Coordinated expansion of memory T follicular helper and B cells mediates spontaneous clearance of HCV reinfection.

Introduction: Follicular helper T cells are essential for helping in the maturation of B cells and the production of neutralizing antibodies (NAbs) during primary viral infections. However, their role during recall responses is unclear. Here, we used hepatitis C virus (HCV) reinfection in humans as a model to study the recall collaborative interaction between circulating CD4 T follicular helper cells (cTfh) and memory B cells (MBCs) leading to the generation of NAbs. Methods: We evaluated this interaction longitudinally in subjects who have spontaneously resolved primary HCV infection during a subsequent reinfection episode that resulted in either another spontaneous resolution (SR/SR, n = 14) or chronic infection (SR/CI, n = 8). Results: Both groups exhibited virus-specific memory T cells that expanded upon reinfection. However, early expansion of activated cTfh (CD4+CXCR5+PD-1+ICOS+FoxP3-) occurred in SR/SR only. The frequency of activated cTfh negatively correlated with time post-infection. Concomitantly, NAbs and HCV-specific MBCs (CD19+CD27+IgM-E2-Tet+) peaked during the early acute phase in SR/SR but not in SR/CI. Finally, the frequency of the activated cTfh1 (CXCR3+CCR6-) subset correlated with the neutralization breadth and potency of NAbs. Conclusion: These results underscore a key role for early activation of cTfh1 cells in helping antigen-specific B cells to produce NAbs that mediate the clearance of HCV reinfection.

Investigating the role of killer cell immunoglobulin-like receptors and human leukocyte antigen genetic variants in hepatitis C virus infection.

The genetic diversity of killer cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) genes influences the host's immune response to viral pathogens. This study aims to explore the impact of five single nucleotide polymorphisms (SNPs) in KIR3DL2 and HLA-A genes on hepatitis C virus (HCV) infection. A total of 2251 individuals were included in the case-control study. SNPs including KIR3DL2 rs11672983, rs3745902, rs1654644, and HLA-A rs3869062, rs12202296 were genotyped. By controlling various confounding factors using a modified logistic regression model, as well as incorporating stratified analysis, joint effects analysis, and multidimensional bioinformatics analysis, we analyzed the relationship between SNPs and HCV infection. The logistic regression analysis showed a correlation between KIR3DL2 rs11672983 AA, KIR3DL2 rs3745902 TT, and increased HCV susceptibility (p < 0.01). Stratified analysis indicated that KIR3DL2 rs1654644 and HLA-A rs3869062 also heightened HCV susceptibility in certain subgroups. A linear trend of rising HCV infection rates was observed when combining KIR3DL2 rs11672983 AA and KIR3DL2 rs3745902 TT (ptrend = 0.007). Bioinformatics analysis suggested these SNPs' regulatory potential and their role in altering messenger RNA secondary structure, implying their functional relevance in HCV susceptibility. Our findings indicate that KIR3DL2 rs11672983 AA and KIR3DL2 rs3745902 TT are significantly associated with increased susceptibility to HCV infection.

Trends in hepatitis C virus seroprevalence and associated risk factors among msm in Pakistan: insights from a community-based study.

Pakistan bears a substantial burden of hepatitis C virus (HCV) infection, with the second-highest prevalence globally. This community-based cross-sectional study, conducted from January to December 2022 in Punjab, Pakistan, investigates the seroprevalence of HCV among the men who have sex with men (MSM) population. The study identifies demographic and behavioral risk factors associated with HCV infection within this population group. Among the 501 participants, the study found an HCV seroprevalence of 14.86%. The association between demographic characteristics and seroprevalence is assessed by calculating the percentage of positive cases, revealing notable associations with age, education level, and self-identified sexual orientation. Furthermore, the study identified several behavioral risk factors positively associated with HCV seroprevalence, including sharing personal items such as razors and toothbrushes, histories of surgery, blood transfusion, dental procedures, intravenous drug use, and therapeutic injection histories. These risk factors were identified through structured interviews, and the prevalence of HCV seropositivity among the exposed groups was calculated accordingly. Interestingly, a lower HCV positivity rate was observed among self-reported HIV-positive individuals, contradicting previous research. The findings underscore the need for comprehensive, targeted prevention strategies such as risk factor awareness campaigns and educational programs tailored for the MSM population in Pakistan. Further research is warranted to validate these findings and better understand the complex interplay of factors contributing to HCV seroprevalence in this high-risk population.

Immunogenicity study of a Novel DNA-Based HCV vaccine candidate.

In this study, we aimed to evaluate the immunogenic profile of a chimeric DNA-based hepatitis C virus (HCV) vaccine candidate encoding the full-length viral core-E1-E2 (HCV-CE) fragment. The vaccine candidate was designed to uniformly express the HCV genotype 4 core-E1-E2 protein. The recombinant HCV-CE protein was bacterially expressed in C41 (DE3) cells, and then BALB/c mice were immunized with different combinations of DNA/DNA or DNA/protein prime/boost immunizations. The proper construction of our vaccine candidate was confirmed by specific amplification of the encoded fragments and basic local alignment search tool (BLAST) results of the nucleotide sequence, which revealed a high degree of similarity with several HCV serotypes/genotypes. The platform for bacterial expression was optimized to maximize the yield of the purified recombinant HCV-CE protein. The recombinant protein showed high specific antigenicity against the sera of HCV-infected patients according to the ELISA and western blot results. The predicted B- and T-cell epitopes showed high antigenic and interferon-γ (IFN-γ) induction potential, in addition to cross-genotype conservation and population coverage. The mice antisera further demonstrated a remarkable ability to capture 100% of the native viral antigens circulating in the sera of HCV patients, with no cross-reactivity detected in control sera. In conclusion, the proposed HCV vaccination strategy demonstrated promising potential regarding its safety, immunogenicity, and population coverage.

Lasting differential gene expression of circulating CD8 T cells in chronic HCV infection with cirrhosis identifies a role for Hedgehog signaling in cellular hyperfunction.

Background: The impact of chronic hepatic infection on antigen non-specific immune cells in circulation remains poorly understood. We reported lasting global hyperfunction of peripheral CD8 T cells in HCV-infected individuals with cirrhosis. Whether gene expression patterns in bulk CD8 T cells are associated with the severity of liver fibrosis in HCV infection is not known. Methods: RNA sequencing of blood CD8 T cells from treatment naïve, HCV-infected individuals with minimal (Metavir F0-1 ≤ 7.0 kPa) or advanced fibrosis or cirrhosis (F4 ≥ 12.5 kPa), before and after direct-acting antiviral therapy, was performed. CD8 T cell function was assessed by flow cytometry. Results: In CD8 T cells from pre-DAA patients with advanced compared to minimal fibrosis, Gene Ontology analysis and Gene Set Enrichment Analysis identified differential gene expression related to cellular function and metabolism, including upregulated Hedgehog (Hh) signaling, IFN-α, -γ, TGF-ß response genes, apoptosis, apical surface pathways, phospholipase signaling, phosphatidyl-choline/inositol activity, and second-messenger-mediated signaling. In contrast, genes in pathways associated with nuclear processes, RNA transport, cytoskeletal dynamics, cMyc/E2F regulation, oxidative phosphorylation, and mTOR signaling, were reduced. Hh signaling pathway was the top featured gene set upregulated in cirrhotics, wherein hallmark genes GLI1 and PTCH1 ranked highly. Inhibition of Smo-dependent Hh signaling ablated the expression of IFN-γ and perforin in stimulated CD8 T cells from chronic HCV-infected patients with advanced compared to minimal fibrosis. CD8 T cell gene expression profiles post-DAA remained clustered with pre-DAA profiles and disparately between advanced and minimal fibrosis, suggesting a persistent perturbation of gene expression long after viral clearance. Conclusions: This analysis of bulk CD8 T cell gene expression in chronic HCV infection suggests considerable reprogramming of the CD8 T cell pool in the cirrhotic state. Increased Hh signaling in cirrhosis may contribute to generalized CD8 T cell hyperfunction observed in chronic HCV infection. Understanding the lasting nature of immune cell dysfunction may help mitigate remaining clinical challenges after HCV clearance and more generally, improve long term outcomes for individuals with severe liver disease.

Prevalence and risk factors of Hepatitis C virus infection in the Upper East Region of Ghana; a community-based cross-sectional study.

Hepatitis C virus (HCV) infection remains a major cause of liver related morbidity and mortality worldwide. Epidemiologic data on seroprevalence, viremia prevalence and risk factors remain limited in sub-Saharan Africa. In Ghana, HCV-related deaths are estimated to have increased since 2015. Risk factors associated with HCV infection in Ghana are not well described. The aim of this study was to determine the prevalence of, and risk factors associated with hepatitis C virus infection in the Upper East Region located in the northern part of Ghana. A community-based cross-sectional study was conducted in 9 communities in the Upper East region of Ghana. A total of 1,769 participants aged ≥12 years were screened for HCV antibody (anti-HCV) using rapid diagnostic testing (RDT). Seventy-four participants undertook HCV RNA testing after a positive anti-HCV result. Multivariate logistic regression was used to determine risk factors associated with HCV seropositivity. The anti-HCV prevalence was 8.4%, with 149 out of 1,769 testing anti-HCV positive. Mean age (±SD) of seropositive persons was 45.4 (±16.3) years. The highest anti-HCV seroprevalence was amongst persons aged 60 years and above. Forty-four out of 74 (59.5%) seropositive cases had viremic infection and the estimated viremic prevalence in the screened population was 5.0%. Predictors of HCV seropositivity were age (OR 1.03 95% CI 1.01-1.04), history of female genital mutilation or circumcision (OR 1.63 95% CI 1.04-2.55), sexual activity (OR 2.57 95% CI 1.38-4.79), positive maternal HCV status (OR 10.38 95% CI 4.13-26.05) and positive HIV status (OR 4.03 95% CI 1.35-12.05). In conclusion, the Upper East Region demonstrates a high Hepatitis C antibody prevalence. Almost 60% of individuals have viremic infection, however the cost of RNA testing is a barrier to virological diagnosis. There is a need to educate the population about HCV-associated risk factors to reduce HCV transmission and burden of disease.

Detection of Equine Parvovirus-Hepatitis Virus and Equine Hepacivirus in Archived Sera from Horses in France and Australia.

Reports of newly discovered equine hepatotropic flavi- and parvoviruses have emerged throughout the last decade in many countries, the discovery of which has stimulated a great deal of interest and clinical research. Although commonly detected in horses without signs of disease, equine parvovirus hepatitis (EqPV-H) and equine hepacivirus (EqHV) have been associated with liver disease, including following the administration of contaminated anti-toxin. Our aim was to determine whether EqPV-H and EqHV are present in Australian horses and whether EqPV-H was present in French horses and to examine sequence diversity between strains of both viruses amongst infected horses on either side of the globe. Sera from 188 Australian horses and 256 French horses from horses with and without clinical signs of disease were collected. Twelve out of 256 (4.7%) and 6 out of 188 (3.2%) French and Australian horses, respectively, were positive for the molecular detection of EqPV-H. Five out of 256 (1.9%) and 21 out of 188 (11.2%) French and Australian horses, respectively, were positive for the molecular detection of EqHV. Australian strains for both viruses were genomically clustered, in contrast to strains from French horses, which were more broadly distributed. The findings of this preliminary survey, with the molecular detection of EqHV and EqPV-H in Australia and the latter in France, adds to the growing body of awareness regarding these recently discovered hepatotropic viruses. It has provided valuable information not just in terms of geographic endemicity but will guide equine clinicians, carers, and authorities regarding infectious agents and potential impacts of allogenic tissue contamination. Although we have filled many gaps in the world map regarding equine hepatotropic viruses, further prospective studies in this emerging field may be useful in terms of elucidating risk factors and pathogenesis of these pathogens and management of cases in terms of prevention and diagnosis.

The red alga Porphyridium as a host for molecular farming: Efficient production of immunologically active hepatitis C virus glycoprotein.

Microalgae are promising production platforms for the cost-effective production of recombinant proteins. We have recently established that the red alga Porphyridium purpureum provides superior transgene expression properties, due to the episomal maintenance of transformation vectors as multicopy plasmids in the nucleus. Here, we have explored the potential of Porphyridium to synthesize complex pharmaceutical proteins to high levels. Testing expression constructs for a candidate subunit vaccine against the hepatitis C virus (HCV), we show that the soluble HCV E2 glycoprotein can be produced in transgenic algal cultures to high levels. The antigen undergoes faithful posttranslational modification by N-glycosylation and is recognized by conformationally selective antibodies, suggesting that it adopts a proper antigenic conformation in the endoplasmic reticulum of red algal cells. We also report the experimental determination of the structure of the N-glycan moiety that is attached to glycosylated proteins in Porphyridium. Finally, we demonstrate the immunogenicity of the HCV antigen produced in red algae when administered by injection as pure protein or by feeding of algal biomass.

High prevalence of hepatitis C virus infection among incarcerated persons: Results from the Louisiana Hepatitis C Elimination Plan's opt-out testing program in prisons.

In the United States, modelling studies suggest a high prevalence of hepatitis C virus (HCV) infection in incarcerated populations. However, limited HCV testing has been conducted in prisons. Through the Louisiana Hepatitis C Elimination Plan, persons incarcerated in the eight state prisons were offered HCV testing from 20 September 2019 to 14 July 2022, and facility entry/exit HCV testing was introduced. Multivariable logistic regression was used to evaluate associations with HCV antibody (anti-HCV) positivity and viremia. Of 17,231 persons in the eight state prisons screened for anti-HCV, 95.1% were male, 66.7% were 30-57 years old, 3% were living with HIV, 68.2% were Black and 2904 (16.9%) were anti-HCV positive. HCV RNA was detected in 69.3% of anti-HCV positive individuals tested. In the multivariable model, anti-HCV positivity was associated with older age including those 30-57 (odds ratio [OR] 3.53, 95% confidence interval [CI] 2.96-4.20) and those ≥58 (OR 10.43, 95% CI 8.66-12.55) as compared to those ≤29 years of age, living with HIV (OR 1.68, 95% CI 1.36-2.07), hepatitis B (OR 1.83, 95% CI 1.25-2.69) and syphilis (OR 1.51, 95% CI 1.23-1.86). HCV viremia was associated with male sex (OR 1.89, 95% CI 1.36-2.63) and Black race (OR 1.42, 95% CI 1.20-1.68). HCV prevalence was high in the state prisons in Louisiana compared to community estimates. To the extent that Louisiana is representative, to eliminate HCV in the United States, it will be important for incarcerated persons to have access to HCV testing and treatment.

Seroprevalence and co-infection of HBV, HCV, and HIV among patients visiting selected hospitals in Anyigba, Kogi State.

Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), and Human Immunodeficiency Virus (HIV) remain a public health challenge globally. This study determined the prevalence and coinfection of HBV, HCV, and HIV among patients visiting Maria Goretti Hospital, Grimard Catholic Hospital, and Good News Hospital Anyigba, Kogi State. In a cross-sectional study, sera samples collected from 400 consenting patients were screened for HBV, HCV, and HIV using commercial immunodiagnostic test kits. Of the 400 subjects, 12 (3.0%), 4 (1.0%), and 16 (4.0%) were infected with HBV, HCV, and HIV, respectively. One participant was co-infected with HCV and HIV, while none was simultaneously infected with HBV and HIV. Participants aged 11-20 years had higher hepatitis B-surface antigenemia, while ages 21-30 years and 31-40 years had higher prevalence of HCV and HIV, respectively. Contrary to HBV and HCV positivity, HIV seropositivity was significantly predicted by the ages of exposure (p = 0.002). Males and females were equally infected with HBV (3.0% each), while more males than females were infected with HCV (1.5%) and HIV (4.6%). However, the difference between the occurrence of viral infections and patients' sex was not significant (p > 0.05). The single participants were more predisposed to HBV while the married subjects had more HCV and HIV mono-infection. However, neither the occurrence of HBV nor HCV or HIV was significantly predicted by the marital status of the individuals (p > 0.05). Subjects with no formal education had a higher positivity rate of HCV and HIV compared to other levels of education, while the tertiary level of education had higher exposure to HBsAg. Occupationally, students were more predisposed to HBV and HCV, while the unemployed participants were more predisposed to HIV. However, neither education nor the occupation of participants was significantly related to any of the viral infections (p > 0.05). Lack of knowledge of disease prevention significantly influenced the occurrence of HBV (p = 0.02), HCV (p = 0.04), and HIV (p = 0.04). Conclusively, the status of HBV, HCV, and HIV infection is low compared with findings of previous epidemiological studies in the area. However, the continuous circulation of the three viral infections and the high disease occurrence in the poorly informed participants suggest the need for increased public health education about infection control and prevention strategies in the area.

Hepatitis C virus-related autoimmunity before and after viral clearance: a single center, prospective, observational study.

BACKGROUND: Hepatitis C virus (HCV) chronic infection is frequently associated to autoimmune manifestations. The aim of this study was to prospectively evaluate the occurrence of clinical and/or laboratory features of autoimmunity in a cohort of 140 consecutive HCV chronically infected patients treated with direct-acting antiviral agents (DAAs) and followed-up for 96 weeks. METHODS: All patients were screened for cryoglobulins, rheumatoid factor (RF), C3, C4, antinuclear antibody (ANA), anti-smooth muscle (ASMA), anti-liver kidney microsome type 1 (anti-LKM1), anti-mitochondrial antibodies (AMA), anti-neutrophil cytoplasmic antibodies (ANCA), and anti-liver cytosol type 1/soluble liver antigen (anti-LC1/SLA) autoantibodies before therapy and 12, 48 and 96 weeks after treatment. They were then grouped according to the expression of laboratory findings and related autoimmune diseases. RESULTS: At baseline, autoimmune manifestations were found in 70 patients: 83% of them were cryoglobulinemic, whereas ANA, AMA, perinuclear ANCA (pANCA) and LKM/LC1 autoantibodies were found in the remaining 17%. An autoimmune disease was diagnosed in 9 cases, two of them featuring an autoimmune liver disease (AILD). At the end of follow-up, despite viral clearance and regression of vasculitis, cryoglobulins persisted in 12 patients (21%), and autoantibodies disappeared or decreased in most of cases but, with the exception of the 2 patients diagnosed as AILD, associated autoimmune diseases remained stable. In one patient with relapsing cryoglobulinemia and ANA positivity, type-1 autoimmune hepatitis was defined. Conversely, autoantibodies first appeared after viral clearance in 5 patients, of whom one was diagnosed with type-1 autoimmune hepatitis and one with pANCA+ primary sclerosing cholangitis. CONCLUSIONS: Following DAA-induced viral clearance, cryoglobulins may persist or reappear. Autoantibodies changed dynamically in step with the disappearance of a previously diagnosed or the occurrence of a new AILD. A longer follow-up will be necessary to establish the possible diagnosis of a newly onset AILD, the reactivation of cryoglobulinemic vasculitis and even its progression to non-Hodgkin lymphoma.

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.

Implementation of Universal Hepatitis C Virus Screening in a Tertiary Cancer Center.

BACKGROUND: The prevalence of chronic hepatitis C virus (HCV) infection in the United States is ≤1%. Universal HCV screening is recommended nationwide. Here we describe our experience implementing universal HCV screening at a cancer center. METHODS: In October 2016, universal HCV screening with HCV antibody (anti-HCV) was initiated for all new outpatients. Universal screening was promoted through widespread provider education, orders in the Epic electronic health records (EHRs), SmartSets, and automated EHR reminders. The effort focused on patients with solid tumors, because universal screening in patients with hematologic malignancies was already standard practice. Primary outcomes were the proportion of patients screened and the proportion of patients with reactive anti-HCV test results linked to HCV care. The secondary outcome was the incidence of HCV-associated hepatocellular carcinoma as a second primary malignancy (HCC-SPM) in patients with a history of other cancers before HCC diagnosis. Epic's Reporting Workbench Business Intelligence tools were used. Statistical significance was defined as P<.05 on chi-square analysis. RESULTS: From April 2016 through April 2023, 56,075 patients with solid tumors were screened for HCV, of whom 1,300 (2.3%) had reactive anti-HCV test results. The proportion of patients screened was 10.1% in the 6 months before study implementation and 34.4% in the last 6 months of the study (P<.001). HCV screening was ordered using SmartSets in 39,332 (45.8%) patients and in response to automated EHR reminders in 10,972 (12.8%) patients. Most patients with reactive anti-HCV test results were linked to care (765/1,300; 59%), most with proven HCV infection were treated (425/562; 76%), and most treated patients achieved sustained virologic response (414/425; 97%). The incidence of HCC-SPMs was 15% in historical controls treated from 2011 to 2017 and 5.7% following implementation of universal screening (P=.0002). CONCLUSIONS: Universal HCV screening can be successfully implemented in cancer hospitals using an EHR-based multipronged approach to eliminate HCV and prevent HCV-associated HCC-SPMs.

[Six Sigma driven QC management in hepatitis C serology]. / La méthodologie six sigma dans la gestion des contrôles de qualité en sérologie de l'hépatite C.

The Westgard quality control (QC) rules are often applied in infectious diseases serology to validate the quality of results, but this requires a reasonable tradeoff between maximum sensitivity to errors and minimum false rejections. This article, in addition to illustrate the six sigma methodology in the QC management of the (anti-HCV Architect®) test, it discusses the main influencing factors on sigma value. Data from low positive and in-kit control materials spreading over 6 months and using four reagent kits, were used to calculate the precision of the test. The difference between the control material reactivity and the cut-off defined the error budget. Sigma values were > 6, which indicates that the method produces four erroneous results per million tests. The application of the six sigma concept made it possible to argue the choice of the new QC strategy (use of 13S rule with one positive control) and to relax the existing QC rules. This work provides a framework for infectious diseases serology laboratories to evaluate tests performances against a quality requirement and design an optimal QC strategy.

Programmed cell death-1 is involved with peripheral blood immune cell profiles in patients with hepatitis C virus antiviral therapy.

Mutations in the non-structural protein regions of hepatitis C virus (HCV) are a cause of a non-sustained virological response (SVR) to treatment with direct-acting antivirals (DAAs) for chronic hepatitis; however, there are non-SVR cases without these mutations. In this study, we examined immune cell profiles in peripheral blood before and after ombitasvir/paritaprevir/ritonavir treatment and screened for genes that could be used to predict the therapeutic effects of DAAs. Fluorescence-activated cell sorting analysis indicated that the median frequencies of programmed cell death-1-positive (PD-1+) effector regulatory T cells (eTregs), PD-1+CD8+ T cells, and PD-1+Helper T cells were decreased significantly in SVR cases, but without significant changes in non-SVR cases. The frequency of PD-1+ naïve Tregs was significantly higher in the SVR group than in the non-SVR group before and after treatment. Similar results were found in patients treated with other DAAs (e.g., daclatasvir plus asunaprevir) and supported an immune response after HCV therapy. RNA-sequencing analysis indicated a significant increase in the expression of genes associated with the immune response in the SVR group, while genes related to intracellular and extracellular signal transduction were highly expressed in the non-SVR group. Therefore, we searched for genes associated with PD-1+ eTregs and CD8+ T cells that were significantly different between the SVR and non-SVR groups and found that T-box transcription factor 21 was associated with the non-SVR state. These results indicate that PD-1-related signaling pathways are associated with a non-SVR mechanism after DAAs treatment separate from mutation-related drug resistance.

Hepatitis C Virus E1E2 Structure, Diversity, and Implications for Vaccine Development.

Hepatitis C virus (HCV) is a major medical health burden and the leading cause of chronic liver disease and cancer worldwide. More than 58 million people are chronically infected with HCV, with 1.5 million new infections occurring each year. An effective HCV vaccine is a major public health and medical need as recognized by the World Health Organization. However, due to the high variability of the virus and its ability to escape the immune response, HCV rapidly accumulates mutations, making vaccine development a formidable challenge. An effective vaccine must elicit broadly neutralizing antibodies (bnAbs) in a consistent fashion. After decades of studies from basic research through clinical development, the antigen of choice is considered the E1E2 envelope glycoprotein due to conserved, broadly neutralizing antigenic domains located in the constituent subunits of E1, E2, and the E1E2 heterodimeric complex itself. The challenge has been elicitation of robust humoral and cellular responses leading to broad virus neutralization due to the relatively low immunogenicity of this antigen. In view of this challenge, structure-based vaccine design approaches to stabilize key antigenic domains have been hampered due to the lack of E1E2 atomic-level resolution structures to guide them. Another challenge has been the development of a delivery platform in which a multivalent form of the antigen can be presented in order to elicit a more robust anti-HCV immune response. Recent nanoparticle vaccines are gaining prominence in the field due to their ability to facilitate a controlled multivalent presentation and trafficking to lymph nodes, where they can interact with both the cellular and humoral components of the immune system. This review focuses on recent advances in understanding the E1E2 heterodimeric structure to facilitate a rational design approach and the potential for development of a multivalent nanoparticle-based HCV E1E2 vaccine. Both aspects are considered important in the development of an effective HCV vaccine that can effectively address viral diversity and escape.

The role of inflammasome in chronic viral hepatitis.

Infections of hepatotropic viruses cause a wide array of liver diseases including acute hepatitis, chronic hepatitis and the consequently developed cirrhosis and hepatocellular carcinoma (HCC). Among the five classical hepatotropic viruses, hepatitis B virus (HBV) and hepatitis C virus (HCV) usually infect human persistently and cause chronic hepatitis, leading to major troubles to humanity. Previous studies have revealed that several types of inflammasomes are involved in the infections of HBV and HCV. Here, we summarize the current knowledge about their roles in hepatitis B and C. NLRP3 inflammasome can be activated and regulated by HBV and HCV. It is found to exert antiviral function or mediates inflammatory response in viral infections depending on different experimental models. Besides NLRP3 inflammasome, IFI16 and AIM2 inflammasomes participate in the pathological process of hepatitis B, and NALP3 inflammasome may sense HCV infection in hepatocytes. The inflammasomes affect the pathological process of viral hepatitis through its downstream secretion of inflammatory cytokines interleukin-1ß (IL-1ß) and IL-18 or induction of pyroptosis resulting from cleaved gasdermin D (GSDMD). However, the roles of inflammasomes in different stages of viral infection remains mainly unclear. More proper experimental models of viral hepatitis should be developed for specific studies in future, so that we can understand more about the complexity of inflammasome regulation and multifunction of inflammasomes and their downstream effectors during HBV and HCV infections.

A potential new way to facilitate HCV elimination: The prediction of viremia in anti-HCV seropositive patients using machine learning algorithms.

BACKGROUND AND STUDY AIMS: The present study was undertaken to design a new machine learning (ML) model that can predict the presence of viremia in hepatitis C virus (HCV) antibody (anti-HCV) seropositive cases. PATIENTS AND METHODS: This retrospective study was conducted between January 2012-January 2022 with 812 patients who were referred for anti-HCV positivity and were examined for HCV ribonucleic acid (HCV RNA). Models were constructed with 11 features with a predictor (presence and absence of viremia) to predict HCV viremia. To build an optimal model, this current study also examined and compared the three classifier data mining approaches: RF, SVM and XGBoost. RESULTS: The highest performance was achieved with XGBoost (90%), which was followed by RF (89%), SVM Linear (85%) and SVM Radial (83%) algorithms, respectively. The four most important key features contributing to the models were: alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (ALB) and anti-HCV levels, respectively, while "ALB" was replaced by the "AGE" only in the XGBoost model. CONCLUSION: This study has shown that XGBoost and RF based ML models, incorporating anti-HCV levels and routine laboratory tests (ALT, AST, ALB), and age are capable of providing HCV viremia diagnosis with 90% and 89% accuracy, respectively. These findings highlight the potential of ML models in the early diagnosis of HCV viremia, which may be helpful in optimizing HCV elimination programs.

Screening for hepatitis C virus at the time of mammography using rapid diagnostic tests in women aged between 50 and 74 years (Mamm'OC NCT05067374).

Chronic hepatitis C Virus (HCV) infection presents a global health challenge, with significant morbidity and mortality worldwide. Despite remarkable progress in treatment options, achieving elimination targets by 2030, as set by the World Health Organization, remains elusive. Our study aimed to address this gap by integrating HCV screening into a national breast cancer screening program. Between March 2022 and March 2023, a prospective cross-sectional multicenter study was conducted in four radiology centers in Montpellier, France. We proposed HCV screening to consecutive women undergoing mammography, targeting 1,500 participants aged 50-74 years. A rapid diagnostic test (RDT) for HCV antibodies (HCV Ab) was performed on capillary whole blood, with positive cases undergoing serological and RNA confirmation. Participants also completed a questionnaire on demographic data and risk factors. Acceptance rates, HCV prevalence, and linkage to care were assessed. The acceptance rate for this integrated screening approach was 82.4%. Notably, the seroprevalence of HCV was found to be 0.65%. Linkage to care was prompt, and the cascade of care demonstrated successful treatment outcomes. Importantly, the majority of detected infections were successfully resolved. These findings underscore the feasibility and acceptability of integrating HCV screening with breast cancer screening programs providing updated prevalence data and valuable insights for refining future screening strategies.

Exploring the Impact of Different Inflammatory Cytokines on Hepatitis C Virus Infection.

Hepatitis C virus (HCV) infection is a global health concern affecting millions worldwide. Chronic HCV infection often leads to liver inflammation and can progress to cirrhosis and hepatocellular carcinoma. Inflammatory cytokines are crucial in modulating the immune response during HCV infection. This review aims to investigate the impact of different inflammatory cytokines on HCV infection and associated immune responses. This review was conducted to identify relevant studies on the interplay between inflammatory cytokines and HCV infection. The analysis focused on the effects of key inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 (IL-1), and interferon-gamma (IFN-γ), on HCV replication, immune cell activation, and liver inflammation. The findings reveal that these inflammatory cytokines can significantly influence HCV infection and the subsequent immune response. TNF-α, IL-6, and IL-1 have been shown to enhance HCV replication, while IFN-γ exerts antiviral effects by inhibiting viral replication and promoting immune cell-mediated clearance of infected hepatocytes. Moreover, these cytokines contribute to the recruitment and activation of immune cells, such as natural killer cells, T cells, and macrophages, which play critical roles in controlling HCV infection. Understanding the precise mechanisms by which inflammatory cytokines impact HCV infection is crucial for developing more targeted therapeutic strategies. Modulating the levels or activity of specific cytokines may provide opportunities to attenuate HCV replication, reduce liver inflammation, and improve treatment outcomes. In conclusion, this review highlights the significance of inflammatory cytokines in influencing HCV infection and associated immune responses.