The association between hepatitis B mutants and hepatocellular carcinoma: A meta-analysis

Occult Hepatitis B Virus Infection in Hepatic Diseases and Its Significance for the WHO's Elimination Plan of Viral Hepatitis

Liver damage can progress through different stages, resulting in cirrhosis or hepatocellular carcinoma (HCC), conditions that are often associated with viral infections. Globally, 42% and 21% of cirrhosis cases correlate with HBV and HCV, respectively. In the Americas, the prevalence ranges from 1% to 44%. The WHO has the goal to eliminate viral hepatitis, but it is important to consider occult HBV infection (OBI), a clinical condition characterized by the presence of HBV genomes despite negative surface antigen tests. This review aims to provide an overview of recent data on OBI, focusing on its role in the development of hepatic diseases and its significance in the WHO Viral Hepatitis Elimination Plan. Specific HBV gene mutations have been linked to HCC and other liver diseases. Factors related to the interactions between OBI and mutated viral proteins, which induce endoplasmic reticulum stress and oxidative DNA damage, and the potential role of HBV integration sites (such as the TERT promoter) have been identified in HCC/OBI patients. Health initiatives for OBI research in Latin American countries are crucial to achieving the WHO's goal of eradicating viral hepatitis by 2030, given the difficulty in diagnosing OBI and its unclear association with hepatic diseases.

Contemporary and historical human migration patterns shape hepatitis B virus diversity

Infection by hepatitis B virus (HBV) is responsible for approximately 296 million chronic cases of hepatitis B, and roughly 880,000 deaths annually. The global burden of HBV is distributed unevenly, largely owing to the heterogeneous geographic distribution of its subtypes, each of which demonstrates different severity and responsiveness to antiviral therapy. It is therefore crucial to the global public health response to HBV that the spatiotemporal spread of each genotype is well characterized. In this study, we describe a collection of 133 newly sequenced HBV strains from recent African immigrants upon their arrival in Belgium. We incorporate these sequences-all of which we determine to come from genotypes A, D, and E-into a large-scale phylogeographic study with genomes sampled across the globe. We focus on investigating the spatio-temporal processes shaping the evolutionary history of the three genotypes we observe. We incorporate several recently published ancient HBV genomes for genotypes A and D to aid our analysis. We show that different spatio-temporal processes underlie the A, D, and E genotypes with the former two having originated in southeastern Asia, after which they spread across the world. The HBV E genotype is estimated to have originated in Africa, after which it spread to Europe and the Americas. Our results highlight the use of phylogeographic reconstruction as a tool to understand the recent spatiotemporal dynamics of HBV, and highlight the importance of supporting vulnerable populations in accordance with the needs presented by specific HBV genotypes.

A Review of Incidence and Related Risk Factors in the Development of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a primary liver malignancy, ranking as the seventh most common cancer globally and the second leading cause of deaths due to cancer. This review examines the incidence of HCC, its associated risk factors, and constantly changing global trends. Incidence has been noted to be varying worldwide, particularly due to environmental and infectious risk factors. Chronic hepatitis B (HBV) and C (HCV) virus infections, alcohol abuse, aflatoxin exposure, diabetes, obesity, and tobacco consumption are some of the leading risk factors noted. Eastern Asia and sub-Saharan Africa were noted to have the highest disease burden for HCC, with China representing a considerably large majority. On the contrary, the United States reports a lower HCC incidence overall due to improved vaccination programs against HBV; however, with a rising incidence of prominent risk factor in non-alcoholic fatty liver disease (NAFLD), the trend may very well change. Gender disparities were noted to be evident with men experiencing higher rates of HCC compared to women, which may be due to various environmental and biological factors, including alcohol intake, smoking, and androgen hormone levels. Currently, efforts to reduce the overall incidence of HCC include universal HBV vaccinations, antiviral therapies, aflatoxin prevention measures, genetic screening for hereditary hemochromatosis, and early ultrasound evaluation in patients with liver cirrhosis. Understanding these evolving trends and risk factors is essential in combating the rising HCC incidence, especially in Western countries, where risk factors, such as obesity, diabetes, and metabolic disorders, are on the rise.

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.

NAFLD and HBV interplay - related mechanisms underlying liver disease progression

Non-alcoholic fatty liver disease (NAFLD) and Hepatitis B virus infection (HBV) constitute common chronic liver diseases with worldwide distribution. NAFLD burden is expected to grow in the coming decade, especially in western countries, considering the increased incidence of diabetes and obesity. Despite the organized HBV vaccinations and use of anti-viral therapies globally, HBV infection remains endemic and challenging public health issue. As both NAFLD and HBV have been associated with the development of progressive fibrosis, cirrhosis and hepatocellular carcinoma (HCC), the co-occurrence of both diseases has gained great research and clinical interest. The causative relationship between NAFLD and HBV infection has not been elucidated so far. Dysregulated fatty acid metabolism and lipotoxicity in NAFLD disease seems to initiate activation of signaling pathways that enhance pro-inflammatory responses and disrupt hepatocyte cell homeostasis, promoting progression of NAFLD disease to NASH, fibrosis and HCC and can affect HBV replication and immune encountering of HBV virus, which may further have impact on liver disease progression. Chronic HBV infection is suggested to have an influence on metabolic changes, which could lead to NAFLD development and the HBV-induced inflammatory responses and molecular pathways may constitute an aggravating factor in hepatic steatosis development. The observed altered immune homeostasis in both HBV infection and NAFLD could be associated with progression to HCC development. Elucidation of the possible mechanisms beyond HBV chronic infection and NAFLD diseases, which could lead to advanced liver disease or increase the risk for severe complications, in the case of HBV-NAFLD co-existence is of high clinical significance in the context of designing effective therapeutic targets.

Combination of Bone-Modifying Agents with Immunotarget Therapy for Hepatocellular Carcinoma with Bone Metastases

Due to limited investigations about efficacy of tyrosine kinase inhibitors (TKIs) plus immune-checkpoint inhibitors (ICIs) versus TKIs alone, and effects of durations of bone modifying agents (BMAs) on the survival of patients with hepatocellular carcinoma (HCC) and bone metastases (BoM), we aim to compare the efficacy of TKIs both alone and in combination with ICIs, as well as comparing long-term and no or perioperative use of BMAs for patients with HCC and BoM. Patients with pathologically confirmed HCC and BoM were included in the study. They were stratified into the TKIs group and the TKIs + ICIs group, and the perioperative and the long-term use of BMAs group. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR) were calculated to assess the response to these regimes. The cumulative risk of initial skeletal-related events (SREs) was used to evaluate treatment efficacy for bone lesions. A total of 21 (33.9%) patients received TKIs (Sorafenib or Lenvatinib) alone and 41 (66.1%) received TKIs + ICIs. The combination group showed higher ORR than monotherapy group (1/21, 4.7% vs. 9/41, 22.0%; p = 0.1432); Additionally, the TKIs + ICIs group offered improved OS (18 months vs. 31 months; p = 0.015) and PFS (10 months vs. 23 months; p = 0.014), while this survival benefits were more profound in virus-infected patients than those non-infected. Prolonged OS (33 months vs. 16 months; p = 0.0048) and PFS (33 months vs. 11 months; p = 0.0027) were observed in patients with long-term use of BMAs compared with no or perioperative use of BMAs. The TKIs + ICIs combination and long-term adjuvant of BMAs may offer a survival advantage for HCC patients with BoM without severe adverse events, which requires further validations.

Hepatocellular Carcinoma in Mongolia Delineates Unique Molecular Traits and a Mutational Signature Associated with Environmental Agents

PURPOSE

Mongolia has the world's highest incidence of hepatocellular carcinoma (HCC), with ∼100 cases/100,000 inhabitants, although the reasons for this have not been thoroughly delineated.

EXPERIMENTAL DESIGN

We performed a molecular characterization of Mongolian (n = 192) compared with Western (n = 187) HCCs by RNA sequencing and whole-exome sequencing to unveil distinct genomic and transcriptomic features associated with environmental factors in this population.

RESULTS

Mongolian patients were younger, with higher female prevalence, and with predominantly HBV-HDV coinfection etiology. Mongolian HCCs presented significantly higher rates of protein-coding mutations (121 vs. 70 mutations per tumor in Western), and in specific driver HCC genes (i.e., APOB and TSC2). Four mutational signatures characterized Mongolian samples, one of which was novel (SBS Mongolia) and present in 25% of Mongolian HCC cases. This signature showed a distinct substitution profile with a high proportion of T>G substitutions and was significantly associated with a signature of exposure to the environmental agent dimethyl sulfate (71%), a 2A carcinogenic associated with coal combustion. Transcriptomic-based analysis delineated three molecular clusters, two not present in Western HCC; one with a highly inflamed profile and the other significantly associated with younger female patients.

CONCLUSIONS

Mongolian HCC has unique molecular traits with a high mutational burden and a novel mutational signature associated with genotoxic environmental factors present in this country.

Controversies in the Management of Hepatitis B: Hepatocellular Carcinoma

Hepatitis B is the leading cause of hepatocellular cancer (HCC) worldwide. Untreated, annual HCC incidence rates in chronic hepatitis B subjects are 0.4% in noncirrhotics and 2% to 3% in cirrhotics. Surveillance with ultrasound with/without α-fetoprotein at 6-month intervals is recommended in at-risk persons including children. Antiviral therapy in chronic hepatitis B with entecavir or tenofovir significantly lowers the risk of HCC across all stages of liver disease, and lowers the risk of HCC recurrence following curative therapy. There are insufficient data to recommend use of tenofovir over entecavir in the prevention of de novo or recurrent HCC postcurative therapy.

Prevalence of Dual-Positivity for Both Hepatitis B e Antigen and Hepatitis B e Antibody Among Hospitalized Patients with Chronic Hepatitis B Virus Infection

Objective

The detection of dual-positivity for both hepatitis B e antigen (HBeAg) and hepatitis B e antibody (anti-HBe) is not typically performed for patients with hepatitis B virus (HBV). This cross-sectional study was designed to figure out the prevalence of dual-positivity for both HBeAg and anti-HBe (DEP) among hospitalized patients with chronic hepatitis B virus infection (C-HBVI).

Patients and Methods

Data from 2820 cases with C-HBVI from two centers in China were retrospectively analyzed. Univariate and multivariate logistic regression analyses were undertaken to identify the risk factors for liver fibrosis (LF) and acute-on-chronic liver failure (ACLF).

Results

There were 165 (5.9%), 688, and 1903 patients in DEP, HBeAg+/anti-HBe-, and HBeAg-/anti-HBe+ groups, respectively. The DEP patients’ median age was 43.6 years old and 71.5% of them were male. They had higher levels of alanine transaminase, total bilirubin, and international normalized ratio. Furthermore, DEP cases had a higher proportion of liver cirrhosis, and it was associated with non-invasive testing of LF, including aspartate transaminase (AST)-to-platelet ratio index (APRI) >1.5 (odds ratio (OR) = 1.96, 95% confidence interval (CI): 1.27–3.03, P = 0.002) and fibrosis-4 (FIB-4) score >1.45 (OR = 2.07, 95% CI: 1.28–3.34, P = 0.003). DEP also contributed to the elevated risk of ACLF (OR = 4.80, 95% CI: 2.02–11.39, P < 0.001).

Conclusion

DEP cases are at higher risks of LF and ACLF than other patients with HBV infection. A fast diagnosis and an active monitoring of liver diseases for DEP patients are extremely vital.

Efficacy and safety of lenvatinib monotreatment and lenvatinib-based combination therapy for patients with unresectable hepatocellular carcinoma: a retrospective, real-world study in China

Background

Lenvatinib and lenvatinib-based combination treatments are widely used in patients with unresectable hepatocellular carcinoma (uHCC) in clinical practice, but their curative effect and safety need further study in the real world.

Methods

This was a retrospective study involving patients with uHCC receiving lenvatinib monotherapy and lenvatinib-based combination treatment between Nov, 2018 and Sep, 2020 in Nanfang Hospital. Efficacy was evaluated with objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), time to tumor progression (TTP), and overall survival (OS). Treatment-related adverse events (TRAEs) were recorded and graded. Efficacy and safety of monotherapy and combination therapy were compared. Stratified analysis was performed according to systemic line of treatment and medication regimen for combination therapy.

Results

For lenvatinib monotherapy (n = 39), OS and PFS were 80 weeks and 24.3 weeks, respectively. For combination treatment (n = 72), median OS and PFS were 99 weeks and 45.6 weeks, respectively. OS, PFS, and TTP for patients in the combination treatment cohort were significantly longer compared to those of patients in the monotreatment cohort (OS: P = 0.04, PFS: P = 0.003; TTP, P = 0.005). The incidence of TRAEs could be controlled both in the monotherapy cohort and the combination treatment cohort. In the monotherapy cohort, OS and PFS were significantly decreased in the second-line treatment group compared with the first-line treatment group, while no differences were observed in the combination cohort. The efficacy of triple therapy (lenvatinib plus PD-1 antibody plus TACE or HAIF) was similar to lenvatinib plus PD-1 antibody or lenvatinib plus TACE or HAIF.

Conclusions

Our real-world study showed that lenvatinib monotherapy and lenvatinib-based combination therapy were well tolerated, with encouraging efficacies in patients with uHCC. Lenvatinib-based combination therapy showed a better curative effect compared with lenvatinib single-agent therapy. In patients who have failed first-line TKI treatment, lenvatinib-based combination therapy may be a better choice than lenvatinib single-agent therapy. Lenvatinib-based triple therapy may not have an advantage over dual therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02200-7.

Drug-resistant and immune-escape hepatitis B virus mutants, occult hepatitis B infection and coinfections in public hospital patients from Argentina

Argentina exhibits low serological prevalence for Hepatitis B virus (HBV); however, occult hepatitis B infection (OBI) has been reported in blood donors, Amerindians and individuals coinfected with hepatitis C virus (HCV), and/or human immunodeficiency virus (HIV). The aim of this study was to analyze the genetic diversity of HBV and to evaluate serological marker associations and coinfections with HCV and HIV in patients attending and treated in a public hospital in the province of Buenos Aires, Argentina. A total of 189 HBV reactive samples (HBsAg and/or anti-HBc) were analyzed for HBV DNA characterization. All reactive samples were tested for anti-HCV and HIV-antigen/antibody using CMIA assays. Thirty-six samples exhibited detectable HBV DNA, 7 of which were OBI. HBV sequences were classified as subgenotypes A1, A2, B2, D3, F1b, F3 and F4. Mutations related to the ability to escape the host's immune response, resistance to antiviral therapy and progression to disease were found in patients, partly due to the variable sensitivity of HBsAg, the reverse transcriptase, the basal core promoter and the preCore. HCV and HIV prevalence was 10% and most of the genotypes found in the sequences were genotype 1 and B/F recombinant subtype, respectively. Of the total samples analyzed, 7 exhibited coinfections. This study shows the frequency of OBI, subgenotype distribution, HBV mutations and coinfections, which may have important clinical implications in public hospital patients. Planned prevention, detection and treatment adherence are needed to reduce transmission and morbidity in vulnerable populations.

The Mechanisms of HBV-Induced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common malignancy, and the hepatitis B virus (HBV) is its major pathogenic factor. Over the past decades, it has been confirmed that HBV infection could promote disease progression through a variety of mechanisms, ultimately leading to the malignant transformation of liver cells. Many factors have been identified in the pathogenesis of HBV-associated HCC (HBV-HCC), including HBV gene integration, genomic instability caused by mutation, and activation of cancer-promoting signaling pathways. As research in the progression of HBV-HCC progresses, the role of many new mechanisms, such as epigenetics, exosomes, autophagy, metabolic regulation, and immune suppression, is also being continuously explored. The occurrence of HBV-HCC is a complex process caused by interactions across multiple genes and multiple steps, where the synergistic effects of various cancer-promoting mechanisms accelerate the process of disease evolution from inflammation to tumorigenesis. In this review, we aim to provide a brief overview of the mechanisms involved in the occurrence and development of HBV-HCC, which may contribute to a better understanding of the role of HBV in the occurrence and development of HCC.

Using structural analysis to explore the role of hepatitis B virus mutations in immune escape from liver cancer in Chinese, European and American populations

Hepatitis B virus (HBV) infection is an important problem threatening human health. After HBV virus invades human body, it may assemble a complete virus particle in the cytoplasm to trigger the immune reaction, especially the interaction between the HBV virus and the host that mediated by CD8⁺ T cell. We collected the sequences of HBV from the HBVdb database, then screened candidate mutation sites in Chinese, European and American populations based on conservation and physicochemical properties. After that we constructed the three-dimensional structure of Major histocompatibility complex class I (MHC I) -peptide complexes, performed molecular docking, run molecular dynamics to compare the binding free energy, stability, and affinity of MHC I-peptide complexes with the aim to estimate the effect of peptide mutation. The specific HBV virus subtypes of the Chinese, European and American population were studied and the candidate mutation sites were used to predict the mutant peptide antigen. Finally, based on physical and chemical properties and peptide antigen prediction scores, 21 HBV mutation sites were selected. Then combined with specific Human lymphocyte antigen (HLA) subtypes, 11 mutations were found to have a significant negative impact on affinity, stability and binding free energy. Overall, our work found important potential mutations, which provide an evaluation of HBV mutations and a clue of it in immunotherapy.Communicated by Ramaswamy H. Sarma.

Machine-learning based patient classification using Hepatitis B virus full-length genome quasispecies from Asian and European cohorts

Chronic infection with Hepatitis B virus (HBV) is a major risk factor for the development of advanced liver disease including fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The relative contribution of virological factors to disease progression has not been fully defined and tools aiding the deconvolution of complex patient virus profiles is an unmet clinical need. Variable viral mutant signatures develop within individual patients due to the low-fidelity replication of the viral polymerase creating 'quasispecies' populations. Here we present the first comprehensive survey of the diversity of HBV quasispecies through ultra-deep sequencing of the complete HBV genome across two distinct European and Asian patient populations. Seroconversion to the HBV e antigen (HBeAg) represents a critical clinical waymark in infected individuals. Using a machine learning approach, a model was developed to determine the viral variants that accurately classify HBeAg status. Serial surveys of patient quasispecies populations and advanced analytics will facilitate clinical decision support for chronic HBV infection and direct therapeutic strategies through improved patient stratification.

Occult hepatitis B infection by a recombinant D/C virus in an immunosuppressed patient

Approximately 300 million people worldwide were living with chronic hepatitis B virus infection as of 2016, however, this number does not account for those who might be living with occult hepatitis B virus infection due to difficulty diagnosing this condition. The multiple genotypes and the ability of the hepatitis B virus to acquire mutations that down-regulate its expression make occult hepatitis B virus infection a very elusive diagnosis. This is especially worrisome when there is a need to start immunosuppressive therapies, since there is a risk of reactivation in undiagnosed patients. We present a case of female patient who was referred to the consultation because she was about to start chemotherapy with an anti-CD20 agent and had a positive anti-HBc and anti-HBs. During routine workup an occult hepatitis B virus infection was diagnosed. Upon further study mutations in the PreCore and Basal Core Promoter regions were identified, as well as, a double genotype D/C. Therapy with tenofovir was initiated before the patient was started on chemotherapy. This case highlights the importance of comprehensive studying of patients who present with apparently resolved chronic hepatitis B virus infection, especially when they are about to start immunosuppressive therapies.

Characterization and Clinical Significance of Natural Variability in Hepatitis B Virus Reverse Transcriptase in Treatment-Naive Chinese Patients by Sanger Sequencing and Next-Generation Sequencing

Mutations in hepatitis B virus (HBV) reverse transcriptase (RT) are associated with nucleos(t)ide analogue (NA) resistance during long-term antiviral treatment. However, the characterization of mutations in HBV RT in untreated patients has not yet been well illustrated. The objective of this study was to investigate the characterization and clinical significance of natural variability in HBV RT in treatment-naive patients. HBV RT sequences were analyzed in 427 patients by Sanger sequencing and in 66 patients by next-generation sequencing. Primary or secondary NA resistance (NA^r) mutations were not found, except A181T in RT (rtA181T) by Sanger sequencing, but they were detected by next-generation sequencing. Mutations were found in 56 RT amino acid (aa) sites by Sanger sequencing, 36 of which had mutations that could lead to changes in B or T cell epitopes in the RT or S protein. The distribution of mutations was diverse in different sections within the RT region. Multiple mutations showed significant association with HBV DNA, HBsAg, HBeAg, age, and severity of liver fibrosis. Mutations at rt251, rt266, rt274, rt280, rt283, rt284, and rt286 were found most in the advanced liver disease (ALD) group by next-generation sequencing. The present study demonstrates that next-generation sequencing (NGS) was more suitable than Sanger sequencing to monitor NA^r mutations at a low rate in the treatment-naive patients, and that mutations in the RT region might be involved in the progression to ALD.

High Frequency of Either Altered Pre-Core StartCodon or Weakened Kozak Sequence in the CorePromoter Region in Hepatitis B Virus A1 Strainsfrom Rwanda

Hepatitis B virus (HBV) is endemic in Rwanda and is a major etiologic agent for chronic liver disease in the country. In a previous analysis of HBV strains from Rwanda, the S genes of most strains segregated into one single clade of subgenotype, A1. More than half (55%) of the anti-HBe positive individuals were viremic. In this study, 23 complete HBV genomes and the core promoter region (CP) from 18 additional strains were sequenced. Phylogenetic analysis of complete genomes confirmed that most Rwandan strain formed a single unique clade, within subgenotype A1. Strains from 17 of 22 (77%) anti-HBe positive HBV carriers had either mutated the precore start codon (9 strains with either CUG, ACG, UUG, or AAG) or mutations in the Kozak sequence preceding the pre-core start codon (8 strains). These mutually exclusive mutations were also identified in subgenotypes A1 (70/266; 26%), A2 (12/255; 5%), and A3 (26/49; 53%) sequences from the GenBank. The results showed that previous, rarely described HBV variants, expressing little or no HBeAg, are selected in anti-HBe positive subgenotype Al carriers from Rwanda and that mutations reducing HBeAg synthesis might be unique for a particular HBV clade, not just for a specific genotype or subgenotype.

Genotypes and Hot Spot Mutations of Hepatitis B Virus in Northwest Chinese Population and Its Correlation with Diseases Progression

Hepatitis B virus (HBV) infection is a critical incentive for chronic hepatitis B (CHB), liver cirrhosis (LC), and hepatocellular carcinoma (HCC). Different genotypes and genome mutations of HBV have been found to be related to the progression of these liver diseases. However, their clinical significance is still under debate. The objective of this study was to determine the association of HBV genotypes and hot spot mutations in the reverse transcriptase (RT) and basal core promoter-precore (BCP-PreC) region with HBV-infected diseases in a northwest Chinese population. HBV genotyping and DNA sequencing were performed in samples of 980 patients. Appropriate statistical methods were adopted to assess HBV genetic features and its clinical association. It was found that the prevalent HBV genotype in northwestern Chinese patients was HBV/C (61.33%), followed by HBV/B (36.63%). In RT region, in addition to the reported nucleoside analogue- (NA-) resistance missense mutations, new silent mutations at rt169 and rt180 were found to raise the risk of HCC in patients with HBV/C. And the heterozygous mutation status of rt169/rt180 was associated with the increased risk of both HCC and NA resistance (OR > 1, P < 0.01) regardless of HBV genotypes. In BCP-PreC region, multiple mutations and combinations, especially at nt 1762/1764 and nt 1896/1899, were characterized to be the causes of spurious HBeAg negativity and liver function injury, as well as the risk factors for HCC progression (P < 0.01). Additionally, a novel mutation at nt1799G>C was likely found to increase the risk of HCC in patients with HBV/B. These findings revealed an association between HBV genotypes and HBV genetic mutations in RT and BCP-PreC region and progression of hepatitis B. It would be helpful for risk evaluation and diagnostic improvement based on these genetic features.

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.

Estimating the impact of test-and-treat strategies on hepatitis B virus infection in China by using an age-structured mathematical model

The potential impact of increasing test-and-treat coverage on hepatitis B virus (HBV) infection remains unclear in China. The objective of this study was to develop a dynamic compartmental model at a population level to estimate the long-term effect of this strategy.Based on the natural history of HBV infection and 3 serosurvey data of hepatitis B in China, we proposed an age- and time-dependent discrete model to predict the number of new HBV infection, the number of chronic HBV infection, and the number of HBV-related deaths for the time from 2018 to 2050 under 5 different test-and-treat coverage and compared them with current intervention policy.Compared with current policy, if the test-and-treat coverage was increased to 100% since 2018, the numbers of chronic HBV infection, new HBV infection, and HBV-related deaths in 2035 would be reduced by 26.60%, 24.88%, 26.55%, respectively, and in 2050 it would be reduced by 44.93%, 43.29%, 43.67%, respectively. In contrast, if the test-and-treat coverage was increased by 10% every year since 2018, then the numbers of chronic HBV infection, new HBV infection, and HBV-related deaths in 2035 would be reduced by 21.81%, 20.10%, 21.40%, respectively, and in 2050 it would be reduced by 41.53%, 39.89%, 40.32%, respectively. In particular, if the test-and-treat coverage was increased to 75% since 2018, then the annual number of HBV-related deaths would begin to decrease from 2018. If the test-and-treat coverage was increased to above 25% since 2018, then the hepatitis B surface antigen (HBsAg) prevalence for population aged 1 to 59 years in China would be reduced to below 2% in 2035. Our model also showed that in 2035, the numbers of chronic HBV infection and HBV-related deaths in 65 to 69 age group would be reduced the most (about 1.6 million and 13 thousand, respectively).Increasing test-and-treat coverage would significantly reduce HBV infection in China, especially in the middle-aged people and older people. The earlier the treatment and the longer the time, the more significant the reduction. Implementation of test-and-treat strategy is highly effective in controlling hepatitis B in China.

Deep sequencing of HBV pre-S region reveals high heterogeneity of HBV genotypes and associations of word pattern frequencies with HCC

Hepatitis B virus (HBV) infection is a common problem in the world, especially in China. More than 60–80% of hepatocellular carcinoma (HCC) cases can be attributed to HBV infection in high HBV prevalent regions. Although traditional Sanger sequencing has been extensively used to investigate HBV sequences, NGS is becoming more commonly used. Further, it is unknown whether word pattern frequencies of HBV reads by Next Generation Sequencing (NGS) can be used to investigate HBV genotypes and predict HCC status. In this study, we used NGS to sequence the pre-S region of the HBV sequence of 94 HCC patients and 45 chronic HBV (CHB) infected individuals. Word pattern frequencies among the sequence data of all individuals were calculated and compared using the Manhattan distance. The individuals were grouped using principal coordinate analysis (PCoA) and hierarchical clustering. Word pattern frequencies were also used to build prediction models for HCC status using both K-nearest neighbors (KNN) and support vector machine (SVM). We showed the extremely high power of analyzing HBV sequences using word patterns. Our key findings include that the first principal coordinate of the PCoA analysis was highly associated with the fraction of genotype B (or C) sequences and the second principal coordinate was significantly associated with the probability of having HCC. Hierarchical clustering first groups the individuals according to their major genotypes followed by their HCC status. Using cross-validation, high area under the receiver operational characteristic curve (AUC) of around 0.88 for KNN and 0.92 for SVM were obtained. In the independent data set of 46 HCC patients and 31 CHB individuals, a good AUC score of 0.77 was obtained using SVM. It was further shown that 3000 reads for each individual can yield stable prediction results for SVM. Thus, another key finding is that word patterns can be used to predict HCC status with high accuracy. Therefore, our study shows clearly that word pattern frequencies of HBV sequences contain much information about the composition of different HBV genotypes and the HCC status of an individual.

HBV infection can lead to many liver complications including hepatocellular carcinoma (HCC), one of the most common liver cancers in China. High-throughput sequencing technologies have recently been used to study the genotype sequence compositions of HBV infected individuals and to distinguish chronic HBV (CHB) infection from HCC. We used NGS to sequence the pre-S region of a large number of CHB and HCC individuals and designed novel word pattern based approaches to analyze the data. We have several surprising key findings. First, most HBV infected individuals contained mixtures of genotypes B and C sequences. Second, multi-dimensional scaling (MDS) analysis of the data showed that the first principal coordinate was closely associated with the fraction of genotype B (or C) sequences and the second principal coordinate was highly associated with the probability of HCC. Third, we also designed K-nearest neighbors (KNN) and support vector machine (SVM) based classifiers for CHB and HCC with high prediction accuracy. The results were validated in an independent data set.

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.