Then and now: The progress in hepatitis B treatment over the past 20 years

Advances in the Pharmacological Management of Chronic Hepatitis B

BACKGROUND

Hepatitis B, a vaccine-preventable liver infection, remains a global public health problem. Dedicated groups of experts and funding are focusing on achieving a functional cure to eradicate this disease by 2030.

AREAS OF UNCERTAINTY

With more than 40 molecules available or under investigation as new treatments for hepatitis B virus (HBV) infection, none of them is curative so far. Available treatments are effective in suppressing HBV replication and in decreasing the risk of developing cirrhosis, liver failure, hepatocellular carcinoma, and death, but do not eliminate the virus, and the risk of hepatocellular carcinoma remains. Nucleoside/nucleotide analogs are recommended as first-line therapy for patients with chronic hepatitis B infection to inhibit viral replication and lower the HBV DNA values, but long-term therapy is usually needed to maintain suppression. Cessation of the therapy in accordance with clinical guidelines can result in virological and clinical relapse.

DATA SOURCES

PubMed, Web of Science, clinicaltrials.gov , and gray literature sources were searched for articles discussing HBV management and new therapies.

RESULTS

With current nucleoside/nucleotide analog therapies, fewer than 5% of patients lose hepatitis B surface antigen after 12 months, which underscores the need for new drugs that can achieve a functional cure. New therapies are being developed, including small interfering RNAs. Bepirovirsen, a modified antisense oligonucleotide, shows promising results and a good safety profile, but requires further exploration in larger number of patients to determine whether a functional cure is possible.

CONCLUSIONS

Eradication of HBV infection with currently available therapies is not yet possible. Experts are developing innovative treatments, such as bepirovirsen, to achieve functional cure for this disease and to reduce morbidity and mortality associated with hepatic cirrhosis and hepatocellular carcinoma.

Optimal Treatment Based on Interferon No Longer Makes Clinical Cure of Chronic Hepatitis B Far Away: An Evidence-Based Review on Emerging Clinical Data

Chronic hepatitis B (CHB) remains a major global public health problem. The functional cure is the ideal therapeutic target recommended by the latest guidelines, and pursuing a functional cure has become the key treatment end point of current therapy and for upcoming clinical trials. In this review, based on the latest published clinical research evidence, we analyzed the concept and connotation of clinical cures and elaborated on the benefits of clinical cures in detail. Secondly, we have summarized various potential treatment methods for achieving clinical cures, especially elaborating on the latest research progress of interferon-based optimized treatment strategies in achieving clinical cures. We also analyzed which populations can achieve clinical cures and conducted a detailed analysis of relevant virological and serological markers in screening clinical cure advantage populations and predicting clinical cure achievement. In addition, we also introduced the difficulties that may be encountered in the current pursuit of achieving a clinical cure.

The Epidemiology of Hepatitis B Virus Infection in Korea: 15-Year Analysis

BACKGROUND

The purpose of this study is to investigate the epidemiological changes in chronic hepatitis B (CHB) and assess the impact of coronavirus disease 2019 (COVID-19) over the past 15 years in a region endemic to hepatitis B virus (HBV).

METHODS

National Health Insurance Service claims data of hepatitis B patients spanning from 2007 to 2021 was utilized. To compare the characteristics of the hepatitis B group, a control group adjusted for age and gender through propensity score matching analysis was established.

RESULTS

The number of patients with CHB has consistently increased over the past 15 years. The average age of the CHB patient group has shown a yearly rise, while the prevalence of male dominance has gradually diminished. The proportions of hepatocellular carcinoma, liver cirrhosis, and decompensation have exhibited a declining pattern, whereas the proportion of liver transplants has continuously risen. Patients with CHB have demonstrated significantly higher medical and medication costs compared to the control group. Moreover, patients with CHB have shown a higher prevalence of comorbidities along with a significantly higher rate of concomitant medication usage. During the COVID period, the HBV group experienced a substantial decrease in the number of outpatient visits and overall medical costs compared to the control group.

CONCLUSION

The epidemiology of CHB has undergone significant changes over the past 15 years, encompassing shifts in prevalence, severity, medical costs, and comorbidities. Furthermore, the impact of COVID-19 has been observed to decrease healthcare utilization among patients with CHB when compared to controls.

Decreasing incidence of hepatocellular carcinoma among most racial groups: SEER-22, 2000-2019

BACKGROUND

Hepatocellular carcinoma (HCC) incidence was rising in the United States. Previously, using data collected by the Surveillance, Epidemiology, and End Results (SEER) Program through 2017, we found that overall incidence had begun to decline, although not in Black and American Indian/Alaska Native (AI/AN) populations. Utilizing expanded SEER data encompassing ~50% of the population, we examined secular trends and demographic differences in HCC incidence through 2019.

METHODS

We included cases of HCC diagnosed in adults aged ≥20 years residing in SEER-22 registry areas. We examined case counts, incidence rates (per 100,000 person-years), annual percent changes (APCs), and calendar years when APCs changed significantly.

RESULTS

HCC incidence increased from 5.56 in 2000 to 8.89 in 2009 (APC, 5.17%), then rose more slowly during 2009-2015 (APC, 2.28%). After peaking at 10.03 in 2015, incidence fell to 9.20 in 2019 (APC, -2.26%). In Asian/Pacific Islanders (A/PI), the decline began in 2007 and accelerated in 2015 (APCs: 2007-2015, -1.84%; 2015-2019, -5.80%). In 2014, incidence began to fall in the White (APC: 2014-2019, -1.11%) and Hispanic populations (APC: 2014-2019, -1.72%). In 2016, rates began to fall in Black individuals (APC: 2016-2019, -6.05%). In the AI/AN population, incidence was highest in 2017, although the subsequent decline was not statistically significant. In 2019, population-specific rates were: White, 6.94; Black, 10.74; A/PI, 12.11; AI/AN, 14.56; Hispanic, 15.48.

CONCLUSION

HCC incidence is now decreasing in most US racial/ethnic populations, including among Black individuals. The onset of decline differed among racial/ethnic groups and wide disparities in HCC rates remain.

The Role of Red Cell Distribution Width as a Prognostic Marker in Chronic Liver Disease: A Literature Review

Liver disease is one of the leading public health problems faced by healthcare practitioners regularly. As such, there has been a search for an inexpensive, readily available, non-invasive marker to aid in monitoring and prognosticating hepatic disorders. Recently, red blood cell distribution width (RDW) has been found to be associated with various inflammatory conditions with implications for its use as a potential marker for assessing disease progression and prognosis in multiple conditions. Multiple factors effect red blood cell production whereby a dysfunction in any process can lead to anisocytosis. Furthermore, a chronic inflammatory state leads to increased oxidative stress and produces inflammatory cytokines causing dysregulation and increased intracellular uptake and use of both iron and vitamin B12, which leads to a reduction in erythropoiesis causing an increase in RDW. This literature review reviews in-depth pathophysiology that may lead to an increase in RDW and its potential correlation with chronic liver diseases, including hepatitis B, hepatitis C, hepatitis E, non-alcoholic fatty liver disease, autoimmune hepatitis, primary biliary cirrhosis, and hepatocellular carcinoma. In our review, we examine the use of RDW as a prognostic and predictive marker for hepatic injury and chronic liver disease.

Hepatitis B Virus-Associated Hepatocellular Carcinoma and Chronic Stress

The Hepatitis B virus is one of the most significant hepatocarcinogens globally. The carcinogenic mechanisms of this virus are complex, and may include interactions with the host’s immune system. Certain factors, such as stress on the body, can also potentiate these mechanisms. Stress, although adaptive in an acute form, is deleterious to health when chronic and can both suppress and activate the host’s defense system. In hepatocellular carcinoma, this can lead to tumor initiation and progression. Those that are more prone to stress, or exposed to situations that incite stress, may be at higher risk of developing cancer. Racial disparities, for example, are a source of chronic psychosocial stress in America and predispose minorities to poorer outcomes. As it remains perplexing why some individuals with chronic hepatitis B develop feared complications while others do not, it is important to recognize as many risk factors as possible, including those often overlooked such as chronic stress.

Apolipoprotein E, a Crucial Cellular Protein in the Lifecycle of Hepatitis Viruses

Apolipoprotein E (ApoE) is a multifunctional protein expressed in several tissues, including those of the liver. This lipoprotein component is responsible for maintaining lipid content homeostasis at the plasma and tissue levels by transporting lipids between the liver and peripheral tissues. The ability of ApoE to interact with host-cell surface receptors and its involvement in several cellular pathways raised questions about the hijacking of ApoE by hepatotropic viruses. Hepatitis C virus (HCV) was the first hepatitis virus reported to be dependent on ApoE for the completion of its lifecycle, with ApoE being part of the viral particle, mediating its entry into host cells and contributing to viral morphogenesis. Recent studies of the hepatitis B virus (HBV) lifecycle have revealed that this virus and its subviral envelope particles also incorporate ApoE. ApoE favors HBV entry and is crucial for the morphogenesis of infectious particles, through its interaction with HBV envelope glycoproteins. This review summarizes the data highlighting the crucial role of ApoE in the lifecycles of HBV and HCV and discusses its potential role in the lifecycle of other hepatotropic viruses.

Comparative prevalence of hepatitis B virus infection among pregnant women accessing free maternal care in a tertiary hospital in Ghana

Hepatitis B virus infection is endemic in sub-Saharan Africa, and accounts for a significant proportion of morbidities and mortalities in Ghana. Infection with HBV during pregnancy can result in life-threatening complications to both mother and child. To improve their quality of life, the free maternal care was introduced to grant pregnant women cost-free access to antenatal and postnatal services. The study analysed the prevalence of HBV infection among pregnant women receiving free antenatal care in a tertiary hospital in Ghana. This was a retrospective cross-sectional study, where secondary data of pregnant women who accessed free antenatal services at the Trafalga hospital, Ho, from 2016 to 2017 were retrieved from the hospital's database. Data on hepatitis B surface antigen reactivity test, age and period of turnout were analysed with Microsoft Excel and Graph pad prism version 6. A total of 2,634 pregnant women assessed free antenatal care from January 2016 -December 2017, with 10% rise in turnout in 2017. The age of the study population was fairly young, ranging from 13-52 years and mean of 29.87±5.83. The prevalence of HBV infection among pregnant women in the entire study was estimated to be 6.0%, while that of 2016 and 2017 were 5.3% and 6.7% respectively. Turnout for antenatal services peaked in July, which also recorded the highest prevalence of HBV infection among the pregnant women. Our study, first of its kind show an HBV prevalence of 6.0% among a large population of pregnant women who accessed free antenatal services at a tertiary hospital in Ghana. The study evaluates the influence of the free maternal care policy on antenatal attendance and HBV infection rates among pregnant women.

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.

Health-related quality of life for adults living with hepatitis B in the United States: a qualitative assessment

BACKGROUND

In 2019, an estimated 296 million people were living with chronic hepatitis B virus (HBV) globally with approximately 2.4 million living within the United States. Those living with HBV require years if not decades of regular monitoring to prevent liver complications from occurring. The aim of this study was to explore the working conceptual framework of health related quality of life (HRQL) for those living with chronic HBV through qualitative analysis.

METHODS

Data were collected by in-depth telephone interviews conducted in 2019 using purposeful sampling as part of a disease understanding assessment on the HBV patient experience within the United States. A directed content analysis approach was utilized by creation of a codebook to guide the organization of data, codes were developed by review of the literature (a priori) and through line-by-line reading of a subsample of queries. All transcripts were analyzed by at least two members of the study team and intercoder reliability was assessed using Dedoose software.

FINDINGS

A sample of 19 individuals living with chronic HBV were included within this study. Themes identified from transcripts noted the significant overlap between the reported experience of HBV and constructs within the HRQL model. The psychological impact of chronic HBV on study participants' HRQL overall was considerable and contributed to depression, anxiety, homelessness, drug use, and incarceration.

CONCLUSION

Our analysis supports the hypothesis that HBV impacts HRQL and often negatively affects emotional health. Our findings suggest that it would be beneficial to include HRQL assessment in the medical management of HBV, so that interventions can focus on reducing the burden of disease and improving quality of life for those living with HBV.

Cure everyone and vaccinate the rest: The patient perspective on future hepatitis B treatment

Those living with chronic hepatitis B virus (HBV) require years, if not decades, of regular monitoring to prevent liver complications from occurring. An estimated 292 million people were living with chronic HBV globally in 2018 with approximately 2.4 million of those residing within the United States (US). This study is one of the first of its kind that aims to explore the treatment preferences for those living with chronic HBV through qualitative interviews. Participant data were collected by in-depth telephone interviews using a semi-structured discussion guide. A codebook guided the organization of data, and codes were developed by review of the literature (a priori) and through line-by-line reading of a subsample of queries. All data transcripts (N = 19) were independently double coded. Overarching themes identified from the data specific to the treatment modalities and implications of a functional HBV cure included the concern about side effects, treatment modality, frequency, duration, cost-effectiveness and overall impact on their lives. Qualitative data analysis revealed the significant impact that an HBV functional cure would have on quality of life. Benefits of a cure were described as not having a finite course of treatment, improving overall vitality, and reducing the fear and anxiety associated with lifelong infection and potential development of liver cancer. Many individuals expressed the desire for a cure for HBV, stating it would be life-changing, and a 'miracle'. As new therapies are in development, more research should examine in detail the treatment preferences of those living with HBV.

A Review and Clinical Understanding of Tenofovir: Tenofovir Disoproxil Fumarate versus Tenofovir Alafenamide

HIV is a serious chronic medical condition. Significant improvements in antiretroviral therapy have led to a transformation in its management. No curative treatment is available for HIV, and lifelong therapy is required with a combination of agents to control viral replication and prevent complications. Some of the older agents are notorious for many side effects, making patient compliance difficult, which is critical to preventing HIV resistance. Tenofovir is one of the newer, more tolerable, nucleotide reverse transcriptase inhibitors on the market; is a mainstay of many antiretroviral therapy combinations; and is now available in 2 different formulations, tenofovir disoproxil fumarate (TDF) and, the more recent, tenofovir alafenamide (TAF). These 2 formulations have very different pharmacokinetics, which seem to affect their efficacy and safety. This manuscript provides insight into the history of TDF and TAF development, their unique pharmacokinetics and pharmacology, clinically important adverse effects, monitoring, interactions, resistance, review of clinical studies, and guideline recommendations and clinical applications for tenofovir’s various indications.

The chances of hepatic resection curing hepatocellular carcinoma

BACKGROUND & AIMS

The popular sense of the word "cure" implies that a patient treated for a specific disease will return to have the same life expectancy as if he/she had never had the disease. In analytic terms, it translates into the concept of statistical cure which occurs when a group of patients returns to having similar mortality to a reference population. The aim of this study was to assess the probability of being cured from hepatocellular carcinoma (HCC) by hepatic resection.

METHODS

Data from 2,523 patients undergoing resection for HCC were used to fit statistical cure models, to compare disease-free survival (DFS) after surgery to the survival expected for patients with chronic hepatitis and/or cirrhosis and the general population, matched by sex, age, race/ethnicity and year of diagnosis.

RESULTS

The probability of resection enabling patients with HCC to achieve the same life expectancy as those with chronic hepatitis and/or cirrhosis was 26.3%. The conditional probability of achieving this result was time-dependent, requiring about 8.9 years to be accomplished with 95% certainty. Considering the general population as a reference, the cure fraction decreased to 17.1%. Uncured patients had a median DFS of 1.5 years. In multivariable analysis, patient's age and the risk of early HCC recurrence (within 2 years) were independent determinants of the chance of cure (p <0.001). The chances of being cured ranged between 36.0% for individuals at low risk of early recurrence to approximately 3.6% for those at high risk.

CONCLUSION

Estimates of the chance of being cured of HCC by resection showed that cure is achievable, and its likelihood increases with the passing of recurrence-free time. The data presented herein can be used to inform decision making and to provide patients with accurate information.

LAY SUMMARY

Data from 2,523 patients who underwent resection for hepatocellular carcinoma were used to estimate the probability that resection would enable treated patients to achieve the same life expectancy as patients with chronic hepatitis and/or cirrhosis, and the general population. Herein, the cure model suggests that in patients with hepatocellular carcinoma, resection can enable patients to achieve the same life expectancy as those with chronic liver disease in 26.3% of cases and as the general population in 17.1% of cases.

Trends in chronic hepatitis B treatment-related research from 1973 to 2018: a bibliometric and visual analysis

OBJECTIVE

Chronic hepatitis B (CHB) is a worldwide disease and the most common cause of liver cancer. This study aimed to identify specific areas of research activity concerning CHB treatment between 1973 and 2018 and to aid in identifying new areas for future development.

METHODS

The literature was searched from the GoPubMed and Web of Science databases using terms related to CHB treatment, analyzed with bibliometric methods and visualized using VOSviewer.

RESULTS

A total of 9486 and 5883 papers were collected from PubMed and Web of science, respectively. The studies focused on two clusters of topics: antiviral therapy for CHB and progressive diseases, and drug resistance. Studies related to antiviral drugs concentrated on lamivudine (n = 788), entecavir (n = 390), and adefovir dipivoxil (n = 376). Studies addressing conditions developing from CHB highlighted hepatocellular carcinoma (n = 403) and cirrhosis (n = 223). China (n = 1978) contributed the most publications. The 10 most quantitatively prolific organizations were in France. All 20 of the most cited papers investigated antiviral treatments for CHB or CHB-associated cirrhosis.

CONCLUSIONS

Research on CHB treatment over the past 45 years has concentrated on antiviral therapy, CHB-associated progressive conditions, drug resistance and immunization. Although work on CHB treatment has made considerable progress, new approaches must be explored.

Exosomes Modulate the Viral Replication and Host Immune Responses in HBV Infection

Although current diagnosis and treatment of hepatitis B virus (HBV) infection can maintain viral suppression, new therapies need to be invented to sustain off-treatment virologic suppression and reduce side effects. Exosomes act as intercellular communicators to facilitate direct transfer of proteins, lipids, and nucleic acids between cells in vitro and in vivo. Pioneering work has demonstrated that exosomal cargos changed markedly during HBV infection. An improved understanding of the functions of exosomes during HBV infection could lead to a powerful new strategy for preventing and treating HBV. In this review, we point out the role of exosomes in HBV infection: (1) exosomes could directly participate in HBV replication; (2) exosomes modulate immune response during HBV infections; (3) exosomal RNAs and proteins might be selected as novel biomarkers for the diagnosis of HBV infections; and (4) exosomes can also be designed as vaccines.

HEPATITIS B AND C IN PREGNANT WOMEN ATTENDED BY A PRENATAL PROGRAM IN AN UNIVERSITARY HOSPITAL IN RIO DE JANEIRO, BRAZIL: RETROSPECTIVE STUDY OF SEROPREVALENCE SCREENING

BACKGROUND

Hepatitis B and C are diseases with high morbimortality and constitute a global public health problem. In Brazil, the prevalence is not homogeneous, oscillating among different regions, but it is estimated that currently about 1% of the population present chronic disease related to the B virus and that there are 1.5 million infected with the C virus. Despite the development of hepatitis B vaccine, improvement in diagnostic methods and therapeutic advances in the field of viral hepatitis, there is still a large number of people who continues to be infected by these viruses, especially in populations at risk and also due to several factors, including vaccination and migration policies. Vertical and perinatal transmissions are of great importance in the epidemiology of viral hepatitis and the blood tests performed during prenatal care constitute a great opportunity for screening and identifying these viruses.

OBJECTIVE

To evaluate the seroprevalence of markers for B and C viruses in women who underwent prenatal care at the Hospital Universitário Antônio Pedro (Antonio Pedro University Hospital) from 2006 to 2013 and to compare the results found with regional data and those described in the specific literature.

METHODS

A descriptive, cross-sectional, quantitative study with retrospective data collected from 635 records of pregnant women attended at the Prenatal Service of the Hospital Universitário Antônio Pedro, Niterói, state of Rio de Janeiro, from March 2006 until December 2013. The database was built in the Microsoft Office Access program and was later exported to Microsoft Office Excel. For the processing and analysis of the data, it was used the SPSS (Statistical Package for Social Science, IBM) version 22.0, for Windows.

RESULTS

Twelve cases with positive HBsAg (1.9%), 189 cases with positive anti-HBs (35.9%) and seven positive anti-HCV patients (1.3%) were observed. There was no significant association between age and positivity for HBsAg, anti-HBs and anti-HCV (P =0.205, 0.872 and 0.676, respectively). There was a direct relationship between the anti-HBs positivity and the last four years of the study (P<0.0001).

CONCLUSION

A high prevalence of HBsAg was observed, higher than the expected for the evaluated region; there was a prevalence of anti-HCV, consistent with the current Brazilian reality; and a likely low rate of hepatitis B immunization, with a relatively high rate of susceptibility to this infection and no case of co-infection between B and C viruses and HIV. It is emphasized not only the need to trace hepatitis B and C, without exceptions, during prenatal care, since even though the current advances in therapy may not cure, at least they may allow a better quality of life for patients with chronic disease and the mandatory completion of immunoprophylaxis in all newborns. Special attention should be given to those patients susceptible to HBV, with prompt diagnosis and referral for specific vaccination.

The impact of currently licensed therapies on viral and immune responses in chronic hepatitis B: Considerations for future novel therapeutics

Despite the availability of a preventative vaccine, chronic hepatitis B (CHB) remains a global healthcare challenge with the risk of disease progression due to cirrhosis and hepatocellular carcinoma. Although current treatment strategies, interferon and nucleos(t)ide analogues have contributed to reducing morbidity and mortality related to CHB, these therapies are limited in providing functional cure. The treatment paradigm in CHB is rapidly evolving with a number of new agents in the developmental pipeline. However, until novel agents with functional cure capability are available in the clinical setting, there is a pressing need to optimize currently licensed therapies. Here, we discuss current agents used alone and/or in combination strategies along with the impact of these therapies on viral and immune responses. Novel treatment strategies are outlined, and the potential role of current therapies in the employment of pipeline agents is discussed.

Update Treatment for HBV Infection and Persistent Risk for Hepatocellular Carcinoma: Prospect for an HBV Cure

Since the discovery of the hepatitis B virus (HBV) by Blumberg et al. in 1965, its genome, sequence, epidemiology, and hepatocarcinogenesis have been elucidated. Globally, hepatitis B virus (HBV) is still responsible for the majority of hepatocellular carcinoma (HCC). HCC is the sixth-most common cancer in the world and the second-most common cancer death. The ultimate goal of treating HBV infection is the prevention of HCC. Fortunately, anti-HBV treatment with nucleos(t)ide analogues (NAs), which began with lamivudine in 1998, has resulted in remarkable improvements in the survival of patients with chronic hepatitis B and a reduced incidence of HCC. These results were documented with lamivudine, entecavir, and tenofovir. Nonetheless, as the duration of antiviral treatment increases, the risk for HCC still remains despite undetectable HBV DNA in serum, as reported by different investigators with observation up to 4⁻5 years. In our own experience, we are witnessing the development of HCC in patients who have received antiviral treatment. Some have enjoyed negative serum HBV DNA for over 12 years before developing HCC. Current treatment with NAs can effectively suppress the replication of the virus but cannot eradicate the covalently closed circular DNA (cccDNA) that is within the nucleus of hepatocytes. There still remains a great need for a cure for HBV. Fortunately, several compounds have been identified that have the potential to eradicate HBV, and there are ongoing clinical trials in progress in their early stages.

Beasley's 1981 paper: The power of a well-designed cohort study to drive liver cancer research and prevention

The 1981 Lancet paper by Beasley et al., "Hepatocellular carcinoma and hepatitis B virus. A prospective study of 22707 men in Taiwan" is a seminal publication that clearly demonstrated that chronic infection with hepatitis B virus (HBV), as measured by seropositivity for the hepatitis B surface antigen (HBsAg), preceded the development of hepatocellular carcinoma (HCC). In doing so, this study paved the way for liver cancer prevention efforts through the implementation of hepatitis B vaccination programs. In this commentary, we will describe the discovery of HBV, which led to the study by Beasley et al.; summarize the major findings of the Beasley paper and its implications; discuss the importance of well-designed cohort studies for prevention activities; and consider the ramifications of the Beasley study and the work that has followed since.

Hepatitis B in Solid-Organ Transplant Procedures Other Than Liver

Transplant is often the best treatment available for patients with end-stage organ failure. Hepatitis B virus infection in transplant procedures other than liver is a major concern because it can be a significant cause of morbidity and mortality after transplant. Due to the increased risk of hepatic complications, such as fibrosing cholestatic hepatitis or histologic deterioration after transplant, systematic use of nucleoside or nucleotide analogues shortly before or at the time of transplant is recommended (tenofovir or entecavir are preferable to lamivudine) in all patients, whatever the baseline histologic evaluation. Sustained viral suppression may result in regression of fibrosis, which in turn may lead to decreased disease-related morbidity and improved survival. Finally, due to the high mortality after nonliver transplant procedures, decompensated cirrhosis from chronic hepatitis B should be considered as a contraindication to nonliver transplant but an indication to combined organ transplant (ie, liver-kidney transplant). Because of the high prevalence of hepatitis B virus exposure in allograft donors and recipients, hepatitis B virus status must be considered during organ allocation. Prevention of hepatitis B virus-related complications in transplant recipients starts with vaccination and donor-recipient matching.

Rapamycin modulation of p70 S6 kinase signaling inhibits Rift Valley fever virus pathogenesis

Despite over 60 years of research on antiviral drugs, very few are FDA approved to treat acute viral infections. Rift Valley fever virus (RVFV), an arthropod borne virus that causes hemorrhagic fever in severe cases, currently lacks effective treatments. Existing as obligate intracellular parasites, viruses have evolved to manipulate host cell signaling pathways to meet their replication needs. Specifically, translation modulation is often necessary for viruses to establish infection in their host. Here we demonstrated phosphorylation of p70 S6 kinase, S6 ribosomal protein, and eIF4G following RVFV infection in vitro through western blot analysis and in a mouse model of infection through reverse phase protein microarrays (RPPA). Inhibition of p70 S6 kinase through rapamycin treatment reduced viral titers in vitro and increased survival and mitigated clinical disease in RVFV challenged mice. Additionally, the phosphorylation of p70 S6 kinase was decreased following rapamycin treatment in vivo. Collectively these data demonstrate modulating p70 S6 kinase can be an effective antiviral strategy.

Prevention of liver tumor formation in woodchucks with established hepatocellular carcinoma by treatment with cationic liposome-DNA complexes

Background

Approximately 250 million people worldwide are chronically infected with hepatitis B virus (HBV) and more than half of the hepatocellular carcinoma (HCC) cases are attributed to this infection. As HCC has a high mortality rate, and current treatment options are remarkably limited, the development of new therapeutic treatment strategies is warranted.

Methods

In this study, woodchucks infected with woodchuck hepatitis virus (WHV), and with pre-existing liver tumors, were used as a model to investigate if complexes of cationic liposomes and non-coding DNA (JVRS-100) were effective in treatment of HCC.

Results

It was observed that the high serum viral load that is present in a typical chronic WHV infection (i.e., approximately 100-fold higher than human viral loads) results in immune suppression and resistance to treatment with JVRS-100. Treatment of woodchucks with lower serum viral load that more closely matched with the viral load usually seen in human HBV infection appears a better model for immunotherapeutic development based on the responsiveness to JVRS-100 treatment. In the latter case, marked declines in WHV DNA and WHV surface antigen were determined over the 12-week treatment period and WHV markers stayed suppressed during most time points of the 12-week follow-up period. Even more remarkably, the formation of new liver tumors was not observed in woodchucks treated with a well-tolerated dose of JVRS-100, as compared to several new tumors that developed in vehicle-treated control animals.

Conclusions

Although there was little decrease in the volumes of the liver tumors existing at the time of treatment, it is generally accepted that preventing the spread and metastasis of almost always fatal cancers such as HCC and thus, reducing it to a chronic and treatable disease can also be a successful therapeutic approach. The results in woodchucks warrant the investigation of JVRS-100 as an intervention to prevent liver cancer in patients chronically infected with HBV and at high risk for HCC development.

Establishment of a human hepatocellular cell line capable of maintaining long-term replication of hepatitis B virus

Hepatitis B virus (HBV) is a virus whose replication cycle cannot be completely reproduced using cultured cell lines. Here, we report an engineered cell line capable of supporting the complete HBV life cycle. We generated HepG2 cells over-expressing the HBV entry receptor human NTCP (sodium taurocholate cotransporting polypeptide), and defective in RIG-I (retinoic acid-inducible gene-I)-like receptor signaling, by knocking down the IPS-1 (IFNβ-promoter stimulator-1) adaptor molecule. The resultant NtG20.i7 cells were susceptible to HBV, and its replication was detectable at 14 days post-infection and persisted for at least 35 days with a gradual increase of HBV core expression. The cells produced infectious HBV in the culture supernatant, and the addition of preS1 peptide myr47-WT, which blocks HBV entry, impaired the persistence of the infection. These findings suggest that the persistence of the infection was maintained by continuous release of infectious HBV virions and their re-infection. This system is useful for expanding our basic understanding of the HBV replication cycle and for screening of anti-HBV chemicals.

Lamivudine/Adefovir Treatment Increases the Rate of Spontaneous Mutation of Hepatitis B Virus in Patients

The high levels of genetic diversity shown by hepatitis B virus (HBV) are commonly attributed to the low fidelity of its polymerase. However, the rate of spontaneous mutation of human HBV in vivo is currently unknown. Here, based on the evolutionary principle that the population frequency of lethal mutations equals the rate at which they are produced, we have estimated the mutation rate of HBV in vivo by scoring premature stop codons in 621 publicly available, full-length, molecular clone sequences derived from patients. This yielded an estimate of 8.7 × 10⁻⁵ spontaneous mutations per nucleotide per cell infection in untreated patients, which should be taken as an upper limit estimate because PCR errors and/or lack of effective lethality may inflate observed mutation frequencies. We found that, in patients undergoing lamivudine/adefovir treatment, the HBV mutation rate was elevated by more than sixfold, revealing a mutagenic effect of this treatment. Genome-wide analysis of single-nucleotide polymorphisms indicated that lamivudine/adefovir treatment increases the fraction of A/T-to-G/C base substitutions, consistent with recent work showing similar effects of lamivudine in cellular DNA. Based on these data, the rate at which HBV produces new genetic variants in treated patients is similar to or even higher than in RNA viruses.

Major changes in the number and indications of liver biopsy for chronic liver diseases over one decade in France

AIMS

French clinical practice guidelines on the use of liver biopsy (LB) published in 2002 focused on ultrasound guidance (USG) and ambulatory LB. The aims of this study were as follows: (i) to evaluate the number and indications for LB for chronic liver diseases and (ii) to evaluate LB modalities according to French clinical practice guidelines. Data recorded included the number and indications for LB, procedures, use of USG, and complications.

RESULTS

A total of 131 centers participated: 8741 LB were performed versus 12 000 in 1997; ambulatory LB was performed in 48.6% of cases (vs. 27% in 1997; P<0.001). USG during LB was used in 89.7% of the centers, among which 42 (31.8%) used real-time USG (vs. 56 and 22%, respectively, in 1997; P<0.01). The main indications for LB were chronic hepatitis C in 24.6% of cases (vs. 54.1% in 1997; P<0.001), and viral B or B-delta in 15.0% (vs. 5.8%; P<0.001). Severe complications were less frequent at centers with systematical USG during LB than at those without such guidance (P<0.01).

CONCLUSION

In this large nationwide study, major trends were as follows: (i) a marked decrease in LB number, related to a decrease in LB for chronic viral hepatitis C; (ii) increased use of USG; and (iii) an increase in the number of ambulatory LB. Severe complications decreased significantly at centers in which USG was systematically applied.

Hepatitis B and its Relationship With Oxidative Stress

CONTEXT

Despite the great breakthroughs we have witnessed in the last 50 years in the prevention, diagnosis, and treatment of hepatitis B, we are still far from eradicating or even curing the disease. Achieving further progress in controlling this disease will not be possible without discovering the exact pathogenesis behind it. One prime suspect in the pathogenesis of various diseases is oxidative stress. This review will exclusively explore hepatitis B in the context of oxidative stress to obtain a more comprehensive clinical perspective on its pathogenesis and eventual medical therapy.

EVIDENCE ACQUISITION

We systematically searched PubMed, Google Scholar, Web of Science, EMBASE, and Scopus using an extensive list of keywords in the following three categories: 1) Hepatitis B and oxidation 2) Hepatitis B and antioxidant system 3) Effects of approved anti-hepatitis B drugs on redox status. All relevant articles were obtained and reviewed carefully after the exclusion criteria were deployed.

RESULTS

There is great evidence indicating extensive oxidative stress occurs in hepatitis B. This oxidative stress takes place on multiple levels, including lipid peroxidation, DNA oxidation, protein oxidation, and reactive oxygen and nitrogen species production. However, there are also conflicting results with regard to antioxidant therapy and antioxidant status in hepatitis B, some of which may be explained by the concept of "compensatory gaps." Nevertheless, further studies are indicated to reach a more thorough judgment.

CONCLUSIONS

Despite the presence of vast oxidative stress in hepatitis B, antioxidant therapy is not always effective as a treatment strategy, especially considering that antioxidants can act as "double-edged swords" or antioxidants; if not used at the right time or place or in the right combination, these substances can easily become pro-oxidants. Therefore, several studies will be needed to determine suitable antioxidant therapies. We propose the "2-step Combined Antioxidant Adjuvant Therapy for hepatitis B (2CAAT Hep B)" as a new strategy for antioxidant adjuvant therapy. We also suggest developing an international platform and database for antioxidant adjuvant therapy in hepatitis B (IPAATH and IDAATH) to canalize this field of research in a standardized direction, especially when complexity is a problem.

Pharmacokinetics and biodistribution of recently-developed siRNA nanomedicines

Small interfering RNA (siRNA) is a promising drug candidate, expected to have broad therapeutic potentials toward various diseases including viral infections and cancer. With recent advances in bioconjugate chemistry and carrier technology, several siRNA-based drugs have advanced to clinical trials. However, most cases address local applications or diseases in the filtering organs, reflecting remaining challenges in systemic delivery of siRNA. The difficulty in siRNA delivery is in large part due to poor circulation stability and unfavorable pharmacokinetics and biodistribution profiles of siRNA. This review describes the pharmacokinetics and biodistribution of siRNA nanomedicines, focusing on those reported in the past 5years, and their pharmacological effects in selected disease models such as hepatocellular carcinoma, liver infections, and respiratory diseases. The examples discussed here will provide an insight into the current status of the art and unmet needs in siRNA delivery.

Improved antiviral efficacy using TALEN-mediated homology directed recombination to introduce artificial primary miRNAs into DNA of hepatitis B virus

Chronic infection with hepatitis B virus (HBV) remains an important global health problem. Currently licensed therapies have modest curative efficacy, which is as a result of their transient effects and limited action on the viral replication intermediate comprising covalently closed circular DNA (cccDNA). Gene editing with artificial HBV-specific endonucleases and use of artificial activators of the RNA interference pathway have shown anti-HBV therapeutic promise. Although results from these gene therapies are encouraging, maximizing durable antiviral effects is important. To address this goal, a strategy that entails combining gene editing with homology-directed DNA recombination (HDR), to introduce HBV-silencing artificial primary microRNAs (pri-miRs) into HBV DNA targets, is reported here. Previously described transcription activator-like effector nucleases (TALENs) that target the core and surface sequences of HBV were used to introduce double stranded breaks in the viral DNA. Simultaneous administration of donor sequences encoding artificial promoterless anti-HBV pri-miRs, with flanking arms that were homologous to sequences adjoining the TALENs' targets, augmented antiviral efficacy. Analysis showed targeted integration and the length of the flanking homologous arms of donor DNA had a minimal effect on antiviral efficiency. These results support the notion that gene editing and silencing may be combined to effect improved inhibition of HBV gene expression.

Immune Activation in the Liver by Nucleic Acids

Viral infection in the liver, including hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, is a major health problem worldwide, especially in developing countries. The infection triggers a pro-inflammatory response in patients that is crucial for host defense. Recent studies have identified multiple transmembrane and cytosolic receptors that recognize pathogen-derived nucleic acids, and these receptors are essential for driving immune activation in the liver. In addition to sensing DNA/RNA from pathogens, these intracellular receptors can be activated by nucleic acids of host origin in response to sterile injuries. In this review, we discuss the expanding roles of these receptors in both immune and nonimmune cells in the liver.

Viral Load Pattern Among Hepatitis B Surface Antigen-positive Patients: Laboratory Perspective and Implications for Therapy

BACKGROUND

Hepatitis B viral infection is an old medical problem with worldwide distribution. It is usually diagnosed using serologic methods. However, the decision as to which patient to treat or not remains challenging due to the poor sensitivity of serologic markers as prognostic or severity markers. Viral load (VL) determination using polymerase chain reaction techniques is a useful tool in decision-making.

AIM

To determine the proportion of hepatitis B-positive patients who fall into different care groups based on the Society for Gastroenterology and Hepatology in Nigeria (SOGHIN) and National Institute for Health and Care Excellence guidelines, respectively, using result of hepatitis B virus (HBV) DNA determination.

MATERIALS AND METHODS

This is a retrospective and descriptive study. Data from all patients sent to the medical microbiology laboratory, National Hospital Abuja over a period of 28 months (November 2012 to February 2015) for hepatitis B DNA VL determinations were analyzed using Microsoft Excel 2010 (Microsoft Corporation, Redmond, WA, USA) and IBM SPSS version 20.0 (IBM SPSS, Inc., Chicago, IL, USA).

RESULTS

A total 666 patients, with mean age of 33.2 years, were tested. For those whose ages were known 36.2% (100/276) were below 30 years and 63.8% (176/276) 30 years and above. Exactly 66.7% (444/666) were males and the remaining 33.3% (222/666) were females. The VL of the patients varied from 20 to 1.7 × 10(8) IU/ml, with an average of 3.5 × 10(6) IU/ml. Around 76.1% (507/666) had measurable assay levels (20 - 1.7 × 10(8) IU/ml); 10.8% (76/666) had below 20 IU/ml and 3.8% (25/666) above 1.7 × 10(8) IU/ml. About 9.3% (62/666) had no detectable HBV DNA in their samples. About 46.8% (312/666) of the patients had levels between 20 and 2 × 10(3) IU/ml; 16.4% (109/666) had between 2001 and 2 × 10(4) IU/ml while 16.7% (111/666) had VL of between 20,001 and 1.7 × 10(8) IU/ml. Males tended to have detectable and higher VLs than females (P = 0.04).

CONCLUSION

HBV DNA assay used in accordance with existing treatment guidelines will improve quality of care. To avoid unnecessary liver biopsy, there is a need to further fine-tune the SOGHIN guidelines.

Progress With Developing Use of Gene Editing To Cure Chronic Infection With Hepatitis B Virus

Chronic infection with hepatitis B virus (HBV) occurs in approximately 6% of the world's population. Carriers of the virus are at risk for life-threatening complications, and developing curative treatment remains a priority. The main shortcoming of licensed therapies is that they do not affect viral covalently closed circular DNA (cccDNA), a stable intermediate of replication. Harnessing gene editing to mutate cccDNA provides the means to inactivate HBV gene expression permanently. Reports have described use of engineered zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeats (CRISPR) with CRISPR-associated (Cas) nucleases. Although inhibition of viral replication has been demonstrated, reliably detecting mutations in cccDNA has been difficult. Also, the dearth of murine models that mimic cccDNA formation has hampered analysis in vivo. To reach a stage of clinical use, efficient delivery of the editors to HBV-infected hepatocytes and limiting unintended off-target effects will be important. Investigating therapeutic efficacy in combination with other treatment strategies, such as immunotherapies, may be useful to augment antiviral effects. Advancing gene editing as a mode of treating HBV infection is now at an interesting stage and significant progress is likely to be made in the immediate future.

Hepatocellular carcinoma mouse models: Hepatitis B virus-associated hepatocarcinogenesis and haploinsufficient tumor suppressor genes

The multifactorial and multistage pathogenesis of hepatocellular carcinoma (HCC) has fascinated a wide spectrum of scientists for decades. While a number of major risk factors have been identified, their mechanistic roles in hepatocarcinogenesis still need to be elucidated. Many tumor suppressor genes (TSGs) have been identified as being involved in HCC. These TSGs can be classified into two groups depending on the situation with respect to allelic mutation/loss in the tumors: the recessive TSGs with two required mutated alleles and the haploinsufficient TSGs with one required mutated allele. Hepatitis B virus (HBV) is one of the most important risk factors associated with HCC. Although mice cannot be infected with HBV due to the narrow host range of HBV and the lack of a proper receptor, one advantage of mouse models for HBV/HCC research is the numerous and powerful genetic tools that help investigate the phenotypic effects of viral proteins and allow the dissection of the dose-dependent action of TSGs. Here, we mainly focus on the application of mouse models in relation to HBV-associated HCC and on TSGs that act either in a recessive or in a haploinsufficient manner. Discoveries obtained using mouse models will have a great impact on HCC translational medicine.

Prevention of hepatitis B virus infection: from the past to the future

About 3-5 % of the world's population is chronically infected by hepatitis B virus (HBV) and is at risk of developing liver cirrhosis or hepatocellular carcinoma. The risk of dying prematurely because of chronic HBV infection is higher in younger people. The current strategies to prevent HBV infection involve immunization (active and/or passive) and antiviral chemoprophylaxis. The vaccines available for active immunization, containing hepatitis B surface antigen, are safe and confer long-term immunity in most healthy subjects. Since the vaccination is unsatisfactory in some patients, e.g., those with chronic kidney disease, human immunodeficiency virus infection, type I diabetes mellitus, and celiac disease, new strategies of vaccination are required. The neonatal, infant, and adolescent routine program vaccination in about 180 countries has greatly decreased the disease burden. Passive immunization with specific HBV immunoglobulins is recommended after single acute exposure, in infants born to infected mothers, and in HBV-infected patients undergoing liver transplantation combined with nucleoside/nucleotide analogues (chemoprophylaxis). Chemoprophylaxis is also indicated in HBV carrier candidates for immunosuppressive treatment and in patients with occult B infection undergoing immunosuppressive therapy or hematopoietic stem cell transplantation. Since HBV is not eradicable by an immune response or by antiviral drugs developed so far, the only preventive strategy remains global neonatal vaccination in all countries, firstly in HBV-endemic countries.

The RNA sensor RIG-I dually functions as an innate sensor and direct antiviral factor for hepatitis B virus

Host innate recognition triggers key immune responses for viral elimination. The sensing mechanism of hepatitis B virus (HBV), a DNA virus, and the subsequent downstream signaling events remain to be fully clarified. Here we found that type III but not type I interferons are predominantly induced in human primary hepatocytes in response to HBV infection, through retinoic acid-inducible gene-I (RIG-I)-mediated sensing of the 5'-ε region of HBV pregenomic RNA. In addition, RIG-I could also counteract the interaction of HBV polymerase (P protein) with the 5'-ε region in an RNA-binding dependent manner, which consistently suppressed viral replication. Liposome-mediated delivery and vector-based expression of this ε region-derived RNA in liver abolished the HBV replication in human hepatocyte-chimeric mice. These findings identify an innate-recognition mechanism by which RIG-I dually functions as an HBV sensor activating innate signaling and to counteract viral polymerase in human hepatocytes.

Oxidative stress and cell damage in a model of precancerous lesions and advanced hepatocellular carcinoma in rats

Hepatocellular carcinoma (HCC) is the third most frequent cause of cancer deaths throughout the world. This study was aimed to analyze oxidative stress and cell damage in a multistage model of liver carcinogenesis induced by diethylnitrosamine (DEN) in rats. Male Wistar rats weighing 145–150 g were divided into three groups: control, precancerous lesions (PL) (which received 100 mg DEN once a week every 6 weeks up to 28 weeks), and advanced HCC (50 mg DEN once/twice per week up to 19 weeks). Lipid peroxidation (TBARS), superoxide dismutase (SOD) activity, and expression of transforming growth factor-1 beta (TGF)-1β, endothelial and inducible nitric oxide syntahese (eNOS, iNOS), NADPH quinone oxireductase (NQO)-1, nuclear factor erythroid 2-related factor (NrF)2, kelch-like ECH-associated protein (Keap)1 and heat shock protein (HSP)70 were measured. TBARS concentration was augmented in the PL and advanced HCC groups. SOD activity, TGF-1β and Nrf2 expression were higher in animals with precancerous lesions. In advanced HCC, expression of NQO1 and iNOS increased while there was a decrease in HPS70 expression. Data obtained provide evidence for the differential activation of proteins involved in oxidative stress and cell damage during progression of carcinogenesis in an animal model of HCC.