HCV virology and diagnosis

Nanodiagnostics in global eradication of hepatitis C virus

Hepatitis C, caused by the hepatitis C virus (HCV), is a prevalent liver disease with severe outcomes, including cirrhosis and hepatocellular carcinoma. Traditional diagnostic methods primarily detect antiviral antibodies (anti-HCV) or viral RNA, but these approaches have limitations. Anti-HCV antibodies may take 2-4 weeks to develop in acute cases and can be absent in some individuals, leading to undiagnosed early-stage infections. This poses significant challenges for public health, particularly in resource-limited settings where early detection is crucial. This article explores the development of biosensors engineered to directly detect HCV surface antigens, such as envelope proteins. These biosensors provide a promising solution for earlier and more accurate diagnosis by identifying viral components at the initial stages of infection. By focusing on direct detection of viral antigens, these innovations could enhance early diagnosis, facilitate timely intervention, and reduce virus transmission. We evaluate the advancements in biosensor technology over the past decade and their potential to improve HCV detection in clinical and field settings, ultimately supporting global efforts to eliminate HCV as a public health threat.

Liver-related aspects of valoctocogene roxaparvovec gene therapy for hemophilia A: expert guidance for clinical practice

ABSTRACT

Adeno-associated virus-based gene therapy (valoctocogene roxaparvovec) is an attractive treatment for hemophilia A. Careful clinical management is required to minimize the risk of hepatotoxicity, including assessment of baseline liver condition to determine treatment eligibility and monitoring liver function after gene therapy. This article describes recommendations (developed by a group of hemophilia experts) on hepatic function monitoring before and after gene therapy. To prevent harmful liver-related effects, gene therapy is contraindicated in patients with uncontrolled liver infections, autoimmune hepatitis, liver stiffness ≥8 kPa, or cirrhosis. Before using gene therapy in patients with liver steatosis or other liver disorders, the risk of liver damage should be considered using a highly individualized approach. Treatment is not recommended in patients with abnormal liver enzymes, including alanine aminotransferase (ALT) at any level above the upper limit of normal (ULN). Therefore, pretreatment assessment of liver health should include laboratory tests, abdominal ultrasound, and liver stiffness measurements by transient elastography (TE). In the first year after therapy, ALT levels should be monitored 1 to 2 times per week to detect elevations ≥1.5× ULN, which may require immunosuppressant therapy. Patients with ALT elevation should receive prednisone 60 mg/d for 2 weeks, followed by stepwise tapering when ALT returns to baseline. ALT monitoring should continue long term (every 3-6 months), along with abdominal ultrasound (every 6 months) and TE (yearly) evaluations. When patients with good liver health are selected for treatment and closely monitored thereafter, ALT elevations can be promptly treated and are expected to resolve without long-term hepatic sequelae.

One-step, rapid, nanoparticle-based biosensor platform for the simultaneous identification of hepatitis B virus and hepatitis C virus in clinical applications

OBJECTIVES

Viral hepatitis caused by hepatitis B virus (HBV) and hepatitis C virus (HCV) infections remain a major global public health challenge, particularly in low- and middle-income countries. It is crucial to utilize a pointof-care (POC) testing platform that is sensitive, specific, rapid, and user-friendly for screening and diagnosis of the two infections. Here, a novel molecular diagnostic assay, integrating multiplex loop-mediated isothermal amplification with a gold nanoparticle-based lateral flow biosensor (mLAMP-AuNPs-LFB) was developed and applied for one-step, visual, rapid, sensitive, and specific identification of HBV and HCV.

METHODS

The AuNPs-based LFB was devised and constructed for the simultaneous detection of HBV and HCV. The HBV-LAMP and HCV-LAMP primers were designed against the S and 5'-untranslated region (5'-UTR) genes from the major HBV genotypes (B, C, D, B/C recombinant, and C/D recombinant) and HCV subtypes (1b, 2a, 3a, 3b, and 6a) in China, respectively. Our assay conditions, both multiplex-LAMP amplification temperature and time were optimized. The sensitivity and specificity of our assay were tested, and the feasibility of our assay was verified through clinical samples.

RESULTS

The AuNPs-based LFB used here was successfully manufactured according to our devise manual. The two unique independent primer pairs were successfully designed based on the S and 5'-UTR genes, respectively. The optimal mLAMP-AuNPs-LFB detection process, involving rapid nucleic acid isolation (10 min), mLAMP (63 °C for 35 min), and visual AuNPs-LFB interpretation (less than 2 min), could be completed within 50 min. The HBV&HCV-mLAMP-AuNPs-LFB assay can detect the target genes (HBV-S and HCV-5'-UTR) with as low as 20 copies of plasmid template per test, and the specificity was 100% for the experimental pathogens.

CONCLUSIONS

The preliminary results manifested that our mLAMP-AuNPs-LFB assay is a valuable tool and has tremendous potential as a POC testing approach for HBV and HCV identification, especially in undeveloped regions.

Efficacy of 8-week daclatasvir-sofosbuvir regimen in chronic hepatitis C: a systematic review and meta-analysis

BACKGROUND

The high rates of the sustained virologic response 12 weeks after treatment (SVR12) in real world settings provoked the adoption of shortened courses of the costly direct-acting antivirals (DAAs) regimens. This study provides, to our knowledge, the first systematic review and meta-analysis for the efficacy of the shortened 8-week course of sofosbuvir (SOF) plus daclatasvir (DCV), the most accessible DAAs in the low-middle income countries (LMICs).

METHODS

We performed a proportion meta-analysis to determine a reliable rate of SVR12 by pooling all studies that evaluated the results of the 8-week regimen of DCV + SOF. In addition, we applied sensitivity analyses using two imputation paradigms: a conservative approach, and a pragmatic approach to avoid overestimating the efficacy of the 8-week regimen in studies that followed a response-guided treatment (RGT) approach.

RESULTS

Six studies with a total of 159 patients were included. The pooled SVR12 rate ranged from 91 to 97% in the included scenarios. The pragmatic scenario showed that the pooled SVR12 was 97% (95% confidence interval (CI) 91%; 100%) with lower variability as assessed by the prediction interval. The conservative approach revealed an SVR12 of 93% (95% CI 84%; 95%).

CONCLUSION

The 8-week course of 60 mg DCV with SOF provided a comparable SVR12 to the standard 12-week regimen in treatment-naïve, non-HIV co-infected patients with a minimum estimated efficacy of 90%.

A therapeutic approach for the hepatitis C virus: in silico design of an antisense oligonucleotide-based candidate capsid inhibitor

Direct-acting antiviral (DAA) drugs have been shown to effectively reduce viral load and cure a high proportion of hepatitis C virus (HCV) infections. However, costs associated with the course of therapy and any possible adverse effects should also be considered. It is important to acknowledge, moreover, that certain groups may not be eligible for treatment. Given that there is currently no approved vaccine for HCV infection, the need for an effective, safe, and accessible treatment remains a crucial priority. The aim of this study is to develop an antisense oligonucleotide (ASO)-based therapeutic drug that can inhibit HCV capsid. After analyzing 817 HCV capsid protein mRNA sequences using the NCBI Virus Data Portal, a conserved region of 7 nucleotides (nt) was identified in all genotypes (1-7). However, because of its high GC% content, this region is not a suitable target for ASO. Conversely, the other highly conserved region, which is only 8 nt long, was preserved in 801 datasets after removing missing and differing sequence data. The candidate ASO was then investigated using computer simulations to assess its potential. Thus, it is possible that the ASO sequence consisting of 8 nt could be a viable therapeutic target for the inhibition of HCV capsid. Furthermore, the 7 nt sequence, which is conserved in all datasets, may be targeted using alternative strategies in lieu of ASO-based targeting.

Performance of Elecsys® HCV Duo Immunoassay for Diagnosis and Assessment of Treatment Response in HCV Patients with or without HIV Infection

BACKGROUND/OBJECTIVES

The Elecsys® HCV Duo immunoassay (Roche Diagnostics International Ltd., Rotkreuz, Switzerland) detects both antibodies to hepatitis C virus (anti-HCV) and HCV core antigen (HCV-Ag) and has shown excellent diagnostic performance in blood donor samples. We aim to validate its use for diagnosing chronic HCV infection and assessing sustained virological response (SVR) post-direct-acting antivirals (DAAs) in patients with or without HIV infection.

METHODS

Blood samples from 100 healthy controls, as well as 64 HCV mono-infection and 136 HCV-HIV coinfections, were collected before and 12-24 weeks after DAAs. The assay performance for determining active infection at baseline and SVR was compared with HCV RNA.

RESULTS

Overall, 156 (78.0%) of HCV-infected patients had HCV genotype 1, and the SVR rate was 96.5%. The sensitivity, specificity, and area under the ROC curve (AUROC) for HCV diagnosis at baseline were 99.50% (95% confidence interval [CI], 96.82-99.97%), 100% (95%CI, 95.39-100%), and 0.998 (95%CI, 0.992-1.003), respectively. The corresponding results for HCV-Ag in determining SVR were 57.14% (95%CI, 20.24-88.19%), 97.41% (95%CI, 93.73-99.04%), and 0.773 (95%CI, 0.543-1.003), respectively. The assay also exhibited comparable sensitivity and specificity between HCV mono- and coinfection.

CONCLUSIONS

Our study showed that the Elecsys® HCV Duo immunoassay effectively diagnosed HCV infection, regardless of HIV status, making it suitable for managing high-risk populations in resource-limited settings.

Interplay between lipid metabolism, lipid droplets and RNA virus replication

Lipids play essential roles in the cell as components of cellular membranes, signaling molecules, and energy storage sources. Lipid droplets are cellular organelles composed of neutral lipids, such as triglycerides and cholesterol esters, and are also considered as cellular energy reserves, yet new functions have been recently associated with these structures, such as regulators of oxidative stress and cellular lipotoxicity, as well as modulators of pathogen infection through immune regulation. Lipid metabolism and lipid droplets participate in the infection process of many RNA viruses and control their replication and assembly, among others. Here, we review and discuss the contribution of lipid metabolism and lipid droplets over the replication cycle of RNA viruses, altogether pointing out potentially new pharmacological antiviral targets associated with lipid metabolism.

Risk Factors Associated with Hepatitis C Subtypes and the Evolutionary History of Subtype 1a in Mexico

The Hepatitis C Virus (HCV), with its diverse genotypes and subtypes, has significantly impacted the health of millions of people worldwide. Analyzing the risk factors is essential to understanding the spread of the disease and developing appropriate prevention strategies. This study aimed to identify risk factors associated with HCV subtype transmission and calculate the emergence time of subtype 1a in Mexico. A cross-sectional study was conducted from January 2014 to December 2018, involving 260 HCV-infected adults. HCV infection was confirmed via Enzyme-Linked Immunosorbent Assay, and viral load was measured by real-time PCR. Genotyping/subtyping tools were the Line Probe Assay and Sanger sequencing of the non-structural region 5B (NS5B). The most frequent HCV subtype was 1a (58.5%), followed by subtypes 1b (19.2%), 3a (13.1%), 2b (5.4%), 2a/2c (2.7%), 2a (0.8%), and 4a (0.4%). Intravenous drug use and tattoos were significant risk factors for subtypes 1a and 3a, while hemodialysis and blood transfusion were linked with subtype 1b. For the evolutionary analysis, 73 high-quality DNA sequences of the HCV subtype 1a NS5B region were used, employing a Bayesian coalescent analysis approach. This analysis suggested that subtype 1a was introduced to Mexico in 1976, followed by a diversification event in the mid-1980s. An exponential increase in cases was observed from 1998 to 2006, stabilizing by 2014. In conclusion, this study found that HCV subtypes follow distinct transmission routes, emphasizing the need for targeted prevention strategies. Additionally, the findings provide valuable insights into the origin of HCV subtype 1a. By analyzing the history, risk factors, and dynamics of the HCV epidemic, we have identified these measures: limiting the harm of intravenous drug trafficking, enhancing medical training and infrastructure, and ensuring universal access to antiviral treatments. The successful implementation of these strategies could lead to an HCV-free future in Mexico.

Distinct Characteristic Binding Modes of Benzofuran Core Inhibitors to Diverse Genotypes of Hepatitis C Virus NS5B Polymerase: A Molecular Simulation Study

The benzofuran core inhibitors HCV-796, BMS-929075, MK-8876, compound 2, and compound 9B exhibit good pan-genotypic activity against various genotypes of NS5B polymerase. To elucidate their mechanism of action, multiple molecular simulation methods were used to investigate the complex systems of these inhibitors binding to GT1a, 1b, 2a, and 2b NS5B polymerases. The calculation results indicated that these five inhibitors can not only interact with the residues in the palm II subdomain of NS5B polymerase, but also with the residues in the palm I subdomain or the palm I/III overlap region. Interestingly, the binding of inhibitors with longer substituents at the C5 position (BMS-929075, MK-8876, compound 2, and compound 9B) to the GT1a and 2b NS5B polymerases exhibits different binding patterns compared to the binding to the GT1b and 2a NS5B polymerases. The interactions between the para-fluorophenyl groups at the C2 positions of the inhibitors and the residues at the binding pockets, together with the interactions between the substituents at the C5 positions and the residues at the reverse β-fold (residues 441-456), play a key role in recognition and the induction of the binding. The relevant studies could provide valuable information for further research and development of novel anti-HCV benzofuran core pan-genotypic inhibitors.

Catalytic hairpin assembly triggering amplified DNAzyme-feedback for sensitive detection of hepatitis C virus genotype 1b

Developing a simple, reliable, and sensitive hepatitis C virus (HCV) genetic sensing platform is of great significance for diagnosing diseases and selecting appropriate antiviral treatments. Herein, a tandem nucleic acid amplification strategy for sensitive detection of HCV genotype 1b (HCV-1b) was developed by stringing the catalytic hairpin assembly (CHA) and the triggered DNAzyme amplifier. The hairpin reactants were initiated by the target to produce lots of triggering double-stranded DNA sequences which can efficiently activate the subsequent blocked DNAzyme. Thereby, the continuous cleavage of substrate was realized, resulting in the fluorescence signal amplification. The DNA-based isothermal CHA-DNAzyme (CDz) sensing platform was successfully applied for sensitive detection of HCV-1b with the limit of detection (84 pM) and showed good selectivity. Moreover, the practical detection of target DNA in the complex biologic matrix indicated that the developing strategy had good potential for early HCV infection diagnosis.

The pharmacological role of Ginsenoside Rg3 in liver diseases: A review on molecular mechanisms

Liver diseases are a significant global health burden and are among the most common diseases. Ginssennoside Rg3 (Rg3), which is one of the most abundant ginsenosides, has been found to have significant preventive and therapeutic effects against various types of diseases with minimal side effects. Numerous studies have demonstrated the significant preventive and therapeutic effects of Rg3 on various liver diseases such as viral hepatitis, acute liver injury, nonalcoholic liver diseases (NAFLD), liver fibrosis and hepatocellular carcinoma (HCC). The underlying molecular mechanism behind these effects is attributed to apoptosis, autophagy, antioxidant, anti-inflammatory activities, and the regulation of multiple signaling pathways. This review provides a comprehensive description of the potential molecular mechanisms of Rg3 in the development of liver diseases. The article focuses on the regulation of apoptosis, oxidative stress, autophagy, inflammation, and other related factors. Additionally, the review discusses combination therapy and liver targeting strategy, which can accelerate the translation of Rg3 from bench to bedside. Overall, this article serves as a valuable reference for researchers and clinicians alike.

Biosensor-based multiple cross displacement amplification platform for visual and rapid identification of hepatitis C virus

Hepatitis C remains a global health problem, especially in poverty-stricken areas. A rapid and sensitive point-of-care (POC) diagnostic tool is critical for the early detection and timely treatment of hepatitis C virus (HCV) infection. Here, for the first time, we reported a novel molecular diagnostic assay, termed reverse transcription multiple cross displacement amplification integrated with a gold-nanoparticle-based lateral flow biosensor (RT-MCDA-AuNPs-LFB), which was developed for rapid, sensitive, specific, and visual identification of HCV. HCV-RT-MCDA induced rapid isothermal amplification through a specific primer set targeting the 5'untranslated region gene from the major HCV genotypes 1b, 2a, 3b, 6a, and 3a that are prevalent in China. The optimal reaction temperature and time for RT-MCDA-AuNPs-LFB were 68°C and 25 min, respectively. The limit of detection of the assay was 10 copies per test, and the specificity was 100% for the experimental strains. The whole detection procedure, including crude nucleic acid isolation (~5 min), RT-MCDA (68°C, 25 min), and visual AuNPs-LFB result confirmation (less than 2 min), was performed within 35 min. The preliminary results indicated that the HCV-RT-MCDA-AuNPs-LFB assay could be a valuable tool for sensitive, specific, visual, cost-saving, and rapid detection of HCV and has potential as a POC diagnostic platform for field screening and early clinical detection of HCV infection.

Rapid, visual, label-based biosensor platform for identification of hepatitis C virus in clinical applications

OBJECTIVES

In the current study, for the first time, we reported a novel HCV molecular diagnostic approach termed reverse transcription loop-mediated isothermal amplification integrated with a gold nanoparticles-based lateral flow biosensor (RT-LAMP-AuNPs-LFB), which we developed for rapid, sensitive, specific, simple, and visual identification of HCV.

METHODS

A set of LAMP primer was designed according to 5'untranslated region (5'UTR) gene from the major HCV genotypes 1b, 2a, 3b, 6a, and 3a, which are prevalent in China. The HCV-RT-LAMP-AuNPs-LFB assay conditions, including HCV-RT-LAMP reaction temperature and time were optimized. The sensitivity, specificity, and selectivity of our assay were evaluated in the current study. The feasibility of HCV-RT-LAMP-AuNPs-LFB was confirmed through clinical serum samples from patients with suspected HCV infections.

RESULTS

An unique set of HCV-RT-LAMP primers were successfully designed targeting on the 5'UTR gene. The optimal detection process, including crude nucleic acid extraction (approximately 5 min), RT-LAMP reaction (67℃, 30 min), and visual interpretation of AuNPs-LFB results (~ 2 min), could be performed within 40 min without specific instruments. The limit of detection was determined to be 20 copies per test. The HCV-RT-LAMP-AuNPs-LFB assay exhibited high specificity and anti-interference.

CONCLUSIONS

These preliminary results confirmed that the HCV-RT-LAMP-AuNPs-LFB assay is a sensitive, specific, rapid, visual, and cost-saving assay for identification of HCV. This diagnostic approach has great potential value for point-of-care (POC) diagnostic of HCV, especially in resource-challenged regions.

Akkermansia muciniphila might improve anti-PD-1 therapy against HCC by changing host bile acid metabolism

PD-1 monoclonal antibodies (mAb) have demonstrated remarkable efficacy in a variety of cancers, including Hepatocellular carcinoma (HCC). However, the patient response rates remain suboptimal, and a significant proportion of initial responders may develop resistance to this therapeutic approach. Akkermansia muciniphila (AKK), a microorganism implicated in multiple human diseases, has been reported to be more abundant in patients who exhibit favorable responses to PD-1mAb. However, the underlying mechanism has yet to be elucidated. In our study, we found that AKK could enhance the efficacy of PD-1mAb against HCC in a tumor-bearing mouse model. It promotes HCC tumor cells apoptosis and raise the CD8+ T proportion in the tumor microenvironment. Additionally, AKK downregulates PD-L1 expression in tumor cells. Furthermore, the analysis of metabonomics demonstrates that AKK induces alterations in the host's bile acid metabolism, leading to a significant increase in serum TUDCA levels. Considering the immunosuppresive roles of TUDCA in HCC development, it is plausible to speculate that AKK may reinforce the immunotherapy of PD-1mAb against HCC through its impact on bile acid metabolism.

Past, Present, and Future of Liver-Brain Axis in Alzheimer's Disease: A Bibliometric Review

Background

No effective drugs currently exist to cure Alzheimer's disease (AD) due to its complexity and the lack of understanding of the involved molecular signaling and pathways. The relationship between liver health and AD is now widely recognized. Still, molecular links and shared pathways between the liver and brain remain unclear, making the liver-brain axis in AD therapies a new area for exploration. However, bibliometric studies on this topic are lacking.

Objective

This study aims to review the liver-brain axis in AD and identify future research hotspots and trends through bibliometric analysis.

Methods

Articles and reviews related to AD and liver and its related diseases were searched in the Web of Science Core Collection (WoSCC) database up to 2024. Data were processed and visually analyzed using VOSviewer, CiteSpace, and Pajek.

Results

We collected 1,777 articles on AD and liver and its related diseases from 2,517 institutions across 80 countries. Keyword cluster analysis identified 11 clusters, with 'insulin resistance,' 'amyloid-beta,' 'apolipoprotein-E,' 'oxidative stress,' and 'inflammation' appearing most frequently, and exhibiting strong total link strength. These results indicate that these topics have been the primary focus of research on the liver-brain axis in AD.

Conclusions

This study is the first to comprehensively analyze the liver-brain axis in AD using bibliometric methods. The research results identify recent research frontiers and hotspots, aiding scholars in gaining a deeper understanding of the correlation between AD and the liver.

Liposome-Mediated Anti-Viral Drug Delivery Across Blood-Brain Barrier: Can Lipid Droplet Target Be Game Changers?

Lipid droplets (LDs) are subcellular organelles secreted from the endoplasmic reticulum (ER) that play a major role in lipid homeostasis. Recent research elucidates additional roles of LDs in cellular bioenergetics and innate immunity. LDs activate signaling cascades for interferon response and secretion of pro-inflammatory cytokines. Since balanced lipid homeostasis is critical for neuronal health, LDs play a crucial role in neurodegenerative diseases. RNA viruses enhance the secretion of LDs to support various phases of their life cycle in neurons which further leads to neurodegeneration. Targeting the excess LD formation in the brain could give us a new arsenal of antiviral therapeutics against neuroviruses. Liposomes are a suitable drug delivery system that could be used for drug delivery in the brain by crossing the Blood-Brain Barrier. Utilizing this, various pharmacological inhibitors and non-coding RNAs can be delivered that could inhibit the biogenesis of LDs or reduce their sizes, reversing the excess lipid-related imbalance in neurons. Liposome-Mediated Antiviral Drug Delivery Across Blood-Brain Barrier. Developing effective antiviral drug is challenging and it doubles against neuroviruses that needs delivery across the Blood-Brain Barrier (BBB). Lipid Droplets (LDs) are interesting targets for developing antivirals, hence targeting LD formation by drugs delivered using Liposomes can be game changers.

Shear Wave Elastography for Assessing Liver Stiffness in HCV-Infected Kidney Transplant Recipients after Direct-Acting Antiviral Treatment: A Comparative Study with Magnetic Resonance Elastography

Hepatitis C virus (HCV) infection can lead to hepatic fibrosis. The advent of direct-acting antivirals (DAAs) has substantially improved sustained virological response (SVR) rates. In this context, kidney transplant recipients (KTRs) are of particular interest due to their higher HCV infection rates and uncertain renal excretion and bioavailability of DAAs. We investigated liver stiffness after DAA treatment in 15 HCV-infected KTRs using ultrasound shear wave elastography (SWE) in comparison with magnetic resonance elastography (MRE). KTRs were treated with DAAs (daclatasvir and sofosbuvir) for three months and underwent SWE at baseline, end of therapy (EOT), and 3 (EOT+3) and 12 months (EOT+12) after EOT. Fourteen patients achieved SVR12. Shear wave speed (SWS)-as a surrogate parameter for tissue stiffness-was substantially lower at all three post-therapeutic timepoints compared with baseline (EOT: -0.42 m/s, p < 0.01; CI = -0.75--0.09, EOT+3: -0.43 m/s, p < 0.01; CI = -0.75--0.11, and EOT+12: -0.52 m/s, p < 0.001; CI = -0.84--0.19), suggesting liver regeneration after viral eradication and end of inflammation. Baseline SWS correlated positively with histopathological fibrosis scores (r = 0.48; CI = -0.11-0.85). Longitudinal results correlated moderately with APRI (r = 0.41; CI = 0.12-0.64) but not with FIB-4 scores (r = 0.12; CI = -0.19-0.41). Although higher on average, SWE-derived measurements correlated strongly with MRE (r = 0.64). In conclusion, SWE is suitable for non-invasive therapy monitoring in KTRs with HCV infection.

Hepatitis-virus-positive patients management in dental office

BACKGROUND

Hepatitis is a condition characterized by inflammation of the liver, which can be caused by several viruses including hepatitis A, B, C, D and E. This condition can affect the oral health of patients and increase the risk of complications during dental management. The clinical management of hepatitis patients in the dental setting requires a comprehensive and individualized approach to ensure safety and optimal treatment outcomes. This article aims to provide a comprehensive overview of the current literature on the dental management of patients with different forms of hepatitis.

METHODS

The article focuses on the specific challenges associated with dental treatments in hepatitis patients, including increased risk of infection and bleeding. Additionally, the article provides recommendations for dental practitioners, including infection control measures, communication with medical providers, and the use of prophylactic antibiotics.

RESULTS

The authors show that the dental management of patients with hepatitis requires a thorough understanding of the specific challenges associated with this condition, as well as the implementation of appropriate preventive measures to ensure the safety and well-being of these patients.

CONCLUSIONS

Further research is needed to better understand the impact of hepatitis on oral health and the most effective approaches to managing dental treatments in this patient population.

Bioinformatics analysis of multi-epitope peptide vaccines against Hepatitis C virus: a molecular docking study

BACKGROUND

Hepatitis C Virus (HCV) infection is one of the causal agents of liver disease burden. Six multiple antigenic peptides were synthesized including (P315, P412, and P517) plus (P1771, P2121, and P2941) to induce humoral and cellular responses, respectively against HCV infection.

AIM

This paper aimed to employ computational tools to evaluate the efficacy of each peptide individually and to determine the most effective one for better vaccine development and/or immunotherapy.

METHODS

VaxiJen web and AllerTOP servers were used for antigenicity and allergenicity prediction, respectively. The ToxinPred web server was used to investigate the peptide toxicity. Each peptide was docked with its corresponding receptors.

RESULTS

No peptides were expected to be toxic. P315 and P2941 are predicted to have robust antigenic properties, lowest allergenicity, and minimal sOPEP energies. In turn, P315 (derived from gpE1) formed the highest hydrophobic bonds with the BCR and CD81 receptors that will elicit B cell function. P2941 (derived from NS5B) was shown to strongly bind to both CD4 and CD8 receptors that will elicit T cell function.

CONCLUSION

P315 successfully bound to B cell (BCR and CD81) receptors. Also, P2941 is strongly bound to T cell (CD4 and CD8) receptors.

The impact of HCV chronic positivity and clearance on extrahepatic morbidity in thalassemia major patients: an observational study from MIOT Network

BACKGROUND

No study has evaluated the effect of hepatitis C virus (HCV) infection on the wide spectrum of complications affecting patients with thalassemia.

OBJECTIVES

This multicenter study prospectively assessed the relationship of HCV infection with diabetes mellitus and cardiovascular complications in patients with thalassemia major (TM).

METHODS

We considered 1057 TM patients (539 females; 29.79±10.08 years) enrolled in the MIOT Network and categorized into 4 groups: negative patients (group 1a, N=460), patients who spontaneously cleared the virus within 6months (group 1b, N=242), patients who eradicated the virus after the treatment with antiviral therapy (group 2, N=102), and patients with chronic HCV infection (group 3, N=254).

RESULTS

Group 1a and 1b were considered as a unique group (group 1). For both groups 1 and 3, a match 1:1 for age and sex with group 2 was performed. The effective study cohort consisted of 306 patients (three groups of 102 patients). During a mean follow-up of 67.93±39.20months, the group 3 experienced a significantly higher % increase/month in aspartate transaminase levels and left ventricular mass index than both groups 1 and 2. The changes in iron overload indexes were comparable among the three groups. Compared to group 1, the chronic HCV group showed a significantly higher risk of diabetes (hazard ratio-HR=5.33; p=0.043) and of cardiovascular diseases (HR=3.80; p=0.034).

CONCLUSION

Chronic HCV infection is associated with a significant higher risk of diabetes mellitus and cardiovascular complications in TM patients and should be approached as a systemic disease in which extrahepatic complications increase the weight of its pathological burden.

Pseudotyped Virus for Flaviviridae

Members of Flaviviridae are enveloped single positive-stranded RNA viruses including hepacivirus, pestivirus, pegivirus, and mosquito-transmitted flavivirus, which are important pathogens of infectious diseases and pose serious threats to human health. Pseudotyped virus is an artificially constructed virus-like particle, which could infect host cells similar to a live virus but cannot produce infectious progeny virus. Therefore, pseudotyped virus has the advantages of a wide host range, high transfection efficiency, low biosafety risk, and accurate and objective quantification. It has been widely used in biological characteristics, drug screening, detection methods, and vaccine evaluation of Flaviviridae viruses like hepatitis C virus, Japanese encephalitis virus, dengue virus, and Zika virus.

Evaluation of interactions between the hepatitis C virus NS3/4A and sulfonamidobenzamide based molecules using molecular docking, molecular dynamics simulations and binding free energy calculations

The Hepatitis C Virus (HCV) NS3/4A is an attractive target for the treatment of Hepatitis C infection. Herein, we present an investigation of HCV NS3/4A inhibitors based on a sulfonamidobenzamide scaffold. Inhibitor interactions with HCV NS3/4A were explored by molecular docking, molecular dynamics simulations, and MM/PBSA binding free energy calculations. All of the inhibitors adopt similar molecular docking poses in the catalytic site of the protease that are stabilized by hydrogen bond interactions with G137 and the catalytic S139, which are known to be important for potency and binding stability. The quantitative assessments of binding free energies from MM/PBSA correlate well with the experimental results, with a high coefficient of determination, R2 of 0.92. Binding free energy decomposition analyses elucidate the different contributions of Q41, F43, H57, R109, K136, G137, S138, S139, A156, M485, and Q526 in binding different inhibitors. The importance of these sidechain contributions was further confirmed by computational alanine scanning mutagenesis. In addition, the sidechains of K136 and S139 show crucial but distinct contributions to inhibitor binding with HCV NS3/4A. The structural basis of the potency has been elucidated, demonstrating the importance of the R155 sidechain conformation. This extensive exploration of binding energies and interactions between these compounds and HCV NS3/4A at the atomic level should benefit future antiviral drug design.

Establishment and Evaluation of Recombinant Expression of HCV Transmembrane Protein (p7) and Detection of Anti-p7 Antibody in Serum of HCV-Infected Patients by Chemiluminescence

Objective

Our aim was to establish a chemiluminescence method for detecting anti-transmembrane protein (p7) antibody in the serum of patients with hepatitis C virus (HCV) infection.

Methods

The p7 gene was amplified by polymerase chain reaction using the plasmid PUC-p7 containing the p7 nucleic acid sequence of the HCV 1b genotype as the template, and recombinant plasmid pGEX-KG-p7 was constructed. After p7 fusion, the protein was induced and expressed in the prokaryote, extracted, and purified; the anti-p7 antibody detection kit was prepared, and its efficacy was evaluated.

Results

The plasmid pGEX-KG-p7 was constructed correctly, and p7 fusion protein was obtained. The methodological indexes of the kit, the precision test, blank limit and detection limit, etc, met the requirements. The positive rate of serum anti-p7 antibody in 45 patients with HCV infection was 20%.

Conclusions

The kit can be used in screening diagnosis, condition monitoring, prognosis, and disease mechanism and epidemiological study of HCV infection. The p7 protein has immune response in HCV-infected patients.

The potential roles of interleukin-25 in infectious diseases

Interleukin-25 (IL-25), also known as IL-17E, is a recently identified cytokine of the IL-17 family. Numerous studies illustrated that the expression of IL-25 is regulated by multiple pathogens, including parasitic, viral, and bacterial infections. IL-25 has a dual function in infectious diseases. On the one hand, IL-25 activates type 2 immunity via the relevant cytokines, including IL-4, IL-5, and IL-13, which are associated with the development of pathogenic infection-related allergic diseases. On the other hand, IL-25 involves in the recruitment of group 2 innate lymphoid cells (ILC2) to enhanced T helper 2 (Th2) cell differentiation, which are important to the clearance of pathogens. However, the precise roles of IL-25 in infectious diseases remain largely unknown. Thus, the current review will shed light on the pivotal roles of IL-25 in infectious diseases.

The Transmission Route and Selection Pressure in HCV Subtype 3a and 3b Chinese Infections: Evolutionary Kinetics and Selective Force Analysis

Hepatitis C virus (HCV) genotype 3 (GT-3) represents 22–30% of all infections and is the second most common genotype among all HCV genotypes. It has two main subtypes, GT-3a and GT-3b, that present epidemiological differences in transmission groups. This report generated 56 GT-3a and 64 GT-3b whole-genome sequences to conduct an evolutionary kinetics and selective force analysis with reference sequences from various countries. Evolutionary analysis showed that HCV GT-3a worldwide might have been transmitted from the Indian subcontinent to South Asia, Europe, North America and then become endemic in China. In China, GT-3a may have been transmitted by intravenous drug users (IDUs) and become endemic in the general population, while GT-3b may have originated from IDUs and then underwent mutual transmission between blood donors (BDs) and IDUs, ultimately becoming independently endemic in IDUs. Furthermore, the spread of GT-3a and GT-3b sequences from BD and IDU populations exhibit different selective pressures: the proportion of positively selected sites (PPSs) in E1 and E2 from IDUs was higher than in BDs. The number of positive selection sites was higher in GT-3b and IDUs. These results indicate that different selective constraints act along with the GT-3a and GT-3b genomes from IDUs and BDs. In addition, GT-3a and GT-3b have different transmission routes in China, which allows us to formulate specific HCV prevention and control strategies in China.

RT-LAMP-Based Molecular Diagnostic Set-Up for Rapid Hepatitis C Virus Testing

Hepatitis C virus (HCV) infections occur in approximately 3% of the world population. The development of an enhanced and extensive-scale screening is required to accomplish the World Health Organization's (WHO) goal of eliminating HCV as a public health problem by 2030. However, standard testing methods are time-consuming, expensive, and challenging to deploy in remote and underdeveloped areas. Therefore, a cost-effective, rapid, and accurate point-of-care (POC) diagnostic test is needed to properly manage the disease and reduce the economic burden caused by high case numbers. Herein, we present a fully automated reverse-transcription loop-mediated isothermal amplification (RT-LAMP)-based molecular diagnostic set-up for rapid HCV detection. The set-up consists of an automated disposable microfluidic chip, a small surface heater, and a reusable magnetic actuation platform. The microfluidic chip contains multiple chambers in which the plasma sample is processed. The system utilizes SYBR green dye to detect the amplification product with the naked eye. The efficiency of the microfluidic chip was tested with human plasma samples spiked with HCV virions, and the limit of detection observed was 500 virions/mL within 45 min. The entire virus detection process was executed inside a uniquely designed, inexpensive, disposable, and self-driven microfluidic chip with high sensitivity and specificity.

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.

Apolipoprotein E, a Crucial Cellular Protein in the Lifecycle of Hepatitis Viruses

Apolipoprotein E (ApoE) is a multifunctional protein expressed in several tissues, including those of the liver. This lipoprotein component is responsible for maintaining lipid content homeostasis at the plasma and tissue levels by transporting lipids between the liver and peripheral tissues. The ability of ApoE to interact with host-cell surface receptors and its involvement in several cellular pathways raised questions about the hijacking of ApoE by hepatotropic viruses. Hepatitis C virus (HCV) was the first hepatitis virus reported to be dependent on ApoE for the completion of its lifecycle, with ApoE being part of the viral particle, mediating its entry into host cells and contributing to viral morphogenesis. Recent studies of the hepatitis B virus (HBV) lifecycle have revealed that this virus and its subviral envelope particles also incorporate ApoE. ApoE favors HBV entry and is crucial for the morphogenesis of infectious particles, through its interaction with HBV envelope glycoproteins. This review summarizes the data highlighting the crucial role of ApoE in the lifecycles of HBV and HCV and discusses its potential role in the lifecycle of other hepatotropic viruses.

Insight into the Evolving Role of PCSK9

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is the last discovered member of the family of proprotein convertases (PCs), mainly synthetized in hepatic cells. This serine protease plays a pivotal role in the reduction of the number of low-density lipoprotein receptors (LDLRs) on the surface of hepatocytes, which leads to an increase in the level of cholesterol in the blood. This mechanism and the fact that gain of function (GOF) mutations in PCSK9 are responsible for causing familial hypercholesterolemia whereas loss-of-function (LOF) mutations are associated with hypocholesterolemia, prompted the invention of drugs that block PCSK9 action. The high efficiency of PCSK9 inhibitors (e.g., alirocumab, evolocumab) in decreasing cardiovascular risk, pleiotropic effects of other lipid-lowering drugs (e.g., statins) and the multifunctional character of other proprotein convertases, were the cause for proceeding studies on functions of PCSK9 beyond cholesterol metabolism. In this article, we summarize the current knowledge on the roles that PCSK9 plays in different tissues and perspectives for its clinical use.

Rapid Visual Detection of Hepatitis C Virus Using Reverse Transcription Recombinase-Aided Amplification–Lateral Flow Dipstick

Hepatitis C virus (HCV) infection is a global public health threat. Reaching the World Health Organization’s objective for eliminating viral hepatitis by 2030 will require a precise disease diagnosis. While immunoassays and qPCR play a significant role in detecting HCV, rapid and accurate point-of-care testing is important for pathogen identification. This study establishes a reverse transcription recombinase-aided amplification–lateral flow dipstick (RT-RAA-LFD) assay to detect HCV. The intact workflow was completed within 30 min, and the detection limit for synthesized C/E1 plasmid gene-containing plasmid was 10 copies/μl. In addition, the test showed good specificity, with no cross-reactivity observed for hepatitis A virus, hepatitis B virus, HIV, syphilis, and human papillomavirus virus. Using extracted RNAs from 46 anti-HCV antibody-positive samples, RT-RAA-LFD showed 100% positive and negative concordance rates with qPCR. In summary, the RT-RAA-LFD assay established in this study is suitable for the rapid clinical detection of HCV at the community level and in remote areas.

Achieving WHO target of HCV control in Hong Kong: challenges and strategies

With the introduction of effective directly acting antiviral agents (DAAs) therapy, control and elimination of hepatitis C virus (HCV) infection is becoming a feasible goal. In Hong Kong, HCV prevalence in general population is 0.3%-0.5% over the past decades. However, like other high-income areas/countries, high prevalence of HCV infection has been found in several population groups, such as people who inject drugs (PWID), patients undergoing dialysis, and human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/ AIDS) patients. Based on the epidemiological study using data retrieved from the Hong Kong HCV Registry from January 2005 to March 2017, the estimated territory-wide diagnosis rate and treatment rate of HCV infection were only 50.9% and 12.4%, respectively. Although these rates was comparable to many developed countries/areas, the performances remained substantially below 90% and 80%, the 2030 targets proposed by World Health Organization (WHO). In recognition of the challenges, the Hong Kong Government set up the Steering Committee on Prevention and Control of Viral Hepatitis (SCVH) which formulated the Hong Kong Viral Hepatitis Action Plan 2020-2024. The Action Plan adopts four key strategies, as described in the WHO framework for global action, namely, awareness, surveillance, prevention and treatment. With the effective implementation of the Action Plan, especially in targeted screening of high-risk populations and more generalized use of the highly efficacious DAAs for all diagnosed HCV subjects, the goals of reducing HCV transmission and HCV-related morbidity and mortality can be achieved in Hong Kong by 2030.

Characterization of a Novel Hepatitis C Subtype, 6xj, and Its Consequences for Direct-Acting Antiviral Treatment in Yunnan, China

Hepatitis C virus (HCV) has a high rate of genetic variability, with eight genotypes and 91 subtypes. The genetic diversity of HCV genotype 6 (HCV-6) is the highest with 31 subtypes, and this genotype is prevalent in Southeast Asia. In this study, we investigated 160 individuals with chronic hepatitis C in Yunnan Province, China. Using reverse transcription (RT)-PCR and Sanger sequencing, 147 cases were successfully amplified and genotyped as 3b (4.9%), 3a (19.73%), 6n (12.24%), 1b (7.48%), 2a (6.12%), 6a (2.04%), 1a (0.68%), 6v (0.68%), and 6xa (0.68%), with eight sequences remaining unclassified. Subsequently, the eight nearly full-length genomes were successfully amplified and analyzed. The eight complete coding sequences formed a phylogenetic group that was distinct from the previously assigned HCV-6 subtypes and clustered with two previously unnamed HCV-6 sequences. Furthermore, Simplot analysis showed no recombination and the p-distance was more than 15% in comparison to the 6a to 6xi subtypes. Taken together, we identified a new HCV-6 subtype, 6xj, which originated approximately in 1775 according to Bayesian analyses. Moreover, all eight individuals received follow-up assessments at 44 weeks from the beginning of their 12-week treatments of sofosbuvir/velpatasvir (after-treatment week 32). One case relapsed at after-treatment week 32. Next-generation sequencing (NGS) was conducted and showed that the treatment failure case had two suspected antiviral resistance mutations, NS5A V28M (a change of V to M at position 28) and NS5B A442V, compared with the baseline. Overall, this newly identified 6xj subtype further confirmed the high diversity of the HCV-6 genotype. The newly identified resistance-associated amino acid substitutions may help inform future clinical treatments. IMPORTANCE This study investigated the genetic diversity of hepatitis C virus (HCV), particularly in relation to genotype 6, which is prevalent in Yunnan, China, and is often difficult to treat successfully. We identified a new HCV-6 subtype, 6xj, which is an ancient strain. Moreover, all eight individuals with the novel subtype received follow-up assessments at 44 weeks from the beginning of their treatments. One case relapsed after 8 months of withdrawal. NGS was conducted and showed that the isolate from the treatment failure case had two suspected antiviral resistance mutations, NS5A V28M and NS5B A442V, compared with the baseline. Overall, this newly identified 6xj subtype further confirmed the high diversity of the HCV-6 genotype. The newly identified resistance-associated amino acid substitutions may help inform future clinical treatments. We believe that our study makes a significant contribution to the literature based on the results described above.

Hepatitis C Virus Evades Interferon Signaling by Suppressing Long Noncoding RNA Linc-Pint Involving C/EBP-β

Hepatitis C virus (HCV) regulates many cellular genes in modulating the host immune system for benefit of viral replication and long-term persistence in a host for chronic infection. Long noncoding RNAs (lncRNAs) play an important role in the regulation of many important cellular processes, including immune responses. We recently reported that HCV infection downregulates lncRNA Linc-Pint (long intergenic non-protein-coding RNA p53-induced transcript) expression, although the mechanism of repression and functional consequences are not well understood. In this study, we demonstrate that HCV infection of hepatocytes transcriptionally reduces Linc-Pint expression through CCAAT/enhancer binding protein β (C/EBP-β). Subsequently, we observed that the overexpression of Linc-Pint significantly upregulates interferon alpha (IFN-α) and IFN-β expression in HCV-replicating hepatocytes. Using unbiased proteomics, we identified that Linc-Pint associates with DDX24, which enables RIP1 to interact with IFN-regulatory factor 7 (IRF7) of the IFN signaling pathway. We furthermore observed that IFN-α14 promoter activity was enhanced in the presence of Linc-Pint. Together, these results demonstrated that Linc-Pint acts as a positive regulator of host innate immune responses, especially IFN signaling. HCV-mediated downregulation of Linc-Pint expression appears to be one of the mechanisms by which HCV may evade innate immunity for long-term persistence and chronicity. IMPORTANCE The mechanism by which lncRNA regulates the host immune response during HCV infection is poorly understood. We observed that Linc-Pint was transcriptionally downregulated by HCV. Using a chromatin immunoprecipitation (ChIP) assay, we showed inhibition of transcription factor C/EBP-β binding to the Linc-Pint promoter in the presence of HCV infection. We further identified that Linc-Pint associates with DDX24 for immunomodulatory function. The overexpression of Linc-Pint reduces DDX24 expression, which in turn results in the disruption of DDX24-RIP1 complex formation and the activation of IRF7. The induction of IFN-α14 promoter activity in the presence of Linc-Pint further confirms our observation. Together, our results suggest that Linc-Pint acts as a positive regulator of host innate immune responses. Downregulation of Linc-Pint expression by HCV helps in escaping the innate immune system for the development of chronicity.