New WHO guidance for country validation of viral hepatitis B and C elimination

Activation of the cGAS-STING pathway by viral dsDNA leading to M1 polarization of macrophages mediates antiviral activity against hepatitis B virus

BACKGROUND AND AIMS

Activation of the cGAS-STING pathway induces the production of type I interferons, initiating the antiviral immune response, which contributes to the clearance of pathogens. Previous studies have shown that STING agonists promote hepatitis B virus (HBV) clearance; however, few studies have investigated the effect of activating the cGAS-STING pathway in macrophages on HBV.

METHODS

The polarization status of HBV particle-stimulated RAW264.7 macrophages was analyzed. After stimulation with HBV particles, the analysis focused on determining whether the DNA sensors in RAW264.7 macrophages recognized the viral double-stranded DNA (dsDNA) and evaluating the activation of the cGAS-STING pathway. Coculture of mouse macrophages and hepatocytes harboring HBV was used to study the antiviral activity of HBV-stimulated RAW264.7 macrophages.

RESULTS

After stimulation with HBV particles, HBV relaxed circular DNA (rcDNA) was detected in RAW264.7 macrophages, and the protein expression of phospho-STING, phospho-TBK1, and phospho-IRF3 in the STING pathway was increased, as shown by Western blot analysis, which revealed that M1 polarization of macrophages was caused by increased expression of CD86. RT-PCR analyses revealed elevated expression of M1 macrophage polarization-associated cytokines such as TNFα, IL-1β, iNOS, and IFNα/β. In the coculture experiment, both HBsAg and HBeAg expression levels were significantly decreased in AML12-HBV1.3 cells cocultured with the supernatants of HBV-stimulated RAW264.7 macrophages.

CONCLUSION

The results suggest that macrophages can endocytose HBV particles. Additionally, viral dsDNA can be recognized by DNA pattern recognition receptors, which in turn activate the cGAS-STING pathway, promoting the M1 polarization of macrophages, while no significant M2 polarization is observed. Macrophages stimulated with HBV particles exhibit enhanced antiviral activity against HBV.

Factors associated with knowledge and awareness of Hepatitis B in individuals of Chinese descent: Results from a mass point of care testing and outreach campaign in Toronto, Canada

Background

Migrants from hepatitis B virus (HBV) endemic regions are at high risk of having chronic infection. Despite this, HBV knowledge and awareness programming, and low-barrier screening methods such as point of care (POC) testing, among this group have yet to become routine.

Methods

We conducted a mass HBV POC screening and knowledge and awareness campaign for individuals of Chinese descent in Toronto, Canada. POC screening was administered, then participants completed a knowledge questionnaire. Logistic regression identified associations between demographic factors and participants' level of HBV knowledge.

Results

From 2015 to 2018, 33 outreach events resulted in 891 individuals completing testing and the knowledge questionnaire. Individuals averaged 64.4 years old. Most, 62% (N = 552), were female, and 73.6% (N = 656) have been in Canada for <30 years. The average questionnaire score was 70.7% correct, with 65.2% (N = 581) demonstrating a high level of HBV knowledge. Post-secondary education (OR: 2.19, 95% CI: 1.41, 3.39), income of $50,000 to <$75,000 (OR: 2.74, 95% CI: 1.39, 5.43), and having familial history of HBV (OR: 1.72, 95% CI: 1.06, 2.78) were associated with high knowledge. The observed prevalence of HBV was 1.5%, with 13 individuals testing positive on the POC test and confirmatory laboratory testing.

Conclusions

Improving knowledge and awareness of HBV is critical to empowering people, especially migrants who experience barriers to care, to pursue vaccination, testing, and treatment. Combining knowledge outreach and POC test campaigns, enabled discussion and screening for HBV with large numbers of people, and can be tailored for optimal effectiveness for specific groups.

Bidirectional Association between Lichen Planus and Hepatitis C-An Update Systematic Review and Meta-Analysis

Lichen planus (LP) is a chronic, inflammatory mucocutaneous disorder associated with systemic diseases such as hepatitis C (HCV). The objective of this study is to evaluate the association between LP and HCV bidirectionally through a systematic review and meta-analysis. A comprehensive search of studies published was performed in the databases of PubMed, Embase, and Web of Science. Out of 18,491 articles, 192 studies were included. The global prevalence of HCV positive (HCV+) in LP patients registered from 143 studies was 9.42% [95% confidence interval (CI), 7.27-11.58%], and from these, 84 studies showed HCV+ 4-fold more frequent in LP than a control group (OR, 4.48; 95% CI, 3.48-5.77). The global prevalence of LP in patients HCV+ recorded from 49 studies was 7.05% (95% CI, 4.85-9.26%), and from these, 15 registered a 3-fold more LP in HCV (OR, 3.65; 95% CI, 2.14-6.24). HCV+ in LP patients showed great geographic variability (OR, 2.7 to 8.57), and the predominantly cutaneous location was higher (OR, 5.95) than the oral location (OR, 3.49). LP in HCV+ patients was more frequent in the Eastern Mediterranean (OR, 5.51; 95% CI, 1.40-15.57). There is a higher prevalence of HCV+ in LP and vice versa than in the control group, especially in certain geographical areas that should be taken into consideration when doing screening in countries with an upper prevalence of HCV among the general population.

G-quadruplex in hepatitis B virus pregenomic RNA promotes its translation

Hepatitis B virus (HBV) is a hepatotropic DNA virus that has a very compact genome. Due to this genomic density, several distinct mechanisms are used to facilitate the viral life cycle. Recently, accumulating evidence show that G-quadruplex (G4) in different viruses play essential regulatory roles in key steps of the viral life cycle. Although G4 structures in the HBV genome have been reported, their function in HBV replication remains elusive. In this study, we treated an HBV replication-competent cell line and HBV-infected cells with the G4 structure stabilizer pyridostatin (PDS) and evaluated different HBV replication markers to better understand the role played by the G4. In both models, we found PDS had no effect on viral precore RNA (pcRNA) or pre-genomic RNA (pgRNA), but treatment did increase HBeAg/HBc ELISA reads and intracellular levels of viral core/capsid protein (HBc) in a dose-dependent manner, suggesting post-transcriptional regulation. To further dissect the mechanism of G4 involvement, we used in vitro-synthesized HBV pcRNA and pgRNA. Interestingly, we found PDS treatment only enhanced HBc expression from pgRNA but not HBeAg expression from pcRNA. Our bioinformatic analysis and CD spectroscopy revealed that pgRNA harbors a conserved G4 structure. Finally, we introduced point mutations in pgRNA to disrupt its G4 structure and observed the resulting mutant failed to respond to PDS treatment and decreased HBc level in in vitro translation assay. Taken together, our data demonstrate that HBV pgRNA contains a G4 structure that plays a vital role in the regulation of viral mRNA translation.

Codelivery of Cas9 mRNA and guide RNAs edits hepatitis B virus episomal and integration DNA in mouse and tree shrew models

With 296 million chronically infected individuals worldwide, hepatitis B virus (HBV) causes a major health burden. The major challenge to cure HBV infection lies in the fact that the source of persistence infection, viral episomal covalently closed circular DNA (cccDNA), could not be targeted. In addition, HBV DNA integration, although normally results in replication-incompetent transcripts, considered as oncogenic. Though several studies evaluated the potential of gene-editing approaches to target HBV, previous in vivo studies have been of limited relevance to authentic HBV infection, as the models do not contain HBV cccDNA or feature a complete HBV replication cycle under competent host immune system. In this study, we evaluated the effect of in vivo codelivery of Cas9 mRNA and guide RNAs (gRNAs) by SM-102-based lipid nanoparticles (LNPs) on HBV cccDNA and integrated DNA in mouse and a higher species. CRISPR nanoparticle treatment decreased the levels of HBcAg, HBsAg and cccDNA in AAV-HBV1.04 transduced mouse liver by 53%, 73% and 64% respectively. In HBV infected tree shrews, the treatment achieved 70% reduction of viral RNA and 35% reduction of cccDNA. In HBV transgenic mouse, 90% inhibition of HBV RNA and 95% inhibition of DNA were observed. CRISPR nanoparticle treatment was well tolerated in both mouse and tree shrew, as no elevation of liver enzymes and minimal off-target was observed. Our study demonstrated that SM-102-based CRISPR is safe and effective in targeting HBV episomal and integration DNA in vivo. The system delivered by SM-102-based LNPs may be used as a potential therapeutic strategy against HBV infection.

Hepatitis B virus hijacks TSG101 to facilitate egress via multiple vesicle bodies

Hepatitis B virus (HBV) chronically infects 296 million individuals and there is no cure. As an important step of viral life cycle, the mechanisms of HBV egress remain poorly elucidated. With proteomic approach to identify capsid protein (HBc) associated host factors and siRNA screen, we uncovered tumor susceptibility gene 101 (TSG101). Knockdown of TSG101 in HBV-producing cells, HBV-infected cells and HBV transgenic mice suppressed HBV release. Co-immunoprecipitation and site mutagenesis revealed that VFND motif in TSG101 and Lys-96 ubiquitination in HBc were essential for TSG101-HBc interaction. In vitro ubiquitination experiment demonstrated that UbcH6 and NEDD4 were potential E2 ubiquitin-conjugating enzyme and E3 ligase that catalyzed HBc ubiquitination, respectively. PPAY motif in HBc and Cys-867 in NEDD4 were required for HBc ubiquitination, TSG101-HBc interaction and HBV egress. Transmission electron microscopy confirmed that TSG101 or NEDD4 knockdown reduces HBV particles count in multivesicular bodies (MVBs). Our work indicates that TSG101 recognition for NEDD4 ubiquitylated HBc is critical for MVBs mediated HBV egress.

Hepatitis C treatment program in Maputo, Mozambique, the challenge of genotypes and key populations: A 5-year retrospective analysis of routine programmatic data

Background and Aims

Hepatitis C (HCV) programs face challenges, especially linked to key populations to achieve World Health Organization (WHO) goals of eliminating hepatitis. Médecins Sans Frontières and Mozambique's Ministry of Health first implemented HCV treatment in Maputo, in 2016 and harm reduction activities in 2017.

Methods

We retrospectively analyzed routine data of patients enrolled between December 2016 and July 2021. Genotyping was systematically requested up to 2018 and subsequently in cases of treatment failure. Sustainable virological response was assessed 12 weeks after the end of treatment by sofosbuvir-daclatasvir or sofosbuvir-velpatasvir.

Results

Two hundred and two patients were enrolled, with 159 (78.71%) males (median age: 41 years [interquartile range (IQR): 37.10, 47.00]). Risk factors included drug use (142/202; 70.29%). One hundred and eleven genotyping results indicated genotype 1 predominant (87/111; 78.37%). Sixteen patients presented genotype 4, with various subtypes. The people who used drugs and HIV coinfected patients were found more likely to present a genotype 1. Intention-to-treat analysis showed 68.99% (89/129) cure rate among the patients initiated and per-protocol analysis, 88.12% (89/101) cure rate. Nineteen patients received treatment integrated with opioid substitution therapy, with a 100% cure rate versus 59.37% (38/64) for initiated ones without substitution therapy (p < 0.001). Among the resistance testing performed, NS5A resistance-associated substitutions were found in seven patients among the nine tested patients and NS5B ones in one patient.

Conclusion

We found varied genotypes, including some identified as difficult-to-treat subtypes. People who used drugs were more likely to present genotype 1. In addition, opioid substitution therapy was key for these patients to achieve cure. Access to second-generation direct-acting antivirals (DAAs) and integration of HCV care with harm reduction are crucial to program effectiveness.

The burden of hepatitis C virus in the world, China, India, and the United States from 1990 to 2019

Background and aim

Hepatitis C virus infection can lead to an enormous health burden worldwide. Investigating the changes in HCV-related burden between different countries could provide inferences for disease management. Hence, we aim to explore the temporal tendency of the disease burden associated with HCV infection in China, India, the United States, and the world.

Methods

Detailed data on the total burden of disease related to HCV infection were collected from the Global Burden of Disease (GBD) 2019 database. Joinpoint regression models were used to simulate the optimal joinpoints of annual percent changes (APCs). Further analysis of the age composition of each index over time and the relationship between ASRs and the socio-demographic Index (SDI) were explored. Finally, three factors (population growth, population aging, and age-specific changes) were deconstructed for the changes in the number of incidences, deaths, and DALYs.

Results

It was estimated that 6.2 million new HCV infections, 0.54 million HCV-related deaths, and 15.3 million DALYs worldwide in 2019, with an increase of 25.4, 59.1, and 43.6%, respectively, from 1990, are mainly due to population growth and aging. China experienced a sharp drop in age-standardized rates in 2019, the United States showed an upward trend, and India exhibited a fluctuating tendency in the burden of disease. The incidence was increasing in all locations recently.

Conclusion

HCV remains a global health concern despite tremendous progress being made. The disease burden in China improved significantly, while the burden in the United States was deteriorating, with new infections increasing recently, suggesting more targeted interventions to be established to realize the 2030 elimination goals.

Methods and indicators to validate country reductions in incidence of hepatitis C virus infection to elimination levels set by WHO

One of the main goals of the 2016 Global Health Sector Strategy on viral hepatitis is the elimination of hepatitis C virus (HCV) as a public health problem by 2030, defined as an 80% reduction in incidence and 65% reduction in mortality relative to 2015. Although monitoring HCV incidence is key to validating HCV elimination, use of the gold-standard method, which involves prospective HCV retesting of people at risk, can be prohibitively resource-intensive. Additionally, few countries collected quality data in 2015 to enable an 80% decrease by 2030 to be calculated. Here, we first review different methods of monitoring HCV incidence and discuss their resource implications and applicability to various populations. Second, using mathematical models developed for various global settings, we assess whether trends in HCV chronic prevalence or HCV antibody prevalence or scale-up levels for HCV testing, treatment, and preventative interventions can be used as reliable alternative indicators to validate the HCV incidence target. Third, we discuss the advantages and disadvantages of an absolute HCV incidence target and suggest a suitable threshold. Finally, we propose three options that countries can use to validate the HCV incidence target, depending on the available surveillance infrastructure.

In Vivo Modelling of Hepatitis B Virus Subgenotype A1 Replication Using Adeno-Associated Viral Vectors

The paucity of animal models that simulate the replication of the hepatitis B virus (HBV) is an impediment to advancing new anti-viral treatments. The work reported here employed recombinant adeno-associated viruses (AAVs) to model HBV subgenotype A1 and subgenotype D3 replication in vitro and in vivo. Infection with subgenotype A1 is endemic to parts of sub-Saharan Africa, and it is associated with a high risk of hepatocellular carcinoma. Recombinant AAV serotype 2 (AAV2) and 8 (AAV8) vectors bearing greater-than-genome-length sequences of HBV DNA from subgenotype A1 and D3, were produced. Transduced liver-derived cultured cells produced HBV surface antigen and core antigen. Administration of AAV8 carrying HBV subgenotype A1 genome (AAV8-A1) to mice resulted in the sustained production of HBV replication markers over a six-month period, without elevated inflammatory cytokines, expression of interferon response genes or alanine transaminase activity. Markers of replication were generally higher in animals treated with subgenotype D3 genome-bearing AAVs than in those receiving the subgenotype A1-genome-bearing vectors. To validate the use of the AAV8-A1 murine model for anti-HBV drug development, the efficacy of anti-HBV artificial primary-microRNAs was assessed. Significant silencing of HBV markers was observed over a 6-month period after administering AAVs. These data indicate that AAVs conveniently and safely recapitulate the replication of different HBV subgenotypes, and the vectors may be used to assess antivirals’ potency.

Including the voice of people living with viral hepatitis: lessons learned from Japan to accelerate progress towards global hepatitis elimination

Despite the growing momentum created by the WHO for eliminating viral hepatitis as a public health threat by 2030, the global response is still slow and more actions are needed to meet the elimination goals, especially in low-income and middle-income countries. Japan is one of a handful of countries currently on track to achieve the WHO hepatitis elimination targets by 2030. To better understand the successful control of viral hepatitis in Japan, it is important to recognize the role of the patient association for viral hepatitis, known as the “Japan Hepatitis Council”, which celebrates its 50th anniversary in 2021. The greatest impact of the Japan Hepatitis Council has been in achieving wider access to antiviral treatments for viral hepatitis. The example of Japan and the Japan Hepatitis Council highlights the need for the engagement of civil society and patient groups to ensure equitable access to hepatitis services and to accelerate the global hepatitis elimination.

Australia could miss the WHO hepatitis C virus elimination targets due to declining treatment uptake and ongoing burden of advanced liver disease complications

Australia was one of the first countries to introduce government-funded unrestricted access to direct-acting antiviral (DAA) therapy, with 88,790 treated since March 2016. However, treatment uptake is declining which could potentially undermine Australia’s progress towards the WHO HCV elimination targets. Using mathematical modelling, we updated estimates for those living with chronic HCV in Australia, new cases of decompensated cirrhosis (DC), hepatocellular carcinoma (HCC), and liver-related mortality among the HCV-cured and viraemic populations from 2015 to 2030. We considered various DAA treatment scenarios incorporating annual treatment numbers to 2020, and subsequent uptake per year of 6,790 (pessimistic), 8,100 (intermediate), and 11,310 (optimistic). We incorporated the effects of excess alcohol consumption and reduction in progression to DC and HCC among cirrhosis-cured versus viraemic individuals. At the end of 2020, we estimated 117,810 Australians were living with chronic HCV. New cases per year of DC, HCC, and liver-related mortality among the HCV viraemic population decreased rapidly from 2015 (almost eliminated by 2030). In contrast, the growing population size of those cured with advanced liver disease meant DC, HCC, and liver-related mortality declined slowly. The estimated reduction in liver-related mortality from 2015 to 2030 in the combined HCV viraemic and cured population is 25% in the intermediate scenario. With declining HCV treatment uptake and ongoing individual-level risk of advanced liver disease complications, including among cirrhosis-cured individuals, Australia is unlikely to achieve all WHO HCV elimination targets by 2030.