Treatment of chronic hepatitis B: Evolution over two decades

N-Heterocycles as Promising Antiviral Agents: A Comprehensive Overview

Viruses are a real threat to every organism at any stage of life leading to extensive infections and casualties. N-heterocycles can affect the viral life cycle at many points, including viral entrance into host cells, viral genome replication, and the production of novel viral species. Certain N-heterocycles can also stimulate the host's immune system, producing antiviral cytokines and chemokines that can stop the reproduction of viruses. This review focused on recent five- or six-membered synthetic N-heterocyclic molecules showing antiviral activity through SAR analyses. The review will assist in identifying robust scaffolds that might be utilized to create effective antiviral drugs with either no or few side effects.

Arsenic trioxide impacts hepatitis B virus core nuclear localization and efficiently interferes with HBV infection

The key to a curative treatment of hepatitis B virus (HBV) infection is the eradication of the intranuclear episomal covalently closed circular DNA (cccDNA), the stable persistence reservoir of HBV. Currently, established therapies can only limit HBV replication but fail to tackle the cccDNA. Thus, novel therapeutic approaches toward curative treatment are urgently needed. Recent publications indicated a strong association between the HBV core protein SUMOylation and the association with promyelocytic leukemia nuclear bodies (PML-NBs) on relaxed circular DNA to cccDNA conversion. We propose that interference with the cellular SUMOylation system and PML-NB integrity using arsenic trioxide provides a useful tool in the treatment of HBV infection. Our study showed a significant reduction in HBV-infected cells, core protein levels, HBV mRNA, and total DNA. Additionally, a reduction, albeit to a limited extent, of HBV cccDNA could be observed. Furthermore, this interference was also applied for the treatment of an established HBV infection, characterized by a stably present nuclear pool of cccDNA. Arsenic trioxide (ATO) treatment not only changed the amount of expressed HBV core protein but also induced a distinct relocalization to an extranuclear phenotype during infection. Moreover, ATO treatment resulted in the redistribution of transfected HBV core protein away from PML-NBs, a phenotype similar to that previously observed with SUMOylation-deficient HBV core. Taken together, these findings revealed the inhibition of HBV replication by ATO treatment during several steps of the viral replication cycle, including viral entry into the nucleus as well as cccDNA formation and maintenance. We propose ATO as a novel prospective treatment option for further pre-clinical and clinical studies against HBV infection.

IMPORTANCE

The main challenge for the achievement of a functional cure for hepatitis B virus (HBV) is the covalently closed circular DNA (cccDNA), the highly stable persistence reservoir of HBV, which is maintained by further rounds of infection with newly generated progeny viruses or by intracellular recycling of mature nucleocapsids. Eradication of the cccDNA is considered to be the holy grail for HBV curative treatment; however, current therapeutic approaches fail to directly tackle this HBV persistence reservoir. The molecular effect of arsenic trioxide (ATO) on HBV infection, protein expression, and cccDNA formation and maintenance, however, has not been characterized and understood until now. In this study, we reveal ATO treatment as a novel and innovative therapeutic approach against HBV infections, repressing viral gene expression and replication as well as the stable cccDNA pool at low micromolar concentrations by affecting the cellular function of promyelocytic leukemia nuclear bodies.

Risk factors for the mortality of hepatitis B virus-associated acute-on-chronic liver failure: a systematic review and meta-analysis

BACKGROUND

Hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) has been confirmed as a prevalent form of end-stage liver disease in people subjected to chronic HBV infection. However, there has been rare in-depth research on the risk factors for the mortality of HBV-ACLF. This study aimed at determining the risk factors for the mortality of HBV-ACLF.

METHODS

The relevant research was selected from four electronic databases that have been published as of August 2023. The existing research was reviewed in accordance with the inclusion and exclusion criteria. The level of quality of previous research was evaluated using the Newcastle-Ottawa scale. Moreover, a pooled estimate of the odds ratios (ORs) with their associated 95% confidence intervals (CIs) was provided through a meta-analysis. The data were combined, and the risk variables that at least two studies had considered were analyzed. The publication bias was examined through Egger's test and Begg's test.

RESULTS

Twenty two studies that conformed to the inclusion criteria were selected from 560 trials. Eight risk variables in terms of HBV-ACLF mortality were determined, which covered INR (OR = 1.923, 95% CI = 1.664-2.221, P < 0.001), Monocytes (OR = 1.201, 95% CI = 1.113-1.296, P < 0.001), Cirrhosis (OR = 1.432, 95% CI = 1.210-1.696, P < 0.001), HE (OR = 2.553, 95% CI = 1.968-3.312, P < 0.001), HE grade (OR = 2.059, 95% CI = 1.561-2.717, P < 0.001), SBP (OR = 1.383, 95% CI = 1.080-1.769, P = 0.010), Hyponatremia (OR = 1.941, 95% CI = 1.614-2.334, P < 0.001), as well as HRS (OR = 2.610, 95% CI = 1.669-4.080, P < 0.001).

CONCLUSION

The most significant risk factors for HBV-ACLF mortality comprise HRS, HE, and HE grade, followed by INR and hyponatremia. The Monocytes, cirrhosis, and SBP have been confirmed as the additional key risk factors for HBV-ACLF mortality.

Computer-aided drug design in seeking viral capsid modulators

Approved or licensed antiviral drugs have limited applications because of their drug resistance and severe adverse effects. By contrast, by stabilizing or destroying the viral capsid, compounds known as capsid modulators prevent viral replication by acting on new targets and, therefore, overcoming the problem of clinical drug resistance. For example. computer-aided drug design (CADD) methods, using strategies based on structures of biological targets (structure-based drug design; SBDD), such as docking, molecular dynamics (MD) simulations, and virtual screening (VS), have provided opportunities for fast and effective development of viral capsid modulators. In this review, we summarize the application of CADD in the discovery, optimization, and mechanism prediction of capsid-targeting small molecules, providing new insights into antiviral drug discovery modalities. Teaser: Computer-aided drug design will accelerate the development of viral capsid regulators, which brings new hope for the treatment of refractory viral diseases.

Exosomes loading Tapasin enhance T cell immune response by autophagy to inhibit HBV replication

Hepatitis B virus (HBV) specific T cell immune response plays a vital role in viral clearance. Dendritic cell derived exosomes (Dexs) can activate T cell immunity effectively. Tapasin (TPN) is involved in antigen processing and specific immune recognition. In the present study, we elucidated that Dexs loading TPN (TPN-Dexs) could enhance CD8⁺ T cell immune response and inhibit virus replication in HBV transgenic mice. T cell immune response and the ability of inhibiting HBV replication were measured in HBV transgenic mice immunized with TPN-Dexs. Meanwhile, CD8⁺ T cell autophagy and specific T cell immune responses were measured in vitro and vivo, and the mechanisms probably involved in were explored. Purified TPN-Dexs could be taken up into the cytoplasm of DCs and upregulate CD8⁺ T cell autophagy to enhance specific T cell immune response. In addition, TPN-Dexs could increase the expression of AKT and decrease the expression of mTOR in CD8⁺ T cells. Further research confirmed that TPN-Dexs could inhibit virus replication and decrease the expression of HBsAg in the liver of HBV transgenic mice. Nevertheless, those also could elicit mice hepatocytes damage. In conclusion, TPN-Dexs could enhance specific CD8⁺ T cell immune responses via the AKT/mTOR pathway to regulate the autophagy and exert the antiviral effect in HBV transgenic mice.

Fast and Ultrasensitive Electrochemical Detection for Antiviral Drug Tenofovir Disoproxil Fumarate in Biological Matrices

Tenofovir disoproxil fumarate (TDF) is an antiretroviral medication with significant curative effects, so its quantitative detection is important for human health. At present, there are few studies on the detection of TDF by electrochemical sensors. This work can be a supplement to the electrochemical detection of TDF. Moreover, bare electrodes are susceptible to pollution, and have high overvoltage and low sensitivity, so it is crucial to find a suitable electrode material. In this work, zirconium oxide (ZrO₂) that has a certain selectivity to phosphoric acid groups was synthesized by a hydrothermal method with zirconyl chloride octahydrate as the precursor. A composite modified glassy carbon electrode for zirconium oxide-chitosan-multiwalled carbon nanotubes (ZrO₂-CS-MWCNTs/GCE) was used for the first time to detect the TDF, and achieved rapid, sensitive detection of TDF with a detection limit of sub-micron content. The ZrO₂-CS-MWCNTs composite was created using sonication of a mixture of ZrO₂ and CS-MWCNTs solution. The composite was characterized using scanning electron microscopy (SEM) and cyclic voltammetry (CV). Electrochemical analysis was performed using differential pulse voltammetry (DPV). Compared with single-material electrodes, the ZrO₂-CS-MWCNTs/GCE significantly improves the electrochemical sensing of TDF due to the synergistic effect of the composite. Under optimal conditions, the proposed method has achieved good results in linear range (0.3~30 μM; 30~100 μM) and detection limit (0.0625 μM). Moreover, the sensor has the merits of simple preparation, good reproducibility and good repeatability. The ZrO₂-CS-MWCNTs/GCE has been applied to the determination of TDF in serum and urine, and it may be helpful for potential applications of other substances with similar structures.

4-Oxooctahydroquinoline-1(2H)-carboxamides as hepatitis B virus (HBV) capsid core protein assembly modulators

Hepatitis B virus (HBV) core protein, the building block of the HBV capsid, plays multiple roles in viral replication, and is an attractive target for development of antiviral agents with a new mechanism of action. In addition to the heteroaryldihydropyrimidines (HAPs), sulfamoylbenzamides (SBAs), dibenzothiazepine derivatives (DBTs), and sulfamoylpyrrolamides (SPAs) that inhibit HBV replication by modulation of viral capsid assembly and are currently under clinical trials for the treatment of chronic hepatitis B (CHB), other chemical structures with activity to modulate HBV capsid assembly have also been explored. Here we describe our continued optimization of a benzamide originating from our high throughput screening. A new bicyclic carboxamide lead featuring an electron deficient non-planar core structure was discovered. Evaluations of its ADMET (absorption, distribution, metabolism, excretion and toxicity) and pharmacokinetic (PK) profiles demonstrate improved metabolic stability and good bioavailability.

Present and future management of viral hepatitis

Viral hepatitis can result in important morbidity and mortality, with its impact on health conditioned by the specific type of hepatitis, the geographical region of presentation and the development and access to new drugs, among other factors. Most acute presentation forms are self-limiting and may even go unnoticed, with just a small percentage of cases leading to acute liver failure that may necessitate transplantation or even cause the death of the patient. However, when they become chronic, as in the case of hepatitis B virus and C virus, unless they are diagnosed and treated adequately they may have severe consequences, like cirrhosis or hepatocarcinoma. Understanding of the mechanisms of transmission, the pathogenesis, the presence of vaccinations and the development over recent years of new highly-efficient, potent drugs have meant that we are now faced with a new scenario in the management of viral hepatitis, particularly hepatitis B virus and hepatitis C virus. The spectacular advances in hepatitis C virus treatment have led the World Health Organization to propose the objective of its eradication by 2030. The key aspect to achieving this goal is to ensure that these treatments reach all the more vulnerable population groups, in whom the different types of viral hepatitis have a high prevalence and constitute a niche that may perpetuate infection and hinder its eradication. Accordingly, micro-elimination programs assume special relevance at the present time.

Prevalence and predictors of hepatitis B virus (HBV) infection in east Africa: evidence from a systematic review and meta-analysis of epidemiological studies published from 2005 to 2020

BACKGROUND

The epidemiology of hepatitis B virus (HBV) in the general population in east Africa is not well documented. In this meta-analysis, we examined 37 full published research articles to synthesise up-to-date data on the prevalence and predictors of the HBV burden for the effective prevention and management of the virus in our region.

METHODS

We examined 37 full published research articles found using PubMed, Scopus, African Journal Online (AJOL), and Google Scholar between May and October 2020. Dichotomous data on HBV prevalence and predictors of infection were extracted from the individual studies. The HBV prevalence, test of proportion, relative risk, and I2 statistics for heterogeneity were calculated using MedCalc software version 19.1.3. Begg's tests was used to test for publication bias. Sources of heterogeneity were analysed through sensitivity analysis, meta-regression, and sub-group analysis at 95% CI. P < 0.05 was considered significant for all analyses.

RESULTS

The prevalence of HBV was generally high (6.025%), with publications from Kenya (8.54%), Uganda (8.454%) and those from between 2011 and 2015 (8.759%) reporting the highest prevalence (P < 0.05). Blood transfusion, scarification, promiscuity, HIV seropositivity, and being male were independent predictors significantly associated with HBV infection (P < 0.05), with the male sex being the most strongly associated predictor of HBV infection. Meta-regressions for the pooled HBV prevalence and sample size, as well as the year of publication, lacked statistical significance (P > 0.05). Omitting the study with the largest sample size slightly increased pooled HBV prevalence to 6.149%, suggesting that the studies are robust. Begg's test showed no evidence of publication bias for overall meta-analysis (p > 0.05).

CONCLUSION

The burden of HBV is still high, with the male sex, blood transfusion, body scarification, and HIV seropositivity being potential predictors of infection. Thus, it is important to scale up control and prevention measures targeting persons at high risk.

Immunosurveillance and molecular detection of hepatitis B virus infection amongst vaccinated children in the West Gonja District in Savanna Region of Ghana

Hepatitis B vaccination is the most effective preventive measure in reducing the incidence of chronic hepatitis B virus (HBV) infection and its consequences such as cirrhosis, hepatocellular carcinoma, liver failure and death. Ghana introduced the universal HBV vaccination in the national Expanded Programme on Immunization in 2002. The current study sought to determine the sero-protection rate and the prevalence of HBV infection among fully vaccinated children in the West Gonja District in the Savanna Region of Ghana. This cross-sectional study recruited three hundred and fifty (350) fully vaccinated children who visited West Gonja Catholic Hospital from September to December 2019 for healthcare. Structured questionnaires were administered to obtain information on the demographics. The clinical history of the participants was obtained from the hospital records. Sera were separated from 2-5ml of blood sample collected from each participant after informed consent had been sought from their parents/guardians. Sera were tested for HBsAg, anti-HBs and anti-HBc using ELISA. Samples positive for HBsAg or anti-HBc were tested for HBV DNA by Real-Time Polymerase Chain Reaction. The overall sero-protection rate (anti-HBs titers ≥ 10 mIU/mL) among the studied participants was 56% with anti-HBs geometric mean titer (GMT) of 95.7 mIU/mL (± 6.0; 95% CI) compared with GMT of 2.8 mIU/mL (± 0.2; 95% CI) among non-seroprotected participants. There was no statistically significant difference in sero-protection rate between males and females (p-value = 0.93) and in relation to age (p-value = 0.20). The prevalence of HBV infection among studied participants as determined by the HBV DNA/HBsAg positivity was 1.4% while anti-HBc sero-positivity was 2%. Even though the sero-protection rate and HBV infection rate reported in the current study compares with that of other international studies further studies need to be conducted to understand the factors related to sero-protection and HBV infection rate in the Savanna Region of Ghana.

Efficacy of entecavir in treating hepatitis B virus-associated membranous nephropathy

OBJECTIVE

hepatitis B virus-associated membranous nephropathy (HBV-MN) is the most common pathological type of hepatitis B virus-associated glomerulonephritis. This study evaluated the efficacy of entecavir antiviral therapy for HBV-MN patients due to the intolerable side effects of interferon-alpha and high incidence rate of drug-resistance in lamivudine therapy.

METHOD

thirty-two patients with HBV-MN were identified by biopsy and treated with entecavir for 52 weeks. These patients were followed up to evaluate outcomes of entecavir-treatment. Descriptive statistics were used to summarize patient demographics and treatment outcomes.

RESULTS

entecavir treatment reduced 24-h urinary protein excretion. The total probability of partial proteinuria and complete remission at 24 and 52 weeks was 53.1 and 78.1 %, respectively. A decrease of circulating HBV-DNA was observed in all patients with active HBV replication. The significant decrease of 24-h urinary protein began at 12 weeks, as early as the decrease of serum HBV-DNA level. The serum HBV DNA titers at baseline and after 52 weeks of treatment were 4.3 ± 2.8 log10 and 2.3 ± 1.7 log10, respectively. Meanwhile, eGFR increased from 100.3 ± 20.5 ml/min/1.73 m2 at baseline to 107.7 ± 15.9 ml/min/1.73 m2 after 52 weeks of treatment. The serum alanine aminotransferase level (ALT) gradually decreased to normal during entecavir antiviral treatment.

CONCLUSIONS

entecavir treatment in HBV-MN patients was carefully described. Complete remission and HBV replication suppression were induced by entecavir treatment in HBV-MN patients. Patients with high serum creatinine (Scr), ALT and low eGFR levels benefit more from entecavir treatment. Entecavir therapy is well tolerated by patients and no adverse reactions were observed.

Medicinal chemistry strategies for discovering antivirals effective against drug-resistant viruses

During the last forty years we have witnessed impressive advances in the field of antiviral drug discovery culminating with the introduction of therapies able to stop human immunodeficiency virus (HIV) replication, or cure hepatitis C virus infections in people suffering from liver disease. However, there are important viral diseases without effective treatments, and the emergence of drug resistance threatens the efficacy of successful therapies used today. In this review, we discuss strategies to discover antiviral compounds specifically designed to combat drug resistance. Currently, efforts in this field are focused on targeted proteins (e.g. multi-target drug design strategies), but also on drug conformation (either improving drug positioning in the binding pocket or introducing conformational constraints), in the introduction or exploitation of new binding sites, or in strengthening interaction forces through the introduction of multiple hydrogen bonds, covalent binding, halogen bonds, additional van der Waals forces or multivalent binding. Among the new developments, proteolysis targeting chimeras (PROTACs) have emerged as a valid approach taking advantage of intracellular mechanisms involving protein degradation by the ubiquitin-proteasome system. Finally, several molecules targeting host factors (e.g. human dihydroorotate dehydrogenase and DEAD-box polypeptide 3) have been identified as broad-spectrum antiviral compounds. Implementation of herein described medicinal chemistry strategies are expected to contribute to the discovery of new drugs effective against current and future threats due to emerging and re-emerging viral pandemics.

Sulfamoylbenzamide-based Capsid Assembly Modulators for Selective Inhibition of Hepatitis B Viral Replication

As the spread of infections caused by hepatitis B virus (HBV) threatens public health worldwide, investigations from multiple perspectives and of various mechanisms of action are urgently required to increase the HBV cure rate. Targeting the encapsidation of the nuclear capsid protein (core protein, HBc) has emerged as an attractive strategy for inhibiting the viral assembly process; however, a drug targeting this mechanism has not yet been approved. We synthesized novel sulfamoylbenzamides (SBAs) as capsid assembly modulators of HBV and found that the effects and safety profiles of compounds 3 and 8 have potential therapeutic applicability against HBV. The formation of tubular particles was time-dependent in the presence of 3, indicating a new mode of protein assembly by SBA compounds. Our findings provide a new entity for developing safe and efficient treatments for HBV infection.

CCL19 enhances CD8+ T-cell responses and accelerates HBV clearance

BACKGROUND

Chemokine (C-C motif) ligand 19 (CCL19) is a leukocyte chemoattractant that plays a crucial role in cell trafficking and leukocyte activation. Dysfunctional CD8⁺ T cells play a crucial role in persistent HBV infection. However, whether HBV can be cleared by CCL19-activated immunity remains unclear.

METHODS

We assessed the effects of CCL19 on the activation of PBMCs in patients with HBV infection. We also examined how CCL19 influences HBV clearance and modulates HBV-responsive T cells in a mouse model of chronic hepatitis B (CHB). In addition, C-C chemokine-receptor type 7 (CCR7) knockdown mice were used to elucidate the underlying mechanism of CCL19/CCR7 axis-induced immune activation.

RESULTS

From in vitro experiments, we found that CCL19 enhanced the frequencies of Ag-responsive IFN-γ⁺ CD8⁺ T cells from patients by approximately twofold, while CCR7 knockdown (LV-shCCR7) and LY294002 partially suppressed IFN-γ secretion. In mice, CCL19 overexpression led to rapid clearance of intrahepatic HBV likely through increased intrahepatic CD8⁺ T-cell proportion, decreased frequency of PD-1⁺ CD8⁺ T cells in blood and compromised suppression of hepatic APCs, with lymphocytes producing a significantly high level of Ag-responsive TNF-α and IFN-γ from CD8⁺ T cells. In both CCL19 over expressing and CCR7 knockdown (AAV-shCCR7) CHB mice, the frequency of CD8⁺ T-cell activation-induced cell death (AICD) increased, and a high level of Ag-responsive TNF-α and low levels of CD8⁺ regulatory T (T_reg) cells were observed.

CONCLUSIONS

Findings in this study provide insights into how CCL19/CCR7 axis modulates the host immune system, which may promote the development of immunotherapeutic strategies for HBV treatment by overcoming T-cell tolerance.

Sero-prevalence of human immunodeficiency virus-hepatitis B virus (HIV-HBV) co-infection among pregnant women attending antenatal care (ANC) in sub-Saharan Africa (SSA) and the associated risk factors: a systematic review and meta-analysis

Background

There is plenitude of information on HIV infection among pregnant mothers attending antenatal care (ANC) in sub-Saharan Africa. However, the epidemiology of HBV–HIV co-infections in the same cohort is not clear despite the common route of transmission of both viruses. The aim of our study was to synthesize data on the prevalence of HBV–HIV co-infection among pregnant women attending ANC in Sub-Saharan Africa to assist in the design of public health interventions to mitigate the challenge.

Methods

The study was done in tandem with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards and the Cochran’s Q test, I² statistics for heterogeneity and the prevalence were calculated using commercially available software called MedCalcs (https://www.medcalc.org). A random effect model was used to pool the prevalence since all the heterogeneities were high (≥ 78%) and P_het < 0.05 indicated significant heterogeneities. The risk factors and risk differences for HBV–HIV co-infection were analyzed. Any likely sources of heterogeneity were analyzed through sensitivity analysis, meta-regression and sub-group analysis. All analyses were done at 95% level of significance and a P < 0.05 was considered significant.

Results

The overall pooled prevalence of HBV–HIV co-infection among pregnant mothers in sub-Saharan Africa was low 3.302% (95%CI = 2.285 to 4.4498%) with heterogeneities (I²) of 97.59% (P > 0.0001). Within regional sub group meta-analyses, West Africa had significantly higher prevalence of 5.155% (95% = 2.671 to 8.392%) with heterogeneity (I²) of 92.25% (P < 0.0001) than any other region (P < 0.001). Articles published from 2004–2010 had significantly higher prevalence of 6.356% (95% = 3.611 to 9.811%) with heterogeneity (I²) 91.15% (P < 0.0001) compared to those published from 2011 to 2019 (P < 0.001). The HIV positive cohort had significantly higher prevalence of HBV–HIV co-infection of 8.312% (95% CI = 5.806 to 11.22%) with heterogeneity (I²)94.90% (P < 0.0001) than the mothers sampled from the general population with a prevalence of 2.152% (95% CI = 1.358 to 3.125%) (P < 0.001). The overall and sub group analyses had high heterogeneities (I² > 89%, P < 0.0001) but was reduced for South Africa (I²) = 78.4% (P = 0.0314). Age, marital status and employment were independent factors significantly associated with risk of HBV–HIV co-infection (P < 0.001) but not extent of gravidity and education level (P > 0.05). After meta-regression for year of publication and sample size for HBsAg positivity, the results were not significantly associated with HBV pooled prevalence for sample size (P = 0.146) and year of publication (P = 0.560). Following sensitivity analysis, the HBsAg pooled prevalence slightly increased to 3.429% (95% CI = 2.459 to 4.554%) with heterogeneity I² = 96.59% (95% CI = 95.93 to 97.14%), P < 0.0001

Conclusion

There is an urgent need for routine HBV screening among HIV positive pregnant mothers attending antenatal care in sub-Saharan Africa to establish the extent of HBV–HIV co-infection in this cohort. Future studies need to investigate the putative risk factors for HBV–HIV co-infection and prioritize plausible control strategies.

Application of High-Performance Liquid Chromatography for Simultaneous Determination of Tenofovir and Creatinine in Human Urine and Plasma Samples

Tenofovir disoproxil fumarate is widely used in the therapy of human immunodeficiency virus and hepatitis B virus; however, a high concentration of the prodrug effects kidney function damage. To control the effectiveness of kidney functions in treated patients, the level of creatinine in the body must be controlled. This work describes a simple, fast, and “plastic-waste” reducing method for the simultaneous determination of tenofovir and creatinine in human urine and plasma. In both assays, only 50 µL of body fluid was required. The tests were carried out by reversed phase high-performance liquid chromatography with UV detection. In urine samples, the limits of detection for tenofovir and creatinine were 4 µg mL⁻¹ and 0.03 µmol mL⁻¹, respectively. In plasma samples, the limits of detection were 0.15 µg mL⁻¹ for tenofovir and 0.0003 µmol mL⁻¹ for creatinine. The method was applied for the determination of tenofovir and creatinine in human urine and plasma samples. The biggest advantage of the elaborated method is the possibility to determine tenofovir and creatinine in one analytical run in both urine and plasma sample collected from HIV and HBV patients. The possibility to reduce the level of laboratory waste in a sample preparation protocol is in the mainstream of a new trend of analytical chemistry which is based on green chemistry.

Antiviral drug utilization and annual expenditures for patients with chronic HBV infection in Guangzhou, China, in 2008-2015

BACKGROUND

The aims of this study were to describe antiviral drug (AD) utilization and costs in patients with chronic HBV infection.

METHODS

We conducted a retrospective study of patients in the hospital and calculated annual proportions of AD utilization and costs among patients. A two-part model was used to estimate adjusted odds ratio (OR) for antiviral therapy and cost ratios for antiviral costs associated with demographics.

RESULTS

Of a total of 14,920 records, 143,658 records were involved in the analysis. The annual proportions of AD utilization were 56.99% (45.65%) for inpatients (outpatients) during 2008-2015 and increased annually. Entecavir (ETV), in particular, increased from 11.08% to 70.26% (11.05% to 49.35%) for inpatients (outpatients). The patients with medical insurance were more likely to use AD than patients without insurance, and the adjusted OR was 1.11 (95% CI: 1.03, 1.19) for inpatients and 1.66 (1.59, 1.73) for outpatients. With the disease progressing, the proportion of antiviral costs in total direct medical costs decreased from 13.91% to 4.07% (71.29% to 49.29%) for inpatients (outpatients).

CONCLUSIONS

The use of AD for chronic HBV infection was less than expected based on established guidelines, and only half of patients received antiviral treatment. However, the AD utilization, especially ETV, increased annually. Reimbursement policy was the most important factor affecting antiviral treatment. Antiviral therapy was an important part of the direct medical costs, especially in the early stage of disease.

Seroepidemiology of Hepatitis B Virus Infection in Native and Immigrant Pregnant Women: A 20-Year Retrospective Study in Taiwan

Universal immunoprophylaxis against hepatitis B virus (HBV) is regarded as a key element to prevent perinatal HBV infection. The aim of the present study was to investigate the changes in the hepatitis B surface antigen (HBsAg)- and hepatitis B envelope antigen (HBeAg)-positive rates in native and immigrant pregnant women, to realize the impact of immigrants, and to identify any weaknesses 30 years after the implementation of hepatitis B vaccination in Taiwan. A total of 20,020 test results of HBsAg and HBeAg in pregnant women-2,915 (14.6%) immigrant women and 17,105 native Taiwanese-from 1996 to 2015 were analyzed for changes during this 20-year retrospective cohort study. Native Taiwanese have a higher HBsAg-positive rate than immigrant women (P < 0.001). However, the HBsAg-positive rates decreased by 0.6% per year among native women, but did not decrease significantly (only by 0.18% per year) among immigrant women. The overall HBsAg-positive rate remained at high levels, 4.8% in the year 2015. The HBeAg-positive rate decreased significantly, by 0.22% per year, in the total women as well as by 0.23% per year in the native women (all P < 0.001); by contrast, the HBeAg-positive rate in immigrants decreased at a slower rate (0.10% per year), without a significant decreasing trend (P = 0.300). Higher HBeAg (+)/HBsAg (+) rate was found for the immigrants than for the native women (P < 0.001). To quickly and effectively lower the risk of vertical transmission, new approaches combined with vaccination may be needed in the post-immunization era.

Hepatitis B-related glomerulonephritis and optimization of treatment

Introduction: Multiple studies have revealed a strong relationship between the development of nephropathy and hepatitis B virus (HBV) infection. The underlying pathogenesis of hepatitis B-related glomerulonephritis (HBV-GN) involves immune complexes, which can be isolated from kidney tissues. Clearance of HBV antigenemia improves renal impairment and proteinuria in HBV-GN patients.Areas covered: In this review, we present our current understanding of the epidemiology, pathogenesis, pathology, diagnosis, and treatment of HBV-GN. We discuss the advantages and disadvantages of oral nucleoside/nucleotide analogs (NAs), and the main pharmaceutical treatment for hepatis B.Expert opinion: Currently, antiviral agents are the main HBV-GN therapeutic agents. Although no randomized controlled clinical trials have compared the efficacy of interferon (IFN) and NA, we suggest IFN treatment for pediatric patients (IFN-α in patients ≥1 year; pegIFN-α in patients ≥3 years) considering treatment duration and absence of resistance. Novel NAs have brought about promising treatment options involving high efficacy viral suppression and low resistance rates. NAs with a high barrier to resistance (e.g. entecavir) are recommended as first-line therapy of HBV-GN. Immunosuppression monotherapy, such as corticosteroids, is of little benefit and potentially harmful to HBV-GN patients due to the possibility of viral reactivation.

Adverse events of nucleos(t)ide analogues for chronic hepatitis B: a systematic review

Nucleos(t)ide analogues (NAs) are the main drug category used in chronic hepatitis B (CHB) treatment. Despite the fact that NAs have a favourable safety profile, undesired adverse events (AEs) may occur during the treatment of CHB. Given the eminent number of patients currently receiving NAs, even a small risk of any of these toxicities can represent a major medical issue. The main objective of this review was to analyse information available on AEs associated with the use of NAs in published studies. We choose the following MesH terms for this systematic review: chronic hepatitis B, side effects and treatment. All articles published from 1 January 1990 up to 19 February 2018 in MEDLINE of PubMed, EMBASE, the Cochrane Library and LILACS databases were searched. A total of 120 articles were selected for analysis, comprising 6419 patients treated with lamivudine (LAM), 5947 with entecavir (ETV), 3566 with tenofovir disoproxil fumarate (TDF), 3096 with telbivudine (LdT), 1178 with adefovir dipivoxil (ADV) and 876 with tenofovir alafenamide (TAF). The most common AEs in all NAs assessed were abdominal pain/discomfort, nasopharyngitis/upper respiratory tract infections, fatigue, and headache. TAF displays the highest density of AEs per patient treated among NAs (1.14 AE/treated patient). In conclusion, treatment of CHB with NAs is safe, with a low incidence of AEs. Despite the general understanding TAF being safer than TDF, the number of patients treated with TAF still is too small in comparison to other NAs to consolidate an accurate safety profile. PROSPERO Registration No. CRD42018086471.

Present and Future Therapies for Chronic Hepatitis B

Chronic hepatitis B (CHB) remains the leading cause of liver-related morbidity and mortality across the world. If left untreated, approximately one-third of these patients will progress to severe end-stage liver diseases including liver failure, cirrhosis, and hepatocellular carcinoma (HCC). High level of serum HBV DNA is strongly associated with the development of liver failure, cirrhosis, and HCC. Therefore, antiviral therapy is crucial for the clinical management of CHB. Current antiviral drugs including nucleoside/nucleotide analogues (NAs) and interferon-α (IFN-α) can suppress HBV replication and reduce the progression of liver disease, thus improving the long-term outcomes of CHB patients. This chapter will discuss the standard and optimization antiviral therapies in treatment-naïve and treatment-experienced patients, as well as in the special populations. The up-to-date advances in the development of new anti-HBV agents will be also discussed. With the combination of the current antiviral drugs and the newly developed antiviral agents targeting the different steps of the viral life cycle or the newly developed agents modulating the host immune responses, the ultimate eradication of HBV will be achieved in the future.

Antiviral Therapy for AECHB and Severe Hepatitis B (Liver Failure)

This chapter describes the principles of antiviral therapy, treatment strategies, medications and recommendations for AECHB, HBV-ACLF, HBV-related liver cirrhosis, HBV-related HCC, and liver transplantation.

Severe exacerbation of chronic hepatitis B is closely related to continuous HBV replication. Therefore, inhibiting HBV replication to reduce viral load may block disease progression and improve the quality of life of these patients. ETV or TDF has been recommend first-line drug for the treatment of AECHB.

A hyperactive immune response due to continuous HBV replication is the main mechanism for development of severe hepatitis B. In addition to comprehensive treatment, early administration of potent nucleoside analogs can rapidly reduce HBV DNA concentration, relieve immune injury induced by HBV, and reduce liver inflammation and patient mortality. Antiviral agents have become important in the treatment of severe exacerbation of chronic hepatitis B.

Long-term antiviral treatment with nucleoside analogs can delay or reverse the progress of liver cirrhosis. Virologic response, viral resistance and adverse drug reactions should be closely monitored during treatment. The treatment should be optimized for maximum effect based on each patient’s responses.

Effective antiviral therapy can suppress HBV replication and reduce the incidence of HBV-related HCC. Patients with HBV-related HCC should receive individualized and optimal multidisciplinary comprehensive treatment. Anti-viral drugs with high efficacy, low resistance and low adverse drug reactions should be selected to improve the patient’s quality of life and prolong survival time.

Methods to prevent HBV reinfection after liver transplantation include passive immunization (HBIG), antiviral treatment (nucleoside analogs) and active immunization (hepatitis B vaccine).

Clinical trials involving sequential combination therapy with NUC and Peg-IFN have shown statistically significant decline in HBsAg levels on treatment and high rates of sustained post-treatment serologic response. Combination therapy with novel DAA and immunotherapeutic approach may hold promise to overcome both cccDNA persistence and immune escape, representing a critical step towards HBV cure.

Novel fluoronucleoside analog NCC inhibits lamivudine-resistant hepatitis B virus in a hepatocyte model

Antiviral drug resistance is the most important factor contributing to treatment failure using nucleos(t)ide analogs such as lamivudine for chronic infection with hepatitis B virus (HBV). Development of a system supporting efficient replication of clinically resistant HBV strains is imperative, and new antiviral drugs are needed urgently to prevent selection of drug-resistant HBV mutants. A novel fluorinated cytidine analog, NCC (N-cyclopropyl-4′-azido-2′-deoxy-2′-fluoro-β-d-cytidine), was recently shown to strongly inhibit human HBV in vitro and in vivo. This study was designed to evaluate the antiviral activity of NCC against lamivudine-resistant HBV. We generated a stable cell line encoding the major pattern of lamivudine-resistant mutations rtL180M/M204V and designated it “HepG2.RL1”. Immuno-transmission electron microscopic examination and enzyme-linked immunosorbent assay were used to detect secretion of HBV-specific particles and antigens. Quantification of extracellular DNA and intracellular DNA of HepG2.RL1 cells by quantitative real-time polymerase chain reaction revealed >625-fold and >5556-fold increases in the 50% inhibitory concentration of lamivudine, respectively, compared with that for the wild-type virus. The results showed that NCC inhibited DNA replication and HBeAg production in wild-type or lamivudine-resistant HBV in a dose-dependent manner. In conclusion, screening for antiviral compounds active against lamivudine-resistant HBV can be carried out with relative ease using hepG2.RL1 cells. NCC is a potential antiviral agent against wild-type HBV and clinical lamivudine-resistant HBV and deserves evaluation for the treatment of HBV infection.

Butyrate inhibits HBV replication and HBV-induced hepatoma cell proliferation via modulating SIRT-1/Ac-p53 regulatory axis

Butyrate, a histone deacetylase inhibitor, has several therapeutic applications, including cancer. However, the effect of butyrate in HBV replication is not known so far. It was hypothesized that butyrate might inhibit HBV replication and host cell proliferation via SIRT-1. It was found that the increased expression of SIRT-1 in Hep G2.2.15 cells (HBV expressing cells) than Hep G2 cells. Next the expression of SIRT-1 and Acetylated p53 (Ac-p53) were measured in the liver biopsy samples of chronic hepatitis B (CHB) patients with high viral load and compared to CHB patients with low viral load and found that there was a high SIRT-1 expression and a low Ac-p53 levels in CHB patients with high viral load compared to CHB patients with low viral load. Incubation of butyrate inhibited SIRT-1 expression and cell proliferation. Inhibition of SIRT-1 by butyrate or SIRT-1 siRNA increased the levels of Ac-p53. The elevated Ac-p53 decreased p-akt, cyclin D1, and thereby inhibited cell proliferation. Incubation of butyrate with Hep G2.2.15 cells also inhibited HBx protein expression, HBV-DNA and hepatitis B surface antigen (HBsAg). Taken together, the data showed that butyrate inhibited HBV replication and cell proliferation by inhibiting SIRT-1 expression in hepatoma cells.

Comprehensive Proteomics Identification of IFN-λ3-regulated Antiviral Proteins in HBV-transfected Cells

Interferon lambda (IFN-λ) is a relatively unexplored, yet promising antiviral agent. IFN-λ has recently been tested in clinical trials of chronic hepatitis B virus infection (CHB), with the advantage that side effects may be limited compared with IFN-α, as IFN-λ receptors are found only in epithelial cells. To date, IFN-λ's downstream signaling pathway remains largely unelucidated, particularly via proteomics methods. Here, we report that IFN-λ3 inhibits HBV replication in HepG2.2.15 cells, reducing levels of both HBV transcripts and intracellular HBV DNA. Quantitative proteomic analysis of HBV-transfected cells was performed following 24-hour IFN-λ3 treatment, with parallel IFN-α2a and PBS treatments for comparison using a dimethyl labeling method. The depth of the study allowed us to map the induction of antiviral proteins to multiple points of the viral life cycle, as well as facilitating the identification of antiviral proteins not previously known to be elicited upon HBV infection (e.g. IFITM3, XRN2, and NT5C3A). This study also shows up-regulation of many effectors involved in antigen processing/presentation indicating that this cytokine exerted immunomodulatory effects through several essential molecules for these processes. Interestingly, the 2 subunits of the immunoproteasome cap (PSME1 and PSME2) were up-regulated whereas cap components of the constitutive proteasome were down-regulated upon both IFN treatments, suggesting coordinated modulation toward the antigen processing/presentation mode. Furthermore, in addition to confirming canonical activation of interferon-stimulated gene (ISG) transcription through the JAK-STAT pathway, we reveal that IFN-λ3 restored levels of RIG-I and RIG-G, proteins known to be suppressed by HBV. Enrichment analysis demonstrated that several biological processes including RNA metabolism, translation, and ER-targeting were differentially regulated upon treatment with IFN-λ3 versus IFN-α2a. Our proteomic data suggests that IFN-λ3 regulates an array of cellular processes to control HBV replication.

Predictors of Therapeutic Outcome to Nucleotide Reverse Transcriptase Inhibitor in Hepatitis B Patients

Hepatitis B is a clinically important public health issue. Infection leads to hepatocellular carcinoma. Therefore, patients need antiviral therapy for prolonged period to prevent the complication of the disease. Data concerning chronic hepatitis B (CHB) patients with high hepatitis B virus (HBV) DNA are limited. The aim of the study was to check the efficacy of the nucleoside reverse transcriptase inhibitors (tenofovir) in terms of suppression of HBV DNA. The secondary end point in the study is to evaluate trends of predictive variables that predict outcome of treatment. In this specific study, we evaluated 140 CHB male and female patients, of these 110 completed 48 weeks of treatment. On the basis of hepatitis B e antigen (HBeAg), patients were stratified; HBV DNA and hepatitis B surface antigen (HBsAg) levels were measured along with liver function tests. All enrolled patients were given tenofovir disoproxil fumarate 300 mg daily before breakfast. Overall, 69.1% of patients showed virologic response. HBeAg-negative patient group showed 68% viral suppression and HBeAg-positive patient group showed 45.9% over 24 months of treatment, while at 48 months it was shown to be 76.7% and 54.1%, respectively. None of the patients suffered HBsAg loss during the 48 months. Baseline high HBV DNA level was found as a significant predictor of response (OR, 1.9; 95% CI = 1.23-3.9, p = 0.005). None of the patients observed had serious adverse events. Mutations in the RT region of polymerase gene are shown to be associated with resistance to antiviral drugs. Among patients suffering with chronic HBV infection, HBeAg-negative patient group have better virologic response as compared with HBeAg-positive group. Higher concentration of HBV DNA at baseline has negative prediction for sustained viral suppression. The A-B motif interdomain rtL122F mutation was found in nonresponder patients in our study. Another mutation rtN248H observed in E motif considered to have effect on DNA primer grip, which forms part of binding pocket.

Evaluation of performance characteristics of hepatitis B e antigen serologic assays

BACKGROUND

Hepatitis B e antigen (HBeAg) is considered an indicator of high hepatitis B virus (HBV) replication. Performance characteristics of commercially available HBeAg assays have not been determined, thus it is unknown whether lack of HBeAg detection is because of test sensitivity or HBV basal core promoter and precore mutations.

OBJECTIVES

We studied the correlation between HBeAg reactivity with HBV DNA levels in three commercially available HBeAg assays using 335 HBsAg and HBV DNA positive serum/plasma samples.

STUDY DESIGN

Diagnostic sensitivity was determined by serial dilutions of a WHO HBeAg standard. The limit of HBeAg detection estimated through regression was 1 IU/mL (Centaur), 97 IU/mL (DiaSorin) and 129 IU/mL (Vitros). Of these 335 samples, enough sample volume remained in 253 samples for head-to-head comparison of the assays.

RESULTS

81 (32%), 41 (16%) and 36 (14%) of the samples were HBeAg positive by the Centaur, DiaSorin and Vitros assays, respectively. Compared to the FDA-approved Centaur assay the specificity of the other two assays was 98%, while sensitivity was 47% for the DiaSorin assay and 41% for the Vitros assay. Significant association was found between HBeAg positive samples and HBV DNA levels >20,000 IU/mL; 31% of HBeAg negative samples (Centaur) had HBV DNA levels >20,000 IU/mL, 26% of HBeAg positive samples had HBV DNA levels <20,000 IU/mL and 5 HBeAg positive samples had HBV DNA levels <2000 IU/mL.

CONCLUSION

Discordance was seen between these HBeAg assays, indicating reliance on HBeAg alone as a marker of high HBV replication can be misleading. Detection and quantification of HBV DNA remains the accurate and reliable marker of HBV replication.

Long Non-coding RNAs: Regulators of Viral Infection and the Interferon Antiviral Response

Interferons (IFNs) are a family of cytokines providing a robust first line of host innate defense against pathogenic infection, and have now been part of the standard treatment for viral infection. However, IFN based therapy can best be described as modestly effective. Long non-coding RNAs (lncRNAs) are a novel class of non-protein-coding RNAs that are capable of regulating gene expression at different levels, including chromatin, transcription, post-transcription, and translation. Recently, lncRNAs are found to be deregulated upon viral infection or IFN treatment, and some of them can modulate viral infection in an IFN-dependent or -independent manner. Due to the crucial roles of lncRNAs in viral infection and the IFN antiviral response, the modulation of specific lncRNAs may be involved to increase the IFN antiviral response and improve the clinical result of IFN-based therapy. In this review, we summarize lncRNAs that are deregulated by viral infection, with special focus on the functions and underlying mechanisms of some essential lncRNAs, and discuss their roles in viral infection and the antiviral response of IFN.

Entecavir and tenofovir reduce hepatitis B virus-related hepatocellular carcinoma recurrence more effectively than other antivirals

Nucleos(t)ide analogues (NAs) have been shown to decrease the risk of hepatocellular carcinoma (HCC) recurrence. This study evaluated whether high-potency NAs (entecavir and tenofovir disoproxil fumarate [TDF]) reduce the risk of tumour recurrence more potently than low-potency NAs after curative treatment of hepatitis B virus (HBV)-related HCC. This study included 607 consecutive HBV-related HCC patients treated with surgical resection or radiofrequency ablation. The patients were categorized into three groups according to antiviral treatment: group A (no antiviral; n = 261), group B (low-potency NA; n = 90) and group C (high-potency NA; n = 256). The primary end-point was recurrence-free survival (RFS). During the duration of follow-up, the median RFS was 29.4, 25.1, and 88.2 months in groups A, B and C, respectively (P < .001, log-rank test). The multivariate Cox analysis indicated that group C had a significantly longer RFS than both group A (adjusted hazard ratio [HR] = 0.39, P < .001) and group B (adjusted HR = 0.47, P < .001). When baseline characteristics were balanced using inverse probability weighting, group C still had a significantly longer RFS than group A (adjusted HR = 0.46, P < .001) and group B (adjusted HR = 0.59, P = .007). Group C had significantly lower risk of viral breakthrough than group B (HR = 0.19, P < .001). Viral breakthrough was an independent risk factor for shorter RFS among groups B and C (adjusted HR = 2.03, P = .007, time-dependent Cox analysis). Antiviral agents with high genetic barrier to resistance (entecavir and TDF) reduced the risk of HCC recurrence compared with other antivirals and no antiviral treatment, especially in patients with high baseline viral load.

Using the chronic kidney disease guidelines to evaluate the renal safety of tenofovir disoproxil fumarate in hepatitis B patients

BACKGROUND

Renal dysfunction remains an issue in tenofovir disoproxil fumarate (TDF) for chronic hepatitis B (CHB) patients.

AIM

To evaluate renal safety of TDF according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines.

METHODS

We retrospectively recruited CHB patients who received either TDF or entecavir (ETV) monotherapy from January 2008 to August 2015. After excluding confounding conditions, 253 patients who received TDF were randomly matched 1:2 with 506 patients who received ETV through the propensity scores, which consisted of age, gender, cirrhosis, chronic kidney disease (CKD) and estimated glomerular filtration rate (eGFR). Renal function deterioration was defined as a drop in GFR category accompanied with a ≥25% eGFR decline. Cumulative incidences of and hazard ratios (HRs) for renal dysfunction were analysed.

RESULTS

The mean eGFR decline was significantly greater in the TDF group over 48 months (TDF vs ETV: 15.73 mL/min/1.73 m² , 95% confidence interval [CI]: 13.76-17.70 vs 5.96 mL/min/1.73 m² , 95% CI: 4.72-7.19; P < 0.001). The cumulative incidence of renal function deterioration was significantly higher in the TDF group (TDF vs ETV: 11.1%, 95% CI: 7.4-14.8 vs 1.7%, 95% CI: 1.0-2.4; P < 0.001). After adjusting for age, pre-existing CKD and diabetes, TDF was independently associated with an increased risk of renal function deterioration (HR 5.36, 95% CI: 2.16-13.35; P < 0.001). Pre-existing CKD (HR 6.71, 95% CI: 2.25-17.65), proteinuria (HR 3.39, 95% CI: 1.23-9.39), and haematuria (HR 4.25, 95% CI: 1.32-13.68) were also independent factors of renal dysfunction.

CONCLUSION

By following the KDIGO guidelines, we confirmed that TDF was associated with a higher risk of renal dysfunction as compared to ETV.

Efficacy of Transarterial Chemoembolisation with or without Antiviral Therapy for Patients with Hepatocellular Carcinoma after Radical Hepatectomy

Objective

This study aimed at assessing the effects of transcatheter arterial chemoembolisation (TACE) and antiviral therapy on improving the prognosis of patients with hepatocellular carcinoma (HCC) after radical hepatectomy.

Methods

This study reviewed the data of 120 patients with HCC who received either radical hepatectomy alone (control group), radical hepatectomy with postoperative TACE (TACE group) or radical hepatectomy with combined postoperative TACE, and antiviral therapy (combined group) from January 2000 to May 2015. To reduce the impact of the possible biases on the conclusion of this study to the minimum, the cases with similar demographic and clinicopathological characteristics were collected and 40 cases were assigned into each group. Recurrence, disease-free survival (DFS), and overall survival (OS) rates were compared.

Results

Median follow-up period was 54.26 ± 22.65 months with a range of 17–110 months. Recurrence after radical surgery was observed for 39 (97.5%) patients in the TACE group, 32 (80%) in the combined group, and 40 (100%) in the control group with median recurrence duration of 33, 43, and 16.5 months, respectively. Postoperative TACE with or without antiviral therapy significantly prolonged the DFS rate compared with radical hepatectomy alone (P = 0.000). TACE combined with antiviral therapy significantly extended the DFS rate compared with TACE alone (P = 0.008). Postoperative TACE with or without antiviral therapy also significantly prolonged the OS rate compared with radical hepatectomy alone (P = 0.000). In addition, antiviral therapy combined with TACE significantly extended the 5-year OS rate of patients compared with individual TACE and radical hepatectomy (67.5% versus 55% and 2.5%; P = 0.032).

Conclusion

TACE is an appropriate therapy for HCC patients after radical hepatectomy. When combined with antiviral therapy, this treatment may further prolong the recurrence time and thus lead to high DFS and OS rates.

Advances with using CRISPR/Cas-mediated gene editing to treat infections with hepatitis B virus and hepatitis C virus

Chronic infections with hepatitis B and hepatitis C viruses (HBV and HCV) account for the majority of cases of cirrhosis and hepatocellular carcinoma. Current therapies for the infections have limitations and improved efficacy is necessary to prevent complications in carriers of the viruses. In the case of HBV persistence, the replication intermediate comprising covalently closed circular DNA (cccDNA) is particularly problematic. Licensed therapies have little effect on cccDNA and HBV replication relapses following treatment withdrawal. Disabling cccDNA is thus key to curing HBV infections and application of gene editing technology, such as harnessing the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system, has curative potential. Several studies have reported good efficacy when employing CRISPR/Cas technologies to disable HBV replication in cultured cells and in hydrodynamically injected mice. Recent advances with HCV drug development have revolutionized treatment of the infection. Nevertheless, individuals may be refractory to treatment. Targeting RNA from HCV with CRISPR/Cas isolated from Francisella novicida may have therapeutic utility. Although preclinical work shows that CRISPR/Cas technology has potential to overcome infection with HBV and HCV, significant challenges need to be met. Ensuring specificity for viral targets and efficient delivery of the gene editing sequences to virus-infected cells are particularly important. The field is at an interesting stage and the future of curative antiviral drug regimens, particularly for treatment of chronic HBV infection, may well entail use of combinations that include derivatives of CRISPR/Cas.

Long-term outcome of telbivudine versus entecavir in treating higher viral load chronic hepatitis B patients without cirrhosis

Chronic hepatitis B (CHB) patients with higher hepatitis B virus (HBV) load (higher viral load [HVL], HBV DNA ≥1 × 10⁷ copies/mL) require antiviral therapy, but data for evaluating the long-term outcome of this therapy with antiviral agents remain limited. We comparatively evaluated the efficacy and the safety of nucleoside analogues in 179 noncirrhotic CHB patients with HVL over 5 years. The HBeAg-positive (n = 104) or HBeAg-negative (n = 75) patients were treated consecutively with telbivudine (LdT, n = 88) or entecavir (ETV, n = 91) and evaluated for viral response, drug resistance and safety. HBV DNA, viral serology, biochemistries, HBV mutation and off-therapy relapse were determined. The cumulative rates of HBV DNA negativity were 86.4% and 94.5% for LdT and ETV at year 5, respectively. The rates of early viral response (EVR, HBV DNA <10³ copies/mL at month 6) under LdT and ETV treatments were 58.0% and 34.1%, respectively (P < .05). Hepatitis B e antigen (HBeAg) and Hepatitis B surface antigen (HBsAg) loss-seroconversions were 47.7% and 18.2% on LdT and 16.5% and 2.2% on ETV (P < .01). Eighteen patients (age 28.2 ± 3.1) experienced HBsAg loss-seroconversion, followed by 33 ± 4.6 month off-therapy without a relapse. Viral mutations and serum creatine kinase elevation were 9.1% and 8.0% on LdT, but only 1.1% and 0% on ETV. Both LdT and ETV suppressed HBV replication in HVL CHB patients within 5 years. LdT therapy achieved a higher EVR, HBeAg and HBsAg seroconversion, especially in the younger patients, whereas ETV caused lower drug resistance and fewer adverse events. This finding might help to identify the optimal treatment for CHB patients with HVL.

Performance verification and comparison of TianLong automatic hypersensitive hepatitis B virus DNA quantification system with Roche CAP/CTM system

AIM

To investigate and compare the analytical and clinical performance of TianLong automatic hypersensitive hepatitis B virus (HBV) DNA quantification system and Roche CAP/CTM system.

METHODS

Two hundred blood samples for HBV DNA testing, HBV-DNA negative samples and high-titer HBV-DNA mixture samples were collected and prepared. National standard materials for serum HBV and a worldwide HBV DNA panel were employed for performance verification. The analytical performance, such as limit of detection, limit of quantification, accuracy, precision, reproducibility, linearity, genotype coverage and cross-contamination, was determined using the TianLong automatic hypersensitive HBV DNA quantification system (TL system). Correlation and Bland-Altman plot analyses were carried out to compare the clinical performance of the TL system assay and the CAP/CTM system.

RESULTS

The detection limit of the TL system was 10 IU/mL, and its limit of quantification was 30 IU/mL. The differences between the expected and tested concentrations of the national standards were less than ± 0.4 Log₁₀ IU/mL, which showed high accuracy of the system. Results of the precision, reproducibility and linearity tests showed that the multiple test coefficient of variation (CV) of the same sample was less than 5% for 10²-10⁶ IU/mL; and for 30-10⁸ IU/mL, the linear correlation coefficient r² = 0.99. The TL system detected HBV DNA (A-H) genotypes and there was no cross-contamination during the “checkerboard” test. When compared with the CAP/CTM assay, the two assays showed 100% consistency in both negative and positive sample results (15 negative samples and 185 positive samples). No statistical differences between the two assays in the HBV DNA quantification values were observed (P > 0.05). Correlation analysis indicated a significant correlation between the two assays, r² = 0.9774. The Bland-Altman plot analysis showed that 98.9% of the positive data were within the 95% acceptable range, and the maximum difference was -0.49.

CONCLUSION

The TL system has good analytical performance, and exhibits good agreement with the CAP/CTM system in clinical performance.

Long-term trends in chronic hepatitis B virus infection associated liver transplantation outcomes in the United States

With effective antiviral therapies, rates of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) and decompensated liver disease requiring liver transplantation (LT) are expected to decrease. We aim to evaluate overall trends in LT waitlist registrations, waitlist survival and likelihood of receiving LT among chronic HBV patients in the United States. Using the United Network for Organ Sharing database, we retrospectively evaluated adults (age≥18) with chronic HBV (with and without HCC) listed for LT from 1992 to 1996 (Era 1) vs 1997 to 2004 (Era 2) vs 2005-2015 (Era 3). Multivariate Cox-regression models evaluated probability of waitlist survival and receiving LT. Overall, 6797 chronic HBV adults were listed for LT. While the total number of HBV patients listed for LT remained stable, the proportion of HBV patients with HCC increased from 5.4% in Era 1 to 39.0% in Era 3. Compared to Era 1, waitlist mortality was higher in Era 2 (HR: 4.55, P<.001) and Era 3 (HR: 3.63, P<.001). However, in the most recent era, waitlist mortality significantly improved (compared to 2005-2007: 2008-2011: HR: 0.74, P=.05, 95% CI: 0.55-0.99; 2012-2015: HR: 0.53, P<.001, 95% CI: 0.38-0.75). Probability of receiving LT was also lower with latter time periods (compared to 2005-2007: 2008-2011: HR: 0.77, P<.001 95% CI: 0.68-0.86; 2012-2015: HR: 0.61, P<.001, 95% CI: 0.54-0.69). Although the number of HBV patients requiring LT remained stable, the proportion of HBV patients with HCC continues to rise. The decrease in waitlist mortality and lower likelihood of LT among HBV patients may reflect the effectiveness of antiviral therapies in delaying disease progression in the current era.

Enhanced antiviral and antifibrotic effects of short hairpin RNAs targeting HBV and TGF-β in HBV-persistent mice

The hepatitis B virus (HBV) causes acute and chronic liver infection, which may lead to liver cirrhosis and hepatocellular carcinoma. Current treatments including interferons and nucleotide analogs, have limited therapeutic effects, underscoring the need to identify effective therapeutic options to inhibit HBV replication and prevent complications. Previous animal models mimicking chronic HBV infection do not faithfully reflect disease progression in humans. Here, we used our established HBV-persistent mouse line with liver fibrosis to evaluate the efficacy of novel therapies. The combination of two short hairpin RNAs (dual-shRNA) against different coding regions of HBV delivered by a self-complementary AAV vector showed better antiviral effects than single shRNA both in vitro and in HBV-persistent mice. The dual-shRNA also exhibited stronger antifibrotic activity in vivo. Vector carrying shRNA against TGF-β, though did not inhibit HBV replication alone, enhanced the antiviral and antifibrotic activities of single and dual HBV shRNAs. Co-administration of TGF-β shRNA and HBV dual-shRNA decreased HBV DNA, HBV RNA, HBsAg, HBeAg, and liver fibrosis markers in serum and tissues, and improved liver morphology more effectively than single treatments. Our results suggest that the combination of shRNAs against HBV and TGF-β could be developed into a viable treatment for human HBV infection.

The Effect of Hepatosteatosis on Response to Antiviral Treatment in Patients with Chronic Hepatitis B: A Meta-Analysis

Background. This study is to systematically analyze the effects of hepatosteatosis on the response to antiviral treatment in patients with chronic hepatitis B (CHB) and hepatosteatosis. Methods. Systematic search was performed in PubMed, Embase, Web of Science, Elsevier, and the Chinese BioMedical literature databases for relevant studies published until February 2016. Treatment outcomes were compared between patients with CHB plus concomitant hepatosteatosis and those without hepatosteatosis. Results. A total of 8 prospective cohort studies (399 patients with CHB plus hepatosteatosis and 688 patients with only CHB) were included. Biochemical and virological response at both 48 and 96 weeks were significantly lower in patients with CHB plus hepatosteatosis as compared to that in patients with only CHB. Subgroup analysis based on methods used for diagnosis of hepatosteatosis and treatment regimens showed that when hepatosteatosis was diagnosed on Doppler ultrasound and treated with nucleotide analogues, patients with CHB plus hepatosteatosis showed lower biochemical (62.7% versus 75.8%, P = 0.002) and virological response (66.2% versus 72.3%, P = 0.006) as compared to that in patients with CHB. Conclusion. Hepatosteatosis lowers the efficacy of antiviral treatment in patients with CHB, especially when hepatosteatosis was diagnosed on ultrasound findings and treated with nucleotide analogues.

Associations between prescribed Chinese herbal medicine and risk of hepatocellular carcinoma in patients with chronic hepatitis B: a nationwide population-based cohort study

OBJECTIVE

Patients with chronic hepatitis B (CHB) are reported to exhibit higher risk of subsequent hepatocellular carcinoma (HCC). However, it remains unclear if Chinese herbal medicine (CHM), an important category of traditional Chinese medicine (TCM), may lower HCC risk in this population. So this study aimed to investigate the effects of CHM on HCC risk among patients with CHB.

METHODS

This cohort study used the Taiwanese National Health Insurance Research Database to identify 21 020 newly diagnosed patients with CHB from 1998 to 2007. Among them, 8640 received CHM products after CHB onset (CHM users), and the remaining 12 380 patients were designated as a control group (non-CHM users). All enrolees were followed until the end of 2012 to measure the incidence rate and HR of HCC.

RESULTS

During 15 years of follow-up, 371 CHM users and 958 non-CHM users developed HCC, representing an incidence rate of 5.28% and 10.18% per 1000 person-years, respectively. CHM users had significantly lower HCC risk compared with non-CHM users (adjusted HR=0.63, 95% CI 0.56 to 0.72). The predominant effect was observed in those receiving CHM products for more than 180 days (adjusted HR=0.52). Some CHM products, such as Hedyotis diffusa, Scutellaria barbata, Rehmannia glutinosa, Isatis tinctoria, Yi Guan Jian, Xiao Chai Hu Tang, Wu Ling San and Gan Lu Yin, were significantly associated with lower risk of HCC.

CONCLUSIONS

The use of CHM was associated with a significantly reduced HCC risk in patients with CHB, which supports the integration of TCM with CHM into clinical practice to influence a favourable prognosis.

A review of strategies to prevent mother-to-infant transmission of hepatitis B virus infection

Hepatitis B virus (HBV) infection causes long-term, life-threatening liver diseases worldwide. HBV is transmitted through either the horizontal or mother-to-infant route, which is the major route of transmission in endemic areas. Administration of hepatitis B immunoglobulin and hepatitis B vaccine to newborns of infected mothers prevents mother-to-infant transmission. Implementation of a universal hepatitis B vaccination program has proven successful in eliminating the infection and related complications. Nevertheless, efforts are still needed to improve global coverage of the hepatitis B vaccine. Infants born to highly viremic mothers are still at risk of infection despite current immunoprophylaxis. An increasing number of reports have shown promising efficacy and safety profiles with the use of nucleoside/nucleotide analogues in highly viremic pregnant women to prevent mother-to-infant transmission.

Prevalence and risk factors for viral blipping in chronic hepatitis B patients treated with nucleos (t) ide analogues

The clinical relevance of viral blipping during nucleos (t) ide analogue (NA) treatment is unclear in chronic hepatitis B (CHB). We investigated the prevalence, risk factors and clinical outcomes for those with viral blipping during NA treatment. A retrospective cohort study investigated consecutively treated CHB patients from May 2008 to February 2015 on the NAs such as entecavir (ETV), tenofovir (TDF) and lamivudine (LAM). Included patients were previously treatment naive. Viral blipping was defined as serum HBV DNA >20 IU/mL on one occasion, and not >200 IU/mL, with subsequent measurement returning to undetectable levels, that is <20 IU/mL. A total of 242 treatment-compliant CHB patients were included with 44 (18.2%) experiencing viral blipping. In multivariable Cox regression, Asian race (HR=7.40, 95% CI 1.01-54.29, P<.049), LAM therapy (vs ETV/TDF, HR=2.53, 95% CI 1.29-4.95, P<.007), higher creatinine (per SD, HR=1.47, 95% CI 1.21-1.79, P<.001), HBeAg positivity (HR=2.68, 95% CI 1.39-5.03, P<.003) and longer time to achieve undetectable HBV DNA (per month, HR=1.05, 95% CI 1.02-1.08, P=.001) were associated with an increased risk of viral blipping. Viral blipping did not show any significant association with viral breakthrough, HBsAg loss, ALT flares or disease progression. Viral blipping is a frequent event during NA therapy; however, it did not lead to any clinically significant outcomes. Thus, it may not require more frequent blood work and patient visits in clinical practice.

Efficacy of switching from adefovir to tenofovir in chronic hepatitis B patients who exhibit suboptimal responses to adefovir-based combination rescue therapy due to resistance to nucleoside analogues (SATIS study)

Background/Aims

It remains to be determined whether switching from adefovir (ADV) to tenofovir (TDF) provides better virological outcomes in patients exhibiting suboptimal responses to ADV plus nucleoside analogue (ADV+NA) therapy for NA-resistant chronic hepatitis B (CHB).

Methods

In this prospective trial, patients who showed partial responses (defined as serum hepatitis B virus [HBV] DNA >60 IU/mL) to ADV+NA therapy for NA resistance were randomly allocated to receive TDF plus NA (TDF+NA group, n=16) or to continue their current therapy (ADV+NA group, n=16). The primary end point was the proportion of patients with complete virological response (CVR, defined as serum HBV DNA <60 IU/mL) at 48 weeks.

Results

The median age was 52 years (16 men), and 28 were positive for hepatitis B e antigen (HBeAg). The baseline characteristics did not differ significantly between the two groups. The proportion with CVR was significantly higher in the TDF+NA group than in the ADV+NA group at 24 weeks (81.3% vs. 25.0%, P=0.001) and 48 weeks (87.5% vs. 37.5%, P=0.002). Furthermore, a decrease in the serum HBV DNA level of >2log₁₀ IU/mL was more likely in the TDF+NA group at both 24 and 48 weeks (68.8% vs. 56.3%, P=0.014 vs. 81.3% vs. 56.3%, P=0.001, respectively). During the follow-up, the rate of HBeAg seroconversion was higher in the TDF+NA group than the ADV+NA group (12.5% vs. 6.25%, P=0.640), as was that for the hepatitis B surface antigen (6.25% vs. 0%, P=0.080). No serious adverse events due to antiviral agents occurred.

Conclusion

In patients exhibiting suboptimal responses to ADV+NA therapy for NA-resistant CHB, switching from ADV to TDF might provide better virological outcomes.

An evaluation of entecavir for the treatment of chronic hepatitis B infection in adults

Entecavir is a nucleoside analogue of 2'-deoxyguanosine whose intracellular triphosphate form inhibits replication of the hepatitis B virus. Entecavir is recommended as a first-line monotherapy option for nucleos(t)ide-naïve patients with HBeAg-positive or -negative chronic hepatitis B infection. Entecavir has a three-step mechanism of action: It maintains viral suppression with a greater than 90% chance of undetectable hepatitis B virus DNA during continuous therapy, improves liver histology, and reduces the risk of liver failure or hepatocellular carcinoma development. The safety profile of long-term entecavir therapy is favorable; however, its optimal treatment duration is unknown. Entecavir monotherapy is not a rescue option for patients with lamivudine/adefovir resistance or baseline lamivudine-resistant mutants; rather, combination treatment is recommended for patients with lamivudine/adefovir resistance.

Research and Development of Hepatitis B Drugs: An Analysis Based on Technology Flows Measured by Patent Citations

Despite the existence of available therapies, the Hepatitis B virus infection continues to be one of the most serious threats to human health, especially in developing countries such as China and India. To shed light on the improvement of current therapies and development of novel anti-HBV drugs, we thoroughly investigated 212 US patents of anti-HBV drugs and analyzed the technology flow in research and development of anti-HBV drugs based on data from IMS LifeCycle databases. Moreover, utilizing the patent citation method, which is an effective indicator of technology flow, we constructed patent citation network models and performed network analysis in order to reveal the features of different technology clusters. As a result, we identified the stagnant status of anti-HBV drug development and pointed the way for development of domestic pharmaceuticals in developing countries. We also discussed about therapeutic vaccines as the potential next generation therapy for HBV infection. Lastly, we depicted the cooperation between entities and found that novel forms of cooperation added diversity to the conventional form of cooperation within the pharmaceutical industry. In summary, our study provides inspiring insights for investors, policy makers, researchers, and other readers interested in anti-HBV drug development.

Factors associated with HBV virological breakthrough

BACKGROUND

Little is known about non-adherence to HBV therapy. This study aimed to investigate the relationship between self-reported missed days of antiviral therapy and HBV virological breakthrough and factors associated with virological breakthrough.

METHODS

A cross-sectional survey of 211 HBV patients receiving oral antiviral therapies was undertaken at three tertiary hospitals in Sydney, Australia. Associations between 0 to >6 missed days in the last 30 days and virological breakthrough (defined as >10-fold rise in serum HBV DNA above nadir or after achieving virological response in the last 12 months) were examined. Logistic regression analyses determined the number of missed days most strongly associated with virological breakthrough and the associated factors. We report odds ratios (ORs) and relative risks (RRs).

RESULTS

Of the 204, 32 participants (15.6%) had quantifiable HBV DNA levels (>20 IU/ml); 15 (46.8%) of them experienced virological breakthrough. Participants reported never missing medication (n=130, 63.7%) or missing 1 day (n=23, 11.3%), >1 day (n=23, 11.3%), 2-6 days (n=15, 7.3%) and >6 days (n=13, 6.4%). The most discriminating definition of non-adherence was missing >1 day of medication (RR=8.3; OR=10.2, 95% CI 3.1, 33.8, receiver operating characteristic curve 0.76). Factors independently associated with virological breakthrough included non-adherence (OR=9.0, 95% CI 2.5, 31.9) diagnosed with HBV ≤14 years (OR=5.3, 95% CI 1.0, 26.2) and age ≤47 years (OR=5.4, 95% CI 1.1, 26.9).

CONCLUSIONS

Results provide an evidence-based definition of non-adherence to inform clinical practice and provide a basis for key patient education messages. Closer monitoring of groups at risk of viral breakthrough is required.

Comparison of the Effects of Telbivudine and Entecavir Treatment on Estimated Glomerular Filtration Rate in Patients with Chronic Hepatitis B

Background/Aims

The aim of this study was to evaluate the estimated glomerular filtration rate (eGFR) during telbivudine (LdT) versus entecavir (ETV) treatment in chronic hepatitis B (CHB) patients with underlying comorbidities such as diabetes mellitus (DM), hypertension, and cirrhosis.

Methods

From 2010 to 2012, 116 CHB patients treated with LdT and 578 treated with ETV were compared in this real-practice cohort. The mean changes in eGFR (Modification of Diet in Renal Disease [MDRD] formula) from baseline to months 6, 12, and 18 were analyzed using a linear mixed model.

Results

In LdT-treated patients, the mean eGFR increased by 7.6% at month 18 compared with the eGFR at baseline (MDRD formula in mL/min/1.73 m²). However, in ETV-treated patients, the mean eGFR decreased by 4.1% at month 18 compared with the eGFR at baseline. In the LdT-treated patients with DM, hypertension, cirrhosis or low eGFR <90 mL/min/1.73 m², the mean eGFR showed a steady improvement, whereas the mean eGFR was reduced in the same subgroups of ETV-treated patients.

Conclusions

The eGFR gradually increased over time during LdT treatment, especially in patients with mild abnormal eGFR at baseline, and in those with DM, hypertension, and cirrhosis, whereas a reduction in eGFR was seen with ETV treatment.

An Effective Molecular Target Site in Hepatitis B Virus S Gene for Cas9 Cleavage and Mutational Inactivation

Chronic hepatitis B infection remains incurable because HBV cccDNA can persist indefinitely in patients recovering from acute HBV infection. Given the incidence of HBV infection and the shortcomings of current therapeutic options, a novel antiviral strategy is urgently needed. To inactivate HBV replication and destroy the HBV genome, we employed genome editing tool CRISPR/Cas9. Specifically, we found a CRISPR/Cas9 system (gRNA-S4) that effectively targeted the HBsAg region and could suppress efficiently viral replication with minimal off-target effects and impact on cell viability. The mutation mediated by CRISPR/Cas9 in HBV DNA both in a stable HBV-producing cell line and in HBV transgenic mice had been confirmed and evaluated using deep sequencing. In addition, we demonstrated the reduction of HBV replication was caused by the mutation of S4 site through three S4 region-mutated monoclonal cells. Besides, the gRNA-S4 system could also reduce serum surface-antigen levels by 99.91 ± 0.05% and lowered serum HBV DNA level below the negative threshold in the HBV hydrodynamics mouse model. Together, these findings indicate that the S4 region may be an ideal target for the development of innovative therapies against HBV infection using CRISPR/Cas9.