Spontaneous Elimination of Hepatitis C Virus Infection

Prevalence, trends, and distribution of hepatitis C virus among the general population in sub-Saharan Africa: A systematic review and meta-analysis

BACKGROUND AND AIMS

Although the evidence is uncertain, existing estimates for hepatitis C virus (HCV) in sub-Saharan Africa (SSA) indicate a high burden. We estimated HCV seroprevalence and viraemic prevalence among the general population in SSA.

METHODS

We searched Medline, Embase, Web of Science, APA PsycINFO, and World Health Organization Africa Index Medicus for community-based studies. Study quality was assessed using the Joanna Briggs Institute critical appraisal tool, and heterogeneity using the index of heterogeneity (I2). Two approaches were deployed. First, we used random-effects meta-analysis to pool prevalence. Second, to derive representative estimates, we weighted each country's HCV seroprevalence using 2021 United Nations country population sizes.

RESULTS

We synthesized 130 studies. Overall, SSA HCV seroprevalence from the random-effects model was 4.17% (95% confidence interval [CI]: 3.71-4.66, I2 = 99.30%). There were no differences between males (4.31%) and females (4.03%). Seroprevalence was 2.25%, 3.31%, and 16.23% for ages ≤20, 21-64, and ≥65 years, respectively, and was higher in rural (6.63%) versus urban (2.93%). There was indication of decrement overtime from 5.74% to 4.35% to 3.03% in the years 1984-2000, 2001-2014, and 2015-2023, respectively. The weighted overall SSA HCV seroprevalence was estimated to be 2.30% (95% CI: 1.59-3.00) with regional variation: Africa-Southern (.79%), Africa-Central (1.47%), Africa-Eastern (2.71%), and Africa-Western (2.88%). HCV viremia among HCV seropositives was 54.77% (95% CI: 47.80-61.66).

CONCLUSIONS

HCV seroprevalence in SSA remains high. Populations aged ≥65 years, rural communities, Africa-Western, and some countries in Africa-Central and Africa-Eastern appear disproportionately affected. These results underline the need for governmental commitment to achieve the 2030 global HCV elimination targets.

A Synopsis of Hepatitis C Virus Treatments and Future Perspectives

Hepatitis C virus (HCV) infection is a worldwide public health problem. Chronic infection with HCV can lead to liver cirrhosis or cancer. Although some immune-competent individuals can clear the virus, others develop chronic HCV disease due to viral mutations or an impaired immune response. IFNs type I and III and the signal transduction induced by them are essential for a proper antiviral effect. Research on the viral cycle and immune escape mechanisms has formed the basis of therapeutic strategies to achieve a sustained virological response (SVR). The first therapies were based on IFNα; then, IFNα plus ribavirin (IFN-RBV); and then, pegylated-IFNα-RBV (PEGIFNα-RIV) to improve cytokine pharmacokinetics. However, the maximum SVR was 60%, and several significant side effects were observed, decreasing patients' treatment adherence. The development of direct-acting antivirals (DAAs) significantly enhanced the SVR (>90%), and the compounds were able to inhibit HCV replication without significant side effects, even in paediatric populations. The management of coinfected HBV-HCV and HCV-HIV patients has also improved based on DAA and PEG-IFNα-RBV (HBV-HCV). CD4 cells are crucial for an effective antiviral response. The IFNλ3, IL28B, TNF-α, IL-10, TLR-3, and TLR-9 gene polymorphisms are involved in viral clearance, therapeutic responses, and hepatic pathologies. Future research should focus on searching for strategies to circumvent resistance-associated substitution (RAS) to DAAs, develop new therapeutic schemes for different medical conditions, including organ transplant, and develop vaccines for long-lasting cellular and humoral responses with cross-protection against different HCV genotypes. The goal is to minimise the probability of HCV infection, HCV chronicity and hepatic carcinoma.

Dynamics of cellular senescence markers after HCV elimination spontaneously or by DAAs in people living with HIV

BACKGROUND

We identified that acute or chronic Hepatitis C (HCV) infection in people living with HIV (PLWHIV) results in different senescence profiles. However, variations in these profiles after HCV elimination, spontaneously or with direct-acting antivirals (DAAs), remain unclear.

METHODS

Longitudinal observational study (48 weeks) in 70 PLWHIV: 23 PLWHIV with active HCV-chronic infection (CHC) before and after HCV eradication with DAAs, 12 PLWHIV who spontaneously clarify the HCV (SC), and 35 controls (HIV). Oxidative stress was quantified at DNA, lipid, protein, and nitrate levels, as well as the antioxidant capacity and glutathione enzyme. The replicative senescence was evaluated by relative telomere length measurement by PCR and twenty-six factors related to Senescence-Associated Secretory Phenotype (SASP) were characterized by Luminex. Differences in senescence markers was evaluated by generalized linear models.

RESULTS

During follow-up, the SC group achieved a significant improvement in glutathione enzyme and lipid peroxidation. The secretion of SASP markers increased but was still lower than that of the HIV group. Overall, the CHC group reduced the levels of oxidative stress and SASP markers to levels like those of the HIV group. No significant differences in telomere shortening were observed between groups.

CONCLUSIONS

As the time since spontaneous resolution of HCV infection increased, patients had an improved senescence profile compared to the HIV group. Elimination of chronic HCV infection by DAAs led to a partial improvement of the senescent profile by restoring oxidative stress levels. However, although some SASP markers reached levels like those of the HIV group, others remained altered.

Spontaneous clearance of chronic hepatitis C in an immunocompetent patient

Spontaneous clearance of chronic hepatitis C virus (HCV) infection is rare and the cases described have been mainly in immunosuppressed patients (HIV). For this reason, we report the case of an immunocompetent patient diagnosed with chronic HCV infection with spontaneous clearance of the virus.

Association of the Sialylation of Antibodies Specific to the HCV E2 Envelope Glycoprotein with Hepatic Fibrosis Progression and Antiviral Therapy Efficacy

The E2 envelope glycoprotein of the hepatitis C virus (HCV) is a major target of broadly neutralizing antibodies that are closely related to a spontaneous cure of HCV infection. There is still no data about the diversity of E2-specific antibodies (Abs) glycosylation. The aim of this study was to analyze the level and sialylation of E2 IgG Abs, the relation of the respective changes to hepatic fibrosis (F) progression and their possible association with the efficacy of interferon-α-2a plus ribavirin (IFN-RBV) antiviral therapy. One hundred three HCV infected treatment-naive patients were examined using ELISA with E2 recombinant protein as antigen and sialic acid-specific Sambucus nigra agglutinin. The efficacy of the IFN-RBV treatment of patients with HCV dominant 1b and 3a genotypes (GT) was evaluated. A significant decrease of E2 Abs sialylation in the late stages of fibrosis was found irrespective of HCV genotype. On this basis, the F4 stage of fibrosis can be discriminated from its F0 or F1-3 stage by an about 75-79% accuracy. HCV infection of 1b genotype is associated with the production of lower sialylated E2 Abs, a higher frequency of F4 stage fibrosis, and a worse response to antiviral therapy. The increased SNA reactivity of E2 Abs was observed in patients with a sustained virological response (SVR). The proportion of SVR responders was significantly higher among patients with 3a genotype. However, for both dominant HCV genotypes (3a and 1b), an increased sialylation of E2 IgG was associated with a higher rate of patients with sustained virological response to antiviral therapy. Thus, the association of alterations of anti-E2 IgG Abs sialylation with hepatic fibrosis stage, HCV genotype, and the efficacy of antiviral therapy enables using these changes as novel noninvasive predictive biomarkers. The clinical potential of these findings is discussed.

Screening for Antiviral Medaka Haploid Embryonic Stem Cells by Genome Wide Mutagenesis

Nervous necrosis virus (NNV), one of the most prevalent fish pathogens, has caused significant losses in both yield and economy to the aquaculture. Host factors involved in NNV infection remain to be identified due to the lack of ideal model for the study of NNV and host interaction. Haploid stem cells have proven to be ideal materials in genetic screens. Here, we generated a cell line HX1G1 (simply named G1) with the activity against red-spotted grouper nervous necrosis virus (RGNNV) by N-ethyl-N-nitrosourea (ENU)-mediated whole genome random mutagenesis from the haploid embryonic stem cell HX1a, a cell clone from haploid cell line HX1 that we previously derived from the medaka fish. G1 cells retained the characteristics of haploidy and pluripotency as indicated by the EBs differentiation ability after genetic mutagenesis. Compared with HX1a cells, no typical cytopathic effects were observed, and the expression of RNA-dependent RNA polymerase (RDRP) was significantly reduced in G1 cells post RGNNV infection, indicating the enhanced anti-RGNNV activity of G1. Furthermore, we demonstrated that RGNNV entry into G1 cells was partially inhibited, and this inhibition might be relevant to the induced mutation of heat shock cognate protein 70 (HSC70) which was decisive for NNV entry. Interestingly, G1 cells were to some extent permissive to RGNNV infection, but RGNNV was spontaneously cleared in G1 cells during serial passage. In addition, we also found that the expression levels of interferon (IFN)-related genes were higher in G1 cells than those in HX1a cells, suggesting that viral clearance might be associated with the elevated expression of IFN-related genes in G1 cells.

VH1-69 antiviral broadly neutralizing antibodies: genetics, structures, and relevance to rational vaccine design

Broadly neutralizing antibodies (bnAbs) are potential therapeutic molecules and valuable tools for studying conserved viral targets for vaccine and drug design. Interestingly, antibody responses to conserved epitopes can be highly convergent at the molecular level. Human antibodies targeting a number of viral antigens have often been found to utilize a restricted set of immunoglobulin germline genes in different individuals. Here we review recent knowledge on V_H1-69-encoded antibodies in antiviral responses to influenza virus, HCV, and HIV-1. These antibodies share common genetic and structural features, and often develop neutralizing activity against a broad spectrum of viral strains. Understanding the genetic and structural characteristics of such antibodies and the target epitopes should help advance novel strategies to elicit bnAbs through vaccination.