Recent advances in the research of hepatitis B virus-related hepatocellular carcinoma: epidemiologic and molecular biological aspects

Global prevalence, cascade of care, and prophylaxis coverage of hepatitis B in 2022: a modelling study

BACKGROUND

The 2016 World Health Assembly endorsed the elimination of hepatitis B virus (HBV) infection as a public health threat by 2030; existing therapies and prophylaxis measures make such elimination feasible, even in the absence of a virological cure. We aimed to estimate the national, regional, and global prevalence of HBV in the general population and among children aged 5 years and younger, as well as the rates of diagnosis, treatment, prophylaxis, and the future burden globally.

METHODS

In this modelling study, we used a Delphi process with data from literature reviews and interviews with country experts to quantify the prevalence, diagnosis, treatment, and prevention measures for HBV infection. The PRoGReSs Model, a dynamic Markov model, was used to estimate the country, regional, and global prevalence of HBV infection in 2022, and the effects of treatment and prevention on disease burden. The future incidence of morbidity and mortality in the absence of additional interventions was also estimated at the global level.

FINDINGS

We developed models for 170 countries which resulted in an estimated global prevalence of HBV infection in 2022 of 3·2% (95% uncertainty interval 2·7-4·0), corresponding to 257·5 million (216·6-316·4) individuals positive for HBsAg. Of these individuals, 36·0 million were diagnosed, and only 6·8 million of the estimated 83·3 million eligible for treatment were on treatment. The prevalence among children aged 5 years or younger was estimated to be 0·7% (0·6-1·0), corresponding to 5·6 million (4·5-7·8) children with HBV infection. Based on the most recent data, 85% of infants received three-dose HBV vaccination before 1 year of age, 46% had received a timely birth dose of vaccine, and 14% received hepatitis B immunoglobulin along with the full vaccination regimen. 3% of mothers with a high HBV viral load received antiviral treatment to reduce mother-to-child transmission.

INTERPRETATION

As 2030 approaches, the elimination targets remain out of reach for many countries under the current frameworks. Although prevention measures have had the most success, there is a need to increase these efforts and to increase diagnosis and treatment to work towards the elimination goals.

FUNDING

John C Martin Foundation, Gilead Sciences, and EndHep2030.

Cell Culture Systems for Studying Hepatitis B and Hepatitis D Virus Infections

The hepatitis B virus (HBV) and hepatitis D virus (HDV) infections cause liver disease, including hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). HBV infection remains a major global health problem. In 2019, 296 million people were living with chronic hepatitis B and about 5% of them were co-infected with HDV. In vitro cell culture systems are instrumental in the development of therapeutic targets. Cell culture systems contribute to identifying molecular mechanisms for HBV and HDV propagation, finding drug targets for antiviral therapies, and testing antiviral agents. Current HBV therapeutics, such as nucleoside analogs, effectively suppress viral replication but are not curative. Additionally, no effective treatment for HDV infection is currently available. Therefore, there is an urgent need to develop therapies to treat both viral infections. A robust in vitro cell culture system supporting HBV and HDV infections (HBV/HDV) is a critical prerequisite to studying HBV/HDV pathogenesis, the complete life cycle of HBV/HDV infections, and consequently identifying new therapeutics. However, the lack of an efficient cell culture system hampers the development of novel antiviral strategies for HBV/HDV infections. In vitro cell culture models have evolved with significant improvements over several decades. Recently, the development of the HepG2-NTCP sec+ cell line, expressing the sodium taurocholate co-transporting polypeptide receptor (NTCP) and self-assembling co-cultured primary human hepatocytes (SACC-PHHs) has opened new perspectives for a better understanding of HBV and HDV lifecycles and the development of specific antiviral drug targets against HBV/HDV infections. We address various cell culture systems along with different cell lines and how these cell culture systems can be used to provide better tools for HBV and HDV studies.

Isolation and Characterization of Targeting-HBsAg VNAR Single Domain Antibodies from Whitespotted Bamboo Sharks (Chiloscyllium plagiosum)

Immunoglobulin new antigen receptor (IgNAR) is a naturally occurring antibody that consists of only two heavy chains with two independent variable domains. The variable binding domain of IgNAR, called variable new antigen receptor (VNAR), is attractive due to its solubility, thermal stability, and small size. Hepatitis B surface antigen (HBsAg) is a viral capsid protein found on the surface of the Hepatitis B virus (HBV). It appears in the blood of an individual infected with HBV and is widely used as a diagnostic marker for HBV infection. In this study, the whitespotted bamboo sharks (Chiloscyllium plagiosum) were immunized with the recombinant HBsAg protein. Peripheral blood leukocytes (PBLs) of immunized bamboo sharks were further isolated and used to construct a VNAR-targeted HBsAg phage display library. The 20 specific VNARs against HBsAg were then isolated by bio-panning and phage ELISA. The 50% of maximal effect (EC₅₀) of three nanobodies, including HB14, HB17, and HB18, were 4.864 nM, 4.260 nM, and 8.979 nM, respectively. The Sandwich ELISA assay further showed that these three nanobodies interacted with different epitopes of HBsAg protein. When taken together, our results provide a new possibility for the application of VNAR in HBV diagnosis and also demonstrate the feasibility of using VNAR for medical testing.

Hepatitis B Virus DNA Integration Drives Carcinogenesis and Provides a New Biomarker for HBV-related HCC

Hepatitis B virus (HBV) DNA integration is an incidental event in the virus replication cycle and occurs in less than 1% of infected hepatocytes during viral infection. However, HBV DNA is present in the genome of approximately 90% of HBV-related HCCs and is the most common somatic mutation. Whole genome sequencing of liver tissues from chronic hepatitis B patients showed integration occurring at random positions in human chromosomes; however, in the genomes of HBV-related HCC patients, there are integration hotspots. Both the enrichment of the HBV-integration proportion in HCC and the emergence of integration hotspots suggested a strong positive selection of HBV-integrated hepatocytes to progress to HCC. The activation of HBV integration hotspot genes, such as telomerase (TERT) or histone methyltransferase (MLL4/KMT2B), resembles insertional mutagenesis by oncogenic animal retroviruses. These candidate oncogenic genes might shed new light on HBV-related HCC biology and become targets for new cancer therapies. Finally, the HBV integrations in individual HCC contain unique sequences at the junctions, such as virus-host chimera DNA (vh-DNA) presumably being a signature molecule for individual HCC. HBV integration may thus provide a new cell-free tumor DNA biomarker to monitor residual HCC after curative therapies or to track the development of de novo HCC.

Low Risk of Occult Hepatitis B Infection among Vietnamese Blood Donors

Occult hepatitis B infection (OBI) is characterized by the presence of low levels of hepatitis B virus (HBV) DNA and undetectable HBsAg in the blood. The prevalence of OBI in blood donors in Asia ranges from 0.013% (China) to 10.9% (Laos), with no data available from Vietnam so far. We aimed to investigate the prevalence of OBI among Vietnamese blood donors. A total of 623 (114 women and 509 men) HBsAg-negative blood donors were screened for anti-HBc and anti-HBs by ELISA assays. In addition, DNA from sera was isolated and nested PCR was performed for the HBV surface gene (S); a fragment of the S gene was then sequenced in positive samples. The results revealed that 39% (n = 242) of blood donors were positive for anti-HBc, and 70% (n = 434) were positive for anti-HBs, with 36% (n = 223) being positive for both anti-HBc and anti-HBs. In addition, 3% of blood donors (n = 19) were positive for anti-HBc only, and 34% (n = 211) had only anti-HBs as serological marker. A total of 27% (n = 170) were seronegative for any marker. Two of the blood donors (0.3%) were OBI-positive and sequencing revealed that HBV sequences belonged to HBV genotype B, which is the predominant genotype in Vietnam.

Genetic Diversity and Possible Origins of the Hepatitis B Virus in Siberian Natives

A total of 381 hepatitis B virus (HBV) DNA sequences collected from nine groups of Siberian native populations were phylogenetically analyzed along with 179 HBV strains sampled in different urban populations of former western USSR republics and 50 strains from Central Asian republics and Mongolia. Different HBV subgenotypes predominated in various native Siberian populations. Subgenotype D1 was dominant in Altaian Kazakhs (100%), Tuvans (100%), and Teleuts (100%) of southern Siberia as well as in Dolgans and Nganasans (69%), who inhabit the polar Taimyr Peninsula. D2 was the most prevalent subgenotype in the combined group of Nenets, Komi, and Khants of the northern Yamalo-Nenets Autonomous Region (71%) and in Yakuts (36%) from northeastern Siberia. D3 was the main subgenotype in South Altaians (76%) and Buryats (40%) of southeastern Siberia, and in Chukchi (51%) of the Russian Far East. Subgenotype C2 was found in Taimyr (19%) and Chukchi (27%), while subgenotype A2 was common in Yakuts (33%). In contrast, D2 was dominant (56%) in urban populations of the former western USSR, and D1 (62%) in Central Asian republics and Mongolia. Statistical analysis demonstrated that the studied groups are epidemiologically isolated from each other and might have contracted HBV from different sources during the settlement of Siberia.

Interpretation of HBV Serologies

Hepatitis B was discovered by researchers who were investigating jaundice associated with blood transfusions as well as parenterally administered medications. Through trial and error, the HBV was identified. There are specific tests that detect HBV infection, whether it is a previous exposure or active infection. The various HBV serologies are reviewed in this work as well. Hepatitis B surface antigen has emerged as a tool in defining treatment endpoint and its significance is reviewed. HBV genotypes are distributed uniquely throughout the world, in particular, genotype C is associated with higher rates of hepatocellular carcinoma. Various HBV genotypes and their impact on the clinical course are discussed. The relationship of HBV serologies and HBV DNA to disease progression is outlined. There are specific recommendations on monitoring those infected with HBV and this is reviewed here. HBV mutations have an impact on the disease course and those of significance are also discussed.

Long-term oncologic outcomes of liver resection for hepatocellular carcinoma in adolescents and young adults: A multicenter study from A hepatitis B virus-endemic area

BACKGROUND

Hepatocellular carcinoma (HCC) is common among adolescents and young adults (AYAs) in areas with endemic hepatitis B virus infection. We sought to characterize clinical features and long-term outcomes among AYAs versus older adults (OAs) who underwent HCC resection.

METHODS

From a Chinese multicenter database, patients were categorized as AYA (aged 13-39 years) versus OA (aged ≥40 years). Patient clinical features, perioperative outcomes, overall survival (OS) and time-to-recurrence (TTR) were compared. Multivariable Cox-regression analyses were performed to identify the impact of age on OS and TTR.

RESULTS

Among 1952 patients, 354(22.2%) were AYAs. AYAs were less likely to have cirrhosis yet were likely to have advanced tumor pathological characteristics than OAs. Postoperative morbidity and mortality were comparable. Compared with OAs, AYAs had a comparable OS but a decreased TTR. Multivariable analyses identified that young age (<40 years) was independently associated with poorer TTR.

CONCLUSIONS

Compared with OAs, AYAs had a higher incidence of recurrence following liver resection among patients with HCC, suggesting that enhanced surveillance for postoperative recurrence may be required among AYAs.

Comprehensive Analysis of Clinically Significant Hepatitis B Virus Mutations in Relation to Genotype, Subgenotype and Geographic Region

Hepatitis B virus (HBV) is a highly variable DNA virus due to its unique life cycle, which involves an error-prone reverse transcriptase. The high substitution rate drives the evolution of HBV by generating genetic variants upon which selection operates. HBV mutants with clinical implications have been documented worldwide, indicating the potential for spreading and developing their own epidemiology. However, the prevalence of such mutants among the different HBV genotypes and subgenotypes has not been systematically analyzed. In the current study, we performed large-scale analysis of 6,479 full-length HBV genome sequences from genotypes A-H, with the aim of gaining comprehensive insights into the relationships of relevant mutations associated with immune escape, antiviral resistance and hepatocellular carcinoma (HCC) development with HBV (sub)genotypes and geographic regions. Immune escape mutations were detected in 10.7% of the sequences, the most common being I/T126S (1.8%), G145R (1.2%), M133T (1.2%), and Q129R (1.0%). HBV genotype B showed the highest rate of escape mutations (14.7%) while genotype H had no mutations (P < 0.001). HCC-associated mutations were detected in 33.7% of the sequences, with significantly higher frequency of C1653T, T1753V and A1762T/G1764A in genotype G than C (P < 0.001). The overall frequencies of lamivudine-, telbivudine-, adefovir-, and entecavir-resistant mutants were 7.3, 7.2, 0.5, and 0.2%, respectively, while only 0.05% showed reduced susceptibility to tenofovir. In particular, the highest frequency of lamivudine-resistant mutations was observed in genotype G and the lowest frequency in genotype E (32.5 and 0.3%; P < 0.001). The prevalence of HBV mutants was also biased by geographic location, with North America identified as one of the regions with the highest rates of immune escape, antiviral resistance, and HCC-associated mutants. The collective findings were discussed in light of natural selection and the known characteristics of HBV (sub)genotypes. Our data provide relevant information on the prevalence of clinically relevant HBV mutations, which may contribute to further improvement of diagnostic procedures, immunization programs, therapeutic protocols, and disease prognosis.

LukS-PV Inhibits Hepatocellular Carcinoma Progression by Downregulating HDAC2 Expression

Hepatocellular carcinoma (HCC) is a common malignant tumor. LukS-PV is the S component of Panton-Valetine leukocidin (PVL), which is secreted by Staphylococcus aureus. This study investigated the effects of LukS-PV on the proliferation, apoptosis, and cell-cycle progression of HCC cells and the mechanisms of its activity. The HCC cells were treated with different LukS-PV concentrations in vitro. Cell Counting Kit-8 and 5-Ethynyl-2'-deoxyuridine (EdU) assays were used to study cell proliferation. Flow cytometry was used to measure apoptosis and cell-cycle progression. Quantitative reverse transcriptase PCR and western blot assays were used to determine mRNA and protein expression levels. Xenograft experiments were performed to determine the in vivo antitumor effect of LukS-PV. Immunostaining was performed to analyze Ki-67 and HDAC2 (histone deacetylase 2) expression. Our results showed that LukS-PV inhibited cell proliferation and induced apoptosis in a concentration-dependent manner in HCC cell lines. LukS-PV also can induce cell-cycle arrest. Moreover, we discovered that LukS-PV attenuated HDAC2 expression and upregulated PTEN; phosphorylated AKT was also reduced. Further studies demonstrated that LukS-PV treatment significantly reduced tumor growth in nude mice and suppressed Ki-67 and HDAC2 levels. Our data revealed a vital role of LukS-PV in suppressing HCC progression by downregulating HDAC2 and upregulating PTEN.

Early and Late Recurrence of Hepatitis B Virus-Associated Hepatocellular Carcinoma

BACKGROUND

Survival after liver resection of hepatocellular carcinoma (HCC) remains poor because of a high incidence of recurrence. We sought to investigate risk factors, patterns, and long-term prognosis among patients with early and late recurrence after liver resection for hepatitis B virus (HBV)-associated HCC.

METHODS

Data of consecutive patients undergoing curative resection for HBV-associated HCC were analyzed. According to the time to recurrence after surgery, recurrence was divided into early (≤2 years) and late recurrence (>2 years). Characteristics, patterns of initial recurrence, and postrecurrence survival (PRS) were compared between patients with early and late recurrence. Risk factors of early and late recurrence and predictors of PRS were identified by univariable and multivariable Cox regression analyses.

RESULTS

Among 894 patients, 322 (36.0%) and 282 (31.5%) developed early and late recurrence, respectively. On multivariable analyses, preoperative HBV-DNA >10⁴ copies/mL was associated with both early and late recurrence, whereas postoperative no/irregular antiviral therapy was associated with late recurrence. Compared with patients with late recurrence, patients with early recurrence had a lower proportion of intrahepatic-only recurrence (72.0% vs. 91.1%, p < .001), as well as a lower chance of receiving potentially curative treatments for recurrence (33.9% vs. 50.7%, p < .001) and a worse median PRS (19.1 vs. 37.5 months, p < .001). Multivariable analysis demonstrated that early recurrence was independently associated with worse PRS (hazard ratio, 1.361; 95% confidence interval, 1.094-1.692; p = .006).

CONCLUSION

Although risk factors associated with early recurrence and late recurrence were different, a high preoperative HBV-DNA load was an independent hepatitis-related risk for both early and late recurrence. Early recurrence was associated with worse postrecurrence survival among patients with recurrence.

IMPLICATIONS FOR PRACTICE

Liver resection is the main curative treatment for hepatocellular carcinoma (HCC), but postoperative survival remains poor because of high recurrence rates. This study investigated the risk factors and patterns of early and late recurrence and found that a high preoperative hepatitis B virus (HBV) DNA load was an independent hepatitis-related risk factor for both. Early recurrence was also independently associated with worse postrecurrence survival. These data may provide insights into different biological origin and behavior of early versus late recurrence after resection for HBV-associated HCC, which could be helpful to make individualized treatment decision for recurrent HCC, as well as strategies for surveillance recurrence after resection.

Hepatitis B Virus: Advances in Prevention, Diagnosis, and Therapy

Currently, despite the use of a preventive vaccine for several decades as well as the use of effective and well-tolerated viral suppressive medications since 1998, approximately 250 million people remain infected with the virus that causes hepatitis B worldwide. Hepatitis C virus (HCV) and hepatitis B virus (HBV) are the leading causes of liver cancer and overall mortality globally, surpassing malaria and tuberculosis. Linkage to care is estimated to be very poor both in developing countries and in high-income countries, such as the United States, countries in Western Europe, and Japan. In the United States, by CDC estimates, only one-third of HBV-infected patients or less are aware of their infection. Some reasons for these low rates of surveillance, diagnosis, and treatment include the asymptomatic nature of chronic hepatitis B until the very late stages, a lack of curative therapy with a finite treatment duration, a complex natural history, and a lack of knowledge about the disease by both care providers and patients. In the last 5 years, more attention has been focused on the important topics of HBV screening, diagnosis of HBV infection, and appropriate linkage to care. There have also been rapid clinical developments toward a functional cure of HBV infection, with novel compounds currently being in various phases of progress. Despite this knowledge, many of the professional organizations provide guidelines focused only on specific questions related to the treatment of HBV infection. This focus leaves a gap for care providers on the other HBV-related issues, which include HBV's epidemiological profile, its natural history, how it interacts with other viral hepatitis diseases, treatments, and the areas that still need to be addressed in order to achieve HBV elimination by 2030. Thus, to fill these gaps and provide a more comprehensive and relevant document to regions worldwide, we have taken a global approach by using the findings of global experts on HBV as well as citing major guidelines and their various approaches to addressing HBV and its disease burden.

The association of vitamin D with hepatitis B virus replication: Bystander rather than offender

BACKGROUND/PURPOSE

Low vitamin D is frequent in hepatitis B virus (HBV)-infected patients and several studies show an inverse association of serum vitamin D level with HBV viral load. However, the causal relationship remains unclear.

METHODS

HBV carriers receiving regular 6-month surveillance without current antiviral treatment or cirrhosis were invited to participate into this trial. The markers of HBV replication included serum HBV DNA and quantitative HBsAg (qHBsAg) levels. Those with undetectable HBV DNA or sufficient vitamin D levels, cancer or electrolyte imbalance were excluded. The eligible subjects were randomized to receive either vitamin D supplement 2000 IU per day for 2 months (vitamin D group) or none (control group).

RESULTS

A total of 196 HBV carriers (93 males and 103 females; mean age 51.9 ± 10.0 years) were screened. Of them, 28 patients had undetectable serum HBV DNA levels, which is defined as spontaneous viral clearance. The vitamin D levels were not different between patients with detectable HBV DNA and those without (p = 0.18). After exclusion, 149 patients were randomized to two groups: 75 in vitamin D group and 74 in control group. After 2 months vitamin D supplement, the serum vitamin D levels were significantly higher in the vitamin D group than the control group (p < 0.001). However, the serum qHBsAg and HBV DNA levels were comparable between these two groups.

CONCLUSION

There is no causal relationship between vitamin D and HBV replication. The role of liver reserve on serum vitamin D levels in patients with chronic HBV infection needs further investigation.

The long-term efficacy of cytokine-induced killer cellular therapy for hepatocellular carcinoma: a meta-analysis

Aim: The long-term efficacy of cytokine-induced killer cellular therapy for hepatocellular carcinoma patients after curative treatments remains controversial. Methods: A meta-analysis was conducted, and the outcomes were the recurrence rate and overall survival. Results: Eight randomized clinical trials with 1038 participants were included. Compared with the control group, cytokine-induced killer cellular therapy group could reduce 1-year, 3-year recurrence rates, as well as improve 1-5 years overall survival for hepatocellular carcinoma patients (p < 0.05). However, it failed to affect the 5-year recurrence rate and 6-year overall survival (p > 0.05). Conclusion: Cytokine-induced killer cellular adjuvant therapy exerted a favorable role in improving early and long-term efficacy for hepatocellular carcinoma patients.

An interferon-like small chemical compound CDM-3008 suppresses hepatitis B virus through induction of interferon-stimulated genes

Oral administration of nucleotide analogues and injection of interferon-α (IFNα) are used to achieve immediate suppression in replication of hepatitis B virus (HBV). Nucleotide analogs and IFNα inhibit viral polymerase activity and cause long-term eradication of the virus at least in part through removing covalently closed circular DNA (cccDNA) via induction of the APOBEC3 deaminases family of molecules, respectively. This study aimed to explore whether the orally administrable low molecular weight agent CDM-3008 (RO8191), which mimics IFNα through the binding to IFNα/β receptor 2 (IFNAR2) and the activation of the JAK/STAT pathway, can suppress HBV replication and reduce cccDNA levels. In primary cultured human hepatocytes, HBV DNA levels were decreased after CDM-3008-treatment in a dose-dependent manner with a half-maximal inhibitory concentration (IC₅₀) value of 0.1 μM, and this was accompanied by significant reductions in cellular cccDNA levels, both HBeAg and HBsAg levels in the cell culture medium. Using a microarray we comprehensively analyzed and compared changes in gene (mRNA) expression in CDM-3008- and IFNα-treated primary cultured human hepatocytes. As reported previously, CDM-3008 mimicked the induction of genes that participate in the interferon signaling pathway. OAS1 and ISG20 mRNA expression was similarly enhanced by both CDM-3008 and IFNα. Thus, CDM-3008 could suppress pgRNA expression to show anti-HBV activity. APOBEC3F and 3G mRNA expression was also induced by CDM-3008 and IFNα treatments, suggesting that cccDNA could be degraded through induced APOBEC3 family proteins. We identified the genes whose expression was specifically enhanced in CDM-3008-treated cells compared to IFNα-treated cells. The expression of SOCS1, SOCS2, SOCS3, and CISH, which inhibit STAT activation, was enhanced in CDM-3008-treated cells suggesting that a feedback inhibition of the JAK/STAT pathway was enhanced in CDM-3008-treated cells compared to IFNα-treated cells. In addition, CDM-3008 showed an additive effect with a clinically-used nucleoside entecavir on inhibition of HBV replication. In summary, CDM-3008 showed anti-HBV activity through activation of the JAK/STAT pathway, inducing the expression of interferon-stimulated genes (ISGs), with greater feedback inhibition than IFNα.

Seroepidemiology of Hepatitis Viruses and Hepatitis B Genotypes of Female Marriage Immigrants in Korea

PURPOSE

The Korean society has moved rapidly toward becoming a multicultural society. This study aimed to estimate the seroprevalence of hepatitis viruses and investigate hepatitis B virus (HBV) genotypic diversity in female marriage immigrants.

MATERIALS AND METHODS

Screening program was conducted at support centers for multicultural families in 21 administrative districts in Korea between July 2011 and January 2017. A total of 963 female marriage immigrants were included in this study. Blood samples were tested for hepatitis viral markers and HBV genotype.

RESULTS

Subjects' median age was 33 years (20-40 years), and they originated from nine countries including Vietnam (n=422, 43.8%), China (n=311, 32.3%), the Philippines (n=85, 8.8%), Cambodia (n=58, 6.0%), and Japan (n=39, 4.0%). About 30% (n=288) of subjects required hepatitis A vaccination. HBsAg positive rate was 5.4% (n=52). Positive HBsAg results were the highest in subjects from Southeast Asia (6.6%, n=38). Anti-HBs positive rate was 60.4% (n=582). About 34% (n=329) of subjects who were negative for anti-HBs and HBsAg required HBV vaccinations. Genotypes B and C were found in 54.6% (n=12) and 45.4% (n=10) of the 22 subjects with HBV, in whom genotypes were tested. Eight (0.8%) subjects were positive for anti-HCV. Positive anti-HCV results were the highest in subjects from Central Asia (7.9%, n=3).

CONCLUSION

Testing for hepatitis viral marker (hepatitis A virus IgG and HBsAg/anti-HBs) is needed for female marriage immigrants. Especially, HBV genotype B is different from genotype C of Koreans. Therefore, interest and attention to vaccination programs for female marriage immigrants are necessary for both clinicians and public health institutes.

Hepatitis B virus infection: Defective surface antigen expression and pathogenesis

Hepatitis B virus (HBV) infection is a global public health concern. HBV causes chronic infection in patients and can lead to liver cirrhosis, hepatocellular carcinoma, and other severe liver diseases. Thus, understanding HBV-related pathogenesis is of particular importance for prevention and clinical intervention. HBV surface antigens are indispensable for HBV virion formation and are useful viral markers for diagnosis and clinical assessment. During chronic HBV infection, HBV genomes may acquire and accumulate mutations and deletions, leading to the expression of defective HBV surface antigens. These defective HBV surface antigens have been found to play important roles in the progression of HBV-associated liver diseases. In this review, we focus our discussion on the nature of defective HBV surface antigen mutations and their contribution to the pathogenesis of fulminant hepatitis B. The relationship between defective surface antigens and occult HBV infection are also discussed.

Viral Factors Affecting the Clinical Outcomes of Chronic Hepatitis B

Chronic hepatitis B (CHB) exhibits a variety of clinical outcomes, ranging from spontaneous resolution of hepatitis B to severe adverse consequences, including the development of cirrhosis, hepatic failure, and hepatocellular carcinoma. The heterogeneous clinical courses of chronic hepatitis B virus (HBV) infection reflect the complex host-virus interactions, and point to the difficulty and necessity of identifying the patients at risk. With the advance of HBV virology, several viral factors have been found to be associated with the long-term clinical outcomes of CHB patients. Different viral factors probe different aspects of CHB. Integration of these viral factors may help to determine the disease state of patients more accurately, and identify the patients who require timely antiviral therapy to prevent the development of detrimental clinical outcomes. In this article, we will introduce the conventional and emerging viral factors that are associated with clinical outcomes and discuss their utility in a clinical setting.

Asia-Pacific clinical practice guidelines on the management of hepatocellular carcinoma: a 2017 update

There is great geographical variation in the distribution of hepatocellular carcinoma (HCC), with the majority of all cases worldwide found in the Asia–Pacific region, where HCC is one of the leading public health problems. Since the “Toward Revision of the Asian Pacific Association for the Study of the Liver (APASL) HCC Guidelines” meeting held at the 25th annual conference of the APASL in Tokyo, the newest guidelines for the treatment of HCC published by the APASL has been discussed. This latest guidelines recommend evidence-based management of HCC and are considered suitable for universal use in the Asia–Pacific region, which has a diversity of medical environments.

Natural history of acute and chronic hepatitis B: The role of HBV genotypes and mutants

Molecular epidemiologic studies reveal remarkable differences in the geographical distribution of hepatitis B virus (HBV) genotypes. The frequency of mutants among HBV genotypes also varies. The role of HBV genotypes/mutants in the pathogenesis of HBV infection and natural history of HBV infection has been extensively investigated. The distribution of HBV genotypes in acute hepatitis B patients reflects the predominant genotypes in a given geographic area. In chronic hepatitis B patients, genotype C and D have a higher frequency of basal core promoter A1762T/G1764A mutations than genotype A and B. HBV genotypes C, D and F carry a higher lifetime risk of cirrhosis and HCC development than genotype A and B. HBV pre-S/S gene mutations were associated with immune escape of hepatitis B immunoglobulin or vaccine-induced immunity. Mutations in the pre-S, core promoter and X regions correlate with an increased risk of cirrhosis and HCC. In summary, HBV genotypes and mutants are associated with the disease progression and long-term outcome of HBV infection. They may serve as viral genetic markers for risk stratification of chronic hepatitis B patients in clinical practice.

Complete genome sequence of a hepatitis B virus isolate of genotype D2, subtype adrq+, from Brazil

Hepatitis B virus (HBV) has been classified into 10 distinct serological subtypes of the surface antigen (HBsAg) that can be predicted by sequencing of the corresponding S gene. HBV genotype D usually displays determinants of subtypes ayw2 or ayw3. On the other hand, subtype adrq+ has been found exclusively in association with genotype C. Here, we describe the first HBV genome (isolate BR32) belonging to genotype D with the serological subtype adrq+. This isolate had a genome length of 3,062 nucleotides (nt), and no recombination events were observed in the BR32 genome that could explain the occurrence of the subtype adr in a genotype D isolate. Analysis of the quasispecies population revealed that 28 out of 30 clones (93%) were of subtype adrq+, while the subtypes of the two remaining could not be determined, since they contained an S residue (instead of K or R) at position 122 of HBsAg. These results will contribute to further epidemiological and evolutionary studies of HBV.

New perspectives of biomarkers for the management of chronic hepatitis B

With recent advances in molecular and genomic investigations, the impact of hepatitis B viral and host factors on the progression of chronic HBV infection has been explored. For viral factors, hepatitis B viral load is a strong predictor for liver disease progression. Hepatitis B viral kinetics appear to be important for successful anti-viral therapy. Serum HBsAg level serves as a complementary marker to viral load for the prediction of HBV-related adverse outcomes in patients with low viral load. In those with low viral load, high serum HBsAg level is associated with higher risks of cirrhosis and HCC. Hepatitis B core-related antigen (HBcrAg) induces host immune responses, and the reduction of the HBcrAg level as well as the increment of total anti-HBc level are significantly associated with favorable outcomes. HBV genotypes (genotype C/D) and mutants (basal core promoter and deletion mutation in pre-S genes) are well known viral genetic markers to predict disease progression. For host factors, serum inflammatory biomarkers have been developed to evaluate the HBV-associated hepatic necroinflammation and fibrosis. Host single nucleotide polymorphism on sodium taurocholate cotransporting polypeptide (NTCP, an HBV entry receptor) may be associated with a decreased risk for cirrhosis and HCC. In conclusion, patients with chronic hepatitis B should be evaluated with relevant viral and host markers to identify those who are at a higher risk of liver disease progression and then receive timely antiviral therapy.

Albumin Binding Function: The Potential Earliest Indicator for Liver Function Damage

Background. Currently there is no indicator that can evaluate actual liver lesion for early stages of viral hepatitis, nonalcoholic fatty liver disease (NAFLD), and cirrhosis. Aim of this study was to investigate if albumin binding function could better reflect liver function in these liver diseases. Methods. An observational study was performed on 193 patients with early NAFLD, viral hepatitis, and cirrhosis. Cirrhosis patients were separated according to Child-Pugh score into A, B, and C subgroup. Albumin metal ion binding capacity (Ischemia-modified albumin transformed, IMAT) and fatty acid binding capacity (total binding sites, TBS) were detected. Results. Both IMAT and TBS were significantly decreased in patients with NAFLD and early hepatitis. In hepatitis group, they declined prior to changes of liver enzymes. IMAT was significantly higher in cirrhosis Child-Pugh class A group than hepatitis patients and decreased in Child-Pugh class B and class C patients. Both IMAT/albumin and TBS/albumin decreased significantly in hepatitis and NAFLD group patients. Conclusions. This is the first study to discover changes of albumin metal ion and fatty acid binding capacities prior to conventional biomarkers for liver damage in early stage of liver diseases. They may become potential earliest sensitive indicators for liver function evaluation.

Diagnostic performance of controlled attenuation parameter for predicting steatosis grade in chronic hepatitis B

BACKGROUND & AIMS

A novel controlled attenuation parameter (CAP) using the signals acquired by the FibroScan® has been developed as a method for evaluating steatosis. The aim of this study is to assess the performance of the CAP for the detection and quantification of steatosis in patients with chronic hepatitis B (CHB).

MATERIAL AND METHODS

136 subjects with CHB underwent liver biopsy and FibroScan® within 60 days. CAP was evaluated retrospectively using raw FibroScan® data. Steatosis was graded as follows: S0 (steatosis < 10% of hepatocytes), S1 (10 to < 30%), S2 (30 to < 60%) or S3 (≥ 60%). Performance was evaluated by area under the receiver operating characteristic (AUROC) curve.

RESULTS

Proportions of each steatosis grade (S0-S3) were 78, 10, 9 and 3%, respectively. Using univariate analysis, liver stiffness measurement (LMS) significantly correlated with fibrosis (τ = 0.43; P < 10-10), sex, necro-inflammatory activity, steatosis, age, NASH, and perisinusoidal fibrosis, and with liver fibrosis (P < 10-8) and perisinusoidal fibrosis (P = 0.008) using multivariate analysis. CAP correlated with steatosis (τ = 0.38, P < 10-7), body mass index, NASH, fibrosis and perisinusoidal fibrosis using univariate analysis, but only steatosis (P < 10-10) and perisinusoidal fibrosis (P = 0.002) using multivariate analysis. AUROCs for LSM were: 0.77 (0.69-0.85), 0.87 (0.80-0.95), and 0.93 (0.83-1.00), respectively, for fibrosis stages F ≥ 2, F ≥ 3 and F = 4. AUROCs for CAP were: 0.82 (0.73-0.92), 0.82 (0.69-0.95), and 0.97 (0.84-1.00) for ≥ S1, ≥ S2 and S3 steatosis, respectively.

CONCLUSIONS

In conclusión CAP is a novel, accurate non-invasive tool and may be suitable for detecting and quantifying steatosis in CHB patients.

Virological Determinants of Spontaneous Postpartum e Antigen Seroconversion and Surface Antigen Seroclearance in Pregnant Women Infected with Hepatitis B Virus

BACKGROUND AND AIMS

We investigated the virological factors predicting spontaneous postpartum hepatitis B e antigen (HBeAg) seroconversion and hepatitis B surface antigen (HBsAg) seroclearance in pregnant women infected with hepatitis B virus (HBV).

METHODS

We invited 419 HBV infected women whose sera had been collected during their pregnancy from August 2002-July 2004 and archived at -30°C, to participate the follow-up in October 2009-March 2010. Various virological factors were determined and compared in women with or without the seroconversion and seroclearance.

RESULTS

A total of 264 (63.0%) antiviral naive women participated in the follow-up with an average observation period of 6.4 years (5.4-7.4). Of 76 women who were HBeAg positive during pregnancy, 42 (55.3%) seroconverted to anti-HBe during follow-up. Compared to pregnant women with HBV DNA ≥3 × 10(7) IU/mL or HBeAg ≥770 S/CO, those with HBV DNA <3 × 10(7) IU/mL or HBeAg <770 S/CO had higher conversion rate, with odds ratios (OR) of 7.32 (95% confidence interval [CI], 2.00-26.78) and 5.94 (95% CI, 1.40-25.16), respectively. Thirty eight (14.4%) women cleared HBsAg; pregnant women with HBsAg levels of 100-999 and <100 IU/mL had higher HBsAg seroclearance rate with OR of 2.58 (95% CI, 1.03-6.43) and 13.33 (95% CI, 5.07-35.07), respectively, compared to those with HBsAg >1000 IU/mL.

CONCLUSIONS

HBeAg-positive pregnant women with HBV DNA <3 × 10(7) IU/mL or HBeAg <770 S/CO are more likely to undergo postpartum HBeAg seroconversion. HBsAg <100 IU/mL is a strong predictor of spontaneous postpartum HBsAg seroclearance.

Core-fucosylation plays a pivotal role in hepatitis B pseudo virus infection: a possible implication for HBV glycotherapy

The functions of cell surface proteins, such as growth factor receptors and virus/bacteria-entry receptors, can be dynamically regulated by oligosaccharide modifications. In the present study, we investigated the involvement of glycosylation in hepatitis B virus (HBV) entry into hepatoma cells. Infection of oligosaccharide-remodeling hepatoma cells with a pseudo virus of HBV, bio-nanocapsule (BNC), was evaluated by flow cytometry and confocal microscopy. Among various experiments using several hepatoma cells, marked difference was observed between Huh6 cells and HB611 cells, which were established by HBV gene transfection into hepatoma cells. Comprehensive oligosaccharide analysis showed dramatic increases of core fucosylation in HB611 cells, compared with Huh6 cells. Knock down of fucosyltransferase 8 (FUT8) reduced BNC entry into HB611 cells. In contrast, overexpression of FUT8 in Huh6 cells increased BNC entry. Although expression of sodium taurocholate cotransporting polypeptide (NTCP), which is one of HBV receptors was very similar between Huh6 and HB611 cells, proteins coprecipitated with NTCP were dependent on levels of core-fucosylation, suggesting that core-fucosylation regulates BNC entry into hepatoma cells. Our findings demonstrate that core-fucosylation is an important glycosylation for HBV infection of hepatoma cells through HBV-receptor-mediated endocytosis. Down-regulation of core-fucosylation may be a novel target for HBV therapy.

Epigenetically regulated miR-449a enhances hepatitis B virus replication by targeting cAMP-responsive element binding protein 5 and modulating hepatocytes phenotype

Cellular microRNAs (miRNAs) are able to influence hepatitis B virus (HBV) replication directly by binding to HBV transcripts or indirectly by targeting cellular factors. Here, we investigate the effect of epigenetically regulated miR-449a on HBV replication and the underlying mechanisms. miR-449a expression was lower in human hepatocellular carcinoma (HCC) cells than in primary hepatocytes and could be induced by trichostatin A. Ectopic miR-449a expression in HCC cells strongly enhanced HBV replication, transcription, progeny virions secretion, and antigen expression in a dose-dependent manner. miR-449a directly targeted cAMP-responsive element binding protein 5 (CREB5), which in turn induced the expression of farnesoid X receptor α (FXRα), a transcription factor that facilitates HBV replication. CREB5 knockdown and overexpression demonstrated that it is a negative regulator of HBV replication. Additionally, miR-449a overexpression inhibited proliferation, caused cell cycle arrest, and promoted HCC cell differentiation. The results indicated that epigenetically regulated miR-449a targets CREB5 to increase FXRα expression, thereby promoting HBV replication and gene expression. Our findings provide a new understanding of the role of miRNAs in HBV replication.

Predictive Factors in the Incidence of Cirrhosis in Chronic Hepatitis B Virus Infections

BACKGROUND

Hepatitis B virus (HBV) is among the leading causes of liver cirrhosis worldwide. Predictors of cirrhosis in Iranian chronic hepatitis B (CHB) patients are yet to be clearly identified.

OBJECTIVES

Evaluating the predictive factors of liver cirrhosis in CHB.

PATIENTS AND METHODS

A longitudinal study was conducted during 1995 - 2014 on all CHB patients who were referred to Tehran hepatitis center, Tehran, Iran. The patients were assessed during periodic visits through medical history and laboratory data. Logistic regression analyses were used to determine predictors of cirrhosis.

RESULTS

Two hundred thirty-seven CHB patients were followed for an average duration of 10.6 years, and 41 of these patients developed cirrhosis. The incidence rate of cirrhosis was 2.82/100 person-years. Univariate analyses determined 9 out of 17 factors as significant predictors of outcome in CHB patients. Age of ≥ 45 years, positive hepatitis D virus (HDV), negative HBeAg, platelet count of < 150 (× 10(9))/L, and HBV DNA level of ≥ 2,000 IU/mL were identified as significant independent predictors of liver cirrhosis in multiple logistic analyses.

CONCLUSIONS

Five predictive factors that are simple and easy to measure may be used as parameters for the prediction of liver cirrhosis in CHB patients.

Relationship between hepatitis B virus genotypes and hepatocellular carcinoma

Hepatitis B virus (HBV) genotype is closely related to response to antiviral therapy and the development of liver diseases. In this paper, we will review HBV genotypes, geographic distributions, their modes of transmission, and the occurrence of hepatocellular carcinoma (HCC). HBV genotypes have extensive connections with clinical pathology of HCC. Genotype B HBV is closely related to large-sized HCC, multiple tumors and vascular invasion. Patients with genotypes A or B HBV infection have better responses to interferon therapy, but genotypes seem not to influence the response to nucleotide analogue treatment. Therefore, HBV genotypes can be used as a genetic marker to predict the occurrence of HCC, and help practicing physicians choose optimal anti-viral therapy to prevent the occurrence of HCC.

A novel mutant 10Ala/Arg together with mutant 144Ser/Arg of hepatitis B virus X protein involved in hepatitis B virus-related hepatocarcinogenesis in HepG2 cell lines

Hepatitis B virus (HBV) infection-related hepatocellular carcinoma (HCC) represents a major health problem worldwide. HBV X (HBx) protein is the most common open reading frame that may undergo mutations, resulting in the development of HCC. This study aimed to determine specific HBx mutations that differentiate the central- and para-tumor tissues, and identify their association with HCC development. HBx gene from HCC tumor and para-tumor tissues of 47 HCC patients was amplified, sequenced and statistically analyzed. A novel combination of 2 mutations at residues 10 and 144 was identified which might play a significant role in HCC development. Expression vectors carrying HBx with the specific mutations were constructed and transfected into HepG2 and p53-null HepG2 cells. Compared to wild type (WT) and single mutation of HBx at residue 10 or 144, the 10/144 double mutations strongly up-regulated p21 expression and prolonged G1/S transition in WT- and p53-null HepG2 cells. Apoptosis was also inhibited by HBx harboring 10/44 double-mutation. Binding of 10/144 double-mutant HBx to p53 was lower than WT HBx. Conclusively, the 10/144 double mutation of HBx might play a crucial role in HCC formation.

Hepatitis B vaccination and prevention of hepatocellular carcinoma

Hepatitis B virus (HBV) infection is a global health threat; with 240 million people are chronic carriers of the virus. The infection can cause acute and chronic liver disease including liver cirrhosis and hepatocellular carcinoma (HCC). On the basis of disease burden and the availability of safe and effective vaccines, World Health Organization has recommended that hepatitis B vaccine be incorporated into routine infant and childhood immunization programs for all countries. The efficacy of universal immunization has been proven in many countries, with substantial reductions of the prevalence of HBV carriage in children, adolescents and young adults. Most important, hepatitis B vaccination can protect them from HCC, as has been demonstrated in Taiwan and other countries. Nevertheless, the implementation of worldwide vaccination against HBV indeed requires more effort to overcome the social and economic challenges. To have a global control of HBV infection, we have to continue the universal HBV vaccination, interrupt the possible transmission routes and treat eligible patients with antiviral agents. However, current treatments are still far from ideal as they cannot eradicate intrahepatic HBV cccDNA, and lifelong administration of these agents will pose a major economic burden, especially in the endemic Asia-Pacific region. Thus we need innovative treatment strategies and novel agents with difference modes of action to overcome the unmet medical need for an efficient HBV cure with subsequent global eradication of HBV infection, hopefully by the first half of 21st century.

Isoliensinine, a Bioactive Alkaloid Derived from Embryos of Nelumbo nucifera, Induces Hepatocellular Carcinoma Cell Apoptosis through Suppression of NF-κB Signaling

Isoliensinine (isolie) is an alkaloid produced by the edible plant Nelumbo nucifera. Here, we unveiled that isolie was able to provoke HepG2, Huh-7, and H22 hepatocellular carcinoma (HCC) cell apoptosis. Isolie decreased NF-κB activity and constitutive phosphorylation of NF-κB p65 subunit at Ser536 in HCC cells. Overexpression of p65 Ser536 phosphorylation mimics abrogated isolie-mediated HCC cell apoptosis. Furthermore, intraperitoneal injection of isolie inhibited the growth of Huh-7 xenografts in nude mice. Additionally, isolie given by both intraperitoneal injection and gavage diminished the proliferation of transplanted H22 cells in Kunming mice. Reduced tumor growth in vivo was associated with inhibited p65 phosphorylation at Ser536 and declined NF-κB activity in tumor tissues. Finally, we revealed that isolie was bioavailable in the blood of mice and exhibited no detectable toxic effects on tumor-bearing mice. Our data provided strong evidence for the anti-HCC effect of isolie.

Efficacy and resistance to telbivudine treatment in chronic hepatitis B patients with favorable predictors: a multicenter study in Taiwan

BACKGROUND/PURPOSE

A subgroup analysis of a GLOBE study identified subgroups of chronic hepatitis B (CHB) patients with excellent outcomes to telbivudine (LdT) treatment. The aim of this study was to validate this concept using a real-world clinical population.

METHODS

This prospective, retrospective, and multicenter study examined both HBeAg-positive and HBeAg-negative CHB patients treated with LdT for 2 years.

RESULTS

A total of 116 CHB patients were recruited. Of the 64 HBeAg-positive patients, 35 had favorable baseline characteristics [hepatitis B virus (HBV) DNA ≤ 9 log(10) copies/mL and alanine aminotransferase ≥ 2× the upper limit of normal (ULN)], but only 40% (14/35) achieved polymerase chain reaction (PCR) negativity at week 24. Among the 14 patients with favorable baseline characteristics and on-treatment response, the rates of virologic, biochemical, and serologic response and genotypic resistance were 78.6% (11/14), 64.3% (9/14), 50% (7/14), and 7.1% (1/14), respectively, at week 104 of therapy. Of the 52 HBeAg-negative patients, 34 met the criteria of a baseline serum HBV-DNA level less than 7 log(10) copies/mL, and 29 (85.3%) achieved PCR negativity at week 24. Among the 29 patients with favorable baseline characteristics and on-treatment response, the rates of virologic and biochemical response and genotypic resistance were 96.6% (28/29), 72.4% (21/29), and 6.9% (2/29), respectively. In addition, the PCR negativity at week 24 was the only factor associated with the virologic response and genotypic resistance to LdT treatment.

CONCLUSION

The efficacy and resistance to LdT treatment in CHB patients with favorable predictors were comparable between a real-world clinical population and the GLOBE study. In addition, PCR negativity at week 24 could predict virologic response and genotypic resistance to LdT treatment.

Effect of serum hepatitis B surface antigen levels on predicting the clinical outcomes of chronic hepatitis B infection: A meta-analysis

AIM

The impact of serum hepatitis B surface antigen (HBsAg) levels on the prognosis of chronic hepatitis B virus (HBV) infection remains unclear. This meta-analysis aimed to determine whether serum HBsAg levels influenced the risk of cirrhosis and hepatocellular carcinoma (HCC) development. Furthermore, we explored the role played by serum HBsAg levels in prediction of spontaneous HBsAg seroclearance.

METHODS

We performed this meta-analysis including 11 studies to assess the effect of HBsAg levels on predicting clinical outcomes in chronic HBV carriers. The pooled odds ratios (OR) were calculated using a random or fixed effects model. PUBMED, EMBASE, MEDLINE and the Cochrane Database were searched for articles published from 1990 to May 2014.

RESULTS

Our results showed that high HBsAg levels significantly increased the risk of developing cirrhosis (OR, 2.51; 95% confidence interval [CI], 2.00-3.14; P < 0.01). Pooled data from two studies revealed that high HBsAg levels increased the risk of HCC occurrence (OR, 2.21; 95% CI, 1.52-3.22; P < 0.01). High HBsAg levels were associated with a significant increased risk of late HCC recurrence after curative resection (OR, 2.02; 95% CI, 1.48-2.77; P < 0.01), but not early recurrence (OR, 1.06; 95% CI, 0.89-1.27; P = 0.53). The pooled data indicated that low HBsAg levels were significantly in favor of spontaneous HBsAg seroclearance (OR, 7.89; 95% CI, 4.74-13.13; P < 0.01).

CONCLUSION

High HBsAg levels were associated with development of cirrhosis and HCC comparatively. Therefore, lower serum HBsAg levels were associated with a higher rate of spontaneous HBsAg seroclearance.

MicroRNAs as Important Players in Host-hepatitis B Virus Interactions

Hepatitis B virus (HBV) infection, a major public health problem, causes acute and chronic hepatitis that is often complicated by liver cirrhosis and hepatocellular carcinoma. The pathogenic mechanisms of HBV-related liver disease are not well understood, and the current licensed therapies are not effective in permanently clearing virus from the circulation. In recent years, the role of micro-ribonucleic acids (miRNAs) in HBV infection has attracted great interest. Cellular miRNAs can influence HBV replication directly by binding to HBV transcripts and indirectly by targeting cellular factors relevant to the HBV life cycle. They are also involved in the regulation of cellular genes and signaling pathways that have critical roles in HBV pathogenesis. HBV infection, in turn, can trigger changes in cellular miRNA expression that are associated with distinctive miRNA expression profiles depending on the phase of liver disease. These alterations in miRNA expression have been linked to disease progression and hepatocarcinogenesis. We provide here an up to date review regarding the field of miRNAs and HBV interplay and highlight the potential utility of miRNAs as diagnostic biomarkers and therapeutic targets for the management of HBV-related liver disease.

The evolving epidemiology of hepatocellular carcinoma: a global perspective

Primary liver cancer, the majority of which are hepatocellular carcinomas, is now the second leading cause of cancer death worldwide. Hepatocellular carcinoma is a unique cancer that typically arises in the setting of chronic liver disease at a rate dependent upon the complex interplay between the host, disease and environmental factors. Infection with chronic hepatitis B or C virus is currently the dominant risk factor worldwide. However, changing lifestyle and environmental factors in western countries plus rising neonatal hepatitis B vaccination rates and decreasing exposure to dietary aflatoxins in developing countries are driving an evolution of the epidemiology of this cancer. An understanding of this change is crucial in combating the rising incidence currently being seen in western regions and will underpin the efforts to reduce the mortality rates associated with this cancer.

Role of antiviral therapy in the natural history of hepatitis B virus-related chronic liver disease

Hepatitis B virus (HBV) infection is a dynamic state of interactions among HBV, hepatocytes, and the host immune system. Natural history studies of chronic hepatitis B (CHB) infection have shown an association between active viral replication and adverse clinical outcomes such as cirrhosis and hepatocellular carcinoma. The goal of therapy for CHB is to improve quality of life and survival by preventing progression of the disease to cirrhosis, decompensation, end-stage liver disease, hepatocellular carcinoma (HCC) and death. This goal can be achieved if HBV replication is suppressed in a sustained manner. The accompanying reduction in histological activity of CHB lessens the risk of cirrhosis and of HCC, particularly in non-cirrhotic patients. However, CHB infection cannot be completely eradicated, due to the persistence of covalently closed circular DNA in the nucleus of infected hepatocytes, which may explain HBV reactivation. Moreover, the integration of the HBV genome into the host genome may favour oncogenesis, development of HCC and may also contribute to HBV reactivation.

Hepatitis B virus genotypes and variants

At least 10 hepatitis B virus (HBV) genotypes (A to J) with distinct geographic distributions and several HBV mutants, including precore/core promoter mutations and pre-S/S deletion mutations, have been recognized to be not only predictive of liver disease progression but also associated with response to antiviral therapy. HBV genotype-specific pathogenesis may contribute to heterogeneous clinical outcomes in chronic hepatitis B patients across the world. For example, patients with HBV genotypes C and D infection have a lower rate of spontaneous HBeAg seroconversion. In addition, HBV genotypes C and D have a higher frequency of core promoter and pre-S mutations than genotypes A and B. Genotypes C and D also carry a higher lifetime risk of cirrhosis and HCC development than genotypes A and B. Core promoter and pre-S mutations also correlate with an increased risk of hepatocellular carcinoma (HCC). Therapeutically, genotypes A and B patients have a better response to interferon-based therapy than genotypes C and D patients, but the response to nucleos(t)ide analogs is comparable across different HBV genotypes. In conclusion, HBV genotypes and variants may serve as viral genetic markers to predict disease progression as well as help practicing physicians optimize individualized antiviral therapy in clinical practice.

Treating Immune-tolerant Hepatitis B

Hepatitis B virus (HBV) infection is a major cause of cirrhosis and hepatocellular carcinoma worldwide. On the basis of virus-host interactions, the natural history of HBV carriers can be divided into four chronological phases. In the first immune tolerance phase, HBV carriers are positive for hepatitis B e antigen (HBeAg) and have high HBV replication activity, normal ALT levels as well as minimal liver disease. Ample evidence has shown that patients in the immune tolerance phase have very low viral evolution and minimal risk of fibrosis progression. However, recent immunological studies argued that HBV-specific immune responses already exist in a proportion of immune-tolerant patients and the immune activities are comparable to those in the immune clearance phase. Regarding antiviral therapy, whether these immune-tolerant patients are indicated for treatment remains debated. Previous studies showed that HBeAg-positive patients with normal or near-normal ALT levels, who are assumed to be in the immune tolerance phase, have a lower HBeAg seroconversion rate receiving either pegylated interferon or nucleos(t)ide analogue treatment. The latest clinical trial focusing on-treatment response of immune-tolerant patients with tenofovir disoproxil fumarate-based therapy also confirmed the results. The HBeAg seroconversion rates are <5% at 4 years of treatment. Considering the minimal risk of disease progression and low treatment response rates in immune-tolerant patients, current antiviral therapy should not be recommended unless the patients have advanced liver fibrosis. In addition, novel agents targeting the HBV template known as covalently closed circular DNA and aiming to reduce or eliminate it are urgently required.

Higher proportion of viral basal core promoter mutant increases the risk of liver cirrhosis in hepatitis B carriers

BACKGROUND AND OBJECTIVE

Precore (PC) variant (G1896A) and basal core promoter (BCP) variant (A1762T/G1764A) of HBV are associated with risk of hepatocellular carcinoma in HBV carriers. However, little is known about their impact on the adverse outcomes of hepatitis B e antigen (HBeAg)-negative hepatitis and liver cirrhosis.

METHODS

251 spontaneous HBeAg seroconverters who had genotype B or C infection and received a long-term follow-up were enrolled. PC and BCP mutants were determined qualitatively and quantitatively to correlate with these adverse outcomes. The findings were validated by an independent case-control study, which included 184 patients with biopsy-proven liver fibrosis stages.

RESULTS

In the longitudinal cohort study, BCP mutant and possibly PC wild type were associated with cirrhosis development, but not HBeAg-negative hepatitis. Multivariable analysis showed that only BCP mutant was an independent risk factor for cirrhosis development. Using quantitative analysis of BCP mutant, a higher proportion of BCP mutant, defined as a continuous variable, a dichotomous variable or an ordinal variable, was associated with a higher risk of cirrhosis. If we chose 45% of BCP mutant as the cut-off, the risk of cirrhosis was higher in patients with BCP mutant ≥45% compared to <45% in the longitudinal cohort; this finding was validated by the case-control study (adjusted OR: 2.81, 95% CI 1.40 to 5.67).

CONCLUSIONS

A higher proportion of BCP mutant increases the risk of liver cirrhosis development in HBV carriers with genotype B or C infection.

Dysregulation of retinoic acid receptor diminishes hepatocyte permissiveness to hepatitis B virus infection through modulation of sodium taurocholate cotransporting polypeptide (NTCP) expression

Sodium taurocholate cotransporting polypeptide (NTCP) is an entry receptor for hepatitis B virus (HBV) and is regarded as one of the determinants that confer HBV permissiveness to host cells. However, how host factors regulate the ability of NTCP to support HBV infection is largely unknown. We aimed to identify the host signaling that regulated NTCP expression and thereby permissiveness to HBV. Here, a cell-based chemical screening method identified that Ro41-5253 decreased host susceptibility to HBV infection. Pretreatment with Ro41-5253 inhibited the viral entry process without affecting HBV replication. Intriguingly, Ro41-5253 reduced expression of both NTCP mRNA and protein. We found that retinoic acid receptor (RAR) regulated the promoter activity of the human NTCP (hNTCP) gene and that Ro41-5253 repressed the hNTCP promoter by antagonizing RAR. RAR recruited to the hNTCP promoter region, and nucleotides -112 to -96 of the hNTCP was suggested to be critical for RAR-mediated transcriptional activation. HBV susceptibility was decreased in pharmacologically RAR-inactivated cells. CD2665 showed a stronger anti-HBV potential and disrupted the spread of HBV infection that was achieved by continuous reproduction of the whole HBV life cycle. In addition, this mechanism was significant for drug development, as antagonization of RAR blocked infection of multiple HBV genotypes and also a clinically relevant HBV mutant that was resistant to nucleoside analogs. Thus, RAR is crucial for regulating NTCP expression that determines permissiveness to HBV infection. This is the first demonstration showing host regulation of NTCP to support HBV infection.

Risk stratification of HBV infection in Asia-Pacific region

Hepatitis B virus (HBV) infection is the major etiology of chronic liver disease worldwide and thus a global health problem, especially in Asia-Pacific region. The long-term outcomes of Asian HBV carriers vary widely; however, a significant proportion of them will finally develop end-stage liver disease. Over the past decade, several host and HBV factors predictive of clinical outcomes in Asian HBV carriers have been identified. The community-based REVEAL-HBV study illustrated the strong association between HBV-DNA level at study entry and risk of HCC over time, and male gender, older age, high serum alanine aminotransferase (ALT) level, positive HBeAg, higher HBV-DNA level, HBV genotype C infection and core promoter mutation are independently associated with a higher hepatocellular carcinoma (HCC) risk. Another hospital-based ERADICATE-B cohort further validated the HCC risk started to increase when HBV-DNA level was higher than 2,000 IU/mL. Of particular note, in patients with low viral load (HBV-DNA level <2,000 IU/mL), HBsAg level ≥1,000 IU/mL was a new independent risk factor for HCC. With the results from REVEAL-HBV study, a risk calculator for predicting HCC in adult non-cirrhotic patients has been developed and validated by independent international cohorts (REACH-B). With the combination of HBV-DNA, HBsAg, and ALT levels, ERADICATE-B study proposed an algorithm to predict disease progression and categorize risk levels of HCC as well as corresponding management in Asian HBV carriers. The introduction of transient elastography may further enhance the predictive power. In conclusion, HBsAg level can complement HBV-DNA level for the risk stratification of disease progression in Asian adult patients with chronic HBV infection.

Persistence of hepatitis B virus covalently closed circular DNA in hepatocytes: molecular mechanisms and clinical significance

Covalently closed circular DNA (cccDNA) is the transcriptional template of hepatitis B virus (HBV). Extensive research over the past decades has unveiled the important role of cccDNA in the natural history and antiviral treatment of chronic HBV infection. cccDNA can persist in patients recovering from acute HBV infection for decades. This explains why HBV reactivation occasionally occurs in patients with resolved hepatitis B receiving intensive immunosuppressive agents. In addition, although advances in antiviral treatment dramatically improve the adverse outcomes of chronic hepatitis B (CHB), accumulating evidence demonstrates that current antiviral treatments alone, be they nucleos(t)ide analogs (NAs) or interferon (IFN), fail to cure most CHB patients because of the persistent cccDNA. NA suppresses HBV replication by directly inhibiting viral polymerase, while IFN enhances host immunity against HBV infection. Viral rebound often occurs after discontinuation of antiviral treatment. The loss of cccDNA can be induced by non-cytolytic destruction of cccDNA or immune-mediated killing of infected hepatocytes. It is known that NA has no direct effect on viral transcription or cccDNA stability. Therefore, the long half-life of hepatocytes leads to a very slow decline in cccDNA in patients under antiviral therapy. Novel antiviral agents targeting cccDNA or cccDNA-containing hepatocytes are thus required for curing chronic HBV infection.

Occult hepatitis B virus among the patients with abnormal alanine transaminase

Background:

The occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the sera or in the liver biopsy and the absence of hepatitis B surface antigen (HBsAg) by serological test.

Objectives:

The current study aimed to evaluate the occult HBV infection by polymerase chain reaction (PCR) and determine HBV genotyping among the patients with abnormal alanine transaminase (ALT) in Ahvaz city, Iran.

Patients and Methods:

The sera of 120 patients, 54 (45%) females and 66 (55%) males, with abnormal ALT 40-152 IU were collected. All the patients were negative for HBsAg for more than one year. The patients` sera were tested by PCR using primers specified for the S region of HBV. Then the positive PCR products were sequenced to determine HBV genotyping and phylogenic tree.

Results:

Of these 120 subjects, 12 (10%) patients including 6 (5%) males and 6 (5%) females were found positive for HBV DNA by PCR, which indicated the presence of occult HBV infection among these patients. The sequencing results revealed that genotype D was predominant with sub-genotyping D1 among OBI patients.

Conclusions:

Occult hepatitis B infection is remarkably prevalent in Ahvaz, Iran, and should be considered as a potential risk factor for the transmission of Hepatitis B Virus throughout the community by the carriers.