Hepatitis B virus (HBV) reactivation-The potential role of direct-acting agents for hepatitis C virus (HCV)

Towards Understanding and Identification of Human Viral Co-Infections

Viral co-infections, in which a host is infected with multiple viruses simultaneously, are common in the human population. Human viral co-infections can lead to complex interactions between the viruses and the host immune system, affecting the clinical outcome and posing challenges for treatment. Understanding the types, mechanisms, impacts, and identification methods of human viral co-infections is crucial for the prevention and control of viral diseases. In this review, we first introduce the significance of studying human viral co-infections and summarize the current research progress and gaps in this field. We then classify human viral co-infections into four types based on the pathogenic properties and species of the viruses involved. Next, we discuss the molecular mechanisms of viral co-infections, focusing on virus-virus interactions, host immune responses, and clinical manifestations. We also summarize the experimental and computational methods for the identification of viral co-infections, emphasizing the latest advances in high-throughput sequencing and bioinformatics approaches. Finally, we highlight the challenges and future directions in human viral co-infection research, aiming to provide new insights and strategies for the prevention, control, diagnosis, and treatment of viral diseases. This review provides a comprehensive overview of the current knowledge and future perspectives on human viral co-infections and underscores the need for interdisciplinary collaboration to address this complex and important topic.

Blocking the CXCL1-CXCR2 axis enhances the effects of doxorubicin in HCC by remodelling the tumour microenvironment via the NF-κB/IL-1β/CXCL1 signalling pathway

Inflammation is a core mechanism for oncogenesis. Chemokines act as important mediators of chronic inflammation and the tumour inflammatory response. However, there is limited information on chemokines in hepatocellular carcinoma (HCC), a disease for which almost all cases are derived from chronic liver inflammation. Here, we explored the protumor effects of CXCL1, a commonly elevated inflammatory chemokine in cirrhosis, in HCC. The protumor role was confirmed in clinical samples from HCC patients. CXCL1 enhanced tumorigenesis in the hepatic inflammatory microenvironment directly by acting on tumour cells and indirectly through promoting the recruitment of macrophages. The increase in the number of macrophages in the tumour microenvironment (TME) promoted tumour cell epithelial-mesenchymal transition (EMT) and significantly increased CXCL1 levels in the TME partly through NF-κB/IL-1β activation. To investigate the potential therapeutic value of CXCL1 in HCC with an inflammatory background, an antibody blocking CXCL1 was used alone or combined with the chemotherapy agent doxorubicin (DOX), with the goal of reshaping the TME. It has been shown that blocking CXCL1-CXCR2 inhibits tumour progression and reduces macrophage recruitment in the TME. The combination regimen has been shown to synergistically reduce the number of pro-tumour macrophages in the TME and suppress tumour progression. This provides insight into therapeutic strategies for treating HCC patients with high CXCL1 expression.

Hepatitis Virus and Hepatocellular Carcinoma: Recent Advances

Hepatocellular carcinoma (HCC) remains a global health challenge, causing 600,000 deaths each year. Infectious factors, including hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV), have long been considered the major risk factors for the development and progression of HCC. These pathogens induce hepatocyte transformation through a variety of mechanisms, including insertional mutations caused by viral gene integration, epigenetic changes, and the induction of long-term immune dysfunction. The discovery of these mechanisms, while advancing our understanding of the disease, also provides targets for new diagnostic and therapeutic approaches. In addition, the discovery and research of chronic HEV infection over the past decade indicate that this common hepatitis virus also seems to have the potential to induce HCC. In this review, we provide an overview of recent studies on the link between hepatitis virus and HCC, as well as new diagnostic and therapeutic approaches to HCC based on these findings. Finally, we also discuss the potential relationship between HEV and HCC. In conclusion, these associations will further optimize the diagnosis and treatment of infection-associated HCC and call for better management policies.

Spatiotemporal heterogeneity and impact factors of hepatitis B and C in China from 2010 to 2018: Bayesian space-time hierarchy model

Introduction

Viral hepatitis is a global public health problem, and China still faces great challenges to achieve the WHO goal of eliminating hepatitis.

Methods

This study focused on hepatitis B and C, aiming to explore the long-term spatiotemporal heterogeneity of hepatitis B and C incidence in China from 2010 to 2018 and quantify the impact of socioeconomic factors on their risk through Bayesian spatiotemporal hierarchical model.

Results

The results showed that the risk of hepatitis B and C had significant spatial and temporal heterogeneity. The risk of hepatitis B showed a slow downward trend, and the high-risk provinces were mainly distributed in the southeast and northwest regions, while the risk of hepatitis C had a clear growth trend, and the high-risk provinces were mainly distributed in the northern region. In addition, for hepatitis B, illiteracy and hepatitis C prevalence were the main contributing factors, while GDP per capita, illiteracy rate and hepatitis B prevalence were the main contributing factors to hepatitis C.

Disussion

This study analyzed the spatial and temporal heterogeneity of hepatitis B and C and their contributing factors, which can serve as a basis for monitoring efforts. Meanwhile, the data provided by this study will contribute to the effective allocation of resources to eliminate viral hepatitis and the design of interventions at the provincial level.

Enhanced host immune responses in presence of HCV facilitate HBV clearance in coinfection

Hepatitis B virus (HBV)/Hepatitis C virus (HCV) coinfection is frequently observed because of the common infection routine. Despite the reciprocal inhibition exerted by HBV and HCV genomes, the coinfection of HBV and HCV is associated with more severe forms of liver diseases. However, the complexity of viral interference and underlying pathological mechanism is still unclarified. With the demonstration of absence of direct viral interplay, some in vitro studies suggest the indirect effects of viral-host interaction on viral dominance outcome. Here, we comprehensively investigated the viral replication and host immune responses which might mediate the interference between viruses in HBV/HCV coinfected Huh7-NTCP cells and immunocompetent HCV human receptors transgenic ICR mice. We found that presence of HCV significantly inhibited HBV replication in vitro and in vivo irrespective of the coinfection order, while HBV did not affect HCV replication. Pathological alteration was coincidently reproduced in coinfected mice. In addition to the participation of innate immune response, an involvement of HCV in up-regulating HBV-specific immune responses was described to facilitate HBV clearance. Our systems partially recapitulate HBV/HCV coinfection and unveil the uncharacterized adaptive anti-viral immune responses during coinfection, which renews the knowledge on the nature of indirect viral interaction during HBV/HCV coinfection.

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HCV inhibited HBV replication in Huh7-NTCP cells.

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HCV suppressed HBV in immunocompetent mice.

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Induced innate immune response by HCV limited HBV replication.

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Presence of HCV enhanced HBV specific immune response.

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Moderate and acute live injure was caused by HBV/HCV coinfection.

OUP accepted manuscript

Hepatitis B virus (HBV) remains a global public health problem despite the availability of effective vaccine and antiviral therapy. Cytomegalovirus (CMV), another hepatotropic virus, is also very prevalent in the general population worldwide. Both HBV and CMV can persist in the host and have potential to reactivate especially with weakened host cellular immunity. Superimposed CMV infection can lead to severe HBV reactivation. The pathogenesis of the co-infection of HBV and CMV remains poorly understood. Studies reported conflicting results regarding the inhibitory effect of CMV on HBV replication. There is an unmet need on the management of co-infection of HBV and CMV; research initiatives dedicated to understanding their interactions are urgently needed.

Nanoparticle-Based Lateral Flow Biosensors Integrated With Loop-Mediated Isothermal Amplification for the Rapid and Visual Diagnosis of Hepatitis B Virus in Clinical Application

Hepatitis B virus (HBV) infection remains one of the major public health issues worldwide. Developing a rapid, sensitive, specific, easy-to-operate, and cost-saving approach for the diagnosis of HBV is essential for its therapy and prevention. Here, we first devised a novel approach, termed “loop-mediated isothermal amplification integrated with a nanoparticle-based lateral flow biosensor (LAMP-LFB),” for the detection of HBV in clinical application. The results indicated that a set of LAMP primers based on the S gene were valid for the establishment of HBV-LAMP-LFB. The optimal HBV-LAMP can be carried out at a constant temperature of 65°C for 40 min. The whole detection process, including HBV genomic DNA preparation (∼10 min), LAMP (40 min), and LFB reading (within 2 min), can be accomplished within 60 min. The limit of detection of the HBV-LAMP-LFB assay was 7.5 IU per test. The specificity of this assay was one hundred percent, and there was no cross-reactivity with other pathogens. Hence, these results indicated that the HBV-LAMP-LFB assay established in the current study is a sensitive, rapid, specific, visual, simple, and cost-saving method for the screening of HBV agents. More importantly, the HBV-LAMP-LFB has remarkable potential to develop a point-of-care testing in clinical application, especially in resource-scarce regions.

Profiling the physiological pitfalls of anti-hepatitis C direct-acting agents in budding yeast

Sofosbuvir and Daclatasvir are among the direct-acting antiviral (DAA) medications prescribed for the treatment of chronic hepatitis C (CHC) virus infection as combination therapy with other antiviral medications. DAA-based therapy achieves high cure rates, reaching up to 97% depending on the genotype of the causative hepatitis C virus (HCV). While DAAs have been approved as an efficient and well-tolerated therapy for CHC, emerging concerns about adverse cardiac side effects, higher risk of recurrence and occurrence of hepatocellular carcinoma (HCC) and doubts of genotoxicity have been reported. In our study, we investigated in detail physiological off-targets of DAAs and dissected the effects of these drugs on cellular organelles using budding yeast, a unicellular eukaryotic organism. DAAs were found to disturb the architecture of the endoplasmic reticulum (ER) and the mitochondria, while showing no apparent genotoxicity or DNA damaging effect. Our study provides evidence that DAAs are not associated with genotoxicity and highlights the necessity for adjunctive antioxidant therapy to mitigate the adverse effects of DAAs on ER and mitochondria.

Multiple Cross Displacement Amplification Linked with Nanoparticles-Based Lateral Flow Biosensor in Screening of Hepatitis B Virus in Clinical Application

Background

Hepatitis B virus (HBV) is a common pathogen that predominantly causes severe liver disease, and remains one of a huge challenge worldwide, especially in many resource-constrained areas. Developing a low-cost, sensitive, specific, and rapid approach for screening HBV is critical for its treatment and prevention. In the current study, a novel molecular detection approach, multiple cross displacement amplification (MCDA) coupled with polymer nanoparticle-based lateral flow biosensor (MCDA-LFB), was applied for detection of HBV in blood samples.

Methods

HBV standard substance and clinical donor serum samples were collected and used for the establishment and confirmation of the HBV-MCDA-LFB assay. A set of 10 MCDA primers was designed according to HBV-specific gene S. The HBV-MCDA-LFB assay conditions, including genomic template concentration, MCDA reaction temperature and time were optimized. The sensitivity and specificity of the HBV-MCDA -LFB assay were evaluated in this report. The HBV-MCDA-LFB assay was applied to detect the HBV agent from clinical samples.

Results

The HBV-MCDA primers based on the S gene were valid for establishment of MCDA assay. The HBV-MCDA reaction with optimized conditions could be carried out at a constant temperature 64°C for 35 min. The whole process, including sample preparation (5 min), genomic template extraction (~30 min), MCDA amplification (35 min), and LFB reading (~2 min), could be completed within 80 min. The sensitivity of this assay was 5 IU per reaction. The specificity was 100% for HBV-MCDA-LFB assay.

Conclusion

These results confirmed that the HBV-MCDA-LFB is a low-cost, sensitive, specific, simple, and rapid method for detecting HBV agents. This technique has great potential to develop a point-of-care testing (POCT) method in clinical practice, especially in endemic and resource-constrained regions.

A hepatitis B virus causes chronic infections in equids worldwide

Preclinical testing of novel therapeutics for chronic hepatitis B (CHB) requires suitable animal models. Equids host homologs of hepatitis C virus (HCV). Because coinfections of hepatitis B virus (HBV) and HCV occur in humans, we screened 2,917 specimens from equids from five continents for HBV. We discovered a distinct HBV species (Equid HBV, EqHBV) in 3.2% of donkeys and zebras by PCR and antibodies against EqHBV in 5.4% of donkeys and zebras. Molecular, histopathological, and biochemical analyses revealed that infection patterns of EqHBV resembled those of HBV in humans, including hepatotropism, moderate liver damage, evolutionary stasis, and potential horizontal virus transmission. Naturally infected donkeys showed chronic infections resembling CHB with high viral loads of up to 2.6 × 10⁹ mean copies per milliliter serum for >6 mo and weak antibody responses. Antibodies against Equid HCV were codetected in 26.5% of donkeys seropositive for EqHBV, corroborating susceptibility to both hepatitis viruses. Deltavirus pseudotypes carrying EqHBV surface proteins were unable to infect human cells via the HBV receptor NTCP (Na⁺/taurocholate cotransporting polypeptide), suggesting alternative viral entry mechanisms. Both HBV and EqHBV deltavirus pseudotypes infected primary horse hepatocytes in vitro, supporting a broad host range for EqHBV among equids and suggesting that horses might be suitable for EqHBV and HBV infections in vivo. Evolutionary analyses suggested that EqHBV originated in Africa several thousand years ago, commensurate with the domestication of donkeys. In sum, EqHBV naturally infects diverse equids and mimics HBV infection patterns. Equids provide a unique opportunity for preclinical testing of novel therapeutics for CHB and to investigate HBV/HCV interplay upon coinfection.

Managing viral hepatitis in cancer patients under immune checkpoint inhibitors: should we take the risk?

More patients with chronic hepatitis B and C infection are being exposed to immune checkpoint inhibitors (ICIs), but the safety and efficacy of ICIs in patients with chronic viral hepatitis are still poorly described. To explore this interaction, we identified eight studies of cancer patients with viral hepatitis treated with one or more ICIs, formally assessed tumor responses and safety by grading liver dysfunction. ICIs appear to be relatively safe in HBV/HCV-infected patients, and hepatitis related to viral reactivation is rare. In some patients, viral load regressed during ICI treatment, so immune checkpoints may play a role in viral clearance. HBV/HCV do not appear to be a contraindication to ICIs, although careful clinical and biochemical follow-up is recommended and, whenever necessary, antiviral therapy commenced.

Treatment of Chronic Hepatitis C in Adolescent Patients With Positive HBsAg or With Occult Hepatitis B: Is the Risk of Hepatitis B Reactivation Significant?

BACKGROUND

Reactivation of hepatitis B virus (HBV) infection in patients treated for chronic hepatitis C (HCV) with direct-acting antiviral agents has emerged recently as an important safety issue; however, it has not been adequately studied in pediatric age groups. We aimed to evaluate this risk in adolescent patients infected with chronic HCV and positive for HBsAg and HBcAbs.

PATIENTS AND METHODS

One hundred and fifteen adolescent patients from 12 to 17 years of age, infected with chronic HCV and positive for HBcAbs with or without HBsAg were included in this study. All patients were treated with 1 tablet daily of the fixed-dose combination sofosbuvir/ledipasvir for 12 weeks. Patients were closely monitored throughout the study for virus load, liver functions, and other safety and efficacy outcome measures.

RESULTS

The sustained virologic response 12 (SVR12) rates were 96.7% (95% confidence interval: 88.6-99.1%) in HBsAg positive group and 98.2% (95% confidence interval: 90.4-99.7%) in HBsAg negative with HBcAbs positive group. Throughout the treatment period and the 12 weeks follow-up after treatment, there has been no single case in both HBsAg negative or positive that showed any manifestation of reactivation of hepatitis B, detected levels of HBV-DNA, or deterioration of liver functions.

CONCLUSION

No HBV reactivation was observed in adolescents treated for chronic HCV with direct-acting antiviral agents in our study, in both HBsAg positive or occult hepatitis B. Although results are reassuring, we still recommend close monitoring of liver functions to not miss even rare cases of such a potentially serious condition.

Hepatitis B Virus: Advances in Prevention, Diagnosis, and Therapy

Currently, despite the use of a preventive vaccine for several decades as well as the use of effective and well-tolerated viral suppressive medications since 1998, approximately 250 million people remain infected with the virus that causes hepatitis B worldwide. Hepatitis C virus (HCV) and hepatitis B virus (HBV) are the leading causes of liver cancer and overall mortality globally, surpassing malaria and tuberculosis. Linkage to care is estimated to be very poor both in developing countries and in high-income countries, such as the United States, countries in Western Europe, and Japan. In the United States, by CDC estimates, only one-third of HBV-infected patients or less are aware of their infection. Some reasons for these low rates of surveillance, diagnosis, and treatment include the asymptomatic nature of chronic hepatitis B until the very late stages, a lack of curative therapy with a finite treatment duration, a complex natural history, and a lack of knowledge about the disease by both care providers and patients. In the last 5 years, more attention has been focused on the important topics of HBV screening, diagnosis of HBV infection, and appropriate linkage to care. There have also been rapid clinical developments toward a functional cure of HBV infection, with novel compounds currently being in various phases of progress. Despite this knowledge, many of the professional organizations provide guidelines focused only on specific questions related to the treatment of HBV infection. This focus leaves a gap for care providers on the other HBV-related issues, which include HBV's epidemiological profile, its natural history, how it interacts with other viral hepatitis diseases, treatments, and the areas that still need to be addressed in order to achieve HBV elimination by 2030. Thus, to fill these gaps and provide a more comprehensive and relevant document to regions worldwide, we have taken a global approach by using the findings of global experts on HBV as well as citing major guidelines and their various approaches to addressing HBV and its disease burden.

Preventing infectious complications when treating non-malignant immune-mediated hematologic disorders

Immunosuppressants, targeted antibody therapies, and surgical splenectomy are amongst the treatment choices for immune-mediated non-malignant hematologic disorders, with infection being the most common non-hematological adverse event from these therapies. Corticosteroids are associated with a length-of-treatment and dose-dependent risk for infection, including opportunistic infections. Screening and antimicrobial prophylaxis against tuberculosis, Strongyloides stercoralis, and Pneumocystis jirovecii pneumonia, are indicated in selected patients on steroids and with certain risk factors for infection. Rituximab is associated with hepatitis B virus reactivation. All patients planned to be started on rituximab should be screened for hepatitis B surface antigen and total core antibody, with antiviral prophylaxis given depending on test results. In eculizumab treated patients, immunization against meningococcal serogroups ACWY and B is recommended. In addition, some guidelines suggest antibiotic prophylaxis for the duration of eculizumab treatment. In splenectomized patients, counseling and immunization are cornerstones of infection prevention. Several federal and society guidelines about immunizations and prophylactic antimicrobial therapies for patients treated with various immunosuppressive agents exist and are summarized in this manuscript in a clinical-focused table. In addition, management suggestions are made where no formal guidelines exist.

HCV resistance compartmentalization within tumoral and non-tumoral liver in transplanted patients with hepatocellular carcinoma

BACKGROUND & AIMS

We investigated the HCV-RNA amount, variability and prevalence of resistance-associated substitutions (RASs), in plasma, hepatic tumoral and non-tumoral tissue samples in patients undergoing liver-transplant/hepatic-resection (LT/HR), because of hepatocellular carcinoma and/or cirrhosis.

METHODS

Eighteen HCV-infected patients undergoing LT/HR, 94.0% naïve to direct-acting antivirals (DAAs), were analysed. HCV-RNA was quantified in all compartments. NS3/NS5A/NS5B in plasma and/or in tumoral/non-tumoral tissues were analysed using Sanger and Ultra-deep pyrosequencing (UDPS, 9/18 patients). RASs prevalence, genetic-variability and phylogenetic analysis were evaluated.

RESULTS

At the time of LT/HR, HCV-RNA was quantifiable in all compartments of DAA-naïve patients and was generally lower in tumoral than in non-tumoral tissues (median [IQR] = 4.0 [1.2-4.3] vs 4.3[3.1-4.9] LogIU/µg RNA; P = 0.193). The one patient treated with sofosbuvir + ribavirin represented an exception with HCV-RNA quantifiable exclusively in the liver, but with higher level in tumoral than in non-tumoral tissues (51 vs 7 IU/µg RNA). RASs compartmentalization was found by Sanger in 4/18 infected-patients, and by UDPS in other two patients. HCV-compartmentalization resulted to be associated with HBcAb-positivity (P = 0.013). UDPS showed approximately higher genetic-variability in NS3/NS5A sequences in all compartments. Phylogenetic-analysis showed defined and intermixed HCV-clusters among/within all compartments, and were strongly evident in the only non-cirrhotic patient, with plasma and non-tumoral sequences generally more closely related.

CONCLUSIONS

Hepatic compartments showed differences in HCV-RNA amount, RASs and genetic variability, with a higher segregation within the tumoral compartment. HBV coinfection influenced the HCV compartmentalization. These results highlight HCV-strain diversifications within the liver, which could explain some of the failures occurring even today in the era of DAAs.

Modeling the dynamics of hepatitis B infection, immunity, and drug therapy

Hepatitis B virus infection is the cause of liver diseases such as cirrhosis and liver cancer. Understanding the host-virus mechanisms that mediate virus pathogenesis can help design better preventive measures for disease control. Mathematical models have been used alongside experimental data to provide insight into the role of immune responses during the acute and chronic hepatitis B infections as well as virus dynamics following administration of combined drug therapy. In this paper, we review several modeling studies on virus-host interactions during acute infection, the virus-host characteristics responsible for transition to chronic disease, and the efficacy and optimal control measures of drug therapy. We conclude by presenting our opinion on the future directions of the field.