent RNA polymerase of genotype 4a HCV

AIM

To work on Hepatitis C Virus (HCV), one of the major causes of liver cirrhosis and hepatocellular carcinoma, polymerase of genotype 4a that have no solved structures deposited in the protein data bank (PDB) yet. Understanding the dynamics and testing some novel inhibitors are also covered.

MATERIALS AND METHODS

Molecular Dynamics Simulation (MDS) is performed for a period of 1 μs on comparatively modeled then validated NS5b of subtype 4a. Following MDS analysis, molecular docking is performed to test the inhibitory performance of eight novels suggested guanosine derivatives using 181 different conformations of the protein model gathered during the MDS run after the equilibration period.

KEY FINDINGS

The results yield that the eight modified, at position 2', GTP derivatives (fluorine, Hydroxyl, and sulphonyl oxydanyl) have binding energies comparable to the parent molecule, GTP. Besides, the eight suggested compounds have lower binding energies (and hence better in binding) compared to sofosbuvir (a drug approved by FDA in 2013 against HCV) and ribavirin (a wide range acting antiviral drug used before against HCV).

SIGNIFICANCE

Combined molecular dynamics and molecular docking are able to test the hypothesis of HCV polymerase dynamics doesn't affect the nucleotides (or nucleotide inhibitors) binding to its active site. Despite the reported highly dynamic subtype 4a of HCV; all the nucleotide inhibitors under the study are able to, tightly, bind to NS5b of genotype 4a. This behavior is reported before for the Zika virus polymerase, as well.

Pharmacogenetics of the anti-HCV drug sofosbuvir: a preliminary study

Background

Sofosbuvir is a potent nucleotide HCV NS5B polymerase inhibitor that is also a P-glycoprotein (encoded by the ABCB1 gene) and breast cancer resistance protein (encoded by the ABCG2 gene) substrate. Concerning previous anti-HCV therapies, pharmacogenetics had a significant impact, particularly considering the association of interleukin28B polymorphisms with dual-therapy (ribavirin + pegylated IFN) outcomes.

Objectives

In this work, we investigated the association between sofosbuvir and its prevalent metabolite (GS-331007) plasma concentrations at 1 month of therapy and genetic variants (SNPs) in genes encoding transporters and nuclear factors (ABCB1, ABCG2 and HNF4α) related to sofosbuvir transport.

Patients and methods

Allelic discrimination was performed through real-time PCR, whereas plasma concentrations were evaluated through liquid chromatography. One hundred and thirteen patients were enrolled.

Results

Sofosbuvir concentrations were below the limit of quantification since the drug was converted into its GS-331007 metabolite. ABCB1 2677 G>T (P = 0.044) and HNF4α 975 C>G (P = 0.049) SNPs were associated with GS-331007 metabolite plasma concentrations. In linear multivariate analysis, liver stiffness, insulin resistance, baseline haemoglobin and haematocrit and SNPs in the ABCB1 gene (3435 CT/TT and 1236 TT genotypes) were significant predictors of GS-331007 concentrations. Furthermore, we performed sub-analyses considering the anti-HCV concomitant drug and HCV genotype, identifying specific polymorphisms associated with GS-331007 plasma concentrations: ABCB1 3435 C>T and HNF4α975 C>G in patients treated with daclatasvir, ABCB1 2677 G>T with ledipasvir and ABCB1 3435 C>T, ABCB1 2677 G>T, ABCG2 421 C>A and ABCG2 1194 + 928 C>A with ribavirin.

Conclusions

In this study we suggested sofosbuvir GS-331007 metabolite plasma levels were affected by variants in the ABCB1 and HNFα genes.

The preoperative management of Hepatitis C may improve the outcome after total knee arthroplasty

AIMS

With an ageing population of patients who are infected with hepatitis C virus (HCV), the demand for total knee arthroplasty (TKA) in this high-risk group continues to grow. It has previously been shown that HCV infection predisposes to poor outcomes following TKA. However, there is little information about the outcome of TKA in patients with HCV who have been treated successfully. The purpose of this study was to compare the outcomes of TKA in untreated HCV patients and those with HCV who have been successfully treated and have a serologically confirmed remission.

PATIENTS AND METHODS

A retrospective review of all patients diagnosed with HCV who underwent primary TKA between November 2011 and April 2018 was conducted. HCV patients were divided into two groups: 1) those whose HCV was cured (HCV-C); and 2) those in whom it was untreated (HCV-UT). All variables including demographics, HCV infection characteristics, surgical details, and postoperative medical and surgical outcomes were evaluated. There were 64 patients (70 TKAs) in the HCV-C group and 63 patients (71 TKAs) in the HCV-UT cohort. The mean age at the time of surgery was 63.0 years (sd 7.5; 44 to 79) in the HCV-C group and 61.7 years (sd 6.9; 47 to 88) in the HCV-UT group.

RESULTS

HCV-UT patients had a significantly longer mean hospital stay (3.4 days vs 2.9 days; p = 0.04), were more likely to be transferred to the intensive care unit (14.1% vs 4.3%; p = 0.04), and were significantly more often discharged to a post-acute care facility (39.4% vs 14.3%; p < 0.01). HCV-UT patients had significantly more postoperative infections (15.5% vs 4.3%; p = 0.03), surgical complications (21.1% vs 7.1%; p = 0.02), and revision TKA (12.7% vs 1.4%; p < 0.01) than HCV-C patients.

CONCLUSION

The preoperative treatment of HCV can reduce the risk of complications, including prosthetic joint infection and revision TKA. We recommend that HCV treatment regimens should be integrated into the preoperative optimization protocol for this high-risk group of patients. Cite this article: Bone Joint J 2019;101-B:667-674.

Antigenicity and Immunogenicity of Differentially Glycosylated Hepatitis C Virus E2 Envelope Proteins Expressed in Mammalian and Insect Cells

The development of a prophylactic vaccine for hepatitis C virus (HCV) remains a global health challenge. Cumulative evidence supports the importance of antibodies targeting the HCV E2 envelope glycoprotein to facilitate viral clearance. However, a significant challenge for a B cell-based vaccine is focusing the immune response on conserved E2 epitopes capable of eliciting neutralizing antibodies not associated with viral escape. We hypothesized that glycosylation might influence the antigenicity and immunogenicity of E2. Accordingly, we performed head-to-head molecular, antigenic, and immunogenic comparisons of soluble E2 (sE2) produced in (i) mammalian (HEK293) cells, which confer mostly complex- and high-mannose-type glycans; and (ii) insect (Sf9) cells, which impart mainly paucimannose-type glycans. Mass spectrometry demonstrated that all 11 predicted N-glycosylation sites were utilized in both HEK293- and Sf9-derived sE2, but that N-glycans in insect sE2 were on average smaller and less complex. Both proteins bound CD81 and were recognized by conformation-dependent antibodies. Mouse immunogenicity studies revealed that similar polyclonal antibody responses were generated against antigenic domains A to E of E2. Although neutralizing antibody titers showed that Sf9-derived sE2 induced moderately stronger responses than did HEK293-derived sE2 against the homologous HCV H77c isolate, the two proteins elicited comparable neutralization titers against heterologous isolates. Given that global alteration of HCV E2 glycosylation by expression in different hosts did not appreciably affect antigenicity or overall immunogenicity, a more productive approach to increasing the antibody response to neutralizing epitopes may be complete deletion, rather than just modification, of specific N-glycans proximal to these epitopes.IMPORTANCE The development of a vaccine for hepatitis C virus (HCV) remains a global health challenge. A major challenge for vaccine development is focusing the immune response on conserved regions of the HCV envelope protein, E2, capable of eliciting neutralizing antibodies. Modification of E2 by glycosylation might influence the immunogenicity of E2. Accordingly, we performed molecular and immunogenic comparisons of E2 produced in mammalian and insect cells. Mass spectrometry demonstrated that the predicted glycosylation sites were utilized in both mammalian and insect cell E2, although the glycan types in insect cell E2 were smaller and less complex. Mouse immunogenicity studies revealed similar polyclonal antibody responses. However, insect cell E2 induced stronger neutralizing antibody responses against the homologous isolate used in the vaccine, albeit the two proteins elicited comparable neutralization titers against heterologous isolates. A more productive approach for vaccine development may be complete deletion of specific glycans in the E2 protein.

Novel Guanosine Derivatives as Anti-HCV NS5b Polymerase: A QSAR and Molecular Docking Study

BACKGROUND

IDX-184 is a guanosine derivative having a potent inhibitory performance against HCV NS5b polymerase.

OBJECTIVE

To test three different groups of 2'C - modified analogues of guanosine nucleotide against HCV polymerase.

METHOD

Using combined Quantitative Structure-Activity Relationships (QSAR) and molecular docking, the suggested compounds are studied.

RESULTS

Examining the docked structures of the compounds with experimentally solved NS5b structure (PDB ID: 2XI3) revealed that most of the compounds have the same mode of interaction as that of guanosine nucleotide and hence, NS5b inhibition is possible.

CONCLUSION

It is revealed that sixteen modifications have a better binding affinity to NS5b compared to guanosine. In addition, seven more compounds are better in NS5b binding compared to the approved drug, sofosbuvir, and the compound under clinical trials, IDX-184. Hence, these compounds could be potent HCV NS5b inhibitors. Summary Points: Novel guanosine modifications were introduced in silico and optimized using QM. QSAR and docking calculations are performed to test the binding affinity of the compounds to HCV NS5b active site. Comparison between the binding affinities and the mode of interactions of the compounds and both GTP and IDX-184 is performed. Structural mining to quantify the mode of binding of the compounds to NS5b active site pocket.

New Direct-Acting Antivirals for the Treatment of Patients With Hepatitis C Virus Infection: A Systematic Review of Randomized Controlled Trials

BACKGROUND

New direct-acting antiviral agents (DAAs) approved for the treatment of patients infected by Hepatitis C virus (HCV) are well tolerated and increase sustained virological response (SVR) rate. We summarize current evidence on the efficacy and safety from comparative randomized controlled trials (RCTs) of DAAs.

METHODS

We systematically searched MEDLINE, Embase, Scopus, CENTRAL, and Lilacs as well as a list of reference literature. We included RCTs comparing DAAs with placebo or active control and reporting response rates and adverse events according to antiviral regimens. Risk ratios (RRs) were pooled as appropriate. We assessed the risk of bias of included studies and graded the quality of evidence according to the GRADE method.

RESULTS

We included 28 RCTs, enrolling more than 7000 patients. The quality of evidence was generally low. Twelve-week treatment with DAAs in naïve patients significantly increased SVR12 and SVR24 compared with placebo (RR 1.4, 95% CI 1.3-1.6; RR 1.5, 95% CI 1.4-1.6, respectively). This means that for every 1000 patients, 240 or 260 more patients experienced SVR12 or SVR24 if treated with any DAAs. We could not find RCTs assessing progression of liver disease or development of hepatocellular carcinoma. DAAs were not associated with higher incidence of serious adverse events or discontinuation due to adverse events.

CONCLUSIONS

This systematic review confirms that new DAAs are more effective in inducing SVR than placebo. Outside clinical trials, in real word, HCV cure with DAA regimens occurs in less than 90% of patients, so further comparative evaluations are needed to establish their long-term effects.

Superior Performance of Teaching and Transplant Hospitals in the Management of Hepatic Encephalopathy from 2007 to 2014

Background and Aims: Hepatic encephalopathy is a liver disease complication with significant mortality and costs. The aim of this study was to evaluate the relative performance of facilities based on their teaching status and transplant capability by correlating their connections to mortality, cost, and length of stay from 2007 to 2014. Methods: The Nationwide Inpatient Sample database was utilized to collect information on (USA) American patients admitted with a primary diagnosis of hepatic encephalopathy from 2007-2014. Hospitals were placed into one of four categories using their teaching and transplant status. Using regression analysis, mortality, length of stay and cost adjusted rate ratios were calculated. Results: The study revealed that teaching transplant centers had a mortality risk ratio of 0.783 (95% confidence interval (CI): 0.750-0.819, p < 0.001). Blacks had the highest mortality risk ratio, of 1.273 (95%CI: 1.217-1.331, p < 0.001). Furthermore, teaching transplant hospitals had a cost rate ratio of 1.226 (95%CI: 1.214-1.238, p < 0.001) and a length of stay rate ratio of 1.104 (95%CI: 1.093-1.115, p < 0.001). Conclusions: It appears that admission to transplant facilities for hepatic encephalopathy is associated with reduced mortality but increased costs and longer stay independent of transplantation. Moreover, factors impacting black mortality should also be examined more closely.

Modeling hepatitis C virus protein and p53 interactions in hepatocytes: Implications for carcinogenesis

Hepatitis C virus (HCV) infection has reached epidemic proportions worldwide. Individuals with chronic HCV infection and without access to treatment are at high risk for developing hepatocellular carcinoma (HCC), a liver cancer that is rapidly fatal after diagnosis. A number of factors have been identified that contribute to HCV-driven carcinogenesis such as scarring of the liver, and chronic inflammation. Recent evidence indicates a direct role for HCV-encoded proteins themselves in oncogenesis of infected hepatocytes. The viral protein HCV core has been shown to interact directly with the host tumor suppressor protein p53, and to modulate p53-activity in a biphasic manner. Here, biochemically-motivated mathematical models of HCV-p53 interactions are developed to elucidate the mechanisms underlying this phenomenon. We show that by itself, direct interaction between HCV core and p53 is insufficient to recapitulate the experimental data. We postulate the existence of an additional factor, activated by HCV core that inhibits p53 function. We present experimental evidence in support of this hypothesis. The model including this additional factor reproduces the experimental results, validating our assumptions. Finally, we investigate what effect HCV core-p53 interactions could have on the capacity of an infected hepatocyte to repair damage to its DNA. Integrating our model with an existing model of the oscillatory response of p53 to DNA damage predicts a biphasic relationship between HCV core and the transformative potential of infected hepatocytes. In addition to providing mechanistic insights, these results suggest a potential biomarker that could help in identifying those HCV patients most at risk of progression to HCC.

Hepatitis C Virus Clearance by Direct-acting Antiviral Results in Rapid Resolution of Hepatocytic Injury as Indicated by Both Alanine Aminotransferase and Aspartate Aminotransferase Normalization

Background and Aims: Hepatitis C virus (HCV) infection results in hepatocytic injury with elevation of both alanine aminotransferase (ALT) and aspartate aminotransferase (AST). It remains to be determined if direct-acting antiviral treatment can terminate hepatocytic injury following virologic response. To this end, we evaluated the pattern and predicting factors of ALT and AST normalization during and after direct-acting antiviral treatment with sustained virologic response at 12 weeks (SVR12). Methods: Single-center retrospective study on 115 HCV-infected patients who achieved SVR12 was performed. Results: At treatment week 2, 100% and 45.9% showed decline in HCV RNA to <700 IU/mL and undetectable levels, respectively, and this was associated with 85.5%, 83.9% and 77.4% ALT normalization, AST normalization and ALT and AST normalization. At end of treatment, 85.6% of patients with baseline elevation of both ALT and AST had normalization of both ALT and AST. At posttreatment weeks 12 and 24, 90.8% and 94.8% had normalization of both ALT and AST. HCV clearance also resulted in further decline of both ALT and AST in those with baseline <40 IU. Univariate analysis showed baseline Child-Pugh score of <6, model for end-stage liver disease score of <10, HCV genotype 1, and HCV RNA of <500 IU/mL at treatment week 2 were associated with sustained normalization of both ALT and AST at posttreatment week 12. On multivariate analysis, baseline model for end-stage liver disease score of <10 was significantly associated with normalization of both ALT and AST at posttreatment week 12, independent of baseline Child-Pugh score <6, HCV genotype 1, and HCV RNA of <500 IU/mL at treatment week 2. Conclusions: During direct-acting antiviral therapy, 85.5% and 83.9% had normalization of both ALT and AST as early as in week 2, providing biochemical evidence of hepatocytic injury resolution. Sustained normalization of both ALT and AST was seen in 90.8% at posttreatment weeks 12, and was independently associated with baseline model for end-stage liver disease score of <10.

Hepatitis C in Lebanon: the burden of the disease and the value of comprehensive screening and treatment

PURPOSE

To analyze the hepatitis C virus (HCV) burden in Lebanon and the value of comprehensive screening and treatment for different age groups and fibrosis stages.

METHODS

We used a multicohort, health-state-transition model to project the number of HCV genotype 1 and 4 patients achieving a sustained virologic response 12 weeks after treatment or progressing to compensated cirrhosis (CC), decompensated cirrhosis (DCC), hepatocellular carcinoma (HCC), or liver-related death (LrD) from 2016 to 2036. In the low/medium/high screening scenarios, the proportion of patients screened for HCV was projected to increase to 60%/85%/99%, respectively, by 2036. We analyzed four treatment strategies: 1) no treatment, 2) all-oral direct-acting antivirals (DAAs) given to F3-F4 (CC) patients only, 3) all-oral DAAs to F2-F3-F4 (CC) patients, and 4) all-oral DAAs to all fibrosis patients.

RESULTS

Low, medium, and high HCV screening scenarios projected that 3,838, 5,665, and 7,669 individuals will be diagnosed with HCV infection, respectively, from 2016 to 2036, or 40% of those aged 18-39 years, and 60% of those aged 40-80 years. With no treatment, the projected number of patients reaching CC, DCC, HCC, or LrD in 2036 was 899, 147, 131, and 147, respectively, for the 18-39 years age group. For the 40-80 years age group, these projections were substantially greater: 2,828 CC, 736 DCC, 668 HCC, and 958 LrD. The overall economic burden without treatment reached 150 million EUR. However, introducing DAAs for F0-F4 patients was projected to increase the proportion of remaining life-years spent in sustained virologic response 12 weeks after treatment by 43% and 62% compared to DAAs given at F2-F4 or F3-F4 only, respectively.

CONCLUSION

An enhanced screening policy combined with broader access to DAAs can diminish the future clinical and economic burden of HCV in the Lebanese population and, for the middle-aged and elderly, provide the greatest health benefit with net cost savings.

Value and innovation of direct-acting antivirals: long-term health outcomes of the strategic plan for the management of hepatitis C in Spain

OBJECTIVE

To assess the long-term healthcare costs and health outcomes in association with the access to new direct-acting antivirals (DAAs), during the first year of the National Strategic Plan for Chronic Hepatitis C (SPCHC) in patients with chronic hepatitis C (CHC) in Spain.

METHODS

A decision tree and a lifetime Markov model were developed to simulate the natural history, morbidity, and mortality of a cohort of 51,900 patients with CHC before (pre-DAA strategy) and after (post-DAA strategy) access to DAAs, following SPCHC approval. The percentage of patients treated, transition probabilities, disease management costs, health state utility values, sustained virologic response rates and treatment costs were obtained from the literature and published data from Spain. The results were expressed in terms of costs (€, 2016), quality-adjusted life years (QALYs) and prevention of clinical events, with an annual discount rate of 3%.

RESULTS

The post-DAA strategy would prevent 8,667 cases of decompensated cirrhosis, 5,471 cases of hepatocellular carcinoma, 1,137 liver transplants and 9,608 liver-related deaths. The cohort of 51,900 patients would require investments of 1,606 and 1,230 million euros with the post-DAA and pre-DAA strategies, respectively. This would produce 819,674 and 665,703 QALYs.

CONCLUSIONS

The use of new DAA-based treatments in CHC patients during the first year after the implementation of the SPCHC significantly reduced long-term morbidity and mortality and increased quality of life; demonstrating that this plan is an efficient use of public health resources.

Pharmacodynamic and pharmacokinetic evaluation of the combination of daclatasvir/sofosbuvir/ribavirin in the treatment of chronic hepatitis C

INTRODUCTION

The combination of daclatasvir (DCV), sofosbuvir (SOF), and ribavirin (RBV) is a direct-acting antiviral (DAA) regimen for the treatment of hepatitis C virus (HCV) infection. The inclusion of newer effective DAAs such as SOF and DCV with high efficacy and excellent tolerance introduced a new scenario in HCV infection therapy: high rates of sustained virological response (SVR), shorter therapies, less toxicity, and interferon-free treatments. This combination was approved for the treatment of HCV in treatment-naive or treatment-experienced patients with chronic HCV genotype 1 or 3 infection. Areas covered: This review summarizes the pharmacokinetics, pharmacodynamics, efficacy, and safety of DCV plus SOF and RBV therapy in the treatment of HCV infection. The topics include data regarding drug absorption, distribution, metabolism, excretion, and antiviral activity strategies, such as clinical dose selection and treatment duration. Expert opinion: This combination, taken orally with or without food, has an excellent pharmacokinetic and pharmacodynamic profile. DAC/SOF/RBV achieves very high rates of SVR in treatment-naive and treatment-experienced patients with chronic HCV infection, including difficult-to-treat patients such as those with compensated cirrhosis, post-transplant recurrence, or HIV-1 co-infection.

Pharmacogenetics and the treatment of HIV-/HCV-coinfected patients

This review will summarize the role of pharmacogenetics in the natural history of hepatitis C, particularly in patients with HIV/HCV and will take the perspective of pharmacogenetics and its influence on the response to antiviral therapy and the susceptibility to develop adverse effects. This review will also devote a section to host genetics in other clinical situations, such as disease progression and acute HCV infection, which may determine whether treatment of HIV-/HCV-coinfected patients is implemented or deferred.

Influence of ABCB11 and HNF4α genes on daclatasvir plasma concentration: preliminary pharmacogenetic data from the Kineti-C study

Background

Daclatasvir is an inhibitor of HCV non-structural 5A protein and is a P-glycoprotein substrate. Pharmacogenetics has had a great impact on previous anti-HCV therapies, particularly considering the association of IL-28B polymorphisms with dual therapy outcome.

Objectives

We investigated the association between daclatasvir plasma concentrations at 2 weeks and 1 month of therapy and genetic variants (SNPs) in genes encoding transporters and nuclear factors (ABCB1, ABCB11 and HNF4α).

Patients and methods

Allelic discrimination was achieved through real-time PCR, whereas plasma concentrations were evaluated through LC-MS/MS.

Results

Fifty-two patients were analysed, all enrolled in the Kineti-C study. HNF4α 975 C > G polymorphism was found to be associated with the daclatasvir plasma concentrations at 2 weeks (P = 0.009) and 1 month of therapy (P = 0.006). Linear regression analysis suggested that, at 2 weeks of therapy, age, baseline BMI and haematocrit were significant predictors of daclatasvir concentrations, whereas at 1 month of therapy ABCB111131 CC and HNF4α CG/GG genotypes were significant predictors of daclatasvir concentrations.

Conclusions

These are the first and preliminary results from our clinical study focusing on daclatasvir pharmacogenetics, showing that this approach could have a role in the era of new anti-HCV therapies.

Hepatitis C in healthcare personnel: secondary data analysis of therapies with direct-acting antiviral agents

Background

Hepatitis C Virus (HCV) infections are blood-borne, generally chronic and are associated with increased morbidity and mortality. The aim of this study is to describe the results of therapies with direct-acting antiviral agents (DAAs) in healthcare personnel.

Methods

Secondary data analysis using data from the Statutory Accident Insurance of the Health and Welfare Service. The study surveyed DAA therapies administered to insured parties (healthcare personnel with an HCV infection recognised as an occupational disease) in Germany between 01/01/2014 and 30/11/2016. The end points were results of monitorings carried out twelve weeks after the end of treatment (SVR12), side effects and the results of the assessment of reduced work ability after treatment. Multivariate logistic regression models were constructed to model SVR12.

Results

The study population (n = 180) comprised 74% women, 90% of the participants had an HCV genotype 1 infection. Two-thirds had fibrosis or cirrhosis and were treatment experienced. The most common combined therapy was ledipasvir and sofosbuvir (49%). A DAA therapy with ribavirin was administered in 20% of cases, with (pegylated) interferon and ribavirin used in 2% of cases. The majority of therapies were completed without any side effects. The overall SVR12 rate was 94%. Significant independent predictor of decrease odds of SVR12 was liver cirrhosis. Positive effects on the healthcare personnel’s work ability were observed after successful therapy.

Conclusion

High SVR12 rates were achieved in the sample population, with positive effects on their work ability. Early HCV therapy seems reasonable due to the increased chance of successful treatment of the infection.

Electronic supplementary material

The online version of this article (10.1186/s12995-018-0197-6) contains supplementary material, which is available to authorized users.

Recombinant Flag-tagged E1E2 glycoproteins from three hepatitis C virus genotypes are biologically functional and elicit cross-reactive neutralizing antibodies in mice

Hepatitis C virus (HCV) is a globally disseminated human pathogen for which no vaccine is currently available. HCV is highly diverse genetically and can be classified into 7 genotypes and multiple sub-types. Due to this antigenic variation, the induction of cross-reactive and at the same time neutralizing antibodies is a challenge in vaccine production. Here we report the analysis of immunogenicity of recombinant HCV envelope glycoproteins from genotypes 1a, 1b and 2a, with a Flag tag inserted in the hypervariable region 1 of E2. This modification did not affect protein expression or conformation or its capacity to bind the crucial virus entry factor, CD81. Importantly, in immunogenicity studies on mice, the purified E2-Flag mutants elicited high-titer, cross-reactive antibodies that were able to neutralize HCV infectious particles from two genotypes tested (1a and 2a). These findings indicate that E1E2-Flag envelope glycoproteins could be important immunogen candidates for vaccine aiming to induce broad HCV-neutralizing responses.

No longer 'written off' - times have changed for the BBV-infected dental professional

There is a recognised potential risk of transmission of blood-borne viruses (BBVs) from infected healthcare workers to patients during exposure prone procedures (EPPs). The restrictions placed on performance of EPPs by infected clinicians in the UK have had a particularly significant impact on dentists because of the exposure-prone nature of most dental procedures and the difficulties in identifying alternative career pathways in the profession that do not involve EPPs. More recently, the significant positive impact of antiviral drugs on viral load, together with a re-categorisation of EPPs in dentistry have resulted in evolution of the guidance with a consequent significant improvement to the career prospects of dentists infected with BBVs. This paper provides an update for practitioners on the progress that has been made and outlines the current position with respect to practice restrictions.

Impact of sustained virologic response on short-term clinical outcomes in hepatitis C-related cirrhosis

BACKGROUND

Hepatitis C virus (HCV) is a common cause of cirrhosis, leading to increased morbidity and mortality. Treatment of the underlying etiology has been shown to improve fibrosis and cirrhosis.

AIM

We sought to evaluate the impact of a sustained virologic response on liver chemistries, model for end stage liver disease (MELD) score, Child-Pugh-Turcotte score (CPT), and fibrosis 4 score (FIB4) in patients with liver cirrhosis secondary to HCV with portal hypertension, with or without decompensation.

METHODS

Patients with HCV seen in our transplant clinic between June 2013 and September 2015 were identified using ICD-9 code 573.3. Charts were reviewed retrospectively.

RESULTS

We collected data from 92 patients with a mean pretreatment MELD score of 9.16±2.98. The most common genotype was Ia, n=79 (86%). The mean duration of follow-up was 7.52±2.25 months. Transaminitis improved significantly at follow-up versus pretreatment [mean aspartate transaminase from 81.2±62.9 to 32.4±12.0 (P<0.0001); alanine transaminase 74.7±77.8 to 27.7±19.4 (P<0.0001)]. Albumin, bilirubin, and α-fetoprotein improved significantly. MELD scores improved in patients with pretreatment scores greater than 10 (P<0.0003), but not in patients with pretreatment scores less than 10 (P=0.501). The CPT score decreased from 6.1±0.9 to 5.8±0.9 (P<0.0024). The FIB4 score improved significantly in patients with baseline FIB4 more than 3.24, but not with higher baseline FIB4.

CONCLUSION

Use of direct antivirals in patients with decompensated cirrhosis because of HCV leads to improved MELD, FIB4, and CPT scores.

Outcomes assessment of hepatitis C virus-positive psoriatic patients treated using pegylated interferon in combination with ribavirin compared to new Direct-Acting Antiviral agents

AIM

To evaluate the outcomes in biological treatment and quality of life of psoriatic patients with chronic hepatitis C (CHC) treated with new Direct-Acting Antiviral agents (DAAs) compared to pegylated interferon-2α plus ribavirin (P/R) therapy.

METHODS

This is a retrospective study involving psoriatic patients in biological therapy who underwent anti-hepatitis C virus (HCV) treatment at the Department of Dermatology Galeazzi Orthopaedic Institute Milan, Italy from January 2010 to November 2017. The patients were divided into two groups: patients that underwent therapy with DAAs and patients that underwent HCV treatment with P/R. Patients were assessed by a dermatologist for psoriasis symptoms, collecting Psoriasis Area Severity Index (PASI) scores and the Dermatology Quality of Life Index (DLQI). PASI and DLQI scores were evaluated 24 wk after the end of HCV treatment and were assumed as an outcome of the progression of psoriasis. Switching to a different bDMARD was considered as an inadequate response to biological therapy. The dropout of HCV therapy and sustained virological response (SVR) were considered as outcomes of HCV therapy.

RESULTS

Fifty-nine psoriatic patients in biological therapy underwent antiviral therapy for CHC. Of this, 27 patients were treated with DAAs and 32 with P/R. After 24 wk post treatment, the DLQI and the PASI scores were significantly lower (P < 0.001 and P < 0.005, respectively) in the DAAs group compared with P/R group. None of the patients in the DAAs group (0/27) compared to 8 patients of the P/R group (8/32) needed a shift in biological treatment.

CONCLUSION

DAAs seem to be more effective and safe than P/R in HCV-positive psoriatic patients on biological treatment. Fewer dermatological adverse events may be due to interferon-free therapy.

Vitamin D pathway genetic variants are able to influence sofosbuvir and its main metabolite pharmacokinetics in HCV mono-infected patients

Vitamin D levels and genetic variants were associated with drug outcome/toxicity and concentrations. The plasma exposure of GS-331007, the main sofosbuvir metabolite, has been related to SVR. We evaluated the impact of polymorphisms in genes (CYP27B1, CYP24A1, VDBP and VDR) related to vitamin D pathway on sofosbuvir and GS-331007 plasma levels in HCV mono-infected patients at one month of treatment. Polymorphisms were investigated through real-time PCR; drug plasma quantification was performed through a UHPLC-MS/MS method. GS-331007 levels were associated with CYP24A1rs2248359 and VDRCdx2 variants in all the analyzed patients and linear regression analysis showed that sex, body mass index, HCV genotype, baseline estimated glomerular filtration rate, VDRCdx2AG/GG and CYP27B1-1260TT genotypes significantly predict concentrations. We performed sub-analyses considering the HCV genotype and the concomitant drug, identifying polymorphisms associated with GS-331007 concentrations. This is the first study focusing on vitamin D pathway gene variants and DAAs concentrations, but further studies are required.

Vitamin D pathway gene polymorphisms and hepatocellular carcinoma in chronic hepatitis C-affected patients treated with new drugs

PURPOSE

Since HCV infection may lead to hepatocellular carcinoma (HCC) and vitamin D (deficiency) is related to cancer, we investigated if SNPs in genes involved in vitamin D pathway could predict HCV-related HCC presence in patients treated with new anti-HCV drugs.

METHODS

Patients with chronic hepatitis C and treated with direct-acting antivirals were enrolled. SNPs in VDR, CYP27B1, CYP24A1 and GC genes were assessed through real-time PCR. 258 patients were analyzed.

RESULTS

HCC was present in six patients, all taking sofosbuvir, all males and five/six had cirrhosis. HCV-RNA log levels at baseline were statistically different between patients with and without HCC. VDR FokI T > C SNP resulted associated with HCC: all the CC patients were free from HCC. An association between HCC presence and undetectable HCV-RNA at 1 month of therapy was suggested; cirrhosis was related to HCC. HCC risk factors were age, ribavirin administration, IL28Brs12979860CC and previous treatments; VDR FokICC, sex and insulin resistance were protective factors.

CONCLUSIONS

These data highlighted vitamin D pathway gene SNPs and HCC relationship in the Italian population; further studies are required.

Chromosomal instability and cytotoxicity induced by ribavirin: comparative analysis in cell lines with different drug-metabolizing profiles

Ribavirin is an important component of the treatment for hepatitis C virus (HCV) infection and, in combination with the new direct-acting antiviral (DAA) agents, comprises the major current therapeutic regimens. This study evaluated the cytotoxicity and chromosomal instability induced by ribavirin using the in vitro cytokinesis-block micronucleus cytome (CBMN-Cyt) assay in two cell lines with different expression levels of drug-metabolizing enzymes: human hepatocellular carcinoma cells (HepG2) and Chinese hamster ovary (CHO-K1) cells. HepG2 cells were treated with nine concentrations (from 15.3 μg/ml to 3.9 mg/ml) and CHO-K1 cells were exposed to eight concentrations (from 15.3 μg/ml to 1.9 mg/ml) of ribavirin for 24 h. Ribavirin inhibited cell proliferation in both cell lines, but at different concentrations: 3.9 mg/ml in HepG2 and 244.2 μg/ml in CHO-K1 cells. No significant differences were observed regarding aspects of cell death in HepG2 and CHO-K1 cells, reflecting the absence of cytotoxic effects associated to ribavirin. Ribavirin did not increase the frequency of nucleoplasmic bridges (NPBs) and nuclear bud (NBUD). However, when compared to the negative control, a significant increase in micronuclei (MNi) frequency was observed in both cell lines. However, chromosomal instability was induced by higher concentrations of ribavirin in HepG2 cells (from 61.1 to 976.8 μg/ml), compared with CHO-K1 cells (15.3 and 30.5 μg/ml). These results demonstrate the potential of ribavirin to promote chromosomal instability, and suggest that cells with different expressions of drug-metabolizing enzymes show different susceptibility to ribavirin effects.

Zika virus: novel guanosine derivatives revealed strong binding and possible inhibition of the polymerase

Aim: During the last 2 years, the zika virus (ZIKV) outbreak has rapidly spread worldwide to more than 80 countries. In the last decade, nucleotide inhibitors (NIs) have been widely studied against different viruses such as HCV and human coronaviruses. Materials & methods: In this study, four novel guanosine derivatives were tested in silico against ZIKV polymerase. Discussion: The modified guanosines at position 2′ in the ribose ring gave comparable binding energies to that of GTP; hence, it could compete with GTP for the ZIKV polymerase active site and halt viral replication. Conclusion: The suggested guanosine derivatives had a higher affinity than ribavirin (wide range antiviral drug) in binding to ZIKV polymerase.

Synthesis and biological evaluation of tricyclic matrinic derivatives as a class of novel anti-HCV agents

Background

12N-benzyl matrinic acid analogues had been identified to be a novel scaffold of anti-HCV agents with a specific mechanism, and the representative compound 1 demonstrated a moderate anti-HCV activity. The intensive structure–activity relationship of this kind of compounds is explored so as to obtain anti-HCV candidates with good druglike nature.

Results

Taking compound 1 as the lead, 32 compounds (of which 27 were novel) with diverse structures on the 11-side chain, including methyl matrinate, matrinol, matrinic butane, (Z)-methyl Δ^βγ-matrinic crotonate derivatives were synthesized and evaluated for their anti-HCV activities. Among all the compounds, matrinol 7a demonstrated potential potency with a greatly improved SI value of 136. Pharmacokinetic studies of 7a showed the potential for oral administration that would allow further in vivo safety studies. The free hydroxyl arm in 7a made it possible to prepare pro-drugs for the potential in the treatment of HCV infection.

Conclusions

27 novel 12N-substituted matrinol derivatives were prepared. The SAR study indicated that the introduction of electron-donating substitutions on the benzene ring was helpful for the anti-HCV activity, and the unsaturated 11-side chain might not be favorable for the activity. This study provided powerful information on further strategic optimization and development of this kind of compounds into a novel family of anti-HCV agents. Graphical abstract

Genomic variants link to hepatitis C racial disparities

Chronic liver diseases are one of the major public health issues in United States, and there are substantial racial disparities in liver cancer-related mortality. We previously identified racially distinct alterations in the expression of transcripts and proteins of hepatitis C (HCV)-induced hepatocellular carcinoma (HCC) between Caucasian (CA) and African American (AA) subgroups. Here, we performed a comparative genome-wide analysis of normal vs. HCV+ (cirrhotic state), and normal adjacent tissues (HCCN) vs. HCV+HCC (tumor state) of CA at the gene and alternative splicing levels using Affymetrix Human Transcriptome Array (HTA2.0). Many genes and splice variants were abnormally expressed in HCV+ more than in HCV+HCC state compared with normal tissues. Known biological pathways related to cell cycle regulations were altered in HCV+HCC, whereas acute phase reactants were deregulated in HCV+ state. We confirmed by quantitative RT-PCR that SAA1, PCNA-AS1, DAB2, and IFI30 are differentially deregulated, especially in AA compared with CA samples. Likewise, IHC staining analysis revealed altered expression patterns of SAA1 and HNF4α isoforms in HCV+ liver samples of AA compared with CA. These results demonstrate that several splice variants are primarily deregulated in normal vs. HCV+ stage, which is certainly in line with the recent observations showing that the pre-mRNA splicing machinery may be profoundly remodeled during disease progression, and may, therefore, play a major role in HCV racial disparity. The confirmation that certain genes are deregulated in AA compared to CA tissues also suggests that there is a biological basis for the observed racial disparities.

Evolution of matrinic ethanol derivatives as anti-HCV agents from matrine skeleton

Twenty-two novel 12N-substituted matrinic ethanol derivatives were synthesized and evaluated for their antiviral activities against HCV taking compound 1 as the lead. The SAR study indicated that the shortening of the 11-butyl chain to ethyl chain did not affect the activity significantly. Out of the target compounds, matrinic ethanol 6a demonstrated a potential anti-HCV effect with an EC₅₀ value of 3.2μM and a SI value of 96.6. The free hydroxyl arm in 6a made it possible as a parent structure to prepare pro-drug for the potential application in HCV treatment. This study provided powerful information on further strategic optimization and development of this kind of compounds into a novel family of anti-HCV agents.

Pharmacokinetic drug evaluation of velpatasvir plus sofosbuvir for the treatment of hepatitis C virus infection

INTRODUCTION

The fixed-dose combination therapy of sofosbuvir (SOF) plus velpatasvir (VEL) is the first pangenotypic, direct-acting antiviral (DAA), single-treatment regimen (STR) for the treatment of hepatitis C virus (HCV) infection to be commercialized. It is approved for the treatment of HCV genotypes 1, 2, 3, 4, 5, and 6. Following approval in 2016, new pharmacokinetic and pharmacodynamic data were reported, which led to important clinical applications. Areas covered: This review provides a summary of the pharmacokinetics, pharmacodynamics, efficacy and safety of SOF/VEL therapy for treatment of HCV infection. The topics covered include data regarding the drug's absorption, distribution, metabolism, excretion and antiviral activity strategies, such as clinical dose selection and treatment duration. Expert opinion: This novel combination therapy containing 400 mg of SOF plus 100 mg of VEL, taken orally, once daily, with or without food, has an excellent pharmacokinetic and pharmacodynamic profile. SOF/VEL achieved very high rates of sustained virological response in treatment-naive and treatment-experienced patients with chronic HCV genotype 1-6 infection, including those with compensated cirrhosis or HIV-1 co-infection.

Value of Treating All Stages of Chronic Hepatitis C: A Comprehensive Review of Clinical and Economic Evidence

INTRODUCTION

The goal of chronic hepatitis C (CHC) treatment is to achieve a sustained virologic response (SVR). The new generation of direct-acting antivirals (DAAs) offers 90-100% SVR rates. However, access to these treatments is generally limited to patients with advanced liver disease. The aim of this review is to provide an overview of the clinical and economic benefits of achieving SVR and to better understand the full value of CHC treatment in all stages of liver disease.

METHODS

A comprehensive literature review was performed using the PubMed, Embase, and Cochrane library databases to identify articles examining the clinical, economic, and quality of life benefits associated with SVR. Articles were limited to those published in English language from January 2006 through January 2016. Inclusion criteria were (1) patients with CHC, (2) retrospective and prospective studies, (3) reporting of mortality, liver morbidity, extrahepatic manifestations (EHMs), and economic outcomes and, (4) availability of an abstract or full-text publication.

RESULTS

Overall this review identified 354 studies involving more than 500,000 CHC patients worldwide. Evidence from 38 studies (n = 73,861) shows a significant mortality benefit of achieving SVR in patients with all stages of fibrosis. Long-term studies with follow-up of 5-12 years suggest that, particularly among non-cirrhotic patients, there is a significant decrease in mortality in SVR versus non-SVR groups. Ninety-nine studies conducted in 235,891 CHC patients in all stages of fibrosis show that SVR reduces liver-related mortality, incidence of hepatocellular carcinoma (HCC), and decompensation. A total of 233 studies show that chronic HCV infection is associated with several serious EHMs, some of which can have high mortality. Evidence from four modeling studies shows that delaying treatment to CHC patient populations could significantly increase mortality, morbidity, and medical costs.

CONCLUSIONS

There is a robust body of evidence demonstrating diverse sources of value from achieving SVR in all stages of liver disease. While access to treatment is generally limited to late-stage patients, less restrictive treatment strategies that target HCV eradication have the potential to abate the burdens of mortality, liver morbidity and extrahepatic manifestations, and the associated healthcare costs.

Hepatitis C among healthcare personnel: secondary data analyses of costs and trends for hepatitis C infections with occupational causes

Background

Hepatitis C infection is a global public health issue. Chronic hepatitis C infection is associated with significant morbidity and mortality. The aim of this study is to describe the costs for occupationally-cased hepatitis C infections based on data from an accident insurance carrier.

Methods

This study is a secondary analysis based on the Database of a German Institution for Statutory Accident Insurance. The analysis is based on a sample of insured parties whose hepatitis C infections were recorded as occupational diseases between 1996 and 2013. The analysis is based on recognised hepatitis C cases and incorporates records registered between 1 January 2000 and 31 December 2014.

Results

Within the study period, the number of reported and recognised hepatitis C cases declined by 73 and 86% respectively. The majority of recognised hepatitis C cases (n = 1.121) were female, older than 40 years and were active in a medical nursing profession. In the study period, the costs came to a total of € 87.9 million, of which 60% was attributable to pension payments (€ 51,570,830) and around 15% was attributable to pharmaceutical and medicinal products (€ 12,978,318). Expenses for drugs exhibited heavy increases in 2012 (from around € 500,000–800,000 to € 1.7 million) and 2014 (to € 2.5 million) in particular. Pension payments came to € 1.6 million in 2000 and rose continuously to over € 4 million in 2014. Expenses for occupational rehabilitation accounted for less than 1%.

Conclusions

For hepatitis C infections as an occupational disease, a considerable increase in costs has been observed in recent years, while the number of reports has declined heavily. This rise in costs is explained by the increase in pension payments and, since 2012, by a rise in the costs for drugs. The high costs of anti-viral therapies is offset by the potential for considerable treatment benefits. Healing the infection is expected to generate long-term cost savings for statutory accident insurance carriers, and also for social security systems.

New direct-acting antivirals for patients with chronic HCV infection: can we monitor treatment using an HCV core antigen assay?

We evaluated the diagnostic usefulness of an HCV core antigen (HCV-Ag) assay in HCV-infected patients undergoing treatment with direct-acting antivirals. We analyzed 103 samples from 28 patients. Compared with RT-PCR, sensitivity was 96.2% and specificity was 100%. The correlation between techniques was excellent (Pearson coefficient: 0.871). HCV-Ag proved to be useful in patients with sustained viral response and in patients who experienced treatment failures.

Altered Glycosylation Patterns Increase Immunogenicity of a Subunit Hepatitis C Virus Vaccine, Inducing Neutralizing Antibodies Which Confer Protection in Mice

Hepatitis C virus (HCV) infection is a global health problem for which no vaccine is available. HCV has a highly heterogeneous RNA genome and can be classified into seven genotypes. Due to the high genetic and resultant antigenic variation among the genotypes, inducing antibodies capable of neutralizing most of the HCV genotypes by experimental vaccination has been challenging. Previous efforts focused on priming humoral immune responses with recombinant HCV envelope E2 protein produced in mammalian cells. Here, we report that a soluble form of HCV E2 (sE2) produced in insect cells possesses different glycosylation patterns and is more immunogenic, as evidenced by the induction of higher titers of broadly neutralizing antibodies (bNAbs) against cell culture-derived HCV (HCVcc) harboring structural proteins from a diverse array of HCV genotypes. We affirm that continuous and discontinuous epitopes of well-characterized bNAbs are conserved, suggesting that sE2 produced in insect cells is properly folded. In a genetically humanized mouse model, active immunization with sE2 efficiently protected against challenge with a heterologous HCV genotype. These data not only demonstrate that sE2 is a promising HCV vaccine candidate, but also highlight the importance of glycosylation patterns in developing subunit viral vaccines.

IMPORTANCE

A prophylactic vaccine with high efficacy and low cost is urgently needed for global control of HCV infection. Induction of broadly neutralizing antibodies against most HCV genotypes has been challenging due to the antigenic diversity of the HCV genome. Here, we refined a high-yield subunit HCV vaccine that elicited broadly neutralizing antibody responses in preclinical trials. We found that soluble HCV E2 protein (sE2) produced in insect cells is distinctly glycosylated and is more immunogenic than sE2 produced in mammalian cells, suggesting that glycosylation patterns should be taken into consideration in efforts to generate antibody-based recombinant vaccines against HCV. We further showed that sE2 vaccination confers protection against HCV infection in a genetically humanized mouse model. Thus, our work identified a promising broadly protective HCV vaccine candidate that should be considered for further preclinical and clinical development.

Pharmacokinetics and pharmacodynamics of sofosbuvir and ledipasvir for the treatment of hepatitis C

INTRODUCTION

The sofosbuvir (SOF) plus ledipasvir (LDV) fixed dose combination is the first direct action antiviral (DAA) single-treatment regimen (STR) to be commercialized. It is approved for the treatment of Hepatitis C virus (HCV) genotypes 1,3,4,5 and 6. Following approval in 2014, new pharmacokinetics and pharmacodynamics data were reported, which led to important clinical applications. Areas covered: This article reviews the pharmacokinetic and pharmacodynamic properties of the SOF/LDV fixed dose combination for the treatment of HCV. The topics covered include data regarding the drug´s absorption, distribution, metabolism and excretion and antiviral activity strategies such as the clinical dose selection and treatment duration. Expert opinion: The SOF/LDV fixed dose combination has good pharmacological properties that lead to a high sustained virological response after 12 or 24 weeks of treatment; there is minimal interference with other drugs or associated renal or hepatic impairment, such that dose adjustment is not necessary.

Zika viral polymerase inhibition using anti-HCV drugs both in market and under clinical trials

In the last few months, a new Zika virus (ZIKV) outbreak evolved in America. In accordance, World Health Organization (WHO) in February 2016 declared it as Public Health Emergency of International Concern (PHEIC). ZIKV infection was reported in more than 60 countries and the disease was spreading since 2007 but with little momentum. Many antiviral drugs are available in market or in laboratories under clinical trials, could affect ZIKV infection. In silico docking study were performed on the ZIKV polymerase to test some of Hepatitis C Virus (HCV) drugs (approved and in clinical trials). The results show potency of almost all of the studied compounds on ZIKV polymerase and hence inhibiting the propagation of the disease. In addition, the study suggested two nucleotide inhibitors (IDX-184 and MK0608) that may be tested as drugs against ZIKV infection. J. Med. Virol. 88:2044-2051, 2016. © 2016 Wiley Periodicals, Inc.

International diagnostic guidelines for patients with HCV-related extrahepatic manifestations. A multidisciplinary expert statement

Hepatitis C virus (HCV) infection is responsible for both hepatic and extra-hepatic disorders (HCV-EHDs); these latter are correlated on one hand clearly with HCV lymphotropism causing immune-system dysregulation as well as with viral oncogenic potential, and on the other hand probably with chronic inflammatory status causing cardio-metabolic complications as well as neurocognitive disturbances. The spectrum of HCV-EHDs ranges from mild or moderate manifestations, such as arthralgia, sicca syndrome, peripheral neuropathy, to severe, life-threatening complications, mainly vasculitis and neoplastic conditions. Given the clinical heterogeneity of HCV-EHDs, HCV-infected individuals are inevitably referred to different specialists according to the presenting/prevalent symptom(s); therefore, the availability of comprehensive diagnostic guidelines is necessary for a patient's whole assessment that is decisive for early diagnosis and correct therapeutic approach of various hepatic and HCV-EHDs, regardless of the specific competencies of different physicians or referral centers. In this respect, a multidisciplinary network of experts, the International Study Group of Extrahepatic Manifestations Related to Hepatitis C Virus Infection (ISG-EHCV), was organized with the intention to formulate diagnostic guidelines for the work-up of possible HCV-EHDs. There was a broad consensus among ISG-EHCV members on the proposed guidelines, which essentially are based on two main levels of patient's assessment. At the referral stage, it is proposed that all patients with HCV infection should be invariably examined by means of first-line diagnostic procedures including virological and hepatic parameter evaluation, as well as the detection of clinical findings that may suggest one or more HCV-EHDs. This preliminary assessment should reveal specific HCV-EHDs, which will be deeper analyzed by means of second-line, targeted investigations. The proposed multidisciplinary expert statement represents the first attempt to draw comprehensive diagnostic guidelines for HCV-infected individuals encompassing the entire spectrum of HCV-related disorders, namely typical hepatic manifestations along with less common, often unpredictable HCV-EHDs. The HCV-EHDs may compromise to a substantial degree the overall disease outcome in a significant number of HCV-infected individuals that renders their timely identification and treatment an imperative. In conclusion, the application of standardized but thorough diagnostic guidelines of HCV-EHDs is advisable at the referral stage as well as during the follow-up period of HCV infected patients. It is envisioned that the proposed strategy will result in improvement of clinical outcomes in such patients.

Treatment of chronic hepatitis C with direct-acting antivirals: The role of resistance

The use of direct-acting antivirals (DAAs) to treat chronic hepatitis C has resulted in a significant increase in rates of sustained viral response (around 90%-95%) as compared with the standard treatment of peginterferon/ribavirin. Despite this, however, the rates of therapeutic failure in daily clinical practice range from 10%-15%. Most of these cases are due to the presence of resistant viral variants, resulting from mutations produced by substitutions of amino acids in the viral target protein that reduce viral sensitivity to DAAs, thus limiting the efficacy of these drugs. The high genetic diversity of hepatitis C virus has resulted in the existence of resistance-associated variants (RAVs), sometimes even before starting treatment with DAAs, though generally at low levels. These pre-existing RAVs do not appear to impact on the sustained viral response, whereas those that appear after DAA therapy could well be determinant in virological failure with future treatments. As well as the presence of RAVs, virological failure to treatment with DAAs is generally associated with other factors related with a poor response, such as the degree of fibrosis, the response to previous therapy, the viral load or the viral genotype. Nonetheless, viral breakthrough and relapse can still occur in the absence of detectable RAVs and after the use of highly effective DAAs, so that the true clinical impact of the presence of RAVs in therapeutic failure remains to be determined.

Promising Anti-Hepatitis C Virus Compounds from Natural Resources

Hepatitis C virus (HCV) infection is a major worldwide problem, which involves approximately 170 million people. High morbidity of patients is caused by chronic infection, which leads to liver cirrhosis, hepatocellular carcinoma and other HCV-related diseases. The sustained virological response (SVR) has been markedly improved to be >90% by the current standard interferon (IFN)-free treatment regimens with a combination of direct-acting antiviral agents (DAAs) targeting the viral NS3 protease, NS5A multi-function protein and NS5B RNA-dependent RNA polymerase, compared with 50–70% of SVR rates achieved by the previous standard IFN-based treatment regimens with or without an NS3 protease inhibitor. However, the emergence of DAA-resistant HCV strains and the limited access to the DAAs due to their high cost could be major concerns. Also, the long-term prognosis of patients treated with DAAs, such as the possible development of hepatocellular carcinoma, still needs to be further evaluated. Natural resources are considered to be good candidates to develop anti-HCV agents. Here, we summarize anti-HCV compounds obtained from natural resources, including medicinal plant extracts, their isolated compounds and some of their derivatives that possess high antiviral potency against HCV.

Specific CD8+ T cell response immunotherapy for hepatocellular carcinoma and viral hepatitis

Hepatocellular carcinoma (HCC), chronic hepatitis B (CHB) and chronic hepatitis C (CHC) are characterized by exhaustion of the specific CD8⁺ T cell response. This process involves enhancement of negative co-stimulatory molecules, such as programmed cell death protein-1 (PD-1), cytotoxic T-lymphocyte antigen-4 (CTLA-4), 2B4, Tim-3, CD160 and LAG-3, which is linked to intrahepatic overexpression of some of the cognate ligands, such as PD-L1, on antigen presenting cells and thereby favouring a tolerogenic environment. Therapies that disrupt these negative signalling mechanisms represent promising therapeutic tools with the potential to restore reactivity of the specific CD8⁺ T cell response. In this review we discuss the impressive in vitro and in vivo results that have been recently achieved in HCC, CHB and CHC by blocking these negative receptors with monoclonal antibodies against these immune checkpoint modulators. The article mainly focuses on the role of CTLA-4 and PD-1 blocking monoclonal antibodies, the first ones to have reached clinical practice. The humanized monoclonal antibodies against CTLA-4 (tremelimumab and ipilimumab) and PD-1 (nivolumab and pembrolizumab) have yielded good results in testing of HCC and chronic viral hepatitis patients. Trelimumab, in particular, has shown a significant increase in the time to progression in HCC, while nivolumab has shown a remarkable effect on hepatitis C viral load reduction. The research on the role of ipilimumab, nivolumab and pembrolizumab on HCC is currently underway.

How hepatitis C patients manage the treatment process of pegylated interferon and ribavirin therapy: a qualitative study

BACKGROUND

Hepatitis C virus (HCV) infection is a global public health issue. Adequate treatment for hepatitis C patients is important, but anticipated side effects make patients fearful of receiving treatment. Little is known about the experiences of hepatitis C patients who have completed treatment with pegylated interferon and ribavirin. The purpose of this study was to explore the experiences of hepatitis C patients who had undergone therapy with pegylated interferon and ribavirin and gain an understanding of what factors contributed to completion of treatment.

METHOD

This was a qualitative study with 21 adult hepatitis C patients purposively sampled from outpatient liver clinics of a medical university hospital in Taichung City, Taiwan. Participants had completed 6-12 months of therapy with pegylated interferon and ribavirin. Data were collected through individual, face-to-face, in-depth interviews conducted in the participants' homes from June-October 2013. Data were analysed using conventional content analysis.

RESULTS

Data analysis revealed three themes that described the strategies employed to alleviate and ease symptoms and manage the processes involved: restructuring their lifestyle, adopting a positive attitude, and seeking support.

CONCLUSION

Hepatitis C patients face many challenges during treatment with pegylated interferon and ribavirin. These findings provide knowledge that can be used in designing effective programs to help other Hepatitis C patients manage the side effects of pegylated interferon and ribavirin therapy, complete treatment and improve quality of life.

Symbiotic chemo- and immuno-therapy for hepatitis B and C viruses

Hepatitis B and C viruses (HBV and HCV), both cause serious chronic infections leading to fatal liver diseases. The prototype therapy for both HBV and HCV was based on IFN-α with or without ribavirin. The advent of direct-acting antivirals (DAA) for both HBV and HCV has remarkably improved the standard of treatment for both infections. While HCV can be eliminated following combination DAA therapy, HBV persists even after treatment, requiring life-long therapy with DAAs. Treatment with DAAs is also associated with high cost, the development of resistance and side effects. There is ample published evidence that both HBV and HCV can be eliminated from infected host cells through non-cytolytic immune mechanisms. We need to identify the mechanisms behind this successful elimination of replicating viruses and develop them into novel immunotherapeutic regimens. Moreover, a synergy of, chemo- and immuno-therapeutic strategies will be necessary to eradicate HBV or HCV from a host.

Efficacy and Safety of Ribavirin with Sofosbuvir Plus Ledipasvir in Patients with Genotype 1 Hepatitis C: A Meta-Analysis

BACKGROUND

Sofosbuvir and ledipasvir with or without ribavirin (RBV) regimens (SLR vs. SL) have exhibited promising results for the treatment of patients with hepatitis C virus (HCV) genotype 1 infection.

AIM

To comprehensively compare the efficacy and safety of the SL and SLR regimen for the treatment of chronic HCV genotype 1 infections.

METHODS

The Cochrane Library, PubMed, Web of Science, and EMBASE databases were searched. Only RCTs that compared the efficacy and safety of SL or SLR regimen for the treatment of chronic HCV genotype 1 infection were included. The primary outcome measures were the sustained virological response weeks 12 (SVR12) post-treatment and adverse events (AEs).

RESULTS

Seven studies comprising 2601 patients were included. Compared with the SL regimen, SLR yielded a similar probability of having an SVR12 (RR 1.002, 95 % CI 0.998, 1.017, P = 0.780). Based on subgroup analyses, the addition of RBV to the 8-week SL regimen improved the SVR12 rate. However, the SLR regimen for 12 or 24 weeks did not show a superior SVR12 rate regardless of treatment history and the presence or absence of cirrhosis. The pooled incidence of AEs was higher in patients that received the SLR treatment regimen (RR 1.140, 95 % CI 1.095, 1.187, P = 0.000).

CONCLUSIONS

The 12-week or 24-week SL regimen with a low incidence of AEs is as effective and well tolerated as the SLR regimen for the treatment of patients with chronic HCV genotype 1 infection.