Incidence of hepatocellular carcinoma according to hepatitis B virus genotype in Alaska Native people

Characterising the effectiveness of social determinants of health-focused hepatitis B interventions: a systematic review

Social determinants of health are important in designing effective interventions for hepatitis B virus (HBV) infection. This systematic review characterises equity-oriented, social determinants of health-focused HBV interventions, and describes their effectiveness in terms of the prevention, care, or treatment of HBV in high-income countries. We searched electronic databases for central concepts of 'HBV', 'equity', 'social determinants of health', 'intervention', and 'Organization for Economic Co-operation and Development (OECD) countries'. Screening and data abstraction were conducted independently by two reviewers. Data were abstracted from 66 studies; articles with a comparative study design (n=36) were included in the narrative synthesis, highlighting social determinants of health domains of interventions, HBV-relevant health outcomes, and extra-health social determinants of health effects (ie, those effects that extend beyond health outcomes). Synthesis aligned with six emergent themes corresponding to HBV prevention and care: knowledge and education, diagnosis and screening, immunisation, care initiation, engagement with clinical care and treatment, and upstream prevention. Studies presented a heterogeneous array of HBV-relevant health outcomes. Most interventions were tailored for social determinants of health domains of race, ethnicity, culture, and language; drug use; and socioeconomic status. Across the themes, at least two-thirds of interventions showed comparative effectiveness for addressing HBV. Extra-health social determinants of health outcomes were observed for two studies. Considerable diversity in population-level approaches was observed regarding intervention goals and effectiveness; most interventions were effective at enhancing the prevention, care, or treatment of HBV.

Hepatitis B Virus Genotype Influence on Virological and Enzymatic Measures over Time-A Retrospective Longitudinal Cohort Study

HBV is a hepatotropic virus with multiple genotypes. It is uncertain if specific genotype(s) influence virological measures and/or liver markers over time. It is unclear whether nucleos(t)ide analogue therapy response is influenced by genotype. In this retrospective longitudinal study, we utilized data from The Ottawa Hospital Viral Hepatitis Program (TOHVHP) to evaluate the role of HBV genotype on viral load, liver enzymatic levels, fibrosis progression, and parenchymal inflammation and steatosis over time. HBV DNA, ALT, and AST levels, as well as transient elastography scores for fibrosis (E) and inflammation/steatosis (CAP), were modeled using mixed-effects linear regression. Interaction terms between HBV genotype and time were included to investigate if there was a difference in trends between genotypes. A total of 393 HBV patients infected with genotypes A-E were included. The mean age was 44.4 years, and 56% were male. Asian (50.5%), Black (29.1%), and White (6.4%) patients were well-represented. By multivariate analysis, we found no evidence that the trajectories of these commonly measured viral or liver measures varied over time by HBV genotype in those receiving HBV nucleos(t)ides and in those not on antiviral therapy.

Hepatitis B virus genotypes influence clinical outcomes: A review

Hepatitis B virus (HBV) is a hepatotropic virus that affects approximately 296 million people worldwide. A crucial step to HBV replication is the transcription of its infectious DNA from its viral RNA intermediate. The production of the RNA intermediate hinges on reverse transcription, and therefore the lack of proofreading in that process commonly yields mutants and has led to nine well-described genotypes (A-I) and over 30 known sub-genotypes of the virus. The influence of genotype on HBV infection outcomes, which include fibrosis progression, cirrhosis, and hepatocellular carcinoma (HCC), remain uncertain. This review aims to analyze the influence of HBV genotype on the risk of development of these outcomes. The response to current and future HBV therapies is considered. Further study of larger and more diverse samples will hopefully resolve outstanding uncertainties.

Ethnic differences in hepatocellular carcinoma prevalence and therapeutic outcomes

BACKGROUND

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. The incidence of HCC is affected by genetic and non-genetic factors. Genetically, mutations in the genes, tumor protein P53 (TP53), catenin beta 1 (CTNNB1), AT-rich interaction domain 1A (ARIC1A), cyclin dependent kinase inhibitor 2A (CDKN2A), mannose 6-phosphate (M6P), smooth muscle action against decapentaplegic (SMAD2), retinoblastoma gene (RB1), cyclin D, antigen presenting cells (APC), AXIN1, and E-cadherin, have been shown to contribute to the occurrence of HCC. Non-genetic factors, including alcohol consumption, exposure to aflatoxin, age, gender, presence of hepatitis B (HBV), hepatitis C (HCV), and non-alcoholic fatty liver disease (NAFLD), increase the risk of HCC.

RECENT FINDINGS

The severity of the disease and its occurrence vary based on geographical location. Furthermore, men and minorities have been shown to be disproportionately affected by HCC, compared with women and non-minorities. Ethnicity has been reported to significantly affect tumorigenesis and clinical outcomes in patients diagnosed with HCC. Generally, differences in gene expression and/or the presence of comorbid medical diseases affect or influence the progression of HCC. Non-Caucasian HCC patients are significantly more likely to have poorer survival outcomes, compared to their Caucasian counterparts. Finally, there are a number of factors that contribute to the success rate of treatments for HCC.

CONCLUSION

Assessment and treatment of HCC must be consistent using evidence-based guidelines and standardized outcomes, as well as international clinical practice guidelines for global consensus. Standardizing the assessment approach and method will enable comparison and improvement of liver cancer research through collaboration between researchers, healthcare providers, and advocacy groups. In this review, we will focus on discussing epidemiological factors that result in deviations and changes in treatment approaches for HCC.

The role of hepatitis B virus genome variations in HBV-related HCC: effects on host signaling pathways

Hepatocellular carcinoma (HCC) is a significant global health issue, with a high prevalence in many regions. There are variations in the etiology of HCC in different regions, but most cases are due to long-term infection with viral hepatitis. Hepatitis B virus (HBV) is responsible for more than 50% of virus-related HCC, which highlights the importance of HBV in pathogenesis of the disease. The development and progression of HBV-related HCC is a complex multistep process that can involve host, viral, and environmental factors. Several studies have suggested that some HBV genome mutations as well as HBV proteins can dysregulate cell signaling pathways involved in the development of HCC. Furthermore, it seems that the pathogenicity, progression of liver diseases, response to treatment and also viral replication are different among HBV mutants. Understanding the relationship between HBV genome variations and host signaling pathway alteration will improve our understanding of the molecular pathogenesis of HBV-related HCC. Furthermore, investigating commonly dysregulated pathways in HBV-related HCC is necessary to discover more specific therapeutic targets and develop more effective strategies for HCC treatment. The objective of this review is to address the role of HBV in the HCC progression and primarily focus on the impacts of HBV genome variations on HCC-related signaling pathways.

Pre- and Post-Transcriptional Control of HBV Gene Expression: The Road Traveled towards the New Paradigm of HBx, Its Isoforms, and Their Diverse Functions

Hepatitis B virus (HBV) is an enveloped DNA human virus belonging to the Hepadnaviridae family. Perhaps its main distinguishable characteristic is the replication of its genome through a reverse transcription process. The HBV circular genome encodes only four overlapping reading frames, encoding for the main canonical proteins named core, P, surface, and X (or HBx protein). However, pre- and post-transcriptional gene regulation diversifies the full HBV proteome into diverse isoform proteins. In line with this, hepatitis B virus X protein (HBx) is a viral multifunctional and regulatory protein of 16.5 kDa, whose canonical reading frame presents two phylogenetically conserved internal in-frame translational initiation codons, and which results as well in the expression of two divergent N-terminal smaller isoforms of 8.6 and 5.8 kDa, during translation. The canonical HBx, as well as the smaller isoform proteins, displays different roles during viral replication and subcellular localizations. In this article, we reviewed the different mechanisms of pre- and post-transcriptional regulation of protein expression that take place during viral replication. We also investigated all the past and recent evidence about HBV HBx gene regulation and its divergent N-terminal isoform proteins. Evidence has been collected for over 30 years. The accumulated evidence simply strengthens the concept of a new paradigm of the canonical HBx, and its smaller divergent N-terminal isoform proteins, not only during viral replication, but also throughout cell pathogenesis.

Ascites re-compensation in HBV-related first decompensated cirrhosis after anti-viral therapy

Effective antiviral therapy can significantly improve the long-term prognosis of HBV-related decompensated patients, and re-compensation may be achieved in part of the patients. To explore the re-compensation of ascites after HBV suppression and the risk factors, the clinical outcomes of 196 consecutive patients with HBV-related first decompensated cirrhosis of ascites treated with nucleos(t)ide analogue (NUC) were analyzed retrospectively. Among these patients, the median serum HBV DNA level was 5.0 (IQR, 3.0-6.0) log₁₀ IU/mL before treatment. Most patients were given NUC with high barrier to resistance including ETV (152), TDF (1) and TAF (1). Initial combination of LAM plus ADV and LdT plus ADV was used in 41 patients and 1 patients, respectively. After NUC treatment, the percentage of patients with ascites regression was 77.6%, 81.4%, 70.5%, 93.8%, 80.8% at 12, 24, 36, 48, 60 months, respectively (P<0.001). The distribution of ascites severity showed that the patients' ascites improved, with the proportion of no ascites and mild ascites gradually increased. The proportion of re-compensation of ascites defined as negative HBV DNA, improved liver function and ascites regression (off diuretics) was 59.7%, 70.0%, 52.3%, 59.4%, 46.2% at 12, 24, 36, 48, 60 months (P<0.001). The rate of ascites regression was higher in viral response (VR) cohort when compared with that in non-VR cohort. Univariate and multivariable analysis showed that level of serum ALT (OR:0.988, 95%CI, p=0.029) and load of serum HBV DNA (OR:0.78895%CI, p=0.044) at baseline were risk factors of re-compensation of ascites. This study demonstrated that antiviral therapy could reverse decompensation of ascites in HBV-related first decompensated cirrhosis and the level of ALT and HBV DNA were risk factors of ascites re-compensation.

Incidence of Hepatocellular Carcinoma and Decompensated Liver Cirrhosis and Prognostic Accuracy of the PAGE-B HCC Risk Score in a Low Endemic Hepatitis B Virus Infected Population

Purpose

We aimed to determine incidence of hepatocellular carcinoma (HCC) and decompensated liver cirrhosis in persons with chronic hepatitis B virus (HBV) infection in Denmark stratified by disease phase, liver cirrhosis, and treatment status at baseline. Additionally, we aimed to assess the prognostic value of the PAGE-B HCC risk score in a mainly non-cirrhotic population.

Patients and Methods

In this register-based cohort study, we included all individuals over the age of 18, with chronic HBV infection first registered between 2002 and 2016 in at least one of three nationwide registers. The study population was followed until HCC, decompensated liver cirrhosis, death, emigration, or December 31, 2017, which ever came first.

Results

Among 6016 individuals included in the study, 10 individuals with and 23 without baseline liver cirrhosis developed HCC during a median follow up of 7.3 years (range 0.0-15.5). This corresponded to five-year cumulative incidences of 7.1% (95% confidence interval (CI) 2.0-12.3) and 0.2% (95% CI 0.1-0.4) in persons with and without baseline liver cirrhosis. The five-year cumulative incidence of decompensated liver cirrhosis was 0.7% (95% CI 0.5-1.0). Among 2038 evaluated for liver events stratified by disease phase, incidence of HCC was low in all who were non-cirrhotic and untreated for HBV at baseline. PAGE-B score was evaluated in 1529 persons. The 5-year cumulative incidence of HCC was 0, 0.8 (95% CI 0.5-1.8), and 8.7 (95% CI 1.0-16.4) in persons scoring <10, 10-17 and >17, respectively (c-statistic 0.91 (95% CI 0.84-0.98)).

Conclusion

We found low incidence of HCC and decompensated liver cirrhosis in persons with chronic HBV infection in Denmark. Moreover, the PAGE-B score showed good accuracy for five-year risk of developing HCC in the population with chronic HBV infection in Denmark.

Genomic Variability of Hepatitis B Virus Circulating in Brazilian Western Amazon

The emergence of clinically relevant mutations in the hepatitis B virus (HBV) genome has been a matter of great debate because of the possibility of escape from the host’s immune system, the potential to cause more severe progression of liver diseases and the emergence of treatment-resistant variants. Here we characterized the circulating variants of HBV in Rondônia State, in the north of Brazil. Serum samples of 62 chronic HBV carriers were subjected to PCR assays and clinical data were collected. Mutations and genotypes were characterized through direct sequencing. The findings show the presence of subgenotypes A1 (54.83%, 34/62), D3 (16.13%, 10/62), F2 (16.13%, 10/62), A2 (4.84%, 3/62), D2 (3.23%, 2/62), D1 (1.61%, 1/62), D4 (1.61%, 1/62) and F4 (1.61%, 1/62). Deletions in the pre-S2 region were found in 13.79% (8/58) of the samples, mutations in the S gene in 59.68% (37/62) and RT mutations in 48.39% (30/62). We found a variable genotypic distribution in different locations and important mutations related to immune escape and drug resistance in Western Amazonia, which contributed to genetic surveillance and provided important information to help control the disease.

Molecular and biological characterization of hepatitis B virus subgenotype F1b clusters: Unraveling its role in hepatocarcinogenesis

Hepatitis B virus (HBV) subgenotype F1b infection has been associated with the early occurrence of hepatocellular carcinoma in chronically infected patients from Alaska and Peru. In Argentina, however, despite the high prevalence of subgenotype F1b infection, this relationship has not been described. To unravel the observed differences in the progression of the infection, an in-depth molecular and biological characterization of the subgenotype F1b was performed. Phylogenetic analysis of subgenotype F1b full-length genomes revealed the existence of two highly supported clusters. One of the clusters, designated as gtF1b Basal included sequences mostly from Alaska, Peru and Chile, while the other, called gtF1b Cosmopolitan, contained samples mainly from Argentina and Chile. The clusters were characterized by a differential signature pattern of eight nucleotides distributed throughout the genome. In vitro characterization of representative clones from each cluster revealed major differences in viral RNA levels, virion secretion, antigen expression levels, as well as in the localization of the antigens. Interestingly, a differential regulation in the expression of genes associated with tumorigenesis was also identified. In conclusion, this study provides new insights into the molecular and biological characteristics of the subgenotype F1b clusters and contributes to unravel the different clinical outcomes of subgenotype F1b chronic infections.

HBV Genotype: A Significant Risk Factor in Determining Which Patients With Chronic HBV Infection Should Undergo Surveillance for HCC: The Hepatitis B Alaska Study

BACKGROUND AND AIMS

Information is limited regarding HBV genotype and the outcome of chronic HBV (CHB) infection. We examined the effect of HBV genotype on HCC occurrence in Alaska Native (AN) persons with CHB, where five HBV genotypes are found: A2, B6, C2, D, and F1.

APPROACH AND RESULTS

We calculated HCC incidence per 1,000 person-years of follow-up to determine which groups by age, sex, and genotype met current American Association for the Study of Liver Diseases (AASLD) HCC surveillance criteria. We used Poisson regression to compare HCC risk by genotype, age, sex, and Alaska region. Incidence of HCC was calculated using the sex-specific AASLD cutoff recommended for the Asian population of 50 years for women and 40 years for men. HCC screening was conducted semiannually using alpha-fetoprotein levels and abdominal ultrasound. Among 1,185 AN persons, median follow-up was 35.1 years; 667 (63%) were male. The HBV genotype distribution was 49% D, 18% F, 13% A, 6% C, 3% B, 0.1% H, and 12% undetermined. Sixty-three cases of HCC occurred. HCC incidence for genotype F was 5.73 per 1,000 person-years of follow-up, followed by 4.77 for C, 1.28 for A, 0.47 for D, and 0.00 for B. The HCC risk was higher for genotypes F (relative rate [RR], 12.7; 95% CI, 6.1-26.4), C (RR, 10.6; 95% CI, 4.3-26.0), and A (RR, 2.9; 95% CI, 1.0-8.0) compared to genotypes B and D. Among men < 40 years of age and women < 50 years of age, genotype F had the highest incidence (4.79/1,000 person-years).

CONCLUSIONS

HBV genotype was strongly associated with HCC. HBV genotype should be considered in risk factor stratification.

Infection courses, virological features and IFN-α responses of HBV genotypes in cell culture and animal models

BACKGROUND & AIMS

HBV consists of 9 major genotypes (A to I), 1 minor strain (designated J) and multiple subtypes, which may be associated with different clinical characteristics. As only cell lines expressing genotype D3 have been established, herein, we aimed to establish stable cell lines producing high-titer cell culture-generated HBV (HBVcc) of different genotypes and to explore their infectivity, virological features and responses to treatment.

METHODS

Stable cell lines producing high titers of HBV genotype A2, B2, C1, E, F1b and H were generated by transfecting plasmids containing a replication-competent 1.3x length HBV genome and an antibiotic marker into HepG2 cells that can support HBV replication. Clones with the highest levels of HBV DNA and/or HBeAg were selected and expanded for large-scale purification of HBVcc. HBVcc of different genotypes were tested in cells and a humanized chimeric mouse model.

RESULTS

HBVcc genotypes were infectious in mouse-passaged primary human hepatocytes (PXB cells) and responded differently to human interferon (IFN)-α with variable kinetics of reduction in HBV DNA, HBeAg and HBsAg. HBVcc of all genotypes were infectious in humanized chimeric mice but with variable kinetics of viremia and viral antigen production. Treatment of infected mice with human IFN-α resulted in modest and variable reductions of viremia and viral antigenemia. HBVcc passaged in humanized chimeric mice (HBVmp) infected PXB cells much more efficiently than that of the original HBVcc viral stock.

CONCLUSIONS

Herein, we generated stable cell lines producing HBV of various genotypes that are infectious in vitro and in vivo. We observe genotype-associated variations in viral antigen production, infection kinetics and responses to human IFN-α treatment in these models.

LAY SUMMARY

Stable cell lines producing high-titer cell culture-generated hepatitis B virus (HBV) of various genotypes were established. HBV genotypes showed stable infectivity in both in vitro and in vivo models, which are valuable tools for antiviral development.

Biological Characterization of Hepatitis B virus Genotypes: Their Role in Viral Replication and Antigen Expression

Hepatitis B virus (HBV) inter-host evolution has resulted in genomic diversification reflected in the existence of nine genotypes (A-I) and numerous subgenotypes. There is growing evidence that genotypes influence HBV natural history, clinical outcomes, and treatment response. However, the biological characteristics underlying these differences have not yet been established. By transfecting HuH-7 cells with unit-length constructs of genotypes A2, B2, C1, D1, and F1b, we identified major differences in HBV replicative capacity and antigen expression across genotypes. Genotypes B2 and F1b showed a 2-fold increase in cccDNA levels compared to the other genotypes (p<0.005). Genotype A2 expressed the lowest pgRNA levels, with a 70-fold decrease in relation to the other genotypes (p<0.0001), while genotype B2 showed the lowest Precore RNA levels, with a 100-fold reduction compared to genotype A2 (p<0.0001). The highest intracellular HBV DNA levels were observed for genotype B2 and the lowest for genotypes A2 and C1 (p<0.0001). Regarding antigen expression, genotype F1b secreted the highest HBsAg levels and genotype D1 the lowest (p<0.0001), while genotypes A2 and B2 showed the highest intracellular HBsAg levels (p<0.0001). Interestingly, genotype C1 secreted the highest HBeAg levels, while genotype A2 showed the highest intracellular levels (p<0.0001). Finally, the analysis of the intra/extracellular antigen ratios revealed that most genotypes retained intracellularly 5-20% of the antigens, except the genotype A2 that retained 50% of the total expressed antigens. In conclusion, this study provides new insights into the biological characteristics of HBV genotypes, being the first study to comparatively analyze European (A and D) and Asian (B and C) genotypes with the Latin American (F) genotype. The differences in HBV replication and antigen expression might contribute to understand the differential role of genotypes in pathogenesis.

Canonical and Divergent N-Terminal HBx Isoform Proteins Unveiled: Characteristics and Roles during HBV Replication

Hepatitis B virus (HBV) X protein (HBx) is a viral regulatory and multifunctional protein. It is well-known that the canonical HBx reading frame bears two phylogenetically conserved internal in-frame translational initiation codons at Met2 and Met3, thus possibly generating divergent N-terminal smaller isoforms during translation. Here, we demonstrate that the three distinct HBx isoforms are generated from the ectopically expressed HBV HBx gene, named XF (full-length), XM (medium-length), and XS (short-length); they display different subcellular localizations when expressed individually in cultured hepatoma cells. Particularly, the smallest HBx isoform, XS, displayed a predominantly cytoplasmic localization. To study HBx proteins during viral replication, we performed site-directed mutagenesis to target the individual or combinatorial expression of the HBx isoforms within the HBV viral backbone (full viral genome). Our results indicate that of all HBx isoforms, only the smallest HBx isoform, XS, can restore WT levels of HBV replication, and bind to the viral mini chromosome, thereby establishing an active chromatin state, highlighting its crucial activities during HBV replication. Intriguingly, we found that sequences of HBV HBx genotype H are devoid of the conserved Met3 position, and therefore HBV genotype H infection is naturally silent for the expression of the HBx XS isoform. Finally, we found that the HBx XM (medium-length) isoform shares significant sequence similarity with the N-terminus domain of the COMMD8 protein, a member of the copper metabolism MURR1 domain-containing (COMMD) protein family. This novel finding might facilitate studies on the phylogenetic origin of the HBV X protein. The identification and functional characterization of its isoforms will shift the paradigm by changing the concept of HBx from being a unique, canonical, and multifunctional protein toward the occurrence of different HBx isoforms, carrying out different overlapping functions at different subcellular localizations during HBV genome replication. Significantly, our current work unveils new crucial HBV targets to study for potential antiviral research, and human virus pathogenesis.

A simple-to-use tool for predicting response to peginterferon in HBV DNA suppressed chronic hepatitis B patients in China

BACKGROUND

Rational administration of peginterferon can remarkably reduce serum HBsAg level and improve the rate of HBsAg loss. Considering the high cost and adverse drug reaction of peginterferon, we aimed to develop a simple-to-use scoring system at early stage of treatment to predict low HBsAg level or HBsAg clearance at the end of treatment in virological suppression chronic hepatitis B (CHB) patients.

METHODS

Non-cirrhotic CHB patients with NA (nucleoside/nucleotide analogues)-induced virological suppression initiated either by add-on or switch-to peginterferon for ≥ 48 weeks were enrolled from January 2012 to June 2017 in these two tertiary centers. The retrospective experiment identified 320 suitable patients, including 192 in training and 128 in validation cohorts.

RESULTS

Using logistic regression, a simple-to-use scoring system integrating baseline HBsAg level <1000 IU/mL, HBsAg decline >0.5 log at week 12 and ALT flare at week 12 was developed in the training cohort and good for predicting HBsAg <100 IU/mL, HBsAg <10 IU/mL and HBsAg loss at the end of 48-week treatment. The area under receiver operating characteristics curve was 0.84, 0.86 or 0.78 in the training cohort and 0.88, 0.79 or 0.81 in the validation cohort, respectively.

CONCLUSIONS

Our simple-to-use scoring system may guide for clinicians to decide whether to continue peginterferon in CHB patients to achieve low HBsAg levels or HBsAg clearance at the end of treatment, which might lead more cost-effective decision and get more patients to reach functional cures in Chinese population.

Low Incidence of Adverse Outcomes in Adults With Chronic Hepatitis B Virus Infection in the Era of Antiviral Therapy

BACKGROUND AND AIMS

Outcomes of persons with chronic hepatitis B virus (HBV) infection in the era of antiviral therapy (AVT) are not well characterized. We determined the incidence and factors associated with clinical outcomes in a multiethnic, North American cohort of adults with chronic HBV infection, who were not on AVT at enrollment.

APPROACH AND RESULTS

Adults with chronic HBV infection, not receiving AVT, and without a history of decompensation, HCC, or liver transplantation (LT), were prospectively followed. Participants with known human immunodeficiency virus (HIV), hepatitis C virus, or hepatitis D virus (HDV) coinfection were excluded. During follow-up, treatment could be initiated per standard of care. Clinical outcomes included: incident cirrhosis, decompensation, HCC, OLT, and HBV-related death. Among 1,418 participants analyzed, 51.5% were women, median age was 41.1 years, 75% were Asian, 10% White, 13% Black, 24% HBeAg(+), and 1.5% cirrhosis at baseline. During the study, 274 started treatment, 83 had an alanine aminotransferase flare, 118 of 330 initially HBeAg(+) became HBeAg(-), and 90 of 1,329 became HBsAg(-). After 6,641 person-years follow-up, 8 participants (4 of 21 with baseline cirrhosis) had 12 clinical outcomes (2 decompensation, 5 HCC, 2 OLT, and 3 HBV-related deaths) and 19 of 1,397 had incident cirrhosis. Twenty-one of 26 participants had first outcome before treatment, none had become HBsAg(-), whereas 5/9 HBeAg(+) had become HBeAg(-) at time of first outcome. Cumulative percentage of clinical outcomes was 16% at year 4 in participants with baseline cirrhosis and 2% (including incident cirrhosis) at year 7 in those without.

CONCLUSIONS

Incidence of adverse outcomes was low in this closely monitored, large cohort of North American adults with predominantly inactive, chronic HBV without cirrhosis. Our data highlight the benefits of HBsAg loss and the importance of early diagnosis and treatment to prevent cirrhosis and other complications of chronic HBV infection.

Hepatitis B-related hepatocellular carcinoma: surveillance strategy directed by immune-epidemiology

Hepatitis B infection (HBV) is one of the most common causes of hepatocellular carcinoma (HCC) worldwide. The age of occurrence, prognosis and incidence vary dramatically depending on the region of the world. This geographic variation is largely dependent on the contrasting incidence of HBV, age of transmission of the virus, the timing of integration into the human genome, and different HBV genotypes, as well as environmental factors. It results in a wide difference in viral interaction with the immune system, genomic modulation and the consequent development of HCC in an individual. In this review, we describe many factors implicated in HCC development, provide insight regarding at-risk populations and explain societal recommendations for HCC surveillance in persons living with HBV in different continents of the world.

Current perspectives into the evaluation and management of hepatitis B: a review

Hepatitis B is a widespread disease which affects millions of people worldwide. Chronic hepatitis B (CHB) can lead to significant morbidity and mortality due to complications such as cirrhosis and hepatocellular carcinoma. The pathophysiology of hepatitis is critical to diagnosing CHB. Deciding which patients with CHB should be treated is an important decision as treatment can often lead to better outcomes in the appropriate patient population. The nucleos(t)ide analog inhibitors entecavir and tenofovir are currently the mainstay of treatment as they are able to successfully suppress the virus and lead to fewer complications. Novel therapies are currently being developed which may offer a potential cure for this disease in the future.

Hepatitis B Virus X Gene Differentially Modulates Subgenotype F1b and F4 Replication

Hepatitis B virus (HBV) is classified into ten genotypes and numerous subgenotypes (sgt). In particular, sgt F1b and sgt F4, native of Latin America, have been associated with differences in clinical and virological characteristics. Hepatitis B virus X protein (HBx) is a multifunctional regulatory protein associated with the modulation of viral transcription and replication. In this work, we analyzed the role of the X gene and the encoded X protein in sgtF1b and sgtF4 replication. Transfection with HBx deficient genomes revealed remarkable differences in the replicative capacity of sgtF1b and sgtF4 mutants. The silencing of HBx increased sgtF1b X(-) transcription and replication by more than 2.5 fold compared to the wild type variant, while it decreased sgtF4 X(-) transcription and replication by more than 3 fold. Trans-complementation of HBx restore sgtF1b and sgtF4 wild type transcription and replication levels. In addition, transfection with chimeric variants, carrying wild type (F1b/XF4 and F4/XF1b) or mutated (F1b/X(-)F4 and F4/X(-)F1b) X gene of one sgt in the backbone of the other sgt, showed that the nucleotide sequence of the X gene, that includes regulatory elements that modulate pgRNA transcription, was responsible for the disparity observed between sgtF1b X(-) and sgtF4 X(-). These results showed that sgtF1b and sgtF4 X gene play a central role in regulating HBV transcription and replication, which eventually lead to a common purpose, to reach wild type replication levels of sgtF1b and sgtF4 viruses.

An Association Between Core Mutations in Hepatitis B Virus Genotype F1b and Hepatocellular Carcinoma in Alaskan Native People

Hepatitis B virus (HBV) genotype F1b infection is strongly associated with hepatocellular carcinoma (HCC) in young Alaskan Native (AN) people. However, the mechanisms by which genotype F1b causes HCC are unclear. Here, we analyzed the clinical and virological significance of genotype F1b in long-term serial samples from 20 HCC patients with HBV infection. Complete sequence analyses revealed that all isolates were genotype F1b. In the HCC patients, T1938C and A2051C mutations in the core region had accumulated significantly with A1762T/G1764A mutations in the basal core promoter (BCP) region and G1896A mutation in the precore (PC) region. Several HBV clones containing the core mutations were examined for their replication efficiency and core stability in vitro. Clones containing the A2051C mutation replicated more efficiently than the wild type in association with enhanced stability of core protein dimerization. In chimeric mice with human hepatocytes carrying BCP/PC/2051 mutant but not with wild-type virus, liver fibrosis was induced in association with high levels of serum HBV DNA and hepatitis B surface antigen. Interestingly, microarray analysis and validation study showed that five genes associated with cell proliferation or carcinogenesis, v-myc avian myelocytomatosis viral oncogene homolog, Grb2-associated binding protein 2, bradykinin receptor B2, follistatin, and mitogen-activated protein kinase kinase kinase 8, were significantly up-regulated in human hepatocytes infected with genotype F1b, particularly the BCP/PC/2051 mutant, compared with other genotypes. Conclusion: We have identified an association between Alaska-specific core mutations and HCC development in AN people infected with genotype F1b; accumulation of these core mutations during the course of chronic infection with genotype F1b would contribute to HCC development in AN people earlier in life.

Comprehensive Analysis of Hepatitis B Virus Promoter Region Mutations

Over 250 million people are infected chronically with hepatitis B virus (HBV), the leading cause of liver cancer worldwide. HBV persists, due, in part, to its compact, stable minichromosome, the covalently-closed, circular DNA (cccDNA), which resides in the hepatocytes' nuclei. Current therapies target downstream replication products, however, a true virological cure will require targeting the cccDNA. Finding targets on such a small, compact genome is challenging. For HBV, to remain replication-competent, it needs to maintain nucleotide fidelity in key regions, such as the promoter regions, to ensure that it can continue to utilize the necessary host proteins. HBVdb (HBV database) is a repository of HBV sequences spanning all genotypes (A⁻H) amplified from clinical samples, and hence implying an extensive collection of replication-competent viruses. Here, we analyzed the HBV sequences from HBVdb using bioinformatics tools to comprehensively assess the HBV core and X promoter regions amongst the nearly 70,000 HBV sequences for highly-conserved nucleotides and variant frequencies. Notably, there is a high degree of nucleotide conservation within specific segments of these promoter regions highlighting their importance in potential host protein-viral interactions and thus the virus' viability. Such findings may have key implications for designing antivirals to target these areas.

Interferon-based treatment is superior to nucleos(t)ide analog in reducing HBV-related hepatocellular carcinoma for chronic hepatitis B patients at high risk

BACKGROUND

The effect of nucleos(t)ide analogs (NAs) versus interferon (IFN) on the occurrence of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) is controversial. We assessed whether antiviral strategy affected HCC development in CHB patients at different HCC risks.

METHODS

1112 CHB patients with antiviral therapy were included in this retrospective study. Patients treated with NAs only were classified into NAs group (n = 682) while those received IFN treatment with or without NAs were defined as IFN group (n = 430). Propensity score matching (PSM) was applied to minimize baseline differences.

RESULTS

Totally, 31 patients developed HCC during follow-up (median 5.41 years). The cumulative HCC incidence at 10 years was significantly lower in the IFN group than NAs group (2.7% vs 8.0%, p < 0.001). Similar results were obtained in the PSM-cohort. Patients with IFN-based treatment were less likely to develop HCC than those with NAs (Hazard ratio = 0.15; 95% CI 0.04-0.66; p = 0.012). Subgroup analyses demonstrated that this superiority of IFN in reducing HCC development was obvious in patients at high- but not low-risk of HCC.

CONCLUSIONS

Reduction of HCC development was more significant in CHB patients at higher HCC risk with IFN-based therapy than NAs treatment.

Host and Viral Genetic Variation in HBV-Related Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer in men and the second leading cause of cancer deaths globally. The high prevalence of HCC is due in part to the high prevalence of chronic HBV infection and the high mortality rate is due to the lack of biomarkers for early detection and limited treatment options for late stage HCC. The observed individual variance in development of HCC is attributable to differences in HBV genotype and mutations, host predisposing germline genetic variations, the acquisition of tumor-specific somatic mutations, as well as environmental factors. HBV genotype C and mutations in the preS, basic core promoter (BCP) or HBx regions are associated with an increased risk of HCC. Genome-wide association studies have identified common polymorphisms in KIF1B, HLA-DQ, STAT4, and GRIK1 with altered risk of HBV-related HCC. HBV integration into growth control genes (such as TERT), pro-oncogenic genes, or tumor suppressor genes and the oncogenic activity of truncated HBx promote hepatocarcinogenesis. Somatic mutations in the TERT promoter and classic cancer signaling pathways, including Wnt (CTNNB1), cell cycle regulation (TP53), and epigenetic modification (ARID2 and MLL4) are frequently detected in hepatic tumor tissues. The identification of HBV and host variation associated with tumor initiation and progression has clinical utility for improving early diagnosis and prognosis; whereas the identification of somatic mutations driving tumorigenesis hold promise to inform precision treatment for HCC patients.

HBV subgenotypes F1b and F4 replication induces an incomplete autophagic process in hepatocytes: Role of BCP and preCore mutations

Hepatitis B virus (HBV) genotypes and mutants have been associated with differences in clinical and virological characteristics. Autophagy is a cellular process that degrades long-lived proteins and damaged organelles. Viruses have evolved mechanisms to alter this process to survive in host cells. In this work, we studied the modulation of autophagy by the replication of HBV subgenotypes F1b and F4, and the naturally occurring mutants BCP and preCore. HBV subgenotypes F1b and F4 replication induced accumulation of autophagosomes in hepatoma cells. However, no autophagic protein degradation was observed, indicating a blockage of autophagic flux at later stages. This inhibition of autophagy flux might be due to an impairment of lysosomal acidification in hepatoma cells. Moreover, HBV-mediated autophagy modulation was independent of the viral subgenotypes and enhanced in viruses with BCP and preCore naturally occurring mutations. These results contribute to understand the mechanisms by which different HBV variants contribute to the pathogenesis of HBV infections. In addition, this study is the first to describe the role that two highly prevalent naturally occurring mutations exert on the modulation of HBV-induced autophagy.

X protein variants of the autochthonous Latin American hepatitis B virus F genotype promotes human hepatocyte death by the induction of apoptosis and autophagy

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The impact of BCP mutations on HBV-X biologic activity was analyzed.

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Genotype F wild type and mutant HBV-X induce apoptosis of human hepatocytes.

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HBV-X variants modulate the expression of Bcl-2 family proteins.

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Subgenotypes F1b and F4 HBV-X and variants induce autophagy of human hepatocytes.

The hepatitis B virus X protein (HBV-X) is a multifunctional regulatory protein associated with the pathogenesis of liver disease in chronic HBV infection. Basal core promoter mutations (BCP), associated with the clinical course of chronic HBV infection, affect HBV-X at 130–131 positions. The role of these mutations on HBV-X biological activity remains largely unknown. The aim of this study was to analyze the impact of the presence of different amino acids at 130–131 positions of HBV-X on the biological activity of the protein. Transient expression of wild type and mutant F1b and F4 HBV-X increased cell mortality by the induction of apoptosis in human hepatoma cells. The wild type and mutant HBV-X differentially modulate the expression of pro-apoptotic (Bax) and anti-apoptotic (Bcl-2 and Bcl-X) regulatory proteins of the Bcl-2 family. Furthermore, the expression of HBV-X variants of both subgenotypes induced autophagy of human tumoral hepatocytes. In conclusion, HBV-X variants of the Latin American HBV F genotype promotes human hepatocytes death by the induction of apoptosis and autophagy. The results of this work describe some of the molecular mechanisms by which HBV-X variants contribute to the pathogenesis of liver diseases in the infected liver and help to the biological characterization of genotype F, responsible of the majority of HBV infections in Argentina.

Role of HLA-DP and HLA-DQ on the clearance of hepatitis B virus and the risk of chronic infection in a multiethnic population

BACKGROUND & AIMS

HBV infection exhibits geographical variation in its distribution in South America. While HBV rates are low in central Argentina, the north-western region exhibits intermediate HBV rates. Unfortunately, the reasons that could explain this difference are still unknown.

METHODS

A total of 1440 Argentines were recruited and grouped into HBV patients, HBV-resolved individuals and healthy controls. Genetic ancestry was assessed by analysis of biparental lineages and ancestry autosomal typing. SNPs of HLA-DPA1 (rs3077), HLA-DPB1 (rs9277542), HLA-DQB1 (rs2856718) and HLA-DQB2 (rs7453920) were determined, and HBV genotyping was performed by phylogenetic analysis in HBV patients.

RESULTS

Native American ancestry prevailed in the north-western region when compared with central Argentina (P<.0001). However, no differences were observed among the three groups of each region. The distribution of HBV genotypes revealed significant differences (P<.0001). Three SNPs (rs3077, rs9277542 and rs7453920) showed a significant association with protection against chronic HBV and viral clearance in both regions. The remaining SNP showed a significant association with susceptibility to chronic HBV. The frequency rates of rs3077-T, related to protection against chronic HBV and viral clearance, were lower in north-western Argentina when compared with central Argentina. The same uneven frequency rates were observed for SNP rs9277542.

CONCLUSIONS

This is the first study addressing the associations between the HLA-DP and HLA-DQ loci and the protection against chronic HBV and viral clearance in a multiethnic South American population. The uneven distribution of HLA-DP and HLA-DQ supports the HBV epidemiological differences observed in these two regions of Argentina with dissimilar ancestry genetic background.

Hepatocellular Carcinoma Risk in Alaska Native Children and Young Adults with Hepatitis B Virus: Retrospective Cohort Analysis

OBJECTIVES

To evaluate the hepatocellular carcinoma (HCC) risk in Alaska Native children and young adults with hepatitis B virus (HBV).

STUDY DESIGN

Retrospective analysis of a population-based cohort of Alaska Native persons with HBV followed during 1982-2012. All individuals with HBV were offered HCC screening regardless of age using alpha-fetoprotein every 6 months; persons with an elevated alpha-fetoprotein or persons at high-risk for HCC, such as cirrhosis, family history of HCC, were offered ultrasound. We calculated the HCC incidence/1000 person-years from date of cohort entry until death, diagnosis of HCC, or attaining the age of 40 years (males) or 50 years (females).

RESULTS

We followed 1083 subjects with HBV (56% male) comprising 5 genotypes (A2 [12.5%], B6 [1.7%], C [5.3%], D [49.7%], F1 [18.6%], unknown [12.4%]) for a median of 23.4 years/person. We observed 22 HCC cases (incidence/1000 person-years follow-up: 1.0); 19 HCC cases among persons with genotype F1. There was no significant difference in HCC incidence between males (1.4) and females (0.6). The HCC incidence was significantly higher for persons with genotype F1 (4.4) compared with genotype A2 (0.4) and D (0.2) and remained higher among persons with HBV genotype F1 excluding persons with HCC family history/cirrhosis (1.9).

CONCLUSIONS

Alaska Native children and young adults with HBV genotype F1 are at high risk for HCC and should receive HCC surveillance. For males <40 years of age and females <50 years of age with HBV in regions of the world with a high genotype F prevalence, testing/confirming genotype F can identify persons who could benefit from HCC surveillance.