New therapies for chronic hepatitis B

The Hepatitis B Virus Interactome: A Comprehensive Overview

Despite the availability of a prophylactic vaccine, chronic hepatitis B (CHB) caused by the hepatitis B virus (HBV) is a major health problem affecting an estimated 292 million people globally. Current therapeutic goals are to achieve functional cure characterized by HBsAg seroclearance and the absence of HBV-DNA after treatment cessation. However, at present, functional cure is thought to be complicated due to the presence of covalently closed circular DNA (cccDNA) and integrated HBV-DNA. Even if the episomal cccDNA is silenced or eliminated, it remains unclear how important the high level of HBsAg that is expressed from integrated HBV DNA is for the pathology. To identify therapies that could bring about high rates of functional cure, in-depth knowledge of the virus' biology is imperative to pinpoint mechanisms for novel therapeutic targets. The viral proteins and the episomal cccDNA are considered integral for the control and maintenance of the HBV life cycle and through direct interaction with the host proteome they help create the most optimal environment for the virus whilst avoiding immune detection. New HBV-host protein interactions are continuously being identified. Unfortunately, a compendium of the most recent information is lacking and an interactome is unavailable. This article provides a comprehensive review of the virus-host relationship from viral entry to release, as well as an interactome of cccDNA, HBc, and HBx.

Viral Biomarkers for Hepatitis B Virus-Related Hepatocellular Carcinoma Occurrence and Recurrence

Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide and the fourth leading cause of cancer-related death. The most common risk factor for developing HCC is chronic infection with hepatitis B virus (HBV). Early stages of HBV-related HCC (HBV-HCC) are generally asymptomatic. Moreover, while serum alpha-fetoprotein (AFP) and abdominal ultrasound are widely used to screen for HCC, they have poor sensitivity. Thus, HBV-HCC is frequently diagnosed at an advanced stage, in which there are limited treatment options and high mortality rates. Serum biomarkers with high sensitivity and specificity are crucial for earlier diagnosis of HCC and improving survival rates. As viral-host interactions are key determinants of pathogenesis, viral biomarkers may add greater diagnostic power for HCC than host biomarkers alone. In this review, we summarize recent research on using virus-derived biomarkers for predicting HCC occurrence and recurrence; including circulating viral DNA, RNA transcripts, and viral proteins. Combining these viral biomarkers with AFP and abdominal ultrasound could improve sensitivity and specificity of early diagnosis, increasing the survival of patients with HBV-HCC. In the future, as the mechanisms that drive HBV-HCC to become clearer, new biomarkers may be identified which can further improve early diagnosis of HBV-HCC.

Safety and efficacy of immune checkpoint inhibitors in patients with HBV/HCV infection and advanced-stage cancer: A systematic review

BACKGROUND

Cancer patients with hepatitis B or C virus (HBV/HCV) infection are commonly seen in clinical practice, however, the data of safety and efficacy of immune checkpoint inhibitors (ICIs) among them are sparse, because active HBV/HCV infected patients were generally excluded by clinical trials and the correlation between previous infection and treatment-related adverse events was rarely reported. This review is the first to summarize the results on the safety and efficacy of immune checkpoint inhibitors (ICIs) in HBV/HCV infected cancer patients.

METHOD

We searched literature and conference abstracts in PubMed and Embase followed the PRISMA guideline, using the keywords hepatitis B, hepatitis C, immune checkpoint inhibitor, ipilimumab, nivolumab, pembrolizumab, atezolizumab, durvalumab, avelumab, tremelimumab. Studies described patients with HBV/HCV infection treated with ICIs for advanced stage cancer were included.

FINDINGS

One hundred eighty six patients were identified from 14 articles (8 case reports, 4 case series, 2 trials). Eighty nine patients had HBV infection and 98 had HCV infection (1 both had HBV and HCV). The majority of patients were treated with PD-1 inhibitor monotherapy (140 of 186, 75.3%) and anti-CTLA-4 monotherapy (36 of 186, 19.4%). No treatment-related death was reported. The incidence of grade 3 or 4 hepatic transaminase elevating (HTE) in HBV and HCV infected patients were 3.4% (3/89) and 17.3% (17/98), respectively. 2.8% patients without antivirus therapy experienced virus load increasing, and 1.9% presented virus-related hepatitis. In terms of efficacy, 22 of 118 (18.6%) patients with liver cancer, 11 of 34 (32.4%) with melanoma, 1 of 6 (16.7%) with NSCLC showed objective responses (CR and PR) to ICIs in spite of lines of therapies.

CONCLUSION

ICIs is considered to be safe and effective in advanced cancer patients with hepatitis B or C infection, but still has possibilities to reactive hepatitis virus due to uncertain mechanisms. We recommend that those with viral hepatitis be monitored closely and treated with antiviral therapy if indicated before or during ICIs treatment.

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.

Persistence of hepatitis B surface antibody and immune memory to hepatitis B vaccine among medical college students in Madinah

BACKGROUND

Globally, about 300 million people are infected with hepatitis B virus (HBV). Among the effective approaches to fight HBV infection is immunization. In 1989, an obligatory hepatitis B vaccine program was launched in Saudi Arabia.

OBJECTIVE

Assess hepatitis B surface antibody (anti-HBs) levels among the medical students before and after receiving booster doses of HBV vaccine.

DESIGN

Cross-sectional.

SETTING

Taibah University.

SUBJECTS AND METHODS

Students born between 1993 and 1995 were recruited in this study from the Occupational Health Clinic. Students were screened for anti-HBs levels using chemiluminescent microparticle immunoassay (CMIA) before and after booster HBV vaccine doses.

MAIN OUTCOME MEASURES

Anti-HBs levels before and after booster doses.

SAMPLE SIZE

335.

RESULTS

About half of participants (n=164, 49%) had protective anti-HBs levels ( greater than or equal 10 mIU/mL) to the original primary series of HBV vaccine and received no booster doses. The reimaining 171 (51%) participants were at risk of HBV infection since their anti-HBs levels were less than 10 mIU/mL, despite having received the original primary HBV vaccine. The levels of anti-HBs were higher in female than in male students (P less than .001). In addition, female students showed a stronger humoral immune response to the booster vaccine than male students (P less than .001). When participants were given the three boosters, most participants (98.3%) showed anti-HBs levels of greater than or equal 10 mIU/mL. The results also showed a strong correlation between pre-booster and post-booster anti-HBs levels in the greater than or equal 10 mIU/mL group (r2= 0.52, P less than .001) but not in less than 10 mIU/mL group (r2= 0.003, P=.53).

CONCLUSION

A considerable portion of the participants (about 51%) were at risk of HBV infection since their anti-HBs levels were less than 10 mIU/mL. Booster doses significantly trigger memory immune response and this ensured their protection against the virus. Pre-booster anti-HBs level are a good predictive of post-booster anti-HBs levels in greater than or equal 10 mIU/mL group.

LIMITATIONS

The sample size was small. Shortage of collaborators.

CONFLICT OF INTEREST

None.

Risk of hepatitis B virus reactivation in hepatitis B virus + hepatitis C virus-co-infected patients with compensated liver cirrhosis treated with ombitasvir, paritaprevir/r + dasabuvir + ribavirin

Hepatitis B virus may reactivate in patients with chronic hepatitis C treated with direct-acting antivirals. The aim of this study was to investigate the risk of hepatitis B virus (HBV) reactivation in HBV + hepatitis C virus (HCV)-co-infected patients with compensated liver cirrhosis treated with paritaprevir/ombitasvir/ritonavir, dasabuvir with ribavirin. We reviewed prospectively gathered data from a national cohort of 2070 hepatitis C virus patients with compensated liver cirrhosis who received reimbursed paritaprevir/ombitasvir/r, dasabuvir with ribavirin for 12 weeks from the Romanian National Health Agency during 2015-2016. Twenty-five patients in this cohort were HBs antigen positive (1.2%); 15 untreated with nucleotide analogues agreed to enter the study. These patients were followed up: ALT monthly, serology for HBV and DNA viral load at baseline, EOT and SVR at 12 weeks. Hepatitis B virus (HBV)-co-infected patients were all genotype 1b and 52% females, with a median age of 60 years (51 ÷ 74); 76% were pretreated with peginterferon + ribavirin; 72% were with severe necroinflammatory activity on FibroMax assessment; 40% presented comorbidities; and all were HBe antigen negative. Hepatitis C virus (HCV) SVR response rate was 100%. Hepatitis B virus (HBV)-DNA viral load was undetectable in 7/15 (47%) before therapy, and for the other 8 patients, it varied between below 20 and 867 IU/mL. Five patients (33%) presented virological reactivation (>2 log increase in HBV-DNA levels) during therapy. One patient presented with hepatitis associated with HBV reactivation, and two started anti-HBV therapy with entecavir. Hepatitis B virus (HBV) virological reactivation was present in 33% in our patients. Generally, HBV-DNA elevations were mild (<20 000 IU/mL); however, we report one case of hepatitis associated with HBV reactivation.

Hepatitis A to E: what's new?

Viral hepatitis contributes to significant morbidity and mortality worldwide. While acute infection may be self-limiting, unrecognised chronic infection and under-utilisation of guideline-based approaches to therapy contribute to increasing rates of cirrhosis, hepatocellular carcinoma and death. Our aim was to review the current evidence for screening, diagnosis and treatment in hepatitis A to E. Evidence for this review was sourced from international and Australian guidelines and high-quality clinical trials. MEDLINE was searched using structured key word strategy and retrieved articles were reviewed methodically to inform a brief and up-to-date synopsis of hepatitis A to E. We share some of the recent developments in viral hepatitis, specifically the new therapies for hepatitis C. Direct-acting antiviral therapies are safe, well-tolerated and effective. Subsidies allow access for all Australians with most strains of hepatitis C. We outline evidence underpinning efficacy and safety of treatment for hepatitis B, while clarifying some of the nuances in the setting of pregnancy and immunosuppression. We provide a simplified concept to facilitate understanding of the five phases of hepatitis B; practical for real-world setting. Hepatitis A to E is a broad topic, not all aspects of these viruses can be covered in this short review. We provided suggestions for evidence based guidelines, which are a suitable supplement to this article.

Epigenetic regulation of hepatitis B virus covalently closed circular DNA: Implications for epigenetic therapy against chronic hepatitis B

Hepatitis B virus (HBV) infection represents a significant public health burden worldwide. Although current therapeutics manage to control the disease progression, lifelong treatment and surveillance are required because drug resistance develops during treatment and reactivations frequently occur following medication cessation. Thus, the occurrence of hepatocellular carcinoma is decreased, but not eliminated. One major reason for failure of HBV treatment is the inability to eradicate or inactivate the viral covalently closed circular DNA (cccDNA), which is a stable episomal form of the viral genome decorated with host histones and nonhistone proteins. Accumulating evidence suggests that epigenetic modifications of cccDNA contribute to viral replication and the outcome of chronic HBV infection. Here, we summarize current progress on HBV epigenetics research and the therapeutic implications for chronic HBV infection by learning from the epigenetic therapies for cancer and other viral diseases, which may open a new venue to cure chronic hepatitis B. (Hepatology 2017;66:2066-2077).

The HepTestContest: a global innovation contest to identify approaches to hepatitis B and C testing

BACKGROUND

Innovation contests are a novel approach to elicit good ideas and innovative practices in various areas of public health. There remains limited published literature on approaches to deliver hepatitis testing. The purpose of this innovation contest was to identify examples of different hepatitis B and C approaches to support countries in their scale-up of hepatitis testing and to supplement development of formal recommendations on service delivery in the 2017 World Health Organization hepatitis B and C testing guidelines.

METHODS

This contest involved four steps: 1) establishment of a multisectoral steering committee to coordinate a call for contest entries; 2) dissemination of the call for entries through diverse media (Facebook, Twitter, YouTube, email listservs, academic journals); 3) independent ranking of submissions by a panel of judges according to pre-specified criteria (clarity of testing model, innovation, effectiveness, next steps) using a 1-10 scale; 4) recognition of highly ranked entries through presentation at international conferences, commendation certificate, and inclusion as a case study in the WHO 2017 testing guidelines.

RESULTS

The innovation contest received 64 entries from 27 countries and took a total of 4 months to complete. Sixteen entries were directly included in the WHO testing guidelines. The entries covered testing in different populations, including primary care patients (n = 5), people who inject drugs (PWID) (n = 4), pregnant women (n = 4), general populations (n = 4), high-risk groups (n = 3), relatives of people living with hepatitis B and C (n = 2), migrants (n = 2), incarcerated individuals (n = 2), workers (n = 2), and emergency department patients (n = 2). A variety of different testing delivery approaches were employed, including integrated HIV-hepatitis testing (n = 12); integrated testing with harm reduction and addiction services (n = 9); use of electronic medical records to support targeted testing (n = 8); decentralization (n = 8); and task shifting (n = 7).

CONCLUSION

The global innovation contest identified a range of local hepatitis testing approaches that can be used to inform the development of testing strategies in different settings and populations. Further implementation and evaluation of different testing approaches is needed.

Synthesis of sulfamoylbenzamide derivatives as HBV capsid assembly effector

The synthesis of novel series of sulfamoylbenzamides as HBV capsid assembly effector is reported. The structure was divided into five parts which were independently modified as part of our lead optimization. All synthesized compounds were evaluated for their anti-HBV activity and toxicity in human hepatocytes, lymphocytes and other cells. Additionally, we assessed their effect on HBV cccDNA formation in an HBeAg reporter cell-based assay. Among the 27 compounds reported, several analogs exhibited submicromolar activities and significant reduction of HBeAg secretion. Selected compounds were studied under negative-stain electron microscopy for their ability to disrupt the HBV capsid formation. Structures were modeled into a binding site recently identified in the HBV capsid protein for similar molecules to rationalize the structure-activity relationships for this family of compounds.

Hepatitis B Surface Antigen Promotes the Invasion of Hepatitis B Virus-Related Hepatocellular Carcinoma Cells by Upregulation of Toll-Like Receptor 2

Hepatitis B virus (HBV) infection is one of the major risk factors leading to the development of hepatocellular carcinoma (HCC). Hepatitis B surface antigen (HBsAg) plays a pivotal role in HBV-related HCC pathogenesis, and Toll-like receptor (TLR) 2 is also considered to mediate tumor progression. However, the interaction between HBsAg and TLR2 in HCC progression remains unclear. Thus, the aim of the study was to explore the effect of HBsAg-TLR2 pathway on growth and invasion of HBV-related HCC cells and examine the potential mechanisms been involved. The expression of TLR2 was measured in two different HCC cell lines (HepG2 and HepG2.2.15) with or without recombinant HBsAg by real-time reverse polymerase chain reaction and Western blot. Cellular proliferation, invasion, cytokine productions, and downstream signaling pathways were also measured in TLR2-silencing HepG2.2.15 cells in response to HBsAg stimulation. The mRNA and protein levels of TLR2 were significantly elevated in HepG2.2.15 cells than those in HepG2 cells. HBsAg simulation increased proinflammatory cytokine production and invasion of HepG2.2.15 cells, while this process was inhibited by TLR2 silence. However, TLR2 siRNA transfection alone did not affect the bioactivities of tumor cells. Moreover, HBsAg increased expression of MyD88 and phosphorylation of NF-κB p50 and p38MAPK. Downregulation of TLR2 inhibited HBsAg-induced MyD88 and p-NF-κB, but not p-p38MAPK in HepG2.2.15 cells. In conclusion, HBsAg stimulation promotes the invasion of HBV-related HCC cells. TLR2/MyD88/NF-κB signaling pathway may be involved in this procession by upregulation of cytokine production. The interaction between TLR2 and HBsAg may contribute to the poor prognosis of HBV-related HCC.

Treatment of chronic hepatitis B infection-2017

Since the registration of the first effective nucleoside analogue against the hepatitis B virus almost two decades ago, major progress has been made in the management of chronic hepatitis B infection. However, hepatitis B-related morbidity and mortality remain a major global health threat. This is partly due to the escalating costs and the decrease in compliance related to the need for prolonged therapy for most patients who cannot be "cured". New biomarkers such as quantitative hepatitis B surface antigen might help to determine if hepatitis B e antigen negative patients can be taken off nucleos(t)ide analogues. On the other hand, novel compounds that target the viral life cycle or modulate host immune response are in the pipeline. In the next few years, one should expect breakthrough advancement to be made leading to a "cure" for patients with chronic hepatitis B infection by inducing hepatitis surface antigen loss with or without the development of the hepatitis B surface antibody. In addition, attention and necessary actions should also be taken in patients with hepatitis B infection who are being treated with immunosuppressive therapy and direct anti-viral (DAAs) agents for hepatitis C infection to prevent hepatitis from hepatitis B reactivation.

Toward Elimination of Hepatitis B Virus Using Novel Drugs, Approaches, and Combined Modalities

Hepatitis B virus (HBV) causes significant morbidity and mortality worldwide. The majority of chronically infected individuals do not achieve a functional and complete cure. Treated persons who achieve a long-term sustained virologic response (undetectable HBV DNA), are still at high risk of developing morbidity and mortality from liver complications. This review focuses on novel, mechanistically diverse anti-HBV therapeutic strategies currently in development or in clinical evaluation, and highlights new combination strategies that may contribute to full elimination of HBV DNA and covalently closed circular DNA from the infected liver, leading to a complete cure of chronic hepatitis B.

Notch Signaling Contributes to Liver Inflammation by Regulation of Interleukin-22-Producing Cells in Hepatitis B Virus Infection

The mechanism of hepatitis B virus (HBV) induced liver inflammation is not fully elucidated. Notch signaling augmented interleukin (IL)-22 secretion in CD4+ T cells, and Notch-IL-22 axis fine-tuned inflammatory response. We previously demonstrated a proinflammatory role of IL-22 in HBV infection. Thus, in this study, we analyzed the role of Notch in development of IL-22-producing cells in HBV infection by inhibition of Notch signaling using γ-secretase inhibitor DAPT in both hydrodynamic induced HBV-infected mouse model and in peripheral blood cells isolated from patients with HBV infection. mRNA expressions of Notch1 and Notch2 were significantly increased in livers and CD4+ T cells upon HBV infection. Inhibition of Notch signaling in vivo leaded to the reduction in NKp46+ innate lymphoid cells 22 (ILC22) and lymphoid tissue inducer 4 (LTi4) cells in the liver. This process was accompanied by downregulating the expressions of IL-22 and related proinflammatory cytokines and chemokines in the liver, as well as blocking the recruitment of antigen-non-specific inflammatory cells into the liver and subsequent liver injury, but did not affect HBV antigens production and IL-22 secretion in the serum. Furthermore, IL-22 production in HBV non-specific cultured CD4+ T cells, but not HBV-specific CD4+ T cells, was reduced in response to in vitro inhibition of Notch signaling. In conclusion, Notch siganling appears to be an important mediator of the liver inflammation by modulating hepatic ILC22. The potential proinflammatory effect of Notch-mediated ILC22 may be significant for the development of new therapeutic approaches for treatment of hepatitis B.

Hepatitis B virus inhibits apolipoprotein A5 expression through its core gene

Background

Hepatitis B virus (HBV) infection causes lipid metabolism disorders. Apolipoprotein A5 (ApoA5) is a new apolipoprotein family member that plays an important role in the regulation of lipid metabolism. The present study was to investigate the impact of HBV on ApoA5 expression and its regulatory mechanism.

Methods

Reverse transcription polymerase chain reaction (RT-PCR) and western blotting were used to measure ApoA5 mRNA and protein expression in HepG2 and HepG2.2.15 cells. Enzyme-linked immunosorbent assay (ELISA) was used to measure the serum ApoA5 levels in healthy individuals and HBV patients. HBV infectious clone pHBV1.3 or individual plasmids expressing the HBV genome was cotransfected with the ApoA5 promoter pGL3-Apo5-LUC plasmid into HepG2 cells to assess the luciferase activity. RT-PCR and western blotting methods were used to detect Apo5 mRNA and protein expression, respectively.

Results

The ApoA5 mRNA and protein expression levels were decreased in HepG2.2.15 cells compared with the control HepG2 cells. The serum ApoA5 levels were 196.4 ± 28.7 μg/L in the healthy individuals and 104.5 ± 18.3 μg/L in the HBV patients, statistical analysis showed that the ApoA5 levels were significantly lower in HBV patients than in the healthy individuals (P < 0.05). pHBV1.3 and its core gene inhibited ApoA5 promoter activity and mRNA and protein expression in HepG2 cells.

Conclusion

HBV inhibits ApoA5 expression at both the transcriptional and translational levels through its core gene.

Specific CD8+ T cell response immunotherapy for hepatocellular carcinoma and viral hepatitis

Hepatocellular carcinoma (HCC), chronic hepatitis B (CHB) and chronic hepatitis C (CHC) are characterized by exhaustion of the specific CD8⁺ T cell response. This process involves enhancement of negative co-stimulatory molecules, such as programmed cell death protein-1 (PD-1), cytotoxic T-lymphocyte antigen-4 (CTLA-4), 2B4, Tim-3, CD160 and LAG-3, which is linked to intrahepatic overexpression of some of the cognate ligands, such as PD-L1, on antigen presenting cells and thereby favouring a tolerogenic environment. Therapies that disrupt these negative signalling mechanisms represent promising therapeutic tools with the potential to restore reactivity of the specific CD8⁺ T cell response. In this review we discuss the impressive in vitro and in vivo results that have been recently achieved in HCC, CHB and CHC by blocking these negative receptors with monoclonal antibodies against these immune checkpoint modulators. The article mainly focuses on the role of CTLA-4 and PD-1 blocking monoclonal antibodies, the first ones to have reached clinical practice. The humanized monoclonal antibodies against CTLA-4 (tremelimumab and ipilimumab) and PD-1 (nivolumab and pembrolizumab) have yielded good results in testing of HCC and chronic viral hepatitis patients. Trelimumab, in particular, has shown a significant increase in the time to progression in HCC, while nivolumab has shown a remarkable effect on hepatitis C viral load reduction. The research on the role of ipilimumab, nivolumab and pembrolizumab on HCC is currently underway.