Challenges and perspectives of direct antivirals for the treatment of hepatitis C virus infection

Prevalence of hepatitis C virus infection in Qatar's resident population based on a national screening campaign

Hepatitis C virus (HCV) infection poses a global health challenge, yet its epidemiology in Qatar remains underexplored. This study estimated HCV antibody (Ab) prevalence in Qatar and examined associated socio-demographic factors. From January 2017 to December 2019, the Ministry of Public Health conducted a national HCV awareness and surveillance campaign. A total of 81,615 individuals, including both Qatari nationals and expatriate residents from 137 countries, underwent HCV antibody testing using the Elecsys Anti-HCV II electrochemiluminescence immunoassay. Probability weights were applied to adjust for age, sex, and nationality, to the testing sample. Logistic regression assessed factors associated with HCV Ab positivity. Among individuals tested, 1149 were positive, 80,299 were negative, and 167 were indeterminate. The estimated HCV Ab prevalence in the study sample was 1.4% (95% CI 1.3-1.5%). The weighted HCV Ab prevalence in the resident population of Qatar was also estimated at 1.4% (95% CI 1.2-1.7%). HCV Ab positivity was strongly associated with age, with higher adjusted odds ratios (AORs) in older individuals. Disparities were noted among certain nationalities, with Bangladeshis and Tunisians having lower odds of infection, while Pakistanis, Egyptians, and Yemenis had higher odds of being infected. Males had a 1.97-fold (95% CI 1.47-2.65) higher odds of being HCV Ab positive compared to females. The considerable HCV Ab prevalence in Qatar underscores the need for targeted interventions, prevention and harm reduction strategies, and expanded testing and treatment programs to advance progress toward the 2030 elimination target.

Hepatitis C virus transmission among people who inject drugs in the Middle East and North Africa: mathematical modeling analyses of incidence and intervention impact

Background

The Middle East and North Africa (MENA) region is the most affected by hepatitis C virus (HCV) infection globally. This study aimed to estimate HCV incidence among people who inject drugs (PWID) in MENA and evaluate the impact of interventions.

Methods

A mathematical model was extended and applied to 13 countries with at least one data point on the population size of PWID and HCV antibody prevalence among PWID, generating estimates for the period 2024-2030. The model was calibrated using multiple datasets, primarily derived from systematic reviews and meta-analyses. Multivariable uncertainty analyses were conducted.

Findings

Incidence rate among PWID in the 13 countries combined was 10.4 per 100 person-years (95% UI: 8.0-14.1), with an estimated 42,364 new infections annually (95% UI: 27,990-57,540), accounting for 16.9% (95% UI: 8.3-28.2) of all cases in these countries. These figures varied widely across countries. A 75% reduction in needle/syringe sharing decreased viremic chronic infection prevalence by 14.2% (95% UI: 11.3-17.1), incidence rate by 33.8% (95% UI: 30.2-40.5), and annual new infections by 24.4% (95% UI: 17.7-30.1). A 10% reduction in PWID numbers and a 20% reduction in injection frequency decreased chronic infection prevalence by 1.7% (95% UI: 1.4-2.5), incidence rate by 4.2% (95% UI: 3.9-4.4), and annual new infections by 11.1% (95% UI: 10.9-11.9). Achieving 75% direct-acting antiviral treatment coverage by 2030 decreased chronic infection prevalence by 65.3% (95% UI: 64.8-65.8), incidence rate by 34.5% (95% UI: 29.6-40.3), and annual new infections by 25.3% (95% UI: 19.9-29.3). Combinations of interventions reduced these epidemiologic outcomes by up to 80%.

Interpretation

MENA experiences considerable HCV incidence among PWID. While the interventions showed potential, only large-scale or multi-intervention strategies can achieve meaningful reductions in HCV transmission.

Funding

This publication was made possible by NPRP grant number 12S-0216-190,094 from the Qatar National Research Fund (a member of Qatar Foundation). The authors alone are responsible for the views expressed in this publication and they do not necessarily represent the views, decisions, or policies of World Health Organization.

Prevalence of hepatitis B and C viruses among migrant workers in Qatar

Limited data exist on viral hepatitis among migrant populations. This study investigated the prevalence of current hepatitis B virus (HBV) infection and lifetime hepatitis C virus (HCV) infection among Qatar's migrant craft and manual workers (CMWs), constituting 60% of the country's population. Sera collected during a nationwide COVID-19 population-based cross-sectional survey on CMWs between July 26 and September 9, 2020, underwent testing for HBsAg and HCV antibodies. Reactive samples underwent confirmatory testing, and logistic regression analyses were employed to explore associations with HBV and HCV infections. Among 2528 specimens tested for HBV infection, 15 were reactive, with 8 subsequently confirmed positive. Three samples lacked sufficient sera for confirmatory testing but were included in the analysis through multiple imputations. Prevalence of current HBV infection was 0.4% (95% CI 0.2-0.7%). Educational attainment and occupation were significantly associated with current HBV infection. For HCV infection, out of 2607 specimens tested, 46 were reactive, and 23 were subsequently confirmed positive. Prevalence of lifetime HCV infection was 0.8% (95% CI 0.5-1.2%). Egyptians exhibited the highest prevalence at 6.5% (95% CI 3.1-13.1%), followed by Pakistanis at 3.1% (95% CI 1.1-8.0%). Nationality, geographic location, and occupation were significantly associated with lifetime HCV infection. HBV infection is relatively low among CMWs, while HCV infection falls within the intermediate range, both compared to global and regional levels.

Excellent hepatitis C virus cure rates despite increasing complexity of people who use drugs: Integrated-Test-stage Treat study final outcomes

Achieving hepatitic C virus (HCV) elimination requires linking people who use drugs (PWUD) into care. We report final direct-acting antivirals (DAAs)-based outcomes from the Integrated-Test-stage -Treat (ITTREAT) study. Project ITTREAT (2013-2021), based at an addiction centre, was a 'one-stop' service with innovative linkage to care strategies. Primary outcome was sustained virological response (SVR12) (intention to treat ITT) including whether individuals were recruited in first (period 1) versus last four (period 2 included the COVID-19 pandemic) years of the study. Number recruited were n = 765, mean age 40.9 ± 10.1 years, 78% males, history of current/past injecting drug use (IDU) and alcohol use being 77% and 90%, respectively. Prevalence of a positive HCV PCR was 84% with 19% having cirrhosis. Comparing those recruited in period 2 versus period 1, there was increasing prevalence of IDU, 90% versus 72% (p < .001); homelessness, 67% versus 50% (p < .001); psychiatric diagnosis, 84% versus 50% (p < .001); overdose history 71% versus 31% (p < .001), receiving opioid agonist treatment (OAT) 75% versus 52% (p < .001) and comorbidity 44% versus 25% (p < .001). Of those treated with DAAs (n = 272), ITT SVR rates were 86% (95% CI: 81%-90%), being similar in period 2 versus period 1. Predictors of non-SVR were receiving OAT (OR 0.33, 95% CI: 0.12-0.87, p = .025) and ≥80% adherence (OR 0.01, 95% CI: 0.003-0.041, p < .001). Reinfection rates period 2 versus period 1 (per 100 person-years) were 1.84 versus 1.70, respectively. In the treated cohort, mortality was 15%, being mostly drug-related. Despite increasing complexity of PWUD, high SVR12 rates are achievable with use of OAT and good adherence.

Therapeutic Intervention of Serine Protease Inhibitors against Hepatitis C Virus

Hepatitis C virus (HCV) is a globally prevalent and hazardous disorder that is responsible for inducing several persistent and potentially fatal liver diseases. Current treatment strategies offer limited efficacy, often accompanied by severe and debilitating adverse effects. Consequently, there is an urgent and compelling need to develop novel therapeutic interventions that can provide maximum efficacy in combating HCV while minimizing the burden of adverse effects on patients. One promising target against HCV is the NS3-4A serine protease, a complex composed of two HCV-encoded proteins. This non-covalent heterodimer is crucial in the viral life cycle and has become a primary focus for therapeutic interventions. Although peginterferon, combined with ribavirin, is commonly employed for HCV treatment, its efficacy is hampered by significant adverse effects that can profoundly impact patients' quality of life. In recent years, the development of direct-acting antiviral agents (DAAs) has emerged as a breakthrough in HCV therapy. These agents exhibit remarkable potency against the virus and have demonstrated fewer adverse effects when combined with other DAAs. However, it is important to note that there is a potential for developing resistance to DAAs due to alterations in the amino acid position of the NS3-4A protease. This emphasizes the need for ongoing research to identify strategies that can minimize the emergence of resistance and ensure long-term effectiveness. While the combination of DAAs holds promise for HCV treatment, it is crucial to consider the possibility of drug-drug interactions. These interactions may occur when different DAAs are used concurrently, potentially compromising their therapeutic efficacy. Therefore, carefully evaluating and monitoring potential drug interactions are vital to optimize treatment outcomes. In the pursuit of novel therapeutic interventions for HCV, the field of computational biology and bioinformatics has emerged as a valuable tool. These advanced technologies and methodologies enable the development and design of new drugs and therapeutic agents that exhibit maximum efficacy, reduced risk of resistance, and minimal adverse effects. By leveraging computational approaches, researchers can efficiently screen and optimize potential candidates, accelerating the discovery and development of highly effective treatments for HCV, treatments.

Cellular Release of Infectious Hepatitis C Virus Particles via Endosomal Pathways

Hepatitis C virus (HCV) is a positive-sense, single-stranded RNA virus that causes chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. The release of infectious HCV particles from infected hepatocytes is a crucial step in viral dissemination and disease progression. While the exact mechanisms of HCV particle release remain poorly understood, emerging evidence suggests that HCV utilizes intracellular membrane trafficking and secretory pathways. These pathways include the Golgi secretory pathway and the endosomal trafficking pathways, such as the recycling endosome pathway and the endosomal sorting complex required for transport (ESCRT)-dependent multivesicular bodies (MVBs) pathway. This review provides an overview of recent advances in understanding the release of infectious HCV particles, with a particular focus on the involvement of the host cell factors that participate in HCV particle release. By summarizing the current knowledge in this area, this review aims to contribute to a better understanding of endosomal pathways involved in the extracellular release of HCV particles and the development of novel antiviral strategies.

Patterns and trends of hepatitis C virus infection in Jordan: an observational study

Background

Hepatitis C virus (HCV) infection levels in Jordan remain uncertain. No HCV national population-based survey has ever been conducted in the country. To meet the World Health Organization's target of reducing HCV incidence to ≤5 per 100,000 people per year by 2030, it is essential to determine the infection levels, identify affected individuals and populations, and provide appropriate treatment using direct-acting antivirals to individuals carrying the virus.

Methods

The study utilized the HCV testing database of 28,798 attendees of Biolab Diagnostic Laboratories in Jordan, covering the period from January 19, 2010, to May 26, 2023. Cross-sectional and cohort study analyses were conducted, including estimating HCV antibody (Ab) prevalence, examining associations with HCV Ab positivity, determining the HCV viremic rate, and estimating HCV incidence rate using a retrospective cohort study design.

Results

A total of 27,591 individuals, with a median age of 31.3 and 52.9% being females, underwent HCV Ab testing, while 1,450 individuals, with a median age of 42.2 and 32.8% being females, underwent HCV RNA PCR testing. The study sample HCV Ab prevalence was 4.0% (95% CI: 3.7-4.2%). After applying probability weights, the weighted HCV Ab prevalence was 5.8% (95% CI: 4.6-7.3%). Age was strongly associated with HCV Ab positivity, particularly among individuals aged 50 years or older, who had 10-fold higher odds of being HCV Ab positive compared to those aged 10-19 years. Males had 2.41-fold higher odds of testing positive for HCV Ab compared to females. The HCV viremic rate was 54.1% (95% CI: 43.0-65.0%). The cumulative incidence of HCV infection, after 5 years of follow-up, was estimated to be 0.41% (95% CI: 0.17-0.99%). The HCV incidence rate was calculated at 1.19 per 1,000 person-years (95% CI, 0.50-2.87).

Conclusion

Prevalence and incidence of HCV infection were substantial, estimated at ~5% and 1 per 1,000 person-years, respectively, and highlighting the presence of core groups actively engaged in the virus' acquisition and transmission. The high observed viremic rate indicates the need for expanding HCV treatment efforts to effectively control HCV transmission in Jordan. Utilizing quality diagnostic laboratories and innovative testing strategies is key to identifying infection carriers and facilitating linkage to treatment and care.

Structure-based virtual screening of natural compounds as inhibitors of HCV using molecular docking and molecular dynamics simulation studies

The hepatitis C virus (HCV), which causes hepatitis C, is a viral infection that damages the liver and causes inflammation in the liver. New potentially effective antiviral drugs are required for its treatment owing to various issues associated with the existing medications, including moderate to severe adverse effects, higher costs, and the emergence of drug-resistant strains. The objective of the current study was to utilize computational techniques to assess the anti-HCV efficacy of certain phytochemicals against tetraspanin (CD81) and claudin 1 (CLDN1) entry proteins. A 200-nanosecond molecular dynamics (MD) simulation was employed to examine the stability of the lead-protein complexes. Free binding energy and molecular docking calculations were conducted utilizing MM/GBSA method, and the selectivity of hit compounds for CD81 and CLDN1 was determined. Five significant CD81 and CLDN1 inhibitors were identified: Petasiphenone, Silibinin, Tanshinone IIA, Taxifolin, and Topaquinone. The MM/GBSA analysis of the compounds revealed high free binding energies. All the identified compounds were stable within the CD81 and CLDN1 binding pockets. This study indicated the promising inhibitory potential of the identified compounds against CD81 and CLDN1 receptors and might develop into potential viral entry inhibitors. However, to validate the chemotherapeutic capabilities of the discovered leads extensive preclinical research is required.Communicated by Ramaswamy H. Sarma.

The Magic Methyl and Its Tricks in Drug Discovery and Development

One of the key scientific aspects of small-molecule drug discovery and development is the analysis of the relationship between its chemical structure and biological activity. Understanding the effects that lead to significant changes in biological activity is of paramount importance for the rational design and optimization of bioactive molecules. The "methylation effect", or the "magic methyl" effect, is a factor that stands out due to the number of examples that demonstrate profound changes in either pharmacodynamic or pharmacokinetic properties. In many cases, this has been carried out rationally, but in others it has been the product of serendipitous observations. This paper summarizes recent examples that provide an overview of the current state of the art and contribute to a better understanding of the methylation effect in bioactive small-molecule drug candidates.

Therapeutic strategies and promising vaccine for hepatitis C virus infection

Hepatitis C virus (HCV) infection is still a significant global health problem despite therapeutic advancements. Ribavirin and interferon therapy have been the sole available treatments for HCV infection for a number of years with low efficacy. Thus, currently, a number of therapeutic strategies are being used, including nanoparticles (NPs), micro-RNAs such as small interfering RNA (siRNA), RNAi-based gene silencing and antisense oligonucleotide-based microRNA-122, microRNA-155, and short hairpin RNAs (shRNAs), and immunotherapeutic approaches such as anti-programmed cell death 1(PD-1), monoclonal antibodies (mAb or moAb), and monocyte-derived dendritic cells (Mo-DCs). Furthermore, direct-acting antivirals (DAAs) and host-targeting agents (HTA) were also the current therapeutic approaches with great efficacy. In spite of different clinical trials on HCV vaccine developments, nowadays there is no effective HCV vaccine in opposition to virus due to various challenges including genetic diversity, lack of immunocompetent small animal models, shortage of HCV vaccination testing alternatives, lack of an effective tissue culture method for replicating HCV, and inadequate knowledge regarding to immune responses against HCV infection. Nowadays, mRNA vaccine, recombinant viral vector, peptides vaccine, virus-like particles, DNA vaccine, rational designed vaccine, and recombinant polyantigenic T-cell-based vaccine are novel promising candidates for HCV vaccine based on various clinical trials. This review summarizes the different therapeutic approaches and the advancements of vaccine candidates for HCV infection.

Treatment as prevention for hepatitis C virus in the Middle East and North Africa: a modeling study

Background

Direct-acting antivirals opened an opportunity for eliminating hepatitis C virus (HCV) infection in the Middle East and North Africa (MENA), the region most affected by HCV infection. Impact of HCV treatment as prevention (HCV-TasP) was investigated in 19 MENA countries.

Methods

An age-structured mathematical model was used to assess program impact using epidemiologic and programming measures. The model was fitted to a database of systematically gathered HCV antibody prevalence data. Two main scenarios were investigated for the treatment roll-out to achieve (i) 80% reduction in HCV incidence by 2030, and (ii) incidence rate < 1 per 100,000 person-years by 2030.

Results

In the target-80%-incidence-reduction scenario, number of treatments administrated by 2030 ranged from 2,610 in Lebanon to 180,416 in Sudan with a median of 53,079, and treatment coverage ranged between 40.2 and 78.4% with a median of 60.4%. By 2030, prevalence of chronic infection ranged between 0.0 and 0.3% with a median of 0.1%, and incidence rate, per 100,000 person-years, ranged between 0.9 and 16.3 with a median of 3.2. Program-attributed reduction in incidence rate ranged between 47.8 and 81.9% with a median of 68.5%, and number of averted infections ranged between 401 and 68,499 with a median of 8,703. Number of treatments needed to prevent one new infection ranged from 1.7 in Oman to 25.9 in Tunisia with a median of 6.5. In the target incidence rate  < 1 per 100,000 person-years scenario, number of treatments administrated by 2030 ranged from 3,470 in Lebanon to 211,912 in Sudan with a median of 54,479, and treatment coverage ranged between 55.5 and 95.9% with a median of 87.5%. By 2030, prevalence of chronic infection was less than 0.1%, and incidence rate, per 100,000 person-years, reached less than 1. Program-attributed reduction in incidence rate ranged between 61.0 and 97.5% with a median of 90.7%, and number of averted infections ranged between 559 and 104,315 with a median of 12,158. Number of treatments needed to prevent one new infection ranged from 1.3 in Oman to 25.9 in Tunisia with a median of 5.5.

Conclusion

HCV-TasP is an effective and indispensable prevention intervention to control MENA's HCV epidemic and to achieve elimination by 2030.

Double Positive CD4+CD8+ (DP) T-Cells Display Distinct Exhaustion Phenotype in Chronic Hepatitis C

In chronic hepatitis C (CHC), characterized by exhaustion of T-cell function, increased frequencies of double-positive (DP) (CD4⁺CD8⁺) cells are present in peripheral blood. We compared the exhaustion phenotype between DP and single positive (SP) T-cells, including HCV-specific cells, and assessed the effect of successful HCV treatment on inhibitory receptors expression. Blood samples from 97 CHC patients were collected before and six months post-treatment. PD-1 (programmed cell death protein 1) and Tim-3 (T-cell immunoglobulin and mucin domain-containing molecule-3) expression was assessed by flow cytometry. DP T-cells displayed significantly higher PD-1 expression, lower Tim-3 expression than CD8⁺ SP T-cells and lower percentages of PD-1^-Tim-3^- cells than CD4⁺ SP T-cells, both before and after treatment. PD-1⁺Tim-3⁺ DP T-cells decreased following treatment. HCV-specific cells were more frequent among DP than SP T-cells, both before and after treatment. HCV-specific DP T-cells were characterized by lower PD-1 expression, higher PD-1 and Tim-3 co-expression, and lower percentages of PD-1^-Tim-3^- cells (both before and after treatment) and higher post-treatment Tim-3 than HCV-specific SP T-cells. Their percentages decreased following treatment, but the exhaustion phenotype remained unchanged. DP T-cells in CHC exhibit a distinct exhaustion phenotype from SP T-cells, and these changes mostly persist following successful treatment.

Recent Advances in Antivirals for Japanese Encephalitis Virus

Culex mosquitoes are the primary vectors of the Japanese encephalitis virus (JEV). Since its discovery in 1935, Japanese encephalitis (JE), caused by JEV, has posed a significant threat to human health. Despite the widespread implementation of several JEV vaccines, the transmission chain of JEV in the natural ecosystem has not changed, and the vector of transmission cannot be eradicated. Therefore, JEV is still the focus of attention for flaviviruses. At present, there is no clinically specific drug for JE treatment. JEV infection is a complex interaction between the virus and the host cell, which is the focus of drug design and development. An overview of antivirals that target JEV elements and host factors is presented in this review. In addition, drugs that balance antiviral effects and host protection by regulating innate immunity, inflammation, apoptosis, or necrosis are reviewed to treat JE effectively.

Association of Alpha-1 Antitrypsin Pi*Z Allele Frequency and Progressive Liver Fibrosis in Two Chronic Hepatitis C Cohorts

(1) Background: The inherited alpha-1 antitrypsin (A1AT) deficiency variant 'Pi*Z' emerged as a genetic modifier of chronic liver disease. Controversial data exist on the relevance of heterozygous Pi*Z carriage ('Pi*MZ' genotype) as an additional risk factor in patients with chronic viral hepatitis C to develop progressive liver fibrosis. (2) Methods: Two prospectively recruited cohorts totaling 572 patients with therapy-naïve chronic viral hepatitis C (HCV) were analyzed. The Frankfurt cohort included 337 patients and a second cohort from Leipzig included 235 patients. The stage of liver fibrosis was assessed by liver biopsy, AST-to-platelet ratio index (APRI) score and Fibrosis-4 (FIB-4) score (Frankfurt) as well as liver stiffness measurement (LSM) via transient elastography (Leipzig). All patients were genotyped for the Pi*Z variant (rs28929474) of the SERPINA1 gene. (3) Results: In the Frankfurt cohort, 16/337 (4.7%) patients carried the heterozygous Pi*Z allele while 10/235 (4.3%) in the Leipzig cohort were Pi*Z carriers. In both cohorts, there was no higher proportion of Pi*Z heterozygosity in patients with cirrhosis compared to patients without cirrhosis or patients with cirrhosis vs. no liver fibrosis. Accordingly, Pi*Z frequency was not different in histological or serological stages of liver fibrosis (F0-F4) and showed no clear association with LSM. (4) Conclusions: Evaluation in two representative HCV cohorts does not indicate Pi*Z heterozygosity as a clinically relevant disease modifier in chronic HCV infection. However, validation in even larger cohorts with longitudinal follow-up is warranted.

Improving Access to High-Value, High-Cost Medicines: The Use of Subscription Models to Treat Hepatitis C Using Direct-Acting Antivirals in the United States

State payers may face financial incentives to restrict use of high-cost medications. Yet, restrictions on access to high-value medications may have deleterious effects on population health. Direct-acting antivirals (DAAs), available since 2013, can cure chronic infection with hepatitis C virus (HCV). With prices upward of $90,000 for a treatment course, states have struggled to ensure access to DAAs for Medicaid beneficiaries and the incarcerated, populations with a disproportionate share of HCV. Advance purchase commitments (APCs), wherein a payer commits to purchase a certain quantity of medications at lower prices, offer payers incentives to increase access to high-value medications while also offering companies guaranteed revenue. This article discusses the use of subscription models, a type of APC, to support increased access to high-value DAAs for treating HCV. First, the authors provide background information about HCV, its treatment, and state financing of prescription medications. They then review the implementation of HCV subscription models in two states, Louisiana and Washington, and the early evidence of their impact. The article discusses challenges to evaluating state-sponsored subscription models, and it concludes by discussing implications of subscription models that target DAAs and other high-value, high-cost medicines.

Drug-drug interactions between direct-acting antivirals and co-medications: a territory-wide cohort study

BACKGROUND

The increasing number of direct-acting antiviral (DAA) regimens along with limited number of subjects and co-medications involved in clinical trials results in drug-drug interactions (DDIs) with DAAs is to be determined. We aimed to examine the prevalence and degree of DDIs between DAAs and other co-medications in a territory-wide cohort of chronic hepatitis C virus (HCV) patients.

METHODS

DDIs were assigned to three risk categories: Category 1-no clinically significant DDI; category 2-potential clinically significant interaction (monitoring and caution required); category 3-contraindicated (should not be co-administered).

RESULTS

Of 2981 patients (mean age 59.3 ± 12.3 years; male 60.6%), 810 (48.8%) had genotype 1 and 552 (33.2%) genotype 6 HCV among the 1661 patients with HCV genotype tested; 769 (25.8%) received sofosbuvir/velpatasvir, 510 (17.1%) sofosbuvir/ledipasvir, and 865 (29.0%) glecaprevir/pibrentasvir. More than one-fourth (26.3%) of the patients have polypharmacy (≥ 3 co-medications) in all patients, 27.0% in patients received sofosbuvir/velpatasvir, 25.1% in elbasvir/grazoprevir, and 21.2% in glecaprevir/pibrentasvir. 2037 (68.3%) patient experienced DDI (Category 2: 53.1%; Category 3: 15.2%). The commonest drugs leading to DDIs were calcium channel blockers (31.5%) and proton pump inhibitors (23.0%) in category 2; statins (10.2%), antiplatelet/anticoagulants (3.0%) and antipsychotics (2.9%) in category 3. Changing medication was the most common response from physicians in both category 2 and 3 DDIs.

CONCLUSION

The commonest co-medications leading to contraindication during DAA treatment were statins and antipsychotics. Category 2 and 3 DDIs are often managed by appropriate dose adjustments or temporary discontinuation of relevant co-medications. Careful assessment for potential DDI before DAA use is mandatory to avoid potential harmful effects.

Real-world impact of a subsidy decision of sofosbuvir-velpatasvir for treatment of chronic hepatitis C on clinical practice and patient outcomes

Background and Aim

Sofosbuvir-velpatasvir was recommended for subsidy to treat chronic hepatitis C in Singapore in 2018. We measured the impact of the subsidy decision on clinical practice and patient outcomes. Specifically, we looked at pre- and post-subsidy changes in the utilization and prescribing pattern of chronic hepatitis C treatment and the real-world clinical effectiveness.

Method

Utilization trends and prescribing patterns were assessed using aggregated drug utilization data from public hospitals' dispensing systems and clinical data from the national electronic health record database, respectively. An audit was conducted to evaluate sustained virological response rate 12 weeks post treatment (SVR12).

Results

Use of sofosbuvir-velpatasvir increased sharply since its subsidy listing and dropped subsequently, whereas the utilization of comparator drugs remained low. Prescribing rate of sofosbuvir-velpatasvir increased from 13.7% in the pre-subsidy period to 90.2% in the post-subsidy period; 39.1% of patients previously on pegylated interferon and ribavirin switched to sofosbuvir-velpatasvir following its subsidy listing. In the audit, 365 out of 375 patients (97.3% [95% confidence interval: 95.1-98.6%]) achieved SVR12.

Conclusion

The subsidy decision led to increased accessibility to patients and intended changes in clinical practice. Sofosbuvir-velpatasvir was also clinically effective in the real world. These findings augur well for the continued eradication of chronic hepatitis C infection in Singapore.

Evaluation of Drug Interactions in Patients Treated with DAAs for Hepatitis C Therapy with Comorbidities and Cardiovascular Issues-A Delphi Consensus Project

Orally administered direct-acting antivirals (DAAs) have dramatically changed the possibility of curing HCV (hepatitis C virus) infection, with the two principal HCV regimens based on the combination of glecaprevir + pibrentasvir (GLE-PIB) and sofosbuvir + velpatasvir (SOF-VEL). A combination of drugs containing NS3/4A protease inhibitors, as well as the fact that almost all HCV patients can be treated at present, may expose patients to a higher rate of drug-drug interactions (DDIs). The hepatitis C treatment recommendations from the EASL (European Association for the Study of the Liver) state that, prior to starting treatment with a DAA, a detailed drug history should be taken; yet, the decision on managing the potential DDIs is not always clear. For this reason, a group of Italian cardiologists and hepatologists promoted a survey among colleagues to assess the controversial issues when treating patients with chronic hepatitis C taking concomitant cardiovascular drugs, aiming to reach a consensus on the best practice to apply when treating a patient with chronic hepatitis C who is taking concomitant drugs for cardiovascular diseases. Two consecutive questionnaires were proposed between June and July 2022 to a qualitative Expert Panel (EP) of 14 gastroenterologists, infectologists, hepatologists, and internists, with statistical analyses performed on 100% of the responses for both questionnaires. Agreement among experts was assessed following the Delphi method as developed by the RAND Corporation. The interviewed experts consider DDIs a critical clinical problem to be evaluated in HCV patients. Therefore, dose changes, drug substitution, and discontinuation of concomitant cardiovascular drugs should be discouraged, even if planned for a relatively short period. Since oral DAAs have different DDIs profiles, hepatologists should prefer the antiviral DAA combination presenting the lowest instance of potential interactions.

Sofosbuvir induces gene expression for promoting cell proliferation and migration of hepatocellular carcinoma cells

Direct-acting antivirals (DAAs) have achieved a sustained virological response (SVR) rate of 95–99% in treating HCV. Several studies suggested that treatment with sofosbuvir (SOF), one type of DAAs, may be associated with increased risk of developing HCC. The aim of this study is to investigate the potential mechanisms of SOF on the development of HCC. OR-6 (harboring full-length genotype 1b HCV) and Huh 7.5.1 cells were used to examine the effects of SOF on cell proliferation and migration of HCC cells. SOF-upregulated genes in OR-6 cells were inspected using next generation sequencing (NGS)and the clinical significance of these candidate genes was analyzed using The Cancer Genome Atlas (TCGA) database. We found that SOF increased cell proliferation and cell migration in OR-6 and Huh 7.5.1 cells. Several SOF-upregulated genes screened from NGS were confirmed by real-time PCR in OR-6 cells. Among these genes, PHOSPHO2, KLHL23, TRIM39, TSNAX-DISC1 and RPP21 expression were significantly elevated in the tumor tissues compared with the non-tumor tissues of HCC according to TCGA database. High expression of PHOSPHO2 and RPP21 was associated with poor overall survival of HCC patients. Moreover, knockdown of PHOSPHO2-KLHL23, TSNAX-DISC1, TRIM39 and RPP21 diminished cell proliferation and migration increased by SOF in OR-6 and Huh 7.5.1 cells. In conclusion, SOF-upregulated genes promoted HCC cell proliferation and migration, which might be associated with the development of HCC.

Association between breast cancer and hepatitis C: A joint study of hospitalized patients and nationwide cohorts

Whether hepatitis C virus (HCV) infection is associated with breast cancer risk remains elusive, and we aimed to elucidate it. A nationwide population-based cohort study of the Taiwan National Health Insurance Research Database (TNHIRD) was conducted. Additionally, breast cancer risk factors, and HCV core expression were surveyed in breast cancer patients of a tertiary care center. Three TNHIRD cohorts (1:4:4, propensity score-matched, 2003-2012), including HCV-treated (3646 HCV-infected females with interferon-based therapy ≥6 months), HCV-untreated (n = 14,584) and HCV-uninfected (n = 14,584) cohorts, were enrolled. The HCV-untreated cohort had the highest 9-year breast cancer cumulative incidence (2.017%; 95% confidence interval [CI]: 1.382%-2.846%), while the HCV-treated (1.073%; 0.414%-2.356%), and HCV-uninfected (1.453%; 0.785%-2.486%) cohorts showed no difference. Untreated HCV infection (hazard ratio [HR]: 1.701; 95% CI: 1.205%-2.400), urban residency (1.658, 1.183-2.323), and baseline cardiovascular events (1.920; 1.005-3.668) were associated with incident breast cancers. The interaction analysis showed that particularly among patients <49 years, HCV infection was associated with breast cancer development (2.193; 1.097-4.384). Of 12,170 hospitalized breast cancer patients, 4.90% were HCV Ab-positive. HCV Ab-positive patients were older (60.92+/-10.82 vs 53.91+/-11.38 years, P < 0.0001) and had a higher body mass index (25.39+/-5.1 vs 24.5+/-4.3 kg/m², P = 0.007), rates of diabetes (30.60 vs 19.98%, P < 0.0001), hypertension (46.9 vs 30.39%, P < 0.0001), dyslipidemia (25.52 vs 20.28%, P = 0.031), and hyperuricemia (11.38 vs 5.52%, P < 0.0001) than their counterparts. No HCV core-positive cells were demonstrated in breast cancer tissues. Conclusions: Untreated HCV infection, urbanization, and cardiovascular events were potential risk factors for breast cancer. The HCV-associated risk was most prominent among patients <49 years, might not be associated with in situ HCV core-related oncogenesis but with metabolic alterations, and was reversed by anti-HCV therapy.

Targeting non-structural proteins of Hepatitis C virus for predicting repurposed drugs using QSAR and machine learning approaches

Hepatitis C virus (HCV) infection causes viral hepatitis leading to hepatocellular carcinoma. Despite the clinical use of direct-acting antivirals (DAAs) still there is treatment failure in 5-10% cases. Therefore, it is crucial to develop new antivirals against HCV. In this endeavor, we developed the "Anti-HCV" platform using machine learning and quantitative structure-activity relationship (QSAR) approaches to predict repurposed drugs targeting HCV non-structural (NS) proteins. We retrieved experimentally validated small molecules from the ChEMBL database with bioactivity (IC50/EC50) against HCV NS3 (454), NS3/4A (495), NS5A (494) and NS5B (1671) proteins. These unique compounds were divided into training/testing and independent validation datasets. Relevant molecular descriptors and fingerprints were selected using a recursive feature elimination algorithm. Different machine learning techniques viz. support vector machine, k-nearest neighbour, artificial neural network, and random forest were used to develop the predictive models. We achieved Pearson's correlation coefficients from 0.80 to 0.92 during 10-fold cross validation and similar performance on independent datasets using the best developed models. The robustness and reliability of developed predictive models were also supported by applicability domain, chemical diversity and decoy datasets analyses. The "Anti-HCV" predictive models were used to identify potential repurposing drugs. Representative candidates were further validated by molecular docking which displayed high binding affinities. Hence, this study identified promising repurposed drugs viz. naftifine, butalbital (NS3), vinorelbine, epicriptine (NS3/4A), pipecuronium, trimethaphan (NS5A), olodaterol and vemurafenib (NS5B) etc. targeting HCV NS proteins. These potential repurposed drugs may prove useful in antiviral drug development against HCV.

Recent advancement in small molecules as HCV inhibitors

Hepatitis C virus (HCV) has caused a considerable threat to human health. To date, no treatments are without side effects. The proteins and RNA associated with HCV have specific functions during the viral life cycle. The vulnerabilities to virus are associated with those proteins or RNA. Thus, targeting these proteins and RNA is an efficient strategy to develop anti-HCV therapeutics. The treatment for HCV-infected patients has been greatly improved after the approval of direct-acting antivirals (DAAs). However, the cost of DAAs is unusually high, which adds to the economic burden on patients with chronic liver diseases. So far, many efforts have been devoted to the development of small molecules as novel HCV inhibitors. Investigations on the inhibitory activities of these small molecules have involved the target identification and the mechanism of action. In this mini-review, these small molecules divided into four kinds were elaborated, which focused on their targets and structural features. Furthermore, we raised the current challenges and promising prospects. This mini-review may facilitate the development of small molecules with improved activities targeting HCV based on the chemical scaffolds of HCV inhibitors.

Time to complete hepatitis C cascade of care among patients identified during mass screening campaigns in rural Rwanda: a retrospective cohort study

Background

Since the discovery of direct-acting antivirals, treatment for hepatitis C virus (HCV) is increasingly accessible in low-resource settings, but quality of care in these settings is not known. We described progression through the cascade of care among individuals who screened positive for HCV antibodies during a mass screening campaign in Kirehe and Kayonza, two rural Rwandan districts, in September 2019.

Methods

This retrospective cohort study used routine clinical data to assess proportions of participants completing each stage of the cascade of care, including: (a) screening positive on rapid diagnostic test; (b) return of initial viral load results; (c) detectable viral load; (d) treatment assessment; (e) treatment initiation; (f) return of sustained virological response (SVR12) results; and (g) achieving SVR12. We proposed three indicators to assess timely care provision and used medians and interquartile ranges (IQR) to describe the time to complete the cascade of care.

Results

Overall, 666 participants screened HCV positive, among them, 452 (68.1%) were female and median age was 61 years (IQR: 47, 70). Viral load results were returned for 537 (80.6%) participants of whom 448 (83.4%) had detectable viral loads. Of these, 398 (88.8%) were assessed for treatment, 394 (99%) were initiated, but only 222 (56.3%) had results returned for SVR12. Among those with SVR12 results, 208 (93.7%) achieved SVR12. When assessing timely care provision, we found 65.9% (95% CI: 62.0, 69.7) of initial viral load results were returned ≤ 30 days of screening; 45% (95% CI: 40.1, 49.8) of people with detectable viral load completed treatment assessment ≤ 90 days of initial viral load results; and 12.5% (95% CI: 9.2, 16.3) of SVR12 results were returned ≤ 210 days of treatment initiation among those who initiated treatment. The overall median time from screening to SVR12 assessment was 437 days.

Conclusion

Despite high rates of SVR12 among those who completed all stages of the cascade of care, we identified gaps and delays in the treatment cascade. Improving communication between viral load testing hubs and health facilities could reduce the turn-around time for viral load testing, and actively monitor timeliness of care provision could improve quality of HCV care.

Chronic liver disease in homeless individuals and performance of non-invasive liver fibrosis and injury markers: VALID study

BACKGROUND/AIMS

Community-based assessment and management of chronic liver disease (CLD) in people who are homeless (PWAH) remain poorly described. We aimed to determine prevalence/predictors of CLD in PWAH and assess the performance of non-invasive liver fibrosis and injury markers.

METHODS

The Vulnerable Adult LIver Disease (VALID) study provided a "one-stop" liver service based at homeless hostels. Our primary outcome was the prevalence of clinically significant hepatic fibrosis (CSHF; liver stiffness measurement (LSM) ≥8 kPa).

RESULTS

Total individuals recruited were 127, mean ± SD age 47 ± 9.4 years, 50% (95% CI 41%-59%) and 39% (95% CI 31%-48%) having alcohol dependence and a positive HCV RNA respectively. CSHF was detected in 26% (95% CI 17%-35%), independent predictors being total alcohol unit/week (OR 1.01, 95% CI 1.00-1.02, P = .002) and HCV RNA positivity (OR 2.93, 95% CI 1.12-7.66, P = .029). There was moderate agreement between LSM and Enhanced Liver Fibrosis (ELF) score (kappa 0.536, P < .001) for CSHF as assessed by LSM ≥8 kPa. Those with CSHF had significantly higher levels of IFN-γ (P = .002), IL-6 (P = .001), MMP-2 (P = .006), ccCK-18 (P < .001) and ELF biomarkers (P < .001), compared to those without CSHF. Service uptake was ≥95%. Direct acting antiviral (DAA) treatment completion was 93% (95% CI 77%-99%), sustained virological response (SVR) being 83% (95% CI 64%-94%).

CONCLUSION

There is a significant liver disease burden from HCV and alcohol in PWAH. Non-invasive liver fibrosis and injury markers can help in identifying such individuals in the community. Despite a challenging cohort, excellent service uptake and high DAA-based SVRs can be achieved.

Hepatitis C virus (HCV)-induced ROS/JNK signaling pathway activates the E3 ubiquitin ligase Itch to promote the release of HCV particles via polyubiquitylation of VPS4A

We previously reported that hepatitis C virus (HCV) infection activates the reactive oxygen species (ROS)/c-Jun N-terminal kinase (JNK) signaling pathway. However, the roles of ROS/JNK activation in the HCV life cycle still remain unclear. We sought to identify a novel role of ROS/JNK signaling pathway in the HCV life cycle. Immunoblot analysis revealed that HCV-induced ROS/JNK activation promoted phosphorylation of Itch, a HECT-type E3 ubiquitin ligase, leading to activation of Itch. The siRNA-knockdown of Itch significantly reduced the extracellular HCV infectivity titers, HCV RNA, and HCV core protein without affecting intracellular HCV infectivity titers, HCV RNA, and HCV proteins, suggesting that Itch is involved in release of HCV particles. HCV-mediated JNK/Itch activation specifically promoted polyubiquitylation of an AAA-type ATPase VPS4A, but not VPS4B, required to form multivesicular bodies. Site-directed mutagenesis revealed that two lysine residues (K23 and K121) on VPS4A were important for VPS4A polyubiquitylation. The siRNA-knockdown of VPS4A, but not VPS4B, significantly reduced extracellular HCV infectivity titers. Co-immunoprecipitation analysis revealed that HCV infection specifically enhanced the interaction between CHMP1B, a subunit of endosomal sorting complexes required for transport (ESCRT)-III complex, and VPS4A, but not VPS4B, whereas VPS4A K23R/K121R greatly reduced the interaction with CHMP1B. HCV infection significantly increased ATPase activity of VPS4A, but not VPS4A K23R/K121R or VPS4B, suggesting that HCV-mediated polyubiquitylation of VPS4A contributes to activation of VPS4A. Taken together, we propose that HCV-induced ROS/JNK/Itch signaling pathway promotes VPS4A polyubiquitylation, leading to enhanced VPS4A-CHMP1B interaction and promotion of VPS4A ATPase activity, thereby promoting the release of HCV particles. IMPORTANCE ROS/JNK signaling pathway contributes to liver diseases, including steatosis, metabolic disorders, and hepatocellular carcinoma. We previously reported that HCV activates the ROS/JNK signaling pathway, leading to the enhancement of hepatic gluconeogenesis and apoptosis induction. This study further demonstrates that HCV-induced ROS/JNK signaling pathway activates the E3 ubiquitin ligase Itch to promote release of HCV particles via polyubiquitylation of VPS4A. We provide evidence suggesting that HCV infection promotes the ROS/JNK/Itch signaling pathway and ESCRT/VPS4A machinery to release infectious HCV particles. Our results may lead to a better understanding of the mechanistic details of HCV particle release.

Redesigning of the cap conformation and symmetry of the diphenylethyne core to yield highly potent pan-genotypic NS5A inhibitors with high potency and high resistance barrier

Herein, we report the discovery of several NS5A inhibitors with potency against HCV genotype 1b in the picomolar range. Compounds (15, 33) were of extremely high potency against HCV genotype 1b (EC₅₀ ≈ 1 pM), improved activity against genotype 3a (GT 3a) and good metabolic stability. We studied the impact of changing the cap conformation relative to the diphenylethyne core and/or compound symmetry on both potency and metabolic stability. The analogs obtained exhibited improved potency against HCV genotypes 1a, 1b, 3a and 4a compared to the clinically approved candidate daclatasvir with EC₅₀ values in the low picomolar range and SI₅₀s > 7 orders of magnitude. Compound 15, a symmetrically m-, m'-substituted diphenyl ethyne analog, was 150-fold more potent than daclatasvir against GT 3a, while compound 33, an asymmetrically m-, p-substituted diphenyl ethyne analog, was 35-fold more potent than daclatasvir against GT 3a. In addition, compound 15 exhibited a higher resistance barrier than daclatasvir against genotype 1b.

The Role of RASs /RVs in the Current Management of HCV

The approval of combination therapies with direct-acting antiviral (DAA) regimens has led to significant progress in the field of hepatitis C virus (HCV) treatment. Although most patients treated with these agents achieve a virological cure, resistance to DAAs is a major issue. The rapid emergence of resistance-associated substitutions (RASs), in particular in the context of incomplete drug pressure, has an impact on sustained virological response (SVR) rates. Several RASs in NS3, NS5A and NS5B have been linked with reduced susceptibility to DAAs. RAS vary based on HCV characteristics and the different drug classes. DAA-resistant HCV variant haplotypes (RVs) are dominant in cases of virological failure. Viruses with resistance to NS3-4A protease inhibitors are only detected in the peripheral blood in a time frame ranging from weeks to months following completion of treatment, whereas NS5A inhibitor-resistant viruses may persist for years. Novel agents have been developed that demonstrate promising results in DAA-experienced patients. The recent approval of broad-spectrum drug combinations with a high genetic barrier to resistance and antiviral potency may overcome the problem of resistance.

Hepatitis C Virus Infection in Pregnancy and Children: Its Implications and Treatment Considerations with Directly Acting Antivirals: A Review

Hepatitis C virus infection (HCV) is a global health problem affecting >71 million people worldwide with chronic hepatitis C, 40% reproductive age group, and 8% pregnant women. Intravenous drug abuse, multi-transfusions are major risk factors in adults, while vertical transmission in pediatric population. It commonly presents as a chronic liver disease, has higher risk of liver cirrhosis and even progression to hepatocellular carcinoma. Therefore, proper screening of high-risk populations including pregnancy is recommended. All diagnosed chronic hepatitis C cases should be treated with directly acting anti-virals (DAAs) including pre-conception which has a cure rate of >95%. This would reduce the disease burden, vertical transmission, and disability associated. However, no DAAs regimens recommendation till date due to lack of evidence on adverse fetal outcomes and are concerned about the pharmacokinetic effect regarding physiological changes during pregnancy. Therefore, in this review, we have tried to explore the possible use of DAAs regimens and their safety issues during pregnancy, and possible consideration of few pan-genotypic regimens in the late 2nd and early 3rd trimester. This would not only prevent vertical transmission and decrease disease burden but also help to meet the WHO 2030 target of HCV elimination as a major public health problem.

Elbasvir and grazoprevir for the treatment of hepatitis C

Introduction: Hepatitis C is one of the leading causes of chronic liver disease. The direct-acting-antivirals has revolutionized the chronic hepatitis C treatment. DAAs can achieve a sustained virological response rate >95% in different populations.Area covered: This review summarizes the pharmacokinetics, pharmacodynamics, efficacy, and safety of Elbasvir/Grazoprevir (EBR/GZR).Expert opinion: EBR/GZR is a combination of NS5A and NS3/4A inhibitors. The performance in the EBR/GZR combination's safety and tolerability is appreciated in clinical treatment. EBR/GZR also has a higher barrier to resistance-associated substitutions. Based on clinical trials and real-world experience, elbasvir/grazoprevir is effective in the HCV GT1, 4 infections.

An update on direct antiviral agents for the treatment of hepatitis C

Introduction: The development of direct-acting antiviral (DAA) agents for the treatment of hepatitis C virus (HCV) infection has completely transformed the management of this disease. The advantages of using DAA therapies include high efficacy (sustained virological response (SVR) rate >95%) with minimal side effects, good tolerability, easy drug administration (once daily oral dosing), and short duration of treatment (8-12 weeks). This transformative nature of DAA therapy underpins the goal of the World Health Organization to eliminate HCV infection as a public health threat by 2030.Areas covered: This review seeks to address the current status of DAA therapies, including recent developments, current limitations, and future challenges.Expert opinion: The current DAA regimens, with their high effectiveness and safety profiles, have changed patient perception of HCV infection from a disease that requires complex evaluation and long-term monitoring to a disease that can be cured after one visit to the general practitioner. Despite the remarkably high success rate of DAAs, few patients (4-5%) fail to obtain SVR even after treatment. Five years ahead, the landscape of HCV treatment will undoubtedly continue to evolve, and more pan-genotypic treatment options will be available to all patients.

Silver, copper and copper oxide nanoparticles in the fight against human viruses: progress and perspectives

The rapid development of nanomedicine has created a high demand for silver, copper and copper oxide nanoparticles. Due to their high reactivity and potent antimicrobial activity, silver and copper-based nanomaterials have been playing an important role in the search for new alternatives for the treatment of several issues of concern, such as pathologies caused by bacteria and viruses. Viral diseases are a significant and constant threat to public health. The most recent example is the pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this context, the object of the present review is to highlight recent progress in the biomedical uses of these metal nanoparticles for the treatment and prevention of human viral infections. We discuss the antiviral activity of AgNPs and Cu-based NPs, including their actions against SARS-CoV-2. We also discuss the toxicity, biodistribution and excretion of AgNPs and CuNPs, along with their uses in medical devices or on inert surfaces to avoid viral dissemination by fomites. The challenges and limitations of the biomedical use of these nanoparticles are presented.

Community-Based Assessment and Treatment of Hepatitis C Virus-Related Liver Disease, Injecting Drug and Alcohol Use Amongst People Who Are Homeless: A Systematic Review and Meta-Analysis

BACKGROUND/AIMS

We performed a systematic review and meta-analysis addressing community-based assessment and treatment of hepatitis C virus (HCV)-related liver disease, injecting drug use (IDU) and alcohol use amongst people who are homeless (PWAH).

METHODS

Using systematic review methodology, databases were searched (MEDLINE/ EMBASE/CINAHL) for studies combining PWAH, HCV-related liver disease and community assessment until December 2019. Studies with a sample size ≥ 30, with PWAH constituting at least 30% of the cohort were included and a quality assessment performed. Pooled estimates of key indicators were analysed using meta-analysis.

RESULTS

We identified 39 studies (n = 13,918), 37 categorised as poor quality (Newcastle-Ottawa Scale). Prevalence of homelessness ranged between 30%-100% (37 studies). Eight studies provided all of the following: HCV screening, alcohol/substance use/liver fibrosis assessment and HCV treatment. No study provided interventions for alcohol use, with two providing opioid substitution treatment. Alcohol use prevalence (24 studies) was 4%-97%, being 59% (95% CI 20%-92%) in four studies that included only PWAH. Recent IDU prevalence (16 studies) was 7%-73%, being 21% (95% CI 17%-26%) in four studies that included only PWAH. HCV seroprevalence (25 studies) was 2.5% - 58%; in 13 studies that included only PWAH, this was 20% (95% CI 12%-30%). Prevalence of F4 fibrosis (nine studies) was 6%-28%, being 7% and 16% in two studies that included only PWAH. Direct acting antiviral-based intention-to-treat sustained virological response (SVR) rates (five studies) were 82%-92%, being 92% in the one study that included only PWAH. In the only two randomised controlled trials (RCT) identified, community-based interventions (mental health/peer mentor) significantly increased linkage to care (p = 0.04), HCV treatment (p = 0.005) and SVR rates (p = 0.018).

CONCLUSION

The burden from alcohol/IDU and HCV, and consequently liver disease in PWAH needs addressing. RCT trials assessing community-based interventions to improve liver health in PWAH are needed.

2-O-Methylhonokiol Suppresses HCV Replication via TRAF6-Mediated NF-kB Activation

Hepatitis C virus (HCV) is associated with various liver diseases. Chronic HCV infection is characterized by an abnormal host immune response. Therefore, it is speculated that to suppress HCV, a well-regulated host immune response is necessary. 2-O-methylhonokiol was identified by the screening of anti-HCV compounds using Renilla luciferase assay in Huh 7.5/Con 1 genotype 1b replicon cells. Here, we investigated the mechanism by which 2-O-methylhonokiol treatment inhibits HCV replication using real-time PCR. Our data shows that treatment with 2-O-methylhonokiol activated innate immune responses via nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) pathway. Additionally, the immunoprecipitation result shows that treatment with 2-O-methylhonokiol augmented tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) by preventing p62 from binding to TRAF6, resulting in reduced autophagy caused by HCV. Finally, we reproduced our data with the conditioned media from 2-O-methylhonokiol-treated cells. These findings strongly suggest that 2-O-methylhonokiol enhances the host immune response and suppresses HCV replication via TRAF6-mediated NF-kB activation.

Association between Hepatitis C Virus Infection and Esophageal Cancer: An Asian Nationwide Population-Based Cohort Study

Background: Hepatitis C virus (HCV) infection causes many extrahepatic cancers, and whether HCV infection is associated with esophageal cancer development remains inconclusive. Methods: A nationwide population-based cohort study of the Taiwan National Health Insurance Research Database (TNHIRD) was conducted. Results: From 2003 to 2012, of 11,895,993 patients, three 1:1:1 propensity score-matched cohorts, including HCV-treated (interferon-based therapy ≧6 months, n = 9047), HCV-untreated (n = 9047), and HCV-uninfected cohorts (n = 9047), were enrolled. The HCV-untreated cohort had the highest 9-year cumulative incidence of esophageal cancer among the three cohorts (0.174%; 95% confidence interval (CI): 0.068–0.395) (p = 0.0292). However, no difference in cumulative incidences was identified between the HCV-treated (0.019%; 0.002–0.109%) and HCV-uninfected cohorts (0.035%; 0.007–0.133%) (p = 0.5964). The multivariate analysis showed that HCV positivity (hazard ratio (HR): 5.1, 95% CI HR: 1.39–18.51) and male sex (HR: 8.897; 95% CI HR: 1.194–66.323) were independently associated with the development of esophageal cancer. Of the three cohorts, the HCV-untreated cohort had the highest cumulative incidence of overall mortality at 9 years (21.459%, 95% CI: 18.599–24.460) (p < 0.0001), and the HCV-treated (12.422%, 95% CI: 8.653–16.905%) and HCV-uninfected cohorts (5.545%, 95% CI: 4.225–7.108%) yielded indifferent cumulative mortality incidences (p = 0.1234). Conclusions: Although HCV positivity and male sex were independent factors associated with esophageal cancer development, whether HCV infection is the true culprit or a bystander for developing esophageal cancer remains to be further investigated. Interferon-based anti-HCV therapy might attenuate esophageal risk and decrease overall mortality in HCV-infected patients.

Naturally Occurring Resistance Associated Substitutions in Non-Cirrhotic, Treatment Naive HCV-HIV Co-Infected Patients Does Not Affect the Treatment Response for Anti-HCV Antiviral Therapy

Purpose

Limited literature on the prevalence of baseline resistance associated substitutions (BL-RAS) among HCV–HIV co-infected patients and their association with treatment outcomes is available especially from India. Hence, the present study aimed to study naturally occurring RAS among non-cirrhotic HCV–HIV co-infected patients and their impact on the response to anti-HCV therapy.

Patients and Methods

In this retrospective study, archived blood samples of 80 HCV–HIV co-infected patients, before anti-HCV therapy initiation, were tested for substitutions at the drug acting sites (NS5a and NS5b) in the HCV genome by direct PCR sequencing.

Results

BL-RAS were seen in 19 (23.7%) patients. As well as BL-RAS, all patients were given sofosbuvir (SOF) 400 mg+ daclatasvir (DCV) 60 mg for 12 weeks. Overall, sustained virological response (SVR) was achieved in 63 (78.8%) patients, in 13 with BL-RAS and in 50 without BL-RAS. All the SVR failure cases (n=17) were retreated with SOF (400 mg) +DCV (60 mg)+ ribavirin (RBV) for 24 weeks. SVR was eventually attained in 14 (82.3%) patients, in 4/6 (66.6%) with BL-RAS and in 10/11 (91%) without BL-RAS. On univariate analysis, age more than 30 years (OR: 11.6; 95% CI: 3.0–45.5, p-value<0.001) and female gender (OR: 8.6; 95% CI: 1.1−69, p-value <0.009) were found to be significant factors associated with the attainment of SVR.

Conclusion

BL-RAS are common in HCV–HIV co-infected patients. The existence of BL-RAS, however, did not affect the attainment of SVR among non-cirrhotic, treatment naive HCV–HIV co-infected patients.

Failure on voxilaprevir, velpatasvir, sofosbuvir and efficacy of rescue therapy

BACKGROUND & AIMS

There are limited data on patients with chronic HCV infection in whom combination voxilaprevir (VOX), velpatasvir (VEL), sofosbuvir (SOF) retreatment fails. Thus, we aimed to assess treatment failure and rescue treatment options in these patients.

METHODS

Samples from 40 patients with HCV genotypes (GT) 1-4 in whom VOX/VEL/SOF retreatment failed were collected within the European Resistance Study Group. Population-based resistance analyses were conducted and clinical parameters and retreatment efficacies were evaluated retrospectively in 22 patients.

RESULTS

Most VOX/VEL/SOF failure patients were infected with HCV GT3a (n = 18, 45%) or GT1a (n = 11, 28%) and had cirrhosis (n = 28, 70%). Previous treatments included an NS3-inhibitor (30%), an NS5A-inhibitor (100%) and SOF (85%). Baseline RAS data from a subgroup of patients before VOX/VEL/SOF retreatment (78%) showed few NS3 RASs apart from Q80K in GT1a (40%), typical NS5A RAS patterns in most patients (74%) and no S282T in NS5B. Sequencing after VOX/VEL/SOF failure was available in 98% of patients and showed only minor changes for NS3 and NS5A RASs. In 22 patients, rescue treatment was initiated with glecaprevir, pibrentasvir alone (n = 2) or with SOF±ribavirin (n = 15), VOX/VEL/SOF±ribavirin (n = 4) or VEL/SOF and ribavirin (n = 1) for 12 to 24 weeks. Sustained virologic response was achieved in 17/21 (81%) patients with a final treatment outcome. Of these, 2 GT3a-infected patients had virologic failure after rescue treatment with VEL/SOF or glecaprevir/pibrentasvir+SOF+ribavirin, and 2 patients with cirrhosis died during treatment or before reaching SVR12.

CONCLUSIONS

VOX/VEL/SOF failure was mainly observed in HCV GT3- and GT1a-infected patients with cirrhosis and was not associated with specific RAS patterns within NS3, NS5A or NS5B target regions. Rescue treatment with multiple targeted therapies was effective in most patients.

LAY SUMMARY

The advent of direct-acting antivirals has enabled the effective cure of chronic hepatitis C in most patients. However, treatment failure occurs in some patients, who are often retreated with a combination regimen called VOX/VEL/SOF, which is associated with very high rates of cure. However, VOX/VEL/SOF retreatment also fails in some patients. Herein, we analysed samples from patients in whom VOX/VEL/SOF retreatment failed and we assessed the efficacy of different rescue therapies, showing that rescue treatment is effective in most patients (81%).

Impact of Interferon-Based Therapy on Hepatitis C-Associated Rheumatic Diseases: A Nationwide Population-Based Cohort Study

Whether hepatitis C virus (HCV) infection-associated risk of rheumatic diseases is reversed by anti-HCV therapy remain elusive. A nationwide population-based cohort study of the Taiwan National Health Insurance Research Database was conducted. Of 19,298,735 subjects, 3 cohorts (1:4:4, propensity score-matched), including HCV-treated (6919 HCV-infected subjects with interferon and ribavirin therapy ≥ 6 months), HCV-untreated (n = 27,676) and HCV-uninfected (n = 27,676) cohorts, were enrolled and followed (2003–2015). The HCV-uninfected cohort had the lowest cumulative incidence of rheumatic diseases (95% confidence interval (CI): 8.416–10.734%), while HCV-treated (12.417–17.704%) and HCV-untreated (13.585–16.479%) cohorts showed no difference in the cumulative incidences. Multivariate analyses showed that HCV infection (95% CI hazard ratio (HR): 1.54–1.765), female sex (1.57–1.789), age ≥ 49 years (1.091–1.257), Charlson comorbidity index ≥ 1 (1.075–1.245), liver cirrhosis (0.655–0.916), chronic obstruction pulmonary disease (1.130–1.360), end-stage renal disease (0.553–0.98), diabetes mellitus (0.834–0.991) and dyslipidemia (1.102–1.304) were associated with incident rheumatic diseases. Among the 3 cohorts, the untreated cohort had the highest cumulative incidence of overall mortality, while the treated and un-infected cohorts had indifferent mortalities. Conclusions: HCV infection, baseline demographics and comorbidities were associated with rheumatic diseases. Although HCV-associated risk of rheumatic diseases might not be reversed by interferon-based therapy, which reduced the overall mortality in HCV-infected patients.

Prevention of Hepatitis C Virus Infection and Liver Cancer

Hepatocellular carcinoma (HCC) is the fifth most prevalent cancer and the second leading cause of cancer-related death worldwide.

Point Shear-Wave Elastography Using Acoustic Radiation Force Impulse Imaging for the Prediction of Liver-Related Events in Patients With Chronic Viral Hepatitis

Chronic viral hepatitis is associated with substantial morbidity and mortality worldwide. The aim of our study was to assess the ability of point shear-wave elastography (pSWE) using acoustic radiation force impulse imaging for the prediction of the following liver-related events (LREs): new diagnosis of HCC, liver transplantation, or liver-related death (hepatic decompensation was not included as an LRE). pSWE was performed at study inclusion and compared with liver histology, transient elastography (TE), and serologic biomarkers (aspartate aminotransferase to platelet ratio index, Fibrosis-4, FibroTest). The performance of pSWE and TE to predict LREs was assessed by calculating the area under the receiver operating characteristic curve and a Cox proportional-hazards regression model. A total of 254 patients with a median follow-up of 78 months were included in the study. LRE occurred in 28 patients (11%) during follow-up. In both patients with hepatitis B virus and hepatitis C virus (HCV), pSWE showed significant correlations with noninvasive tests and TE, and median pSWE and TE values were significantly different between patients with LREs and patients without LREs (both P < 0.0001). In patients with HCV, the area under the receiver operating characteristic curve for pSWE and TE to predict LREs were comparable: 0.859 (95% confidence interval [CI], 0.747-0.969) and 0.852 (95% CI, 0.737-0.967) (P = 0.93). In Cox regression analysis, pSWE independently predicted LREs in all patients with HCV (hazard ratio, 17.9; 95% CI, 5.21-61-17; P < 0.0001) and those who later received direct-acting antiviral therapy (hazard ratio, 17.11; 95% CI, 3.88-75.55; P = 0.0002). Conclusion: Our study shows good comparability between pSWE and TE. pSWE is a promising tool for the prediction of LREs in patients with viral hepatitis, particularly those with chronic HCV. Further studies are needed to confirm our data and assess their prognostic value in other liver diseases.

Remission of long-term hepatic and renal disease induced by HCV after direct-acting antivirals therapy

In addition to liver disease, the hepatitis C virus (HCV) has been associated with autoimmune phenomena, such as mixed cryoglobulin and glomerulonephritis (GN). Until recently, both chronic hepatitis and HCV extra-hepatic manifestations were treated with peg-interferon plus ribavirin, however these drugs presented low efficacy and induced severe side effects. Nowadays, the HCV chronic hepatitis has been treated with direct acting antivirals (DAA), but studies on the DAA therapy for HCV-associated glomerulonephritis are scarce. Here, we describe two cases of HCV-associated glomerulonephritis that were treated with DAAs. In these two cases, previously experienced to peg-interferon plus ribavirin, the sofosbuvir plus simeprevir therapy was effective, without significant side effects, and interrupted the evolution of at least 20 years of both hepatic and renal diseases. These cases join the seven previously described cases that were treated with this DAAs association.

Iminosugars: A host-targeted approach to combat Flaviviridae infections

N-linked glycosylation is the most common form of protein glycosylation and is required for the proper folding, trafficking, and/or receptor binding of some host and viral proteins. As viruses lack their own glycosylation machinery, they are dependent on the host's machinery for these processes. Certain iminosugars are known to interfere with the N-linked glycosylation pathway by targeting and inhibiting α-glucosidases I and II in the endoplasmic reticulum (ER). Perturbing ER α-glucosidase function can prevent these enzymes from removing terminal glucose residues on N-linked glycans, interrupting the interaction between viral glycoproteins and host chaperone proteins that is necessary for proper folding of the viral protein. Iminosugars have demonstrated broad-spectrum antiviral activity in vitro and in vivo against multiple viruses. This review discusses the broad activity of iminosugars against Flaviviridae. Iminosugars have shown favorable activity against multiple members of the Flaviviridae family in vitro and in murine models of disease, although the activity and mechanism of inhibition can be virus-specfic. While iminosugars are not currently approved for the treatment of viral infections, their potential use as future host-targeted antiviral (HTAV) therapies continues to be investigated.

Discovery of BMS-986144, a Third-Generation, Pan-Genotype NS3/4A Protease Inhibitor for the Treatment of Hepatitis C Virus Infection

The discovery of a pan-genotypic hepatitis C virus (HCV) NS3/4A protease inhibitor based on a P1-P3 macrocyclic tripeptide motif is described. The all-carbon tether linking the P1-P3 subsites of 21 is functionalized with alkyl substituents, which are shown to effectively modulate both potency and absorption, distribution, metabolism, and excretion (ADME) properties. The CF₃Boc-group that caps the P3 amino moiety was discovered to be an essential contributor to metabolic stability, while positioning a methyl group at the C1 position of the P1' cyclopropyl ring enhanced plasma trough values following oral administration to rats. The C7-fluoro, C6-CD₃O substitution pattern of the P2* isoquinoline heterocycle of 21 was essential to securing the targeted potency, pharmacokinetic (PK), and toxicological profiles. The C6-CD₃O redirected metabolism away from a problematic pathway, thereby circumventing the time-dependent cytochrome P (CYP) 450 inhibition observed with the C6-CH₃O prototype.

Sofosbuvir, velpatasvir, and voxilaprevir for patients with failure of previous direct-acting antiviral therapy for chronic hepatitis C: Results from the German Hepatitis C-Registry (DHC-R)

Despite the high effectiveness of direct-acting antivirals for the treatment of hepatitis C, a small proportion of patients do not respond to approved regimens. The combination regimen of SOF/VEL/VOX was recently approved for patients with failure to prior NS5A-based treatment. In this German real-world cohort including patients with cirrhosis (27.3 %) and previous decompensation events, 12 weeks of SOF/VEL/VOX resulted in high virologic response rates irrespective of disease severity and prior DAA regimen. Adverse events were mostly mild or moderate and comparable to those seen in the approval studies.

New Antiviral Agents for Treatment of Hepatitis C

Between 70 and 170 million people worldwide are infected with hepatitis C virus (HCV) which frequently causes chronic liver disease and cirrhosis. There are several genotypes and many subtypes of HCV. Direct-acting antiviral agents are effective at eradicating HCV in the vast majority of patients, producing much higher cure rates than were seen with interferon and ribavirin regimens only a few years ago. The chapter reviews the epidemiology and virology of HCV infection. Treatment regimens are complex but a straightforward approach to selection of patients, choice of direct-acting antiviral agents and follow-up is presented.

Genome-wide capture sequencing to detect hepatitis C virus at the end of antiviral therapy

Background

Viral relapse is a major concern in hepatitis C virus (HCV) antiviral therapy. Currently, there are no satisfactory methods to predict viral relapse, especially in the era of direct acting antivirals in which the virus often quickly becomes undetectable using PCR-based approaches that focus on a small viral region. Next-generation sequencing (NGS) provides an alternative option for viral detection in a genome-wide manner. However, owing to the overwhelming dominance of human genetic content in clinical specimens, direct detection of HCV by NGS has a low sensitivity and hence viral enrichment is required.

Methods

Based on template-dependent multiple displacement amplification (tdMDA), an improved method for whole genome amplification (Wang et al., 2017. Biotechniques 63, 21–27), we evaluated two strategies to enhance the sensitivity of NGS-based HCV detection: duplex-specific nuclease (DSN)-mediated depletion of human sequences and HCV probe-based capture sequencing.

Results

In DSN-mediated depletion, human sequences were significantly reduced in the two HCV serum samples tested, 65.3% → 55.6% → 33.7% (#4727) and 68.6% → 56% → 21% (#4970), respectively for no normalization, self- and driver-applied normalization. However, this approach was associated with a loss of HCV sequences perhaps due to its micro-homology with the human genome. In capture sequencing, HCV-mapped sequencing reads occupied 96.8% (#4727) and 22.14% (#4970) in NGS data, equivalent to 1936x and 7380x enrichment, respectively. Capture sequencing was then applied to ten serum samples collected at the end of HCV antiviral therapy. Interestingly, the number of HCV-mapped reads was significantly higher in relapsed patients (n = 5) than those from patients with sustained virological response (SVR) (n = 5), 102.4 ± 72.3 vs. 2.6 ± 0.55, p = 0.014.

Conclusions

Our data provides concept evidence for a highly sensitive HCV detection by capture sequencing. The abundance difference of HCV sequencing reads at the end of HCV antiviral therapy could be applied to predict treatment outcomes.

Reversal of T Cell Exhaustion in Chronic HCV Infection

The long-term consequences of T cell responses’ impairment in chronic HCV infection are not entirely characterized, although they may be essential in the context of the clinical course of infection, re-infection, treatment-mediated viral clearance and vaccine design. Furthermore, it is unclear whether a complete reinvigoration of HCV-specific T cell response may be feasible. In most studies, attempting to reverse the effects of compromised immune response quality by specific blockades of negative immune regulators, a restoration of functional competence of HCV-specific T cells was shown. This implies that HCV-induced immune dysfunction may be reversible. The advent of highly successful, direct-acting antiviral treatment (DAA) for chronic HCV infection instigated investigation whether the treatment-driven elimination of viral antigens restores T cell function. Most of studies demonstrated that DAA treatment may result in at least partial restoration of T cell immune function. They also suggest that a complete restoration comparable to that seen after spontaneous viral clearance may not be attained, pointing out that long-term antigenic stimulation imprints an irreversible change on the T cell compartment. Understanding the mechanisms of HCV-induced immune dysfunction and barriers to immune restoration following viral clearance is of utmost importance to diminish the possible long-term consequences of chronic HCV infection.

Discovery of Hepatitis C Virus: 2020 Nobel Prize in Medicine

Hepatitis C virus (HCV) accounts for hepatitis, cirrhosis, hepatocellular carcinoma, and liver transplantation. Every year, millions of people develop chronic liver diseases. This article provides novel insights into the major breakthroughs in the discovery of hepatitis C virus. 2020 Nobel Prize in Medicine was awarded to Michael Houghton, Harvey Alter, and Charles Rice for their outstanding contribution in the discovery of HCV. Also, this article deals with current findings, challenges, and future prospects in the diagnosis of HCV infection. DAA, along with protease inhibitors, is found to have higher SVR and is a promising drug to treat HCV infection. However, with regard to the emergence of resistance to DAAs, CRISPR-Cas can be the future technique in preventing resistance. Although the current knowledge of molecular mechanisms associated with HCV infection is insufficient, the better understanding of it provides better hope in the treatment of HCV.

Lymphoma

A cancer causing infection on lymphocytes.

Fulminant hepatitis

A decrease in the size of the liver accompanied even by the death of liver parenchyma with the onset of infection with hepatitis virus.

Transfection

The process of introducing nucleic acids into eukaryotic cells without using viral methods.

Huh-7 cells

A type of liver cells grown in the laboratory for research purposes.

Immunoscreening

A biomedical method that helps to detect a protein produced from a cloned gene after it undergoes transcription, followed by the translation process within the cell.

cDNA library

A group of only the genes that are encoded into proteins by an organism.

Sustained virologic response

Absence of any evidence of the presence of HCV in the blood of patients with chronic HCV infection after undergoing antiviral treatment.

Pegylated interferon

A covalent conjugate of recombinant interferon and polyethylene glycol, used as an antiviral and antineoplastic agent.

Immunoelectron microscopy

A technique to localize ultrastructure antigens or antibodies in cells or tissues for the diagnosis of viral infections.

Stellate cells

A major type of liver cell involved in liver cirrhosis.

Hepatitis C virus (HCV) accounts for hepatitis, liver cirrhosis, hepatocellular carcinoma, and liver transplantation. This virus is a single-stranded RNA virus that belongs to the Flaviviridae family. According to the WHO, about 71 million people have chronic HCV infections around the globe in 2020, and hence, it is a plague of humankind. The credit of discovery of HCV goes to Michael Houghton, Harvey Alter, and Charles Rice for which they are awarded 2020 Nobel Prize in Medicine. Their contribution has given better hope to mankind to cure HCV for the first time in the history. With the use of pegylated interferon and ribavirin jointly, higher SVR has been found comparatively, even in patients with chronic liver diseases. However, due to excessive pain tolerated by patients, interferon (IFN)-based therapy is rapidly being replaced with IFN-free DAA regimens. With the onset of resistance to DAA drugs, CRISPR-Cas system can be used to modify the viral genome to impair their ability to develop resistance.

How to cite this article: Laugi H. Discovery of Hepatitis C Virus: 2020 Nobel Prize in Medicine. Euroasian J Hepato-Gastroenterol 2020;10(2): 105–108.