Hepatitis B therapy

Fighting fire with fire: using infectious agents to treat persistent infection

Infectious diseases lead to significant morbidity and mortality. Often, resolution of the acute stage of the disease leads to microbial persistence, resulting in chronic debilitating disease. Management of persistent infections frequently requires lifelong therapy with antimicrobial agents. These infections could be chronic viral infections like HIV, hepatitis B or chronic bacterial persistent infections like prosthetic joint infections caused by multi-drug resistant organisms. Bacteriophages have been designed specifically to target recalcitrant bacterial infections, such as prosthetic joint infections with varying success. In this review, we describe the historic evolution of scenarios and risks associated with innovative therapy using infectious agents to treat other persistent infections.

Entecavir vs. tenofovir disoproxil fumarate in the treatment of chronic hepatitis B patients with severe acute exacerbation

BACKGROUND

The efficacy of different nucleos(t)ide analogs in the treatment of chronic hepatitis B virus (CHB) with severe acute exacerbation (SAE) remained unclear. Thus, this study aimed to compare the short-term efficacy of tenofovir disoproxil fumarate (TDF) and entecavir (ETV) in patients having CHB with SAE.

METHODS

We analyzed consecutive patients with treatment-naive CHB receiving TDF (n = 36) or ETV (n = 65) for SAE. The primary endpoint was overall mortality or receipt of liver transplantation (LT) by 24 weeks. The secondary endpoints are the comparison of ETV vs. TDF influences on renal function and virological and biochemical responses at 4, 12, 24, and 48 weeks.

RESULTS

The baseline characteristics were comparable between the two groups. By 24 weeks, 8 (22%) patients in the TDF group and 10 (15%) patients in the ETV group had either died (n = 15) or received LT (n = 3) ( P  = 0.367). Cox-regression multivariate analysis revealed age ( P  = 0.003), baseline international normalized ratio of prothrombin time ( P  = 0.024), and early presence of hepatic encephalopathy ( P  = 0.003) as independent factors associated with mortality or LT. The two groups of patients achieved comparable biochemical and virological responses at 48 weeks. No significant difference was found in the estimated glomerular filtration rate (eGFR) between the TDF and the ETV groups. However, a significant reduction in the eGFR at 48 weeks, as compared with the baseline, was found in each group.

CONCLUSION

TDF and ETV achieved similar short-term clinical outcomes and treatment responses in CHB patients with SAE.

Integrated network pharmacology and metabolomics to study the potential mechanism of Jiawei Yinchenhao decoction in chronic hepatitis B

Chronic hepatitis B infection (CHB) is a major risk factor for the development of hepatocellular carcinoma (HCC) globally and continues to pose a significant global health challenge. Jiawei Yinchenhao decoction (JWYCH) is a modified version of Yinchenhao decoction (YCHD), which is widely used to treat liver diseases including icteric hepatitis, cholelithiasis, and hepatic ascites. However, the effectiveness and underlying mechanism of JWYCH on CHB are still unclear. This study aimed to investigate the impact of JWYCH on CHB and explore the underlying mechanism via network pharmacology and metabolomics. C57BL/6 mice were administered rAAV-HBV1.3 via hydrodynamic injection (HDI) to establish the CHB model. The infected mice were orally administered JWYCH for 4 weeks. HBsAg, HBeAg, HBV DNA, the serum liver function index, and histopathology were detected. In addition, network pharmacology was used to investigate potential targets, whereas untargeted metabolomics analysis was employed to explore the hepatic metabolic changes in JWYCH in CHB mice and identify relevant biomarkers and metabolic pathways. JWYCH was able to reduce HBeAg levels and improve liver pathological changes in mice with CHB. Additionally, metabolomics analysis indicated that JWYCH can influence 105 metabolites, including pipecolic acid, alpha-terpinene, adenosine, and L-phenylalanine, among others. Bile acid metabolism, arachidonic acid metabolism, and retinol metabolism are suggested to be potential targets of JWYCH in CHB. In conclusion, JWYCH demonstrated a hepatoprotective effect on a mouse model of CHB, suggesting a potential alternative therapeutic strategy for CHB. The effect of JWYCH is associated mainly with regulating the metabolism of bile acid, arachidonic acid, and retinol. These differentially abundant metabolites may serve as potential biomarkers and therapeutic targets for CHB.

Development of benzimidazole-based compounds as novel capsid assembly modulators for the treatment of HBV infection

Hepatitis B virus (HBV) capsid assembly modulators (CAMs) represent a promising therapeutic approach for the treatment of HBV infection. In this study, the hit compound CDI (IC50 = 2.46 ± 0.33 μM) was identified by screening of an in-house compound library. And then novel potent benzimidazole derivatives were designed and synthesized as core assembly modulators, and their antiviral effects were evaluated in vitro and in vivo biological experiments. The results indicated that compound 26f displayed the most optimized modulator of HBV capsid assembly (IC50 = 0.51 ± 0.20 μM, EC50 = 2.24 ± 0.43 μM, CC50 = 84.29 μM) and high selectivity index. Moreover, treatment with compound 26f for 14 days significantly decreased serum levels of HBV DNA levels in the Hydrodynamic-Injection (HDI) mouse model. Therefore, compound 26f could be considered as a promising candidate drug for further development of novel HBV CAMs with the desired potency and safety.

A glycoengineered therapeutic anti-HBV antibody that allows increased HBsAg immunoclearance improves HBV suppression in vivo

Introduction: The effective and persistent suppression of hepatitis B surface antigen (HBsAg) in patients with chronic HBV infection (CHB) is considered to be a promising approach to achieve a functional cure of hepatitis B. In our previous study, we found that the antibody E6F6 can clear HBsAg through FcγR-mediated phagocytosis, and its humanized form (huE6F6 antibody) is expected to be a new tool for the treatment of CHB. Previous studies have shown that the glycosylation of Fc segments affects the binding of antibodies to FcγR and thus affects the biological activity of antibodies in vivo. Methods: To further improve the therapeutic potential of huE6F6, in this study, we defucosylated huE6F6 (huE6F6-fuc-), preliminarily explored the developability of this molecule, and studied the therapeutic potential of this molecule and its underlying mechanism in vitro and in vivo models. Results: huE6F6-fuc- has desirable physicochemical properties. Compared with huE6F6-wt, huE6F6-fuc- administration resulted in a stronger viral clearance in vivo. Meanwhile, huE6F6-fuc- keep a similar neutralization activity and binding activity to huE6F6-wt in vitro. Immunological analyses suggested that huE6F6-fuc- exhibited enhanced binding to hCD32b and hCD16b, which mainly contributed to its enhanced therapeutic activity in vivo. Conclusions: In summary, the huE6F6-fuc- molecule that was developed in this study, which has desirable developability, can clear HBsAg more efficiently in vivo, providing a promising treatment for CHB patients. Our study provides new guidance for antibody engineering in other disease fields.

Antiviral Evaluation of Dispirotripiperazines against Hepatitis B Virus

Hepatitis B virus (HBV) is a hepatotropic DNA virus that replicates by reverse transcription. It chronically infects >296 million people worldwide, including ∼850,000 in the USA, and kills 820,000 annually worldwide. Current nucleos(t)ide analogue (NA) or pegylated interferon α therapies do not eradicate the virus and would benefit from a complementary antiviral drug. We performed a preliminary screen of 28 dispirotripiperazines against HBV, identifying 9 hits with EC50 of 0.7-25 μM. Compound 11826096 displays the most potent activity and represents a promising lead for future optimization. While the mechanism of action is unknown, preliminary assays limit possible targets to activities involved in RNA accumulation, translation, capsid assembly, and/or capsid stability. In addition, we built machine learning models to determine if they were able to predict the activity of this series of compounds. The novelty of these molecules indicated they were outside of the applicability domain of these models.

The peroxisome proliferator-activated receptor γ coactivator-1 alpha rs8192678 (Gly482Ser) variant and hepatitis B virus clearance

BACKGROUND

Chronic hepatitis B virus (CHB) infection is still incurable a major public health problem. It is yet unclear how host genetic factors influence the development of HBV infection. The peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) has been shown to regulate hepatitis B virus (HBV). Several reports found that PPARGC1A variants are involved in a number of distinct liver diseases. Here we investigate whether the PPARGC1A rs8192678 (Gly482Ser) variant is involved in the spontaneous clearance of acute HBV infection and if it participates in chronic disease progression in Moroccan patients.

METHODS

Our study included 292 chronic hepatitis B (CHB) patients and 181 individuals who spontaneously cleared-HBV infection. We genotyped the rs8192678 SNP using a TaqMan allelic discrimination assay and then explored its association with spontaneous HBV clearance and CHB progression.

RESULTS

Our data showed that individuals carrying CT and TT genotypes were more likely to achieve spontaneous clearance (OR = 0.48, 95% CI (0.32-0.73), p = 0.00047; OR = 0.28, 95% CI (0.15-0.53), p = 0.00005, respectively). Subjects carrying the mutant allele T were more likely to achieve spontaneous clearance (OR = 0.51, 95% CI (0.38-0.67), P = 2.68E-06). However, when we investigated the impact of rs8192678 on the progression of liver diseases, we neither observe any influence (p > 0.05) nor found any significant association between ALT, AST, HBV viral loads, and the PPARGC1A rs8192678 genotypes in patients with CHB (p > 0.05).

CONCLUSION

Our result suggests that PPARGC1A rs8192678 may modulate acute HBV infection, and could therefore represent a potential predictive marker in the Moroccan population.

An HBV susceptibility variant of KNG1 modulates the therapeutic effects of interferons α and λ1 in HBV infection by promoting MAVS lysosomal degradation

BACKGROUND

Hepatitis B virus (HBV) infection is one of the main causes of hepatocellular carcinoma (HCC). The relationship between HBV infection and the host genome as well as their underlying mechanisms remain largely unknown.

METHODS

In this study, we performed a whole-genome exon sequencing analysis of 300 sib-pairs of Chinese HBV-infected families with the goal of identifying variants and genes involved in HBV infection. A site-direct mutant plasmid was used to investigate the function of SNP rs76438938 in KNG1. The functional and mechanical studies of KNG1 were conducted with in vitro liver cell lines and a hydrodynamic injection model in vivo. The impact of KNG1 on HBV infection therapy was determined in hepatocytes treated with IFN-α/λ1.

FINDINGS

Our whole-exon association study of 300 families with hepatitis B infection found that SNP rs76438938 in KNG1 significantly increased the risk for HBV infection, and the rs76438938-T allele was found to promote HBV replication by increasing the stability of KNG1 mRNA. By competitively binding HSP90A with MAVS, KNG1 can inhibit the expression of types I and III IFNs by promoting MAVS lysosomal degradation. Such suppression of IFN expression and promotion of HBV replication by Kng1 were further demonstrated with an animal model in vivo. Lastly, we showed that the rs76438938-C allele can improve the therapeutic effect of IFN-α and -λ1 in HBV infection.

INTERPRETATION

This study identified a SNP, rs76438938, in a newly discovered host gene, KNG1, for its involvement in HBV infection and treatment effect through modulating the cellular antiviral process.

FUNDING

This study was supported in part by the Independent Task of State Key Laboratory for Diagnosis and Treatment of Infectious Diseases of the First Affiliated Hospital of Zhejiang University, the China Precision Medicine Initiative (2016YFC0906300), and the Research Center for Air Pollution and Health of Zhejiang University.

HBV-associated DLBCL of poor prognosis: advance in pathogenesis, immunity and therapy

Advanced studies have shown a biological correlation between hepatitis B virus (HBV) and B-cell lymphoma, especially diffuse large B-cell lymphoma (DLBCL). Patients with DLBCL infected with HBV (HBV-associated DLBCL) are clinically characterized by an advanced clinical stage, poor response to front-line immunochemotherapy regimens, and worse clinical prognosis. HBV-associated DLBCL often exhibits abnormal activation of the nuclear factor kappa B pathway as well as mutations in oncogenes, including Myc and BCL-6. Currently, there is no consensus on any specific and effective treatment for HBV-associated DLBCL. Therefore, in this review, we comprehensively and mechanistically analyzed the natural history of HBV infection and immunity, including HBV-mediated oncogenes, immune escape, epigenetic alterations, dysregulated signaling pathways, and potential therapeutic approaches for HBV-associated DLBCL. We hope that an improved understanding of the biology of HBV-associated DLBCL would lead to the development of novel therapeutic approaches, enhance the number of effective clinical trials, and improve the prognosis of this disease.

Randomized Trial of Tenofovir With or Without Peginterferon Alfa Followed by Protocolized Treatment Withdrawal in Adults With Chronic Hepatitis B

INTRODUCTION

Hepatitis B surface antigen (HBsAg) loss is associated with improved long-term outcomes of patients with chronic hepatitis B but is infrequently achieved with current monotherapies. We assessed whether combination strategies that included treatment withdrawal enhanced HBsAg loss.

METHODS

A randomized (1:1) trial of tenofovir disoproxil fumarate (TDF) for 192 weeks with or without peginterferon (PegIFN) alfa-2a for the first 24 weeks, followed by withdrawal of TDF at week 192 with 48 weeks of off-treatment follow-up to week 240. The primary end point was HBsAg loss at week 240.

RESULTS

Of 201 participants (52% HBeAg positive, 12%/6% genotype A/A2, 7% cirrhosis) randomized to TDF + PegIFN (n = 102) or TDF alone (n = 99), 6 participants had lost HBsAg at the end of the treatment phase (week 192), 5 (5.3%) in the combination group, and 1 (1.0%) in the TDF alone group ( P = 0.09). By week 240, 9 participants had cleared HBsAg, 5.3% in combination, and 4.1% in monotherapy arms ( P = 0.73). HBsAg decline and loss occurred earlier with TDF + PegIFN than TDF, with a ≥1-logIU/mL qHBsAg decline by week 24 in 28% in TDF + PegIFN compared with 6% in TDF ( P = 0.04). HBsAg loss occurred in 7 of 12 (58%) with hepatitis B virus subgenotype A2 (all HBeAg positive) compared with only 2 of 189 (1%) with other hepatitis B virus genotypes and in 8 of 93 (8.6%) HBeAg positive vs 1 of 87 (1.1%) HBeAg negative.

DISCUSSION

PegIFN combined TDF followed by protocolized TDF withdrawal led to earlier but not higher percentages of HBsAg clearance. Pretreatment HBeAg positivity and subgenotype A2 were strongly associated with HBsAg clearance.

Characterization of a Novel Capsid Assembly Modulator for the Treatment of Chronic Hepatitis B Virus Infection

The standard of care for the treatment of chronic hepatitis B (CHB) is typically lifelong treatment with nucleos(t)ide analogs (NAs), which suppress viral replication and provide long-term clinical benefits. However, infectious virus can still be detected in patients who are virally suppressed on NA therapy, which may contribute to the failure of these agents to cure most CHB patients. Accordingly, new antiviral treatment options are being developed to enhance the suppression of hepatitis B virus (HBV) replication in combination with NAs ("antiviral intensification"). Here, we describe GS-SBA-1, a capsid assembly modulator (CAM) belonging to class CAM-E, that demonstrates potent inhibition of extracellular HBV DNA in vitro (EC50 [50% effective concentration] = 19 nM) in HBV-infected primary human hepatocytes (PHHs) as well as in vivo in an HBV-infected immunodeficient mouse model. GS-SBA-1 has comparable activities across HBV genotypes and nucleos(t)ide-resistant mutants in HBV-infected PHHs. In addition, GS-SBA-1 demonstrated in vitro additivity in combination with tenofovir alafenamide (TAF). The administration of GS-SBA-1 to PHHs at the time of infection prevents covalently closed circular DNA (cccDNA) formation and, hence, decreases HBV RNA and antigen levels (EC50 = 80 to 200 nM). Furthermore, GS-SBA-1 prevents the production of extracellular HBV RNA-containing viral particles in vitro. Collectively, these data demonstrate that GS-SBA-1 is a potent CAM that has the potential to enhance viral suppression in combination with an NA.

A Phase 2 open label study of ledipasvir/sofosbuvir for 12 weeks in subjects with hepatitis B virus infection

Retrospective data showed that when we administered ledipasvir/sofosbuvir (LDV/SOF) to patients with hepatitis B and C coinfection, there was a modest reduction in hepatitis B surface antigen (HBsAg). Therefore, we hypothesize that similar HBsAg reduction can be seen in hepatitis B virus (HBV) monoinfected subjects. Primary and secondary efficacy endpoints are the decline in HBsAg and HBV DNA at Week 12 from baseline, respectively. We conducted an open-label Phase 2 pilot study to evaluate the safety, tolerability, and antiviral activity of LDV and/or SOF for HBV. Eligible subjects were either suppressed on antivirals (Group B) or inactive chronic HBV (Group A, C, D). Group A and B received LDV/SOF. Group C and D received SOF 400 mg and LDV 90 mg, respectively. All subjects completed the study, and all related adverse events (AEs) were mild. No discontinuations due to AEs or hepatitis flare occurred. At Week 12, HBsAg decline (log₁₀ IU/ml) was similar between Group A (0.399) and B (0.400), less in Group C (0.207), and none in Group D, and there was HBV DNA decline in the inactive chronic HBV groups. LDV and SOF are safe and well tolerated when given to chronic hepatitis B subjects and have modest antiviral activity, particularly when given in combination.

Characterization of a KDM5 small molecule inhibitor with antiviral activity against hepatitis B virus

Chronic hepatitis B (CHB) is a global health care challenge and a major cause of liver disease. To find new therapeutic avenues with a potential to functionally cure chronic Hepatitis B virus (HBV) infection, we performed a focused screen of epigenetic modifiers to identify potential inhibitors of replication or gene expression. From this work we identified isonicotinic acid inhibitors of the histone lysine demethylase 5 (KDM5) with potent anti-HBV activity. To enhance the cellular permeability and liver accumulation of the most potent KDM5 inhibitor identified (GS-080) an ester prodrug was developed (GS-5801) that resulted in improved bioavailability and liver exposure as well as an increased H3K4me3:H3 ratio on chromatin. GS-5801 treatment of HBV-infected primary human hepatocytes reduced the levels of HBV RNA, DNA and antigen. Evaluation of GS-5801 antiviral activity in a humanized mouse model of HBV infection, however, did not result in antiviral efficacy, despite achieving pharmacodynamic levels of H3K4me3:H3 predicted to be efficacious from the in vitro model. Here we discuss potential reasons for the disconnect between in vitro and in vivo efficacy, which highlight the translational difficulties of epigenetic targets for viral diseases.

Innate Immunity, Inflammation, and Intervention in HBV Infection

Hepatitis B virus (HBV) infection is still one of the most dangerous viral illnesses. HBV infects around 257 million individuals worldwide. Hepatitis B in many individuals ultimately develops hepatocellular carcinoma (HCC), which is the sixth most common cancer and the third leading cause of cancer-related deaths worldwide. The innate immunity acts as the first line of defense against HBV infection through activating antiviral genes. Along with the immune responses, pro-inflammatory cytokines are triggered to enhance the antiviral responses, but this may result in acute or chronic liver inflammation, especially when the clearance of virus is unsuccessful. To a degree, the host innate immune and inflammatory responses dominate the HBV infection and liver pathogenesis. Thus, it is crucial to figure out the signaling pathways involved in the activation of antiviral factors and inflammatory cytokines. Here, we review the interplay between HBV and the signal pathways that mediates innate immune responses and inflammation. In addition, we summarize current therapeutic strategies for HBV infection via modulating innate immunity or inflammation. Characterizing the mechanisms that underlie these HBV-host interplays might provide new approaches for the cure of chronic HBV infection.

Viral hepatitis in pregnancy

Viral hepatitis is caused by a heterogenous group of viral agents representing a wide range of phylogenetic groups. Many viruses can involve the liver and cause liver injury but only a subset are delineated as 'hepatitis viruses' based upon their primary site of replication and tropism for hepatocytes which make up the bulk of the liver cell population. Since their discovery, beginning with the agent that caused serum hepatitis in the 1960s, the alphabetic designations have been utilized. To date, we have five hepatitis viruses, A through E, though it is postulated that others may exist. This chapter will focus on those viruses. Note that hepatitis D is included as a subset of hepatitis B, as it cannot exist without concurrent hepatitis B infection. Pregnancy has the potential to affect all aspects of these viral agents due to the unique immunologic and physiologic changes that occur during and after the gestational period. In this review, we will discuss the most common viral hepatitis and their effects during pregnancy.

Hepatitis B x (HBx) as a Component of a Functional Cure for Chronic Hepatitis B

Patients who are carriers of the hepatitis B virus (HBV) are at high risk of chronic liver disease (CLD) which proceeds from hepatitis, to fibrosis, cirrhosis and to hepatocellular carcinoma (HCC). The hepatitis B-encoded X antigen, HBx, promotes virus gene expression and replication, protects infected hepatocytes from immunological destruction, and promotes the development of CLD and HCC. For virus replication, HBx regulates covalently closed circular (ccc) HBV DNA transcription, while for CLD, HBx triggers cellular oxidative stress, in part, by triggering mitochondrial damage that stimulates innate immunity. Constitutive activation of NF-κB by HBx transcriptionally activates pro-inflammatory genes, resulting in hepatocellular destruction, regeneration, and increased integration of the HBx gene into the host genome. NF-κB is also hepatoprotective, which sustains the survival of infected cells. Multiple therapeutic approaches include direct-acting anti-viral compounds and immune-stimulating drugs, but functional cures were not achieved, in part, because none were yet devised to target HBx. In addition, many patients with cirrhosis or HCC have little or no virus replication, but continue to express HBx from integrated templates, suggesting that HBx contributes to the pathogenesis of CLD. Blocking HBx activity will, therefore, impact multiple aspects of the host–virus relationship that are relevant to achieving a functional cure.

Discovery of Novel cccDNA Reducers toward the Cure of Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection is a worldwide disease that causes thousands of deaths per year. Currently, there is no therapeutic that can completely cure already infected HBV patients due to the inability of humans to eliminate covalently closed circular DNA (cccDNA), which serves as the template to (re)initiate an infection even after prolonged viral suppression. Through phenotypic screening, we discovered xanthone series hits as novel HBV cccDNA reducers, and subsequent structure optimization led to the identification of a lead compound with improved antiviral activity and pharmacokinetic profiles. A representative compound 59 demonstrated good potency and oral bioavailability with no cellular toxicity. In an HBVcircle mouse model, compound 59 showed excellent efficacy in significantly reducing HBV antigens, DNA, and intrahepatic cccDNA levels.

Evaluation of HBsAg Seroclearance in Patients with Hepatitis B

Objective

Hepatitis B surface antigen (HBsAg) seroclearance/seroconversion is regarded as an indicator of the ultimate immune control of hepatitis B virus (HBV) infections. HBsAg loss is the most important endpoint, as it shows deep suppression of HBV replication and viral protein expression. This study was aimed to retrospectively evaluate the HBsAg seroclearance/seroconversion status in patients with acute or chronic hepatitis B (CHB) diagnosis.

Materials and methods

Patients diagnosed with acute or CHB at the Harran University Faculty of Medicine Department of Gastroenterology between January 2012 and December 2020 were included in this study. This study was designed as a retrospective historical cohort. Experimental analysis of the data was done with the help of the SPSS version 22.0 package program.

Results

Of 1,053 patients with positive HBsAg, 854 patients with sufficient data in their files were included in this study. There were 494 (57.8%) males and 360 (42.2%) females; the mean age was 42.71 ± 14.31 (range 18-88). The mean duration of illness was 86.13 ± 72.92 months. In the 9-year follow-up of 854 patients, 65 (7.9%) of the last HBsAg test were negative and seroclearance had developed. The last anti-HBs test was positive in 49 (75.4%) of 65 patients who developed seroclearance, and it was found that seroconversion had developed. Twenty-seven of 30 (90%) of the patients who developed seroclearance had liver transplantation. Sixteen of 19 (84.2%) of them had acute hepatitis B, 14 of 477 (2.9%) were hepatitis carriers, 5 of 201 (2.5%) had e-negative CHB, 2 of 36 (5.6%) had cirrhosis, and 1 of 43 (2.3%) of them were delta hepatitis who developed seroclearance disease; none of the 38 e-positive CHB patients developed seroclearance.

Conclusion

In the 9-year follow-up of patients who were positive for HBsAg at their first admission, approximately one-tenth (7.9%) developed seroclearance, and two-thirds also developed seroconversion. After liver transplantation and acute hepatitis B, almost all patients developed seroclearance, whereas, in approximately 3% of carriers (e-negative CHB and cirrhotic patients) seroclearance developed.

How to cite this article

Taşkın MC, Uyanikoglu A, Cindoglu C. Evaluation of HBsAg Seroclearance in Patients with Hepatitis B. Euroasian J Hepato-Gastroenterol 2022;12(2):65-68.

Tale of Viruses in Male Infertility

Male infertility is a condition where the males either become sterile or critically infertile. The World Health Organisation assessed that approximately 9% of the couple have fertility issues where the contribution of the male partner was estimated to be 50%. There are several factors that can amalgamate to give rise to male infertility. Among them are lifestyle factors, genetic factors and as well as several environmental factors. The causes of male infertility may be acquired, congenital or sometimes idiopathic. All these factors adversely affect the spermatogenesis process as well as they impart serious threats to male genital organs thus resulting in infertility. Viruses are submicroscopic pathogenic agents that rely on host for their replication and survival. They enter the host cell, hijack the host cell machinery to aid their own replication and exit the cell for a new round of infection. With the growing abundance of different types of viruses and the havoc they have stirred in the form of pandemics, it is very essential to decipher their route of entry inside the human body and understand their diverse functional roles in order to combat them. In this chapter, we will review how viruses invade the male genital system thus in turn leading to detrimental consequence on male fertility. We will discuss the tropism of various viruses in the male genital organs and explore their sexual transmissibility. This chapter will summarise the functional and mechanistic approaches employed by the viruses in inducing oxidative stress inside spermatozoa thus leading to male infertility. Moreover, we will also highlight the various antiviral therapies that have been studied so far in order to ameliorate viral infection in order to combat the harmful consequences leading to male infertility.

Safety of Biologic Therapies in Patients with Moderate-to-Severe Plaque Psoriasis and Concomitant Viral Hepatitis: A Monocentric Retrospective Study

INTRODUCTION

There are no strong data regarding the treatment with biologics (especially for the most recent anti-IL-17 and anti-IL-23 drugs) of patients with psoriasis and concomitant viral hepatitis. We assessed the safety of biologic drugs in patients with psoriasis who are seropositive for hepatitis B or C and did not receive antiviral prophylaxis.

METHODS

We conducted a retrospective single-center study. The efficacy of biologic treatments was evaluated by assessing the Psoriasis Area and Severity Index (PASI) score during all visits, for a minimum follow-up of 52 weeks. All patients were evaluated by a hepatologist before starting the treatment. They were monitored for reactivation of viral hepatitis.

RESULTS

Twenty patients had positive markers of hepatitis B virus (HBV) or hepatitis C virus (HCV). Seventeen patients had positive markers of HBV infection, and four patients had antibodies for HCV (one patient had serologic evidence of both infections). Anti-IL-23 biologics were the most used in our population, with risankizumab being the most prescribed drug. No patient had evidence of viral reactivation during our study. Study limitations include its retrospective nature and our inclusion of patients with different serological status receiving different biologic drugs.

CONCLUSION

Biologic therapies (including anti-IL-23 drugs) appear to be safe in patients seropositive for HCV or HBV core antibody who did not receive antiviral prophylaxis.

Persistent Hepatitis B Viraemia with Polymerase Mutations among HIV/HBV Co-Infected Patients on HBV-Active ART in KwaZulu-Natal, South Africa

To understand the problem of persistent Hepatitis B virus (HBV) viraemia in HIV/HBV co-infected patients on HBV-active antiretroviral therapy (ART), we assessed the rate of HBV virological response in patients on HBV-active ART in KwaZulu-Natal, South Africa, and analysed factors associated with persistent HBV viraemia. One hundred and fifty eligible participants with a chronic HBV diagnosis, with or without HIV coinfection, were enrolled and followed up after 6 months. The HBV pol gene was sequenced by next-generation sequencing and mutations were determined using the Stanford HBVseq database. Logistic regression analysis was used to assess factors associated with HBV viraemia at 6-month follow-up. The mean duration of HBV-active ART was 24 months. Thirty-seven of one hundred and six (35%) participants receiving HBV-active ART for longer than 6 months had virological failure. Advanced immunosuppression with CD4+ cell counts <200 cells/μL was independently associated with persistent HBV viraemia, aOR 5.276 (95% CI 1.575−17.670) p = 0.007. A high proportion of patients on HBV-active ART are unsuppressed, which will ultimately have an impact on global elimination goals. Better monitoring should be implemented, especially in HIV-coinfected patients with low CD4+ cell counts and followed by early HBV drug-resistance testing.

The Role of Exosomes in Viral Hepatitis and Its Associated Liver Diseases

Exosomes, the important carriers between cells, can carry proteins, micro ribonucleic acids (miRNAs), long non-coding RNAs (lncRNAs) and other molecules to mediate cellular information transduction. They also play an important role in the pathogenesis, prognosis and treatment of viral hepatitis and its associated liver diseases. Several studies have reported that viral hepatitis and its associated liver diseases, including hepatitis A, B, C and E; hepatic fibrosis and hepatocellular carcinoma, were closely associated with exosomes. Exploring the role of exosomes in viral hepatitis and associated liver diseases will enhance our understanding of these diseases. Therefore, this review mainly summarised the role of exosomes in viral hepatitis and its associated liver diseases to identify new strategies for liver diseases in clinical practise.

The hepatitis B virus polymerase

Hepatitis B virus (HBV) is a hepatotropic, partially double-stranded DNA virus that replicates by reverse transcription and is a major cause of chronic liver disease and hepatocellular carcinoma. Reverse transcription is catalyzed by the four-domain multifunctional HBV polymerase (P) protein that has protein-priming, RNA- and DNA-dependent DNA synthesis (i.e., reverse transcriptase), and ribonuclease H activities. P also likely promotes the three strand transfers that occur during reverse transcription, and it may participate in immune evasion by HBV. Reverse transcription is primed by a tyrosine residue in the amino-terminal domain of P, and P remains covalently attached to the product DNA throughout reverse transcription. The reverse transcriptase activity of P is the target for the nucleos(t)ide analog drugs that dominate HBV treatment, and P is the target of ongoing efforts to develop new drugs against both the reverse transcriptase and ribonuclease H activities. Despite the unusual reverse transcription pathway catalyzed by P and the importance of P to HBV therapy, understanding the enzymology and structure of HBV P severely lags that of the retroviral reverse transcriptases due to substantial technical challenges to studying the enzyme. Obtaining a better understanding of P will broaden our appreciation of the diversity among reverse transcribing elements in nature, and will help improve treatment for people chronically infected with HBV.

T cell responses during HBV and HCV infections: similar but not quite the same?

The hepatitis B and C viruses persist by evasion of T cell immunity. Persistence depends upon premature failure of CD4+ T cell help and loss of CD8+ T cell control because of epitope mutational escape and/or functional exhaustion. Powerful new immunological and transcriptomic tools provide insight into the mechanisms of T cell silencing by HBV and HCV. Similarities are apparent, including dysregulated expression of common inhibitory/immune checkpoint receptors and transcription factors. There are also differences. T cell exhaustion is uniform in HCV infection, but varies in HBV infection depending on disease stage and/or protein target. Here, we review recent advances defining similarities and differences in T cell evasion by HBV and HCV, and the potential for reversal following antiviral therapy.

Ubiquitous expression of HBsAg from integrated HBV DNA in patients with low viral load

BACKGROUND & AIMS

Loss of serum HBsAg is a hallmark of spontaneous and therapy induced resolution of HBV infection, since it generally reflects a profound decrease in viral replication. However, integrated HBV DNA can contribute to HBsAg expression independent of viral replication. The relative contributions of these sources of HBsAg are not well understood. Specifically, it is not known whether actively transcribed HBV integration could spread throughout the entire liver.

METHODS

The relative distribution of HBsAg and HBV RNA in liver biopsy tissue from HBeAg-negative (HBe^-) patients was analyzed by immunohistochemistry and in situ hybridization (ISH), respectively. Frozen biopsy tissue was used for molecular analysis of intrahepatic viral RNA, virus-host chimeric transcripts and viral DNA.

RESULTS

Immunohistochemistry and ISH analysis revealed HBsAg and HBV RNA positivity in virtually all hepatocytes in the liver of some HBe^- patients despite very low viremia. Reverse transcription quantitative PCR and RNA-sequencing analysis confirmed high expression levels of HBV envelope-encoding RNAs. However, the amount of viral transcriptional template (covalently closed circular (ccc)DNA) was too low to support this ubiquitous HBV RNA expression. In contrast, levels of total cellular HBV DNA were consistent with ubiquitous HBV integration. Finally, RNA-sequencing revealed the presence of many HBV-host chimeric transcripts with the potential for HBsAg expression.

CONCLUSIONS

Transcriptionally active HBV integration can extend to the entire liver in some HBe^- patients. This can lead to ubiquitous HBsAg expression independent of HBV replication. In such patients, HBsAg is probably not a clinically useful surrogate marker for viral resolution or functional cure.

LAY SUMMARY

Loss of serum hepatitis B surface antigen (HBsAg) indicates resolution of HBV infection. However, integrated HBV DNA can contribute to HBsAg production independently of viral replication. We investigated the extent of HBsAg-producing viral integration in the livers of patients with low serum viral loads. Our findings suggest that transcriptionally active HBV integration can extend to the entire liver in some patients, questioning the clinical utility of HBsAg as a surrogate marker for viral replication.

Safety, Pharmacokinetics, and Pharmacodynamics of the Oral TLR8 Agonist Selgantolimod in Chronic Hepatitis B

BACKGROUND AND AIMS

In patients with chronic hepatitis B (CHB) infection, activation of toll-like receptor 8 may induce antiviral immunity and drive functional cure. Selgantolimod, a toll-like receptor 8 agonist, was evaluated in patients with CHB who were virally suppressed on oral antiviral treatment or viremic and not on oral antiviral treatment.

APPROACH AND RESULTS

In this phase 1b study, patients were randomized 4:1 to receive either selgantolimod or placebo once weekly. Virally suppressed patients received either 1.5 mg (for 2 weeks) or 3 mg (for 2 weeks or 4 weeks). Viremic patients received 3 mg for 2 weeks. The primary endpoint was safety, as assessed by adverse events (AEs), laboratory abnormalities, and vital sign examination. Pharmacokinetic and pharmacodynamic parameters were assessed by plasma analysis. A total of 38 patients (28 virally suppressed, 10 viremic) were enrolled from six sites in Australia, New Zealand, and South Korea. Twenty patients (53%) experienced an AE and 32 (84%) had laboratory abnormalities, all of which were mild or moderate in severity. The most common AEs were headache (32%), nausea (24%), and dizziness (13%). With a half-life of 5 hours, no accumulation of selgantolimod was observed with multiple dosing. Selgantolimod induced transient dose-dependent increases in serum cytokines, including IL-12p40 and IL-1RA, which are important for the expansion and activity of multiple T- cell subsets and innate immunity.

CONCLUSION

Selgantolimod was safe and well-tolerated in virally suppressed and viremic patients with CHB and elicited cytokine responses consistent with target engagement. Further studies with longer durations of selgantolimod treatment are required to evaluate efficacy.

Clearance of pegylated interferon by Kupffer cells limits NK cell activation and therapy response of patients with HBV infection

Pegylated interferon-α (PEG-IFN-α), where IFN-α is attached to polyethylene glycol (PEG), is an approved treatment for chronic hepatitis B virus (HBV) infection, a disease that causes liver-related morbidity and mortality in 257 million people worldwide. It is unknown why only a minority of patients respond to PEG-IFN-α. Using sequential blood samples and liver biopsies of patients with chronic HBV infection before, during, and after PEG-IFN-α treatment, we find that patients with early natural killer (NK) cell activation after PEG-IFN-α injection experienced greater liver inflammation, lysis of HBV-infected hepatocytes, and hepatitis B surface antigen (HBsAg) decline than those without. NK cell activation was associated with induction of interferon-stimulated genes and determined by PEG-IFN-α pharmacokinetics. Patients with delayed increases in PEG-IFN-α concentrations had greater amounts of PEG-specific immunoglobulin M (IgM) immune complexes in the blood and more PEG and IgM detected in the liver than patients with rapid increase in PEG-IFN-α concentration. This was associated with reduced NK cell activation. These results indicate that the immunomodulatory functions of PEG-IFN-α, particularly activation of NK cells, play a pivotal role in the response to treatment and further demonstrate that these functions are affected by PEG-IFN-α pharmacokinetics. Accelerated clearance of antibody-complexed pegylated drugs by Kupffer cells may be important beyond the field of HBV therapeutics. Thus, these findings may contribute to improving the efficacy of pegylated drugs that are now being developed for other chronic diseases and cancer.

Recent Advances in Hepatitis B Treatment

Hepatitis B virus infection affects over 250 million chronic carriers, causing more than 800,000 deaths annually, although a safe and effective vaccine is available. Currently used antiviral agents, pegylated interferon and nucleos(t)ide analogues, have major drawbacks and fail to completely eradicate the virus from infected cells. Thus, achieving a "functional cure" of the infection remains a real challenge. Recent findings concerning the viral replication cycle have led to development of novel therapeutic approaches including viral entry inhibitors, epigenetic control of cccDNA, immune modulators, RNA interference techniques, ribonuclease H inhibitors, and capsid assembly modulators. Promising preclinical results have been obtained, and the leading molecules under development have entered clinical evaluation. This review summarizes the key steps of the HBV life cycle, examines the currently approved anti-HBV drugs, and analyzes novel HBV treatment regimens.

Discovery of Novel Pyrimidine-Based Capsid Assembly Modulators as Potent Anti-HBV Agents

Core assembly modulators of viral capsid proteins have been developed as an effective treatment of chronic hepatitis B virus (HBV) infection. In this study, we synthesized novel potent pyrimidine derivatives as core assembly modulators, and their antiviral effects were evaluated in in vitro and in vivo biological experiments. One of the synthesized derivatives, compound 23h (R¹ = MeSO₂, R² = 1-piperidin-4-amine, R³ = 3-Cl-4-F-aniline) displayed potent inhibitory effects in the in vitro assays (52% inhibition in the protein-based assay at 100 nM and an IC₅₀ value of 181 nM in the serum HBV DNA quantification assay). Moreover, treatment with compound 23h for 5 weeks significantly decreased serum levels of HBV DNA levels (3.35 log reduction) in a human liver-chimeric uPA/SCID mouse model, and these effects were significantly increased when 23h was combined with tenofovir, a nucleotide analogue inhibitor of reverse transcriptase used for the treatment of HBV infection.

Intracellular interferon signalling pathways as potential regulators of covalently closed circular DNA in the treatment of chronic hepatitis B

Infection with the hepatitis B virus (HBV) is still a major global health threat as 250 million people worldwide continue to be chronically infected with the virus. While patients may be treated with nucleoside/nucleotide analogues, this only suppresses HBV titre to sub-detection levels without eliminating the persistent HBV covalently closed circular DNA (cccDNA) genome. As a result, HBV infection cannot be cured, and the virus reactivates when conditions are favorable. Interferons (IFNs) are cytokines known to induce powerful antiviral mechanisms that clear viruses from infected cells. They have been shown to induce cccDNA clearance, but their use in the treatment of HBV infection is limited as HBV-targeting immune cells are exhausted and HBV has evolved multiple mechanisms to evade and suppress IFN signalling. Thus, to fully utilize IFN-mediated intracellular mechanisms to effectively eliminate HBV, instead of direct IFN administration, novel strategies to sustain IFN-mediated anti-cccDNA and antiviral mechanisms need to be developed. This review will consolidate what is known about how IFNs act to achieve its intracellular antiviral effects and highlight the critical interferon-stimulated gene targets and effector mechanisms with potent anti-cccDNA functions. These include cccDNA degradation by APOBECs and cccDNA silencing and transcription repression by epigenetic modifications. In addition, the mechanisms that HBV employs to disrupt IFN signalling will be discussed. Drugs that have been developed or are in the pipeline for components of the IFN signalling pathway and HBV targets that detract IFN signalling mechanisms will also be identified and discussed for utility in the treatment of HBV infections. Together, these will provide useful insights into design strategies that specifically target cccDNA for the eradication of HBV.

Treatment with the Immunomodulator AIC649 in Combination with Entecavir Produces Antiviral Efficacy in the Woodchuck Model of Chronic Hepatitis B

As current interventions for chronic hepatitis B (CHB) rarely induce cure, more effective drugs are needed. Short-term treatment of woodchucks with the novel immunomodulator AIC649, a parapoxvirus-based stimulator of toll-like receptor 9 dependent and independent pathways, has been shown to reduce viral DNA and surface antigen via a unique, biphasic response pattern. The present study evaluated long-term AIC649 treatment in combination with Entecavir for potency and safety in woodchucks. AIC649 monotreatment induced modest reductions in serum viral DNA and surface and e antigens that were associated with the same biphasic response pattern previously observed. Entecavir monotreatment reduced transiently viremia but not antigenemia, while AIC649/Entecavir combination treatment mediated superior viral control. Undetectability of viral antigens and elicitation of antibodies in AIC649/Entecavir-treated woodchucks correlated with the expression of interferons and suppression of viral replication in liver. Combination treatment was well tolerated, and liver enzyme elevations were minor and transient. It was concluded that the AIC649-mediated effects were most likely based on an improvement and/or reconstitution of antiviral immune responses that are typically deficient in CHB. As a combination partner to Entecavir, the antiviral efficacy of AIC649 was markedly enhanced. This preclinical study supports future evaluation of AIC649 for treatment of human CHB.

Tenofovir Alafenamide Rescues Renal Tubules in Patients with Chronic Hepatitis B

Nucles(t)ide analogs (NAs) are effective for chronic hepatitis B (CHB). NAs suppress hepatic decompensation and hepatocarcinogenesis, leading to a dramatic improvement of the natural course of patients with CHB. However, renal dysfunction is becoming an important issue for the management of CHB. Renal dysfunction develops in patients with the long-term treatment of NAs including adefovir dipivoxil and tenofovir disoproxil fumarate. Recently, several studies have reported that the newly approved tenofovir alafenamide (TAF) has a safe profile for the kidney due to greater plasma stability. In this mini-review, we discuss the effectiveness of switching to TAF for NAs-related renal tubular dysfunction in patients with CHB.

The relationship between the clearance of HBsAg and the remodeling of B cell subsets in CHB patients treated with Peg-IFN-α

Background

The seroconversion of the hepatitis B antigen is the ideal outcome for long-acting interferon-pegylated interferon-α (Peg-IFN-α) treatment among patients with chronic hepatitis B (CHB). B-cell response plays an important role in the process of hepatitis B antigen clearance, but the specific mechanism by which B-cell improve hepatitis B virus (HBV) is still unclear.

Methods

A total of 103 CHB patients participated in this study. The patients received 24 weeks of Peg-IFN-α treatment. Flow cytometry was used to detect B-cell surface markers’ cluster of differentiation cluster of differentiation CD19, CD24, and CD27 in the peripheral blood mononuclear cells (PBMCs) of CHB patients before and after 24 weeks of Peg-IFN-α treatment.

Results

After 24 weeks of Peg-IFN-α treatment, the content of memory B cells (CD19⁺CD27⁺) and effector B cells (CD19⁺CD38⁺) increased significantly. Further analysis showed that the clearance of the hepatitis B antigen was correlated with the change value, ΔT, of plasma cells before and after treatment. The B-cell subsets (CD19⁺CD24⁺; CD19⁺CD40⁺; CD19⁺CD40⁺; CD19⁺CD80⁺), was also tested and the results showed that CD19⁺CD24⁺ and CD19⁺CD80⁺ content also increased significantly after treatment.

Conclusions

After Peg-IFN-α treatment, the B-cell subsets of CHB patients are remodeled. Thus, Peg-IFN-α treatment appears to play an important role in the remodeling of B cell subsets and the clearance of HBV antigens. The results of this study provide a theoretical basis and guidance for the clinical treatment of CHB.

Medicinal plants: Treasure for antiviral drug discovery

The pandemic of viral diseases like novel coronavirus (2019-nCoV) prompted the scientific world to examine antiviral bioactive compounds rather than nucleic acid analogous, protease inhibitors, or other toxic synthetic molecules. The emerging viral infections significantly associated with 2019-nCoV have challenged humanity's survival. Further, there is a constant emergence of new resistant viral strains that demand novel antiviral agents with fewer side effects and cell toxicity. Despite significant progress made in immunization and regenerative medicine, numerous viruses still lack prophylactic vaccines and specific antiviral treatments that are so often influenced by the generation of viral escape mutants. Of importance, medicinal herbs offer a wide variety of therapeutic antiviral chemotypes that can inhibit viral replication by preventing viral adsorption, adhering to cell receptors, inhibiting virus penetration in the host cell, and competing for pathways of activation of intracellular signals. The present review will comprehensively summarize the promising antiviral activities of medicinal plants and their bioactive molecules. Furthermore, it will elucidate their mechanism of action and possible implications in the treatment/prevention of viral diseases even when their mechanism of action is not fully understood, which could serve as the base for the future development of novel or complementary antiviral treatments.

Suppression of hepatitis B virus through therapeutic activation of RIG-I and IRF3 signaling in hepatocytes

Hepatitis B virus (HBV) mediates persistent infection, chronic hepatitis, and liver disease. HBV covalently closed circular (ccc)DNA is central to viral persistence such that its elimination is considered the cornerstone for HBV cure. Inefficient detection by pathogen recognition receptors (PRRs) in the infected hepatocyte facilitates HBV persistence via avoidance of innate immune activation and interferon regulatory factor (IRF)3 induction of antiviral gene expression. We evaluated a small molecule compound, F7, and 5'-triphosphate-poly-U/UC pathogen-associated-molecular-pattern (PAMP) RNA agonists of RIG-I, a PRR that signals innate immunity, for ability to suppress cccDNA. F7 and poly-U/UC PAMP treatment of HBV-infected cells induced RIG-I signaling of IRF3 activation to induce antiviral genes for suppression of cccDNA formation and accelerated decay of established cccDNA, and were additive to the actions of entecavir. Our study shows that activation of the RIG-I pathway and IRF3 to induce innate immune actions offers therapeutic benefit toward elimination of cccDNA.

Safety, pharmacokinetics and pharmacodynamics of TQ-A3334, an oral toll-like receptor 7 agonist in healthy individuals

BACKGROUND & AIMS

TQ-A3334, a selective, oral toll-like receptor (TLR)-7 agonist, is being developed to treat chronic hepatitis B (CHB). This study evaluated the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of TQ-A3334 in healthy participants.

RESEARCH DESIGN AND METHODS

The effects of a single-ascending dose of TQ-A3334 (0.2-1.8 mg) combined with food (1.2 mg) were evaluated in 48 healthy participants.

RESULTS

No serious adverse events or discontinuations occurred in the study. The most common adverse reactions were lymphocyte count decreased and headache, which were generally consistent with IFN-α exposure and the mechanism of action of a TLR7 agonist. TQ-A3334 was rapidly absorbed, with a time to maximum plasma concentration of 0.42-0.5 h. Systemic exposure (C_max and AUC) to TQ-A3334 increased with a slight saturation proportion to dose. Food reduced the exposure of TQ-A3334. The concentrations of MCP-1, ISG-15, MX-1, and OAS-1 were observed to be slightly dose-dependent, ranging from 1.0 to 1.8 mg TQ-A3334.

CONCLUSIONS

Oral doses of 0.2-1.8 mg appeared to be safe and tolerated. PD activity was seen at doses ranging from 1.0 to 1.8 mg, indicating its possible future use to treat CHB.

TRIAL REGISTRATION

The trial is registered at the Chinese Clinical Trial website (http://www.chinadrugtrials.org.cn/index.html # CTR20182248).

Antimicrobial Resistance and Antimicrobial Nanomaterials

Back in the mid-nineties, the discovery of antimicrobials denoted a profound and remarkable achievement in medicine which was capable of saving lives. However, recently, antimicrobial resistance became a major global issue facing modern medicine and significantly increased among bacteria, fungi, and viruses which results in reduced efficacy of many clinically important and lifesaving antimicrobials. The growing rise of antimicrobial resistance inflicts a remarkable economic and social burden on the health care system globally. The replacement of conventional antimicrobials by new technology to counteract and lessen antimicrobial resistance is currently ongoing. Nanotechnology is an advanced approach to overcome challenges of such resisted conventional drug delivery systems mainly based on the development and fabrication of nanoparticulate structures. Numerous forms of nanoparticulate systems have been discovered and tried as prospective drug delivery systems, comprising organic and inorganic nanoparticles.

Antimicrobial Resistance and Antimicrobial Nanomaterials

Back in the mid-nineties, the discovery of antimicrobials denoted a profound and remarkable achievement in medicine which was capable of saving lives. However, recently, antimicrobial resistance became a major global issue facing modern medicine and significantly increased among bacteria, fungi, and viruses which results in reduced efficacy of many clinically important and lifesaving antimicrobials. The growing rise of antimicrobial resistance inflicts a remarkable economic and social burden on the health care system globally. The replacement of conventional antimicrobials by new technology to counteract and lessen antimicrobial resistance is currently ongoing. Nanotechnology is an advanced approach to overcome challenges of such resisted conventional drug delivery systems mainly based on the development and fabrication of nanoparticulate structures. Numerous forms of nanoparticulate systems have been discovered and tried as prospective drug delivery systems, comprising organic and inorganic nanoparticles.

Short-term efficacy after switching from adefovir dipivoxil and tenofovir disoproxil fumarate therapy to tenofovir alaferamide for chronic hepatitis B

The aim of the present study was to evaluate the effects of switching to tenofovir alafenamide (TAF) in patients who had received a nucleos(t)ide analog (NA) for the treatment of chronic hepatitis B (CHB). The data from 33 Japanese patients with CHB who received TAF therapy after using NA [adefovir dipivoxil (ADV) and/or tenofovir disoproxil fumarate (TDF)] were retrospectively analyzed. Specifically, the biochemical and virological markers from the start of the TAF treatment to 6 months later were assessed. Comparative evaluation was performed by dividing patients into two groups: Long-term (n=19) and short-term administration groups (n=14), with a cutoff administration duration of 10 years. In all 33 patients, the levels of serum hepatitis B surface antigen (HBsAg; 1,126±1,724 to 1,001±1,591 IU/ml; P<0.0001), serum alkaline phosphatase (ALP) (320±126 to 283±124 U/l; P=0.028), serum bone specific alkaline phosphatase (19.7±9.0 to 17.7±8.0 µg/l; P=0.0006) and urine β2-microglobulin-creatinine ratio (U-BMG/Cr; 5,224±17,471 to 3,547±14,652 µg/g·Cre; P=0.002) significantly decreased from baseline after 6 months. Serum HBsAg, serum ALP and U-BMG/Cr showed a significant reduction in both groups. In conclusion, switching from ADV or TDF to TAF resulted in a decrease in serum HBsAg and improvement in serum ALP and U-BMG/Cr after 6 months of treatment in patients regardless of history of treatment with NA.

Repurposing of Antazoline Hydrochloride as an Inhibitor of Hepatitis B Virus DNA Secretion

Hepatitis B virus (HBV) belongs to Hepadnaviridae family and mainly infects hepatocytes, which can cause acute or chronic hepatitis. Currently, two types of antiviral drugs are approved for chronic infection clinically: interferons and nucleos(t)ide analogues. However, the clinical cure for chronic infection is still rare, and it is a huge challenge for all researchers to develop high-efficiency, safe, non-tolerant, and low-toxicity anti-HBV drugs. Antazoline hydrochloride is a first-generation antihistamine with anticholinergic properties, and it is commonly used to relieve nasal congestion and in eye drops. Recently, an in vitro high-throughput evaluation system was constructed to screen nearly 800 compounds from the Food and Drug Administration (FDA)-approved Drug Library. We found that arbidol hydrochloride and antazoline hydrochloride can effectively reduce HBV DNA in the extracellular supernatant in a dose-dependent manner, with EC₅₀ of 4.321 μmol/L and 2.910 μmol/L in HepAD38 cells, respectively. Moreover, the antiviral effects and potential mechanism of action of antazoline hydrochloride were studied in different HBV replication systems. The results indicate that antazoline hydrochloride also has a significant inhibitory effect on HBV DNA in the extracellular supernatant of Huh7 cells, with an EC₅₀ of 2.349 μmol/L. These findings provide new ideas for screening and research related to HBV agents.

Long-term virological and adherence outcomes to antiviral treatment in a 4-year cohort chronic HBV study

BACKGROUND

Chronic hepatitis B (CHB) treatment adherence has been poorly studied worldwide. We evaluated long-term virological and adherence outcomes to antiviral treatment in CHB patients.

METHODS

A prospective 183 Brazilian CHB patient cohort treated with monotherapy or combination adefovir dipivoxil, entecavir, lamivudine and/or tenofovir disoproxil fumarate was studied in a reference tertiary centre. Treatment adherence was evaluated by a validated questionnaire named 'Assessment of Adherence to Antiviral Therapy Questionnaire' (CEAT-HBV) within three yearly periods (2010/2011, 2013/2014 and 2014/2015).

RESULTS

CEAT-HBV identified 43% (79/183) patients with non-adherence to antiviral treatment and among them, 67% (53/79) were viral load positive. The main causes associated with non-response to antiviral treatment were drug resistance variants followed by non-adherence, insufficient treatment duration and other causes. Single-dose pharmacokinetics demonstrated 35% (23/65) antiviral non-adherence. 2 years after the first assessment, the CEAT-HBV indicated that 71% (101/143) of subjects adhered to treatment (per-protocol population). However, 21% (40/183) of the patients could not be evaluated and were excluded. The main reasons for exclusion were death (20/183), 11 out 20 deaths due to hepatocellular carcinoma. HBV booklet was used for medical education. The third CEAT-HBV assessment (2014/2015) showed that 83% (112/135) patients were compliant with treatment adherence (per-protocol population). Long-term evaluation showed that adherence rate based on CEAT-HBV continue to increase after 4-years (P<0.001).

CONCLUSIONS

The results highlight the importance of CHB therapy adherence assessment monitoring. Long-term adherence outcomes were dynamic and it is possible to increase the migration rate to adherence/HBV-DNA-negative group.

Serum hepatitis B core-related antigen predicts hepatocellular carcinoma in hepatitis B e antigen-negative patients

BACKGROUND

Hepatitis B core-related antigen (HBcrAg) is a novel serum viral marker. Recent studies showed that its level correlates with the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). We aimed to evaluate the accuracy of serum HBsAg and HBcrAg levels at baseline to predict HCC.

METHODS

1400 CHB patients who received nucleos(t)ide analogues (NA) treatment since December 2005 were included. Their stored serum samples at baseline were retrieved to measure HBsAg and HBcrAg levels. The primary endpoint was the cumulative incidence of HCC.

RESULTS

85 (6.1%) patients developed HCC during a mean (± SD) follow-up duration of 45 ± 20 months. Serum HBcrAg level above 2.9 log10 U/mL at baseline was an independent factor for HCC in hepatitis B e antigen (HBeAg)-negative patients by multivariable analysis (adjusted hazard ratio 2.13, 95% CI 1.10-4.14, P = 0.025). HBcrAg above 2.9 log₁₀ U/mL stratified the risk of HCC in HBeAg-negative patients with high PAGE-B score (P = 0.024 by Kaplan-Meier analysis), and possibly in cirrhotic patients (P = 0.08). Serum HBsAg level did not show any correlation with the risk of HCC in all patients or any subgroups.

CONCLUSION

Serum HBcrAg level predicts the risk of HCC accurately in NA-treated HBeAg-negative CHB patients.

Global dynamics of a model of hepatitis B virus infection in a sub-Saharan African rural area

We formulate and systematically study a deterministic compartmental model of Hepatitis B. This model has some important and novel features compared with the well-known basic model in the literature. Specifically, it takes into account the differential susceptibility that follows the vaccine formulation employing three-doses schedule. It points up the HbeAg status of carriers, their levels of viral replication, the fact that treatment being not curative is recommended only to a small proportion of chronic carriers, and finally the fact that only inactive carriers are able to recover from disease. The model has simple dynamical behavior which has a globally asymptotically stable disease-free equilibrium when the basic reproduction number [Formula: see text] and an endemic equilibrium when [Formula: see text]. By the use of Lyapunov functions, when it exists, we prove the global asymptotic stability of the endemic equilibrium under some conditions. Using data from Tokombere, a rural area in Cameroon, numerical simulations are performed. These numerical simulations first confirm analytical results, second they suggest that a policy based on treatment could not significantly impact the course of the infection. Third, they show as it is well known that vaccination is a very effective measure to control the infection. Furthermore, they show that neonatal vaccination influences more the course of infection than mass vaccination strategy. Nevertheless, they picture how much loss between consecutive doses of vaccine could be harmful. Finally, it is suggested that for a Sub-saharan African rural area, two-thirds of expected incidence of Hepatitis B virus infection and one third of expected prevalence of chronic carriers could be averted by 2030 if the birth dose vaccination becomes systematic and if mass vaccination rate increases to up 10%.

In vitro inhibition effects of hepatitis B virus by dandelion and taraxasterol

Hepatitis B virus (HBV) causes hepatitis, which progresses to fatal liver diseases and remains a global health problem. Current treatments for chronic hepatitis B are unable to cure hepatitis. Thus, new antiviral drugs must be developed. In this study, the viral inhibition effects of dandelion and taraxasterol were assessed in HepG2.2.15 cell line. Taraxacum officinale F.H.Wigg. (compositae) with English name dandelion is used as a traditional herb for liver disorders and as a common antiviral agent. Taraxasterol is one of the active compounds of dandelion. The secretion of HBV DNA and HBV surface antigen (HBsAg) and HBeAg was detected using fluorescence quantitative PCR (qPCR) and ELISA, respectively. Intracellular HBsAg was detected by immunofluorescence. In order to demonstrate the potential mechanism of anti-viral activity, the expression levels of host factors polypyrimidine tract binding protein 1 (PTBP1) and sirtuin 1 (SIRT1) were detected with Western blotting and qPCR. Dandelion and taraxasterol effectively reduced the secretion of HBsAg, HBeAg and the HBV DNA in cell supernatants, and significantly reduced the intracellular HBsAg as indicated by immunofluorescence results. Taraxasterol may be one of the main effective components of dandelion. It significantly decreased the protein expression levels of PTBP1 and SIRT1. The present study revealed that dandelion and its component taraxasterol could inhibit HBV and may be a potential anti-HBV drug, whose potential targets were the host factors PTBP1 and SIRT1.

Cytokines predict virological response in chronic hepatitis B patients receiving peginterferon alfa-2a therapy

BACKGROUND

Chronic hepatitis B virus infection remains a major global public health problem. Peginterferon-alpha-2a (PEG-IFN) has direct antiviral and immunoregulatory effects, and it has become one of the first choice drugs for the treatment of chronic hepatitis B (CHB). Cytokines play an important role in immunity, and they directly inhibit viral replication and indirectly determine the predominant pattern of the host immune response.

AIM

To determine the correlation between cytokine/chemokine expression levels and response to PEG-IFN treatment in patients with CHB.

METHODS

Forty-six kinds of cytokines were analyzed before PEG-IFN therapy and at 24 wk during therapy in 26 CHB patients.

RESULTS

The monokine induced by INF-γ (CXCL9) and serum interferon-inducible protein 10 ( IP-10) levels at baseline were higher in virological responders than in non-virological responders (NRs) and decreased during treatment, whereas the NRs did not exhibit significant changes. The macrophage inflammatory protein 1d (MIP-1d) levels at baseline and during treatment were significantly higher in the virological responders than in the NRs, while thymus and activation-regulated chemokine (TARC) levels at baseline and during treatment were significantly lower in the virological responders than in the NRs. The CXCL9, IP-10, MIP-1d, and TARC baseline levels exhibited the expected effects for interferon treatment. The area under the receiver operating characteristic curve values of CXCL9, IP-10, MIP-1d, and TARC for predicting virological responses were 0.787, 0.799, 0.787, and 0.77 (P = 0.01, 0.013, 0.01, and 0.021), respectively.

CONCLUSION

We found that cytokine levels before and during treatment may represent potential biomarkers to select CHB patients who can respond to PEG-IFN. Therefore, cytokines can be used as an indicator of antiviral drug selection before CHB treatment.

Serum Neopterin Levels and IDO Activity as Possible Markers for Presence and Progression of Hepatitis B

Chronic Hepatitis B virus (HBV) is still one of the major reasons for liver related mortality and morbidity all around the world. This study aimed to investigate the possible relationship between the immune system activation and presence, as well as progression, of hepatitis B infection by monitoring the tryptophan degradation and serum neopterin levels in patients with HBV. 110 patients with HBV and 23 healthy subjects were included in the study. The patients had significantly higher neopterin levels and increased kynurenine to tryptophan ratios, which were most probably due to enhanced indoleamine 2,3-dioxygenase (IDO) activity compared to healthy control. A strong positive correlation was found between neopterin levels and IDO activity in patient group. Neopterin levels and IDO activity were markedly increased in patients with histological activity index (HAI) ≥4 compared to HAI<4, and a significant correlation was found between neopterin and HAI. Moreover, there was a significant correlation between albumin levels and IDO activity in HBV patients. These findings suggest that tryptophan degradation results from IFN-γ-induced IDO activation, likewise depletion of albumin synthesis in HBV patients may result from diminished tryptophan availability. In conclusion, based on the study results, serum neopterin levels and IDO activity could provide additional immunological information for monitoring liver histological activity and can be used as prognostic markers in HBV disease.

IFN-α2b inhibits the ethanol enriched-HBV cccDNA through blocking a positive feedback loop of HBx/MSL2/cccDNA/HBV/HBx in liver

Hepatitis B virus (HBV) is a major risk factor for liver diseases, in which HBV covalently closed circular DNA (cccDNA), as the genomic form that templates viral transcription, plays crucial roles in sustaining viral persistence. Clinically, the excessive ethanol intake accelerates the progression of liver diseases with HBV infection. Here, we supposed that ethanol might trigger HBV cccDNA in the liver. Interestingly, we observed that the ethanol remarkably elevated the levels of HBeAg, HBsAg, HBV DNA and cccDNA in HBV-expressing hepatoma cells. Mechanically, the ethanol increased the levels of HBx and MSL2 in vivo and in HBV-expressing HepG2 cells, but not in HBV-free HepG2 cells. Moreover, the down-regulation of MSL2 by small interference RNA could block the ethanol-promoted HBV cccDNA in HepG2.2.15 cells. As a commonly administered treatment for HBV, the effect of IFNα on ethanol-triggered HBV cccDNA remains poorly understood. Strikingly, we showed that the treatment with IFN-α2b inhibited the ethanol-promoted cccDNA through depressing MSL2 in the cells. Thus, we conclude that IFN-α2b inhibits the ethanol-enriched HBV cccDNA through blocking a positive feedback loop of HBx/MSL2/cccDNA/HBV/HBx. Our finding provides new insights into the mechanism by which IFN-α2b inhibits ethanol-enhanced HBV cccDNA. Therapeutically, IFNα may contribute to the cccDNA induced by ethanol in liver.

Efficacy of an Inhibitor of Hepatitis B Virus Expression in Combination With Entecavir and Interferon-α in Woodchucks Chronically Infected With Woodchuck Hepatitis Virus

RG7834 is a small‐molecule inhibitor of hepatitis B virus (HBV) gene expression that significantly reduces the levels of hepatitis B surface antigen (HBsAg) and HBV DNA in a humanized liver HBV mouse model. In the current study, we evaluated the potency of RG7834 in the woodchuck model of chronic HBV infection, alone and in combination with entecavir (ETV) and/or woodchuck interferon‐α (wIFN‐α). RG7834 reduced woodchuck hepatitis virus (WHV) surface antigen (WHsAg) by a mean of 2.57 log₁₀ from baseline and WHV DNA by a mean of 1.71 log₁₀. ETV + wIFN‐α reduced WHsAg and WHV DNA by means of 2.40 log₁₀ and 6.70 log₁₀, respectively. The combination of RG7834, ETV, and wIFN‐α profoundly reduced WHsAg and WHV DNA levels by 5.00 log₁₀ and 7.46 log₁₀, respectively. However, both viral parameters rebounded to baseline after treatment was stopped and no antibody response against WHsAg was observed. Effects on viral RNAs were mainly seen with the triple combination treatment, reducing both pregenomic RNA (pgRNA) and WHsAg RNA, whereas RG7834 mainly reduced WHsAg RNA and ETV mainly affected pgRNA. When WHsAg was reduced by the triple combination, peripheral blood mononuclear cells (PBMCs) proliferated significantly in response to viral antigens, but the cellular response was diminished after WHsAg returned to baseline levels during the off‐treatment period. Consistent with this, Pearson correlation revealed a strong negative correlation between WHsAg levels and PBMC proliferation in response to peptides covering the entire WHsAg and WHV nucleocapsid antigen. Conclusion: A fast and robust reduction of WHsAg by combination therapy reduced WHV‐specific immune dysfunction in the periphery. However, the magnitude and/or duration of the induced cellular response were not sufficient to achieve a sustained antiviral response.