Hepatitis B virus genotype B is associated with earlier HBeAg seroconversion compared with hepatitis B virus genotype C

First Detection of Hepatitis B Virus Subgenotype A5, and Characterization of Occult Infection and Hepatocellular Carcinoma-Related Mutations in Latin American and African Immigrants in Brazil

This study aims to characterize the molecular profile of the hepatitis B virus (HBV) among socially vulnerable immigrants residing in Brazil to investigate the introduction of uncommon HBV strains into the country. Serum samples from 102 immigrants with positive serology for the HBV core antibody (anti-HBc) were tested for the presence of HBV DNA by PCR assays. Among these, 24 were also positive for the HBV surface antigen (HBsAg). The full or partial genome was sequenced to determine genotype by phylogenetic analysis. Participants were from Haiti (79.4%), Guinea-Bissau (11.8%), Venezuela (7.8%), and Colombia (1%). Of the 21 HBV DNA-positive samples, subgenotypes A1 (52.4%), A5 (28.6%), E (9.5%), F2 (4.8%), and F3 (4.8%) were identified. Among the 78 HBsAg-negative participants, four were positive for HBV DNA, resulting in an occult HBV infection rate of 5.1%. Phylogenetic analysis suggested that most strains were likely introduced to Brazil by migration. Importantly, 80% of A5 sequences had the A1762T/G1764A double mutation, linked to an increased risk of hepatocellular carcinoma development. In conclusion, this study is the first report of HBV subgenotype A5 in Brazil, shedding new light on the diversity of HBV strains circulating in the country. Understanding the genetic diversity of HBV in immigrant communities can lead to better prevention and control strategies, benefiting both immigrants and wider society.

Lack of association between early on-treatment HBeAg seroclearance and development of hepatocellular carcinoma or decompensated cirrhosis

Background & Aims

The association between hepatitis B envelope antigen (HBeAg) seroclearance during long-term nucleos(t)ide analogue (NA) treatment and the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB) remains unclear. Here, we aimed to investigate the association of HBeAg seroclearance during potent NA treatment with the development of HCC and decompensated cirrhosis.

Methods

Using a multicenter historical cohort including 2,392 non-cirrhotic adult patients with HBeAg-positive CHB who initiated NA treatment with tenofovir or entecavir, the risk of HCC and decompensated cirrhosis was compared between patients who achieved HBeAg seroclearance within 36 months of NA treatment (the HBeAg-loss group) and those who did not (the HBeAg-maintained group), using inverse probability of treatment weighting.

Results

Over a median of 6.6 years of NA treatment, 1,077 patients achieved HBeAg seroclearance (HBeAg loss rate = 6.0 per 100 person-years), 64 patients developed HCC (HCC incidence rate = 0.39 per 100 person-years), and 46 patients developed decompensated cirrhosis (decompensation incidence rate = 0.28 per 100 person-years). The HBeAg-loss and HBeAg-maintained groups had a similar risk of developing HCC (hazard ratio 0.89; 95% CI 0.47-1.68; p = 0.72) and decompensated cirrhosis (hazard ratio 0.98; 95% CI 0.48-1.81; p = 0.91). Compared with delayed HBeAg seroclearance beyond 10 years of NA treatment, the risk of HCC was comparable in those who achieved earlier HBeAg seroclearance at any time point within 10 years, regardless of baseline age and fibrotic burden.

Conclusions

Early HBeAg seroclearance during NA treatment was not associated with a reduced risk of development of HCC or decompensated cirrhosis in non-cirrhotic HBeAg-positive patients with CHB.

Impact and implications

The association between hepatitis B envelope antigen (HBeAg) seroclearance during long-term nucleos(t)ide analogue treatment and the risk of hepatocellular carcinoma in patients with chronic hepatitis B remains unclear. Our findings indicate that early on-treatment HBeAg seroclearance within 3 years was not associated with the development of hepatocellular carcinoma or decompensated cirrhosis. Achieving HBeAg seroclearance may not be an appropriate surrogate endpoint for preventing the development of liver-related outcomes in non-cirrhotic patients with HBeAg-positive chronic hepatitis B treated with nucleos(t)ide analogues.

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

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

Clinical isolates of hepatitis B virus genotype C have higher in vitro transmission efficiency than genotype B isolates

Serum samples were collected from 54 hepatitis B e antigen (HBeAg)-positive Chinese patients infected with hepatitis B virus (HBV) subgenotype B2 or C2. They were compared for transmission efficiency using same volume of samples or infectivity using same genome copy number. Adding polyethylene glycol (PEG) during inoculation did not increase infectivity of fresh samples but markedly increased infectivity following prolonged sample storage. Differentiated HepaRG cells infected without PEG produced more hepatitis B surface antigen (HBsAg) and higher HBsAg/HBeAg ratio than sodium taurocholate cotransporting polypeptide (NTCP)-reconstituted HepG2 cells infected with PEG. They better supported replication of core promoter mutant in contrast to wild-type (WT) virus by HepG2/NTCP cells. Overall, subgenotype C2 samples had higher viral load than B2 samples, and in general produced more HBeAg, HBsAg, and replicative DNA following same-volume inoculation. Precore mutant was more prevalent in subgenotype B2 and had reduced transmission efficiency. When same genome copy number of viral particles was inoculated, viral signals were not necessarily higher for three WT C2 isolates than four WT B2 isolates. Using viral particles generated from cloned HBV genome, three WT C2 isolates showed slightly reduced infectivity than three B2 isolates. In conclusion, subgenotype C2 serum samples had higher transmission efficiency than B2 isolates in association with higher viral load and lower prevalence of precore mutant, but not necessarily higher infectivity. PEG-independent infection by HBV viremic serum samples is probably attributed to a labile host factor.

Vertical Transmission of Hepatitis B Virus-An Update

Hepatitis B virus (HBV) infection is a major public health problem in the world. Approximately 296 million people are chronically infected. In endemic areas, vertical transmission is a common route of transmission. There are several strategies for the prevention of HBV vertical transmission, such as antiviral treatment during the third trimester of pregnancy and immunoprophylaxis to newborns that includes the administration of hepatitis B immune globulin (HBIG) and an HBV vaccine. Despite this, immunoprophylaxis failure can occur in up to 30% of infants born to HBeAg-positive mothers and/or with high viral load. Therefore, management and prevention of HBV vertical transmission is of paramount significance. In this article, we provided a review of the epidemiology, mechanisms of pathogenesis and risk factors of vertical transmission, as well as the strategies implemented to prevent the infection.

Virological Treatment Monitoring for Chronic Hepatitis B

More than 250 million people worldwide are currently infected with hepatitis B, despite the effectiveness of vaccination and other preventive measures. In terms of treatment, new therapeutic approaches are rapidly developing, promising to achieve the elimination of infected cells and the complete cure of infection. The on-treatment monitoring of these innovative antiviral treatments will require the implementation of new virological tools. Therefore, new biomarkers are being evaluated besides the traditional virological and serological assays in order to obtain information on different steps of the viral replication cycle and to monitor response to therapy more accurately. The purpose of this work is to describe both standard and innovative tools for chronic hepatitis B treatment monitoring, and to analyse their potential and feasibility.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LAY SUMMARY

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

Comparative Analysis of Serum Proteins Between Hepatitis B Virus Genotypes B and C Infection by DIA-Based Quantitative Proteomics

Purpose

In clinical practice, the clinicopathological profiles and outcomes of patients infected with hepatitis B virus (HBV) are different between genotypes B and C. However, little is known about the potential mechanism and differences in specific biological pathways associated with the different genotype. This study aimed to compare the serum protein profile between patients infected with HBV genotype B and those infected with HBV genotype C.

Patients and Methods

A total of 54 serum samples from patients with chronic HBV genotype B infection and those with chronic HBV genotype C infection, and healthy controls were used for the proteomic analysis (n = 18 samples in per group). Serum proteomic profiles were analyzed using data-independent acquisition (DIA)-based liquid chromatography-mass spectrometry to identify differentially expressed proteins (up- or downregulation of at least 1.5-fold) between serum samples from HBV patients infected with HBV genotype B and those infected with genotype C.

Results

We identified 1010 proteins, 53 of which were differentially expressed between the serum samples of the healthy controls and those of HBV genotype B infected patients, and 59 that were differentially expressed between the samples of the healthy controls and those of HBV genotype C infected patients. Furthermore, our results indicated that two proteins identified as being differentially expressed (VWF and C8B) have potential as biomarkers for distinguishing genotype B infected HBV patients from those infected with genotype C.

Conclusion

The results of our DIA-based quantitative proteomic analysis revealed that HBV genotypes B and C are associated with different molecular profiles and may provide fundamental information for further detailed investigations of the molecular mechanism underlying these differences.

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.

Guidelines for Prevention and Treatment of Chronic Hepatitis B

To achieve the goal of the World Health Organization to eliminate viral hepatitis as a major public health threat by 2030, the Chinese Society of Infectious Diseases and the Chinese Society of Hepatology convened an expert panel in 2019 to update the guidelines for the prevention and treatment of chronic hepatitis B (CHB). The current guidelines cover recent advances in basic, clinical, and preventive studies of CHB infection and consider the actual situation in China. These guidelines are intended to provide support for the prevention, diagnosis, and treatment of CHB.

Blood-Based Biomarkers in Hepatitis B Virus-Related Hepatocellular Carcinoma, Including the Viral Genome and Glycosylated Proteins

Hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC) development and is a global public health issue. High performance biomarkers can aid the early detection of HCC development in HBV-infected individuals. In addition, advances in the understanding of the pathogenesis of HBV infection and in clinical laboratory techniques have enabled the establishment of disease-specific tests, prediction of the progression of liver diseases, including HCC, and auxiliary diagnosis of HCC, using blood-based methods instead of biopsies of liver or HCC tissues. Viral factors such as the HBV genotype, HBV genetic mutations, HBV DNA, and HBV-related antigens, as well as host factors, such as tumor-associated proteins and post-translational modifications, especially glycosylated proteins, can be blood-based, disease-specific biomarkers for HCC development in HBV-infected patients. In this review, we describe the clinical applications of viral biomarkers, including the HBV genome and glycosylated proteins, for patients at a risk of HBV-related HCC, based on their molecular mechanisms. In addition, we introduce promising biomarker candidates for practical use, including colony stimulating factor 1 receptor (CSF1R), extracellular vesicles, and cell-free, circulating tumor DNA. The clinical use of such surrogate markers may lead to a better understanding of the risk of disease progression and early detection of HCC in HBV-infected patients, thereby improving their prognosis.

Clinical significance of quantitative e antigen in a cohort of hepatitis B virus-infected children and adults in North America

BACKGROUND

In chronic hepatitis B (CHB) viral infection, e antigen positivity (HBeAg+) is associated with high levels of viral replication and infectivity. Furthermore, HBeAg-positive CHB is associated with a liver disease spectrum ranging from none to severe.

AIM

To assess whether the level of circulating HBeAg is associated with different clinical presentations of HBeAg-positive CHB.

METHODS

A cross-sectional analysis was conducted among HBV mono-infected participants enrolled in Hepatitis B Research Network (HBRN) cohorts to explore clinical and virological associations with quantitative HBeAg (qHBeAg).

RESULTS

Among 763 HBeAg+ participants (56% female; 85% Asian; median age 26 years), multivariable median regression modelling significantly associated qHBeAg with liver injury (inverse qHBeAg association with ALT p<.001 and APRI p<.001), and with both race and age (p=0.01). Among Asians, qHBeAg was inversely related to age; a relationship less clear among Blacks and Whites. Among Asians also, median qHBeAg levels were higher among those infected with HBV genotype C versus B (p<0.001), suggesting causal virologic differences. Across all races, median qHBeAg was higher in women (p=.01). Independent of sex, age, race and HBV genotype, qHBeAg was higher in participants with predominant wild-type versus basal core promoter and/or precore 'stop' viral variants (p<0.001).

CONCLUSION

Lower qHBeAg was observed among HBRN participants with the greatest degree of liver injury independent of demographics and HBV genotype. These data support longitudinal studies to examine the role of qHBeAg in modulating the host immune response and predicting the outcomes of chronic HBV infection.

Translational Strategies to Eliminate Chronic Hepatitis B in Children: Prophylaxis and Management in East Asian Countries

Translational medical research on hepatitis B virus (HBV) infection and chronic hepatitis B (CHB) pathogenesis provides guidance on strengthening the treatment and prevention strategies of CHB. Preventing vertical transmission is the key to eliminating HBV infection in children. The understanding of HBV replication, hepatocyte turnover, and the fate of covalently closed circular DNA (cccDNA) would help establish a personalized application of the guidelines, especially concerning the discontinuation of nucleos(t)ide analog (NA) treatment in children. Transplacental leakage of HBV-infected maternal blood is suggested as the leading cause of vertical transmission. Prenatal maternal prophylaxis could diminish maternal HBV viremia at delivery, to reduce the risk of neonatal HBV infection. The meaning of the expression "no additional risk of breast milk feeding" is thereby explained. Understanding the untreated natural course of CHB in children and the course changeable by treatment is important to apply individualistic strategies and avoid the immoral selection of treatment indications. NAs with potent efficacy and a high barrier to drug resistance should be used as first-line treatment to reduce the likelihood of NA-resistant HBV development because the rate of mutant HBV emergence might count on the infected hepatocyte turnover rate in chronic HBV infection. Although elimination of intranuclear cccDNA is difficult by NAs alone, a cure is possible by human immunity and hepatocyte turnover. The reduction of intranuclear cccDNA occurs after the destruction of HBV-infected hepatocytes, non-cytolytic immune response, apoptosis of hepatocytes, and compensatory cell proliferation. Therefore, consolidation therapy after NA-induced hepatitis B e-antigen seroconversion must be necessary for a sufficient period. This review also summarizes the treatment strategies of CHB in children based on the practical application of translational research.

The evolution and clinical impact of hepatitis B virus genome diversity

The global burden of hepatitis B virus (HBV) is enormous, with 257 million persons chronically infected, resulting in more than 880,000 deaths per year worldwide. HBV exists as nine different genotypes, which differ in disease progression, natural history and response to therapy. HBV is an ancient virus, with the latest reports greatly expanding the host range of the Hepadnaviridae (to include fish and reptiles) and casting new light on the origins and evolution of this viral family. Although there is an effective preventive vaccine, there is no cure for chronic hepatitis B, largely owing to the persistence of a viral minichromosome that is not targeted by current therapies. HBV persistence is also facilitated through aberrant host immune responses, possibly due to the diverse intra-host viral populations that can respond to host-mounted and therapeutic selection pressures. This Review summarizes current knowledge on the influence of HBV diversity on disease progression and treatment response and the potential effect on new HBV therapies in the pipeline. The mechanisms by which HBV diversity can occur both within the individual host and at a population level are also discussed.

Distribution of hepatitis B virus genotypes in the general population of Myanmar via nationwide study

Background

Hepatitis B virus (HBV) infections are a severe health concern worldwide. HBV is a DNA virus with a rapid rate of mutation. Based on heterogeneity of the nucleotide sequence, the HBV strains are divided into nine genotypes, each with a characteristic geographical distribution. Identifying and tracking alterations of HBV genotypes is important in epidemiological and transmission studies, and contributes to predicting the risk for development of severe liver disease and response to antiviral treatment. The present study was undertaken to detect HBV genotypes and sub-genotypes in the general population of different states and regions in Myanmar.

Methods

In 2015, a total of 5547 adults of the general population, residing in seven states, seven regions and the Nay Pyi Taw Union Territory, were screened for Hepatitis B Surface antigen (HBsAg) by the immunochromatographic test (ICT). Of the 353 HBsAg positive samples, the HBVDNA was identified using polymerase chain reactions (PCR) targeting the DNA sequences encoding the Pre-S region. A total of 153 PCR positive samples were subsequently subjected to genotyping by partial genome sequencing in both directions. The resulting sequences were then edited, aligned, and compared with reference sequences using the National Centre for Biotechnology Information (NCBI) web-based genotyping tool.

Results

Three HBV genotypes (HBV genotype B, genotype C and genotype D) were detected in Myanmar, of which genotype HBV genotype C (66.7%) was the most prevalent, followed by HBV genotype D (32%) and HBV genotype B (1.3%). Sub-genotyping revealed a total of 7 variants within the B, C and D genotypes: 2 (B4 and B5) in HBV genotype B, 3 (C1, C5 and C7) in HBV genotype C, and 2 (D3 and D6) in HBV genotype D.

Conclusion

HBV genotype C, sub-genotype C1 was predominantly distributed in all states and regions of Myanmar. This study is the first report on the nationwide distribution of HBV genotypes and sub-genotypes in Myanmar. We believe our findings will enable huge support for the hepatitis disease surveillance program, since HBV infection is one of the National Priority Diseases in Myanmar.

[Long Term Efficacy of Antiviral Therapy: Mortality and Incidence of Hepatocellular Carcinoma]

Multiple studies have shown that oral antiviral therapies reduced the incidence of hepatocellular carcinoma (HCC) and improved the survival of patients with chronic hepatitis B when compared with that of untreated patients. In particular, entecavir and tenofovir share the qualities of high efficacy in reducing the HBV DNA levels, and they have excellent tolerability and safety. These drugs modified the natural history of liver fibrosis, improve liver function, decrease the incidence of HCC, decrease the need for liver transplantation, and improve survival. Many studies have suggested that long-term antiviral therapy reduces the risk of HCC and liver cirrhosis in patients with chronic hepatitis. The mechanism of these drugs in reducing the risk of HCC is not clear. This article reviews the mechanisms of carcinogenic HBV by conducting a review of the literature on the efficacy of therapy for reducing the risk of HCC. A few recent articles have suggested that tenofovir offers advantages over entecavir in terms of HCC prevention, but these articles have the inherent limitations of observational data. No other head-to-head randomized trials exist. Further randomized studies would help provide stronger evidence of the association between the type of antiviral agent and the HCC outcomes. Only achieving complete viral eradication from the liver will truly decrease the mortality and incidence of HCC.

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

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

Rapidly decreased HBV RNA predicts responses of pegylated interferons in HBeAg-positive patients: a longitudinal cohort study

BACKGROUND

As an important anti-HBV drug, pegylated interferon α (PegIFNα) offers promising clinical efficacy, but biomarkers that accurately forecast treatment responses are yet to be elucidated. Here, we evaluated whether HBV RNA could act as an early monitor of pegylated interferon responses.

METHODS

We analyzed a phase 3, multicenter, randomized cohort of 727 HBeAg-positive non-cirrhotic patients receiving a 48-week treatment of PegIFNα-2a or PegIFNα-2b and a 24-week treatment-free follow-up. Serum levels of HBV RNA, HBV DNA, HBeAg, and HBsAg were measured at weeks 0, 12, 24, 48, and 72.

RESULTS

HBeAg seroconversion and HBsAg loss at week 72 were observed in 217 (29.8%) and 21 (2.9%) patients, respectively. During the 48-week treatment, HBV RNA decreased more rapidly than HBV DNA and HBsAg, but HBV RNA and HBeAg shared similar dynamics with positive correlations. Multivariate regression analyses consistently revealed the significance of HBV RNA at weeks 0, 12, 24, and 48 to monitor HBeAg seroconversion but not HBsAg loss. Although baseline HBV RNA only showed a modest AUC performance, HBV RNA with a significant increase of AUC at week 12 outperformed other HBV biomarkers to forecast HBeAg seroconversion (p value < 0.05). HBV RNA ≤ 1000 copies/mL was an optimized cutoff at week 12 that offered better prediction than other HBV biomarkers. This optimized cutoff plus patient age, HBV genotype B, and HBeAg offered a strong estimation of HBeAg seroconversion (accuracy 95.2%, true negative rate 99.8%).

CONCLUSION

HBV RNA at week 12 is an effective monitor of HBeAg seroconversion in HBeAg-positive patients treated with pegylated interferons.

Genotyping of immune-related loci associated with delayed HBeAg seroconversion in immune-active chronic hepatitis B patients

The progression of chronic hepatitis B (CHB) is associated with single-nucleotide polymorphisms (SNPs). In this study, we demonstrated the association between immune-related SNPs and delayed spontaneous HBeAg seroconversion in immune-active CHB patients. In addition, we investigated the impact of delayed spontaneous HBeAg seroconversion-related SNPs on HBeAg seroconversion within 3 years during antiviral treatment. We enrolled 332 CHB patients and genotyped 124 SNPs associated with HBV-infected clinical outcomes, including 32 interleukin-related genes, 62 HLA genes, 9 CD marker genes, 7 NK cell receptor genes, and 14 other genes, using ABI OpenArray as a platform. Comparing the immune-active CHB patients with delayed spontaneous HBeAg seroconversion (persistent HBeAg seropositivity, older than 40 years) to those with early inefficient HBeAg seroconversion (HBeAg seroconversion with high viremia, younger than 40 years), logistic analysis revealed that rs3820998 (TANK), rs2621377 (HLA-DOB), rs3130215 (HLA-DPB2), rs2255336 (KLRK1), and rs11614913 (MIR-196A2) were significantly associated with delayed spontaneous HBeAg seroconversion. Using multivariate analysis, we determined that high serum HBV DNA levels (OR = 1.66, 95% CI = 1.33-2.08), rs3820998 (CA, OR = 3.37, 95% CI = 1.24-9.12), rs2621377 (TC, OR = 4.96, 95% CI = 1.85-13.3), rs2255336 (TT, OR = 0.09, 95% CI = 0.01-0.86), and rs11614913 (TT, OR = 2.53, 95% CI = 1.05-6.11) were five independent risk factors for delayed spontaneous HBeAg seroconversion. After patients received nucleos(t)ide analogue treatment, rs3820998 heterozygous CA variant conversely became the only independent favorable factor for treatment-induced HBeAg seroconversion within 3 years (OR = 0.21, 95% CI = 0.06-0.78). These results indicate that distinct immune-related SNPs play a vital role in regulating HBeAg status in immune-active CHB patients with or without antiviral treatment.

Towards Genotype-Specific Care for Chronic Hepatitis B: The First 6 Years Follow Up From the CHARM Cohort Study

Objective

There is increasing evidence to suggest that, among those with chronic hepatitis B virus infection, the natural history and rate of progression to cirrhosis and hepatocellular carcinoma is influenced by hepatitis B virus genotype. The unique hepatitis B virus genotype C4 circulates among Indigenous Australians. The aim of this work is to describe the process of establishing this cohort and review the first 6 years of available data in an effort to understand the real-world clinical care and natural history of this subgenotype.

Method

We followed a longitudinal cohort of Indigenous Australians from the Northern Territory of Australia with established subgenotype C4 infections. We assigned phases of disease according to Gastroenterological Society of Australia and Asian Pacific Association for the Study of the Liver criteria using clinical and laboratory information that had been collected for clinical management.

Results

Of 193 patients followed over a median of 38 months, 58 (30%) individuals transitioned from 1 disease phase to another, 10 (5%) cleared hepatitis B e antigen, and 6 cleared hepatitis B surface antigen (3%). In this relatively young cohort (median age 40.3 years), 26 (13%) had cirrhosis by the end of the follow up period, with the majority of these being in the immune control phase of disease.

Conclusions

In this cohort of hepatitis B subgenotype C4 patients, we report an aggressive and dynamic clinical phenotype. High rates of cirrhosis at a young age appear to occur in the early phases of disease.

High possibility of hepatocarcinogenesis in HBV genotype C1 infected Cambodians is indicated by 340 HBV C1 full-genomes analysis from GenBank

Approximately 75% of hepatocellular carcinomas (HCC) occur in Asia; core promoter mutations are associated with HCC in HBV genotype C, the dominant genotype in Cambodia. We analyzed these mutations in Cambodian residents and compared them with HBV full genomes registered in GenBank. We investigated the characteristics of 26 full-length HBV genomes among 35 residents positive for hepatitis B surface antigen in Siem Reap province, Cambodia. Genotype C1 was dominant (92.3%, 24/26), with one case of B2 and B4 each. Multiple mutations were confirmed in 24 Cambodian C1 isolates, especially double mutation at A1762T/G1764A in 18 isolates (75.0%), and combination mutation at C1653T and/or T1753V and A1762T/G1764A in 14 isolates (58.3%). In phylogenetic analysis, 16 of 24 isolates were located in the cluster with Laos, Thailand, and Malaysia. In 340 GenBank-registered C1 strains, 113 (33.2%) had combination mutation amongst which 16.5%, 34.2%, and 95.2% were found in ASC, chronic hepatitis, and liver cirrhosis (LC)/HCC respectively (P < 0. 001). Mutations were abundantly found in 24 Cambodian C1 isolates, and 340 C1 strains from GenBank showed mutation in genotype C1 brings high possibility of LC/HCC occurrence. Therefore, we suggest that Cambodian people infected with HBV genotype C1 have high possibility of hepatocarcinogenesis.

Incidence of development of hepatocellular carcinoma in Japanese patients infected with hepatitis B virus is equivalent between genotype B and C in long term

Hepatitis B virus (HBV) genotypes B (HBV/B) and C (HBV/C) are the most prevalent genotypes among Japanese patients with hepatitis. Reportedly, HBV/C infection has been associated with more severe disease progression, manifesting as developing cirrhosis and hepatocellular carcinoma (HCC), than HBV/B infection. However, no long-term studies have examined the development of HCC in HBV/B-infected patients in Japan. The aims of our study were to compare the incidence of HCC in HBV/B- or HBV/C-infected patients. A total of 241 patients were followed up among 295 hepatitis B surface antigen (HBsAg)-positive carriers. Genotypes of HBV were A in 1% (4/295), B in 61% (179/295), C in 37% (110/295) and D in 1% (2/295) patients, and 96% of HBV/B were infected with subgenotype Bj. The mean age at HCC diagnosis was significantly higher in HBV/B than in HBV/C (67.0 ± 10.0 vs 57.7 ± 8.0 years, P < 0.001). The value of FIB-4 index was significantly higher in HBV/B than in HBV/C (P < 0.01). The rate of HCC was higher in HBV/C than in HBV/B, and a significant difference was observed until the 20-year observation period (P = 0.048). However, thereafter, HCC associated with HBV/B increased, and no significant difference was observed between HBV/B and HBV/C. HCC development was consistently observed even in HBV/B infection, especially among elderly patients with advanced fibrosis compared with HBV/C. HBV/B-infected patients developed HCC later in life, and in the long term, we found no differences in incidence of HCC development rates between these two genotypes.

HBV mutations in EnhII/BCP/PC region contribute to the prognosis of hepatocellular carcinoma

Background

Accompanied by HBV infection, HBV mutations gradually occur because HBV polymerase appears proofread deficiencies. In our previous study, we have identified that EnhII/BCP/PC mutations and genotype C of HBV DNA were associated with hepatocellular carcinoma (HCC) risk. In this study, we extend our research to explore HCC prognosis associated genotype and mutations in EnhII/BCP/PC regions.

Methods

We designed a case‐cohort study of 331 HCC patients to evaluate the effects of the HBV genotypes and mutations on HCC survival. Log‐rank test and Cox proportional hazard models were used for the analyses.

Results

Results showed that genotype C, which was more frequent in HBV‐related HCC (77.4%), presented a negative signal with HCC survival. Interestingly, we detected a significant association between EnhII/BCP/PC mutation nt1753 and HCC prognosis (Log‐rank P = 0.034). Subgroup analysis revealed that this risk effect was more pronounced in non‐B genotype (P = 0.090 for heterogeneity test). We also detected a borderline multiplicative interaction between genotypes of nt1753 and HBV genotype on HCC survival (P for interaction = 0.069).

Conclusions

These findings indicated that, in Chinese population, nt1753 in EnhII/BCP/PC region might be a novel marker for HCC prognosis.

Ultrasensitive Electrochemical Biosensor Developed by Probe Lengthening for Detection of Genomic DNA in Human Serum

As an alternative to most of the reported nucleic acid amplification-based electrochemical DNA biosensors used for detection of trace levels of genomic DNA, we herein present a novel detection concept. The proposed system involves the conversion of two short double-stranded DNAs (dsDNAs), labeled with a thiol-tag or biotin-tag, into a single integrated dsDNA containing thiol and biotin at both terminals in the presence of target DNA through ligase chain reaction (LCR) and followed by the immobilization of these integrated dsDNAs on a bovine serum albumin (BSA)-modified gold electrode surface. Owing to rapid depletion of the two short dsDNAs via LCR, the integrated dsDNAs were generated in an exponential manner so that this sensoring approach offered a limit of detection of 25 yoctomoles (15 copies in 50 μL sample volumes), a high discrimination of single-base mismatch and a wide linear concentration range (across 6 orders of magnitude) for target DNA. Significantly, the proposed sensor, which has simplicity in operation and ease of miniaturization, detected the target of interest in total nucleic acid extracts derived from clinical serum samples with excellent results, thereby demonstrating its considerable diagnostic potential in fields ranging from virus detection to the diagnosis of genetic diseases.

Diagnostic and prognostic value of mRNA expression of phospholipase C β family genes in hepatitis B virus‑associated hepatocellular carcinoma

Four phospholipase C β (PLCB) isoforms, PLCB1, PLCB2, PLCB3 and PLCB4, have been previously investigated regarding their roles in the metabolism of inositol lipids and cancer. The present study aimed to explore the association between PLCB1-4 and hepatocellular carcinoma (HCC). Data from 212 patients with hepatitis B virus-associated HCC were used to analyze the diagnostic and prognostic significance of PLCB genes in. A nomogram predicted the survival probability. Gene set enrichment analysis explored gene ontology terms and the metabolic pathways associated with PLCB genes. Validation of the prognostic values of PLCB genes was performed using the Gene Expression Profiling Interactive Analysis website. PLCB1 and PLCB2 were revealed to have diagnostic value for HCC (0.869 and 0.836 area under the curve, respectively; both P≤0.05). The combination analysis of these genes had an advantage over each alone (0.905 PLCB1 and PLCB2, and 0.877 PLCB1 and PLCB3 area under the curve; P≤0.05). PLCB1 was associated with overall survival (OS) and recurrence-free survival (RFS; adjusted P=0.002 and P=0.001, respectively). A nomogram predicted survival probability of patients with HCC at 1, 3- and 5-years. Gene set enrichment analysis indicated that PLCB1 and PLCB2 are involved in the cell cycle, cell division and the PPAR signaling pathway, among other functions. Validation using GEPIA revealed that PLCB1 and PLCB2 were associated with OS and PLCB1 and PLCB4 were associated with RFS. PLCB1 and PLCB2 exhibited diagnostic value for HCC and their combination had an advantage over each individually. PLCB1 has OS and RFS prognostic value for patients with HCC.

A rapid and sensitive recombinase aided amplification assay to detect hepatitis B virus without DNA extraction

Background

Hepatitis B virus (HBV) infection is the major public health problem worldwide. In clinical practice, serological and molecular assays are the most commonly used diagnostic methods to detect HBV infection in clinical practices.

Methods

Here we present a rapid and sensitive recombinase aided amplification assay (RAA) to detect HBV at 39.0 °C for 30 min without DNA extraction from serum samples. The analytical sensitivity of RAA assay was 100 copies per reaction and showed no cross reaction with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). The universality of RAA assay was validated by testing of 41 archived serum samples with predefined HBV genotypes (B, C and D).

Results

A total of 130 archived suspected HBV infected serum samples were detected by commercial qPCR with DNA extraction and RAA assay without DNA extraction (heat-treatment). Compared with qPCR assay as a reference, the RAA assay obtained 95.7% sensitivity and 100% specificity and a kappa value of 0.818.

Conclusions

We developed a rapid, convenient, highly sensitive and specific method to detect HBV without DNA extraction in clinical samples. This RAA method of HBV detection is very suitable for clinical testing.

Chronic hepatitis B genotype E in African migrants: response to nucleos(t)ide treatment in real clinical practice

Background

Hepatitis B virus (HBV) genotype E is a poorly studied genotype that almost exclusively occurs in African people. It seems to harbour intrinsic potential oncogenic activity and virological characteristics of immune scape but a paucity of information is available on clinical and virological characteristic of HBV genotype E-infected patients as well as on the efficacy of anti-HBV drugs for such patients. The increasing flow of migrants from high endemic HBV sub-Saharan Africa, where genotype E is the predominant one, to Western countries makes improving such knowledge critical in order to deliver proper medical care.

Methods

Prospective observational study of naïve patients of sub-Saharan origin treated for chronic HBV genotype E infection at a Tropical Medicine clinic sited in Spain from February 2004 to January 2018. The aim of the study was to describe the response of chronic HBV genotype E infection to nucleos(t)ide analogues (NA), entecavir or tenofovir, in real clinical practice.

Results

During the study period, 2209 sub-Saharan patients were assisted at our Tropical Medicine Unit and 609 (27.6%) had chronic HBV (CHB) infection. Genotype information was available for 55 naïve patients initiating treatment with NA (entecavir or tenofovir), 43 (84.3%) of them being genotype E, although 15 were excluded because they did not meet study inclusion criteria. Thus, a total of 28 CHB genotype E patients were included and followed for 24 months at least. Twenty-one patients were in HBeAg-negative chronic hepatitis phase and 7 patients in HBeAg-positive chronic hepatitis phase. After one year of treatment, among those with good adherence, 89.4% (17/19) of the HBeAg-negative patients and 80% of the HBeAg-positive ones had undetectable viral loads. Response rates reached 100% in both groups after 15–18 months of follow-up. Out of the 7 HBeAg-positive patients, 6 (85.7%) presented HBeAg loss in a median time of 31.8 months. Neither serious adverse effects nor hepatocarcinoma cases happened during the study period.

Conclusions

HBV genotype may influence disease progression and antiviral response. Our study provides precious information on the efficacy and safety of NA treatment for CHB genotype E infection, a fairly unknown genotype with and increasing epidemiological impact.

Genotype Matters in Patients with Acute-on-chronic Liver Failure Due to Reactivation of Chronic Hepatitis B

Background

Acute-on-chronic liver failure (ACLF) can be caused by reactivation of chronic hepatitis B virus (HBV) infection (HBV-ACLF). It’s unclear whether HBV genotypes affect the clinical and therapeutical outcomes of patients with HBV-ACLF. This study was to investigate the short-term antiviral response and overall survival in HBV-ACLF patients treated by tenofovir or entecavir.

Methods

Seventy-three consecutive patients with HBV-ACLF were stratified into genotype B group (n = 33) and C group (n = 40). They were prospectively followed-up.

Results

At 2 weeks, the genotype B group had significantly lower HBV-DNA load (P = 0.005), greater HBV-DNA decline (P = 0.026), higher proportion of patients with HBV-DNA < 500 IU/ml (P = 0.007), improved Child-Turcotte-Pugh (CTP; P = 0.032) and model for end-stage liver disease (MELD; P = 0.039) scores compared to the genotype C group. At three months, survivors in both groups had undetectable HBV-DNA loads, comparable CTP (P = 0.850) and MELD (P = 0.861) scores; the genotype C group had markedly lower overall survival rate than the B group (P = 0.013). The genotype (hazard ratio [HR]: 2.138; 95% confidence interval [CI]: 1.034–4.143; P = 0.041), MELD score (HR:1.664, 95%CI: 1.077–2.571; P = 0.022) and HBV-DNA decline (HR: 0.225, 95% CI: 0.067–0.758; P = 0.016) at 2 weeks were significantly associated with mortality at 3 months. No severe adverse event was noted.

Conclusions

Genotype B was associated with better short-term antiviral response and clinical outcome compared to genotype C in patients with HBV-ACLF.

Clinical features of hepatitis B e-antigen positive chronic hepatitis B patients co-existing precore and/or basal core promoter mutations

Aim: Characterize the clinical features of treatment-naive hepatitis B e-antigen (HBeAg)-positive chronic hepatitis B (CHB) patients harboring either precore (PC) or basal core promoter (BCP; PC/BCP) mutations. Methods: Alanine aminotransferase, HBsAg, HBV-DNA, HBV genotypes, PC/BCP mutations and liver stiffness measurement were assessed for 186 treatment-naive HBeAg-positive CHB patients. Results: PC/BCP mutations were found in 40.31% of the treatment-naive HBeAg-positive CHB patients. Patients with PC/BCP mutations showed significantly higher alanine aminotransferase and liver stiffness measurement levels. The serum HBsAg and HBV DNA levels in patients with BCP mutations were significantly lower than those in patients with wild-type virus. PC/BCP mutations were more prevalent in patients in immune clearance phase than those in immune tolerance phase. Conclusion: The emergences of PC/BCP mutations possibly indicate that HBeAg positive patients are experiencing the phase of immune clearance.

Differences in Cpg Island Distribution Between Subgenotypes of the Hepatitis B Virus Genotype

Background

Hepatitis B virus (HBV) genotypes show genomic variations, resulting in different CpG islands in each HBV genotypes or subgenotype. This study aimed to establish reference sequences for each HBV subgenotype of A–H genotypes and to analyze the characteristics of the CpG islands.

Material/Methods

There were 3,037 retrieved whole-genome sequences of HBV genotypes A–H from GenBank, 28 subgenotype reference sequences were established for these genotypes. CpG islands of the subgenotype reference sequences were analyzed, and 939 strains were selected from the 3,037 genomic sequences. Differences in CpG islands between subgenotypes were compared using the chi-squared and non-parametric tests.

Results

Of the 28 subgenotype reference sequences established, 11 subgenotype reference sequences lacked CpG island I, and only F4 contained a new CpG island. Of all selected strains, 48.35% (454/939) contained three traditional CpG islands I, II, and III (no new islands); 45.05% (423/939) lacked CpG island I; 38.98% (366/939) contained only CpG islands II and III; and 12.46% (117/939) contained new islands (genotypes A1, D7) (genotype G had no new islands). Strains with or without CpG island I, or new islands between subgenotypes of each HBV genotype were significantly different (P<0.05). Strains containing CpG islands I, II, and III and new islands among different subtypes in HBV genotypes A, C, and F were significantly different (P<0.05).

Conclusions

Different HBV genotypes and subgenotypes had characteristic CpG island patterns. Strains with or without CpG island I, or new islands among subgenotypes of each HBV genotype, were significantly different.

Serum hepatitis B surface antigen correlates with fibrosis and necroinflammation: A multicentre perspective in China

The kinetics of serum hepatitis B surface antigen (HBsAg) during the natural history of hepatitis B virus (HBV) infection has been studied, but the factors affecting them remain unclear. We aimed to investigate the factors affecting HBsAg titres, using data from multicentre, large-sized clinical trials in China. The baseline data of 1795 patients in 3 multicentre trials were studied, and the patients were classified into 3 groups: hepatitis B early antigen (HBeAg)-positive chronic HBV infection (n = 588), HBeAg-positive chronic hepatitis B (n = 596), and HBeAg-negative chronic hepatitis B (n = 611). HBsAg titres in the different phases were compared, and multiple linear progression analyses were performed to investigate the implicated factors. HBsAg titres varied significantly in different phases (P = .000), with the highest (4.60 log10 IU/mL [10%-90% confidence interval: 3.52 log10 IU/mL-4.99 log10 IU/mL]) in patients with HBeAg-positive chronic HBV infection. In all phases, age and HBV DNA were correlated with serum HBsAg level. In HBeAg-positive chronic hepatitis B patients, a negative correlation between HBsAg titres and fibrosis stage was observed. Alanine amonitransferase or necroinflammatory activity was also correlated with HBsAg titres in HBeAg-negative chronic hepatitis B patients. In conclusion, decreased HBsAg titres may be associated with advancing fibrosis in HBeAg-positive chronic hepatitis B patients or increased necroinflammation in those with HBeAg-negative chronic hepatitis B. Our findings may help clinicians better understand the kinetics of HBsAg and provide useful insights into the management of this disease.

Host and Viral Genetic Variation in HBV-Related Hepatocellular Carcinoma

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

Applications of next-generation sequencing analysis for the detection of hepatocellular carcinoma-associated hepatitis B virus mutations

BACKGROUND

Next-generation sequencing (NGS) is a powerful and high-throughput method for the detection of viral mutations. This article provides a brief overview about optimization of NGS analysis for hepatocellular carcinoma (HCC)-associated hepatitis B virus (HBV) mutations, and hepatocarcinogenesis of relevant mutations.

MAIN BODY

For the application of NGS analysis in the genome of HBV, four noteworthy steps were discovered in testing. First, a sample-specific reference sequence was the most effective mapping reference for NGS. Second, elongating the end of reference sequence improved mapping performance at the end of the genome. Third, resetting the origin of mapping reference sequence could probed deletion mutations and variants at a certain location with common mutations. Fourth, using a platform-specific cut-off value to distinguish authentic minority variants from technical artifacts was found to be highly effective. One hundred and sixty-seven HBV single nucleotide variants (SNVs) were found to be studied previously through a systematic literature review, and 12 SNVs were determined to be associated with HCC by meta-analysis. From comprehensive research using a HBV genome-wide NGS analysis, 60 NGS-defined HCC-associated SNVs with their pathogenic frequencies were identified, with 19 reported previously. All the 12 HCC-associated SNVs proved by meta-analysis were confirmed by NGS analysis, except for C1766T and T1768A which were mainly expressed in genotypes A and D, but including the subgroup analysis of A1762T. In the 41 novel NGS-defined HCC-associated SNVs, 31.7% (13/41) had cut-off values of SNV frequency lower than 20%. This showed that NGS could be used to detect HCC-associated SNVs with low SNV frequency. Most SNV II (the minor strains in the majority of non-HCC patients) had either low (< 20%) or high (> 80%) SNV frequencies in HCC patients, a characteristic U-shaped distribution pattern. The cut-off values of SNV frequency for HCC-associated SNVs represent their pathogenic frequencies. The pathogenic frequencies of HCC-associated SNV II also showed a U-shaped distribution. Hepatocarcinogenesis induced by HBV mutated proteins through cellular pathways was reviewed.

CONCLUSION

NGS analysis is useful to discover novel HCC-associated HBV SNVs, especially those with low SNV frequency. The hepatocarcinogenetic mechanisms of novel HCC-associated HBV SNVs defined by NGS analysis deserve further investigation.

Effect of hepatitis B virus subgenotype on antiviral response in nucleoside-treated hepatitis B envelope antigen-positive patients

AIM

Previous studies have reported that hepatitis B virus (HBV) genotype is not a predictor of treatment response with nucleos(t)ide analog therapy. However, the impact of subgenotype on treatment response is unknown. The aim of this study is to identify the effect of HBV subgenotype on treatment response.

METHODS

In this retrospective study, the derivation dataset comprised patients from the EFFORT study (NCT00962533) telbivudine monotherapy group; patients infected with genotypes B or C from the GLOBE (NCT00057265) and 015 (NCT00131742) studies formed the validation dataset. The HBV subgenotypes were determined using phylogenetic analysis based on the surface or overlapping polymerase gene. Molecular modeling was used to investigate relationships between positions of the substitutions within reverse transcriptase and genotypic resistance.

RESULTS

Of the patients in the derivation dataset, 110, 24, 162, and 1 patients were classified as having HBV subgenotypes B2, C1, C2, or other, respectively, compared to 222, 146, 282, and 51 in the validation dataset, respectively. Patients infected with subgenotype C1 showed a higher virologic response rate and hepatitis B envelope antigen seroconversion rate, and lower genotypic resistance rate than those infected with subgenotypes B2 and C2. Patients with genotypic resistance to telbivudine with subgenotype C1 showed fewer secondary mutations. The crystal structure model of reverse transcriptase showed that these secondary mutations were located around the YMDD motif, which possibly influenced the chance of mutations at rtM204.

CONCLUSION

Hepatitis B virus subgenotype C1 is associated with better antiviral response to nucleoside analogs in hepatitis B envelope antigen-positive patients than B2 and C2 subgenotypes. The exact mechanism needs to be explored further.

Nucleos(t)ide Analogue Treatment for Patients With Hepatitis B Virus (HBV) e Antigen-Positive Chronic HBV Genotype C Infection: A Nationwide, Multicenter, Retrospective Study

Background

Antiviral treatment for hepatitis B virus (HBV) e antigen (HBeAg)-positive chronic HBV infection is still controversial. We assessed whether antiviral treatment reduces the risk of liver disease progression in these patients.

Methods

This study included consecutive patients in 8 large-volume hospitals in Korea who tested positive for HBeAg and had an HBV DNA level of >20000 IU/mL, an alanine aminotransferase (ALT) level of <40 IU/L, and no evidence of cirrhosis. The primary end point was the development of hepatocellular carcinoma (HCC), and the secondary end point was the development of cirrhosis.

Results

A total of 484 patients were included: 87 were in the antiviral treatment group, and 397 were in the control group. Baseline liver function was significantly more favorable for the control group. After matching for propensity score to overcome those differences, the antiviral treatment group had a significantly reduced risk for HCC (hazard ratio [HR], 0.234; log-rank P = .046) and cirrhosis (HR, 0.235; log-rank P = .015), compared with the control group. After balancing the baseline characteristics by using inverse probability weighting, antiviral therapy significantly decreased the risk of HCC (HR, 0.189; log-rank P = .004) and cirrhosis (HR, 0.347; log-rank P = .036).

Conclusion

Antiviral therapy for patients with HBeAg-positive chronic HBV infection and have a high HBV load reduces the risk of HCC, even if the ALT level is below the upper limit of normal.

How viral genetic variants and genotypes influence disease and treatment outcome of chronic hepatitis B. Time for an individualised approach?

Chronic hepatitis B virus (HBV) infection remains a global problem. Several HBV genotypes exist with different biology and geographical prevalence. Whilst the future aim of HBV treatment remains viral eradication, current treatment strategies aim to suppress the virus and prevent the progression of liver disease. Current strategies also involve identification of patients for treatment, namely those at risk of progressive liver disease. Identification of HBV genotype, HBV mutants and other predictive factors allow for tailoured treatments, and risk-surveillance pathways, such as hepatocellular cancer screening. In the future, these factors may enable stratification not only of treatment decisions, but also of patients at risk of higher relapse rates when current therapies are discontinued. Newer technologies, such as next-generation sequencing, to assess drug-resistant or immune escape variants and quasi-species heterogeneity in patients, may allow for more information-based treatment decisions between the clinician and the patient. This article serves to discuss how HBV genotypes and genetic variants impact not only upon the disease course and outcomes, but also current treatment strategies. Adopting a personalised genotypic approach may play a role in future strategies to combat the disease. Herein, we discuss new technologies that may allow more informed decision-making for response guided therapy in the battle against HBV.

Chronic hepatitis B carriers with acute on chronic liver failure show increased HBV surface gene mutations, including immune escape variants

Background

The pathogenesis of acute-on-chronic liver failure (ACLF) in chronic hepatitis B (CHB) is not well understood. The aim of this study was to investigate whether there is an association between HBV polymerase (P)/overlapping surface (S) gene and basal core promoter (BCP)/precore (PC) variants and development of ACLF in CHB.

Methods

Two CHB patient cohorts were compared: (i) ACLF (N = 12) (11/12 M, median age 52 yrs., 5/9 genotype C, 6/12 HBeAg+), (ii) 27 treatment native CHB carriers (15/27 M, median age 44 yrs., 9 genotype B, 10 genotype C, 1 genotype A, 5 genotype D, 2 genotype E). Clonal sequencing of PCR-amplified HBV P/S and BCP/PC gene fragments was done and HBV diversity, frequency of immune escape (IE) and drug resistance (DR) mutations and mutations in BCP/PC gene (G1896A and A1762T/G1764A), were compared between each group.

Results

Our data showed the incidence of IE and clusters of mutations in the HBV S region was significantly greater in ACLF patients vs. treatment naïve CHB patients (p < 0.05). Additionally, a significantly higher frequency of G1896A and A1762T/G1764A mutations were found in HBeAg negative than in ACLF patients (p < 0.0001).

Conclusion

In our study, ACLF was not associated with a specific genomic mutation. However, higher frequency of IE mutations along with various mutations clustering in the HBV S region could contribute to or be an outcome of ACLF in CHB infection. (words 226).

Electronic supplementary material

The online version of this article (10.1186/s12985-017-0870-x) contains supplementary material, which is available to authorized users.

Chronologic changes in serum hepatitis B virus DNA, genotypes, surface antigen mutants and reverse transcriptase mutants during 25-year nationwide immunization in Taiwan

We investigated breakthrough infection and hepatitis B virus (HBV) genetic changes in immunized subjects after 25 years of a universal infant immunization. Specifically, serum HBV DNA, genotypes, surface antigen mutants and nucleoside analog-resistant (NAr) mutants were assessed in 2853 subjects (<25 years old) surveyed in 2009, and these data were compared with the data from previous serosurveys. A comparison across different age-stratified groups using the 2009 data revealed a significant increase in the seropositive rate of anti-HBc (5.51% vs 12.38%, P=.001) and HBV DNA (1.13% vs 3.96%, P=.007) between those 17-22 and 23-24 years of age, possibly due to selective infant immunization in 1984-1986. Well-characterized NAr mutants, potential NAr mutants and surface "a" determinant mutants were detected in none, 15 (45.5%) and nine (27.3%) of 33 HBV DNA-positive subjects, respectively. Of 15 immunized, HBV DNA-positive young adults (18-24 years), three (20%) carried "a" determinant mutants. Amongst 1176 HBsAg-negative subjects evaluated for occult HBV infection, those seropositive for anti-HBc had a higher seropositive rate for HBV DNA (10/110, 9.1% vs 7/1066, 0.66%; P<.001) and "a" determinant mutants (4/110, 3.6% vs 0/1066; P<.001) than those seronegative for anti-HBc. Overall, the HBsAg-positive subjects in six serosurveys showed no significant increase in genotype C frequency in the comparison between the vaccinated and unvaccinated cohorts (25/98, 25.5% versus 14/79, 17.7%, P=.188). Over the 25-year programme, there was no increase in the prevalence of genotype C in HBsAg carriers and no increase in breakthrough HBV infection or surface mutant prevalence beyond adolescence. Nucleic acid amplification should still be considered the primary screening method for occult hepatitis B detection in high-risk recipients.

The virological aspects of hepatitis B

Human hepatitis B virus (HBV) is a hepatotropic virus that is responsible for a significant burden of disease, causing liver disease and hepatocellular carcinoma. It is a small DNA virus with a replication strategy that is similar to that of a retrovirus. HBV is prone to mutagenesis and under the influence of diverse selection pressures, has evolved into a pool of quasispecies, genotypes and mutants, which confers a significant survival advantage. The genome is small, circular, and compact but has a complex replication strategy. The viral life cycle involves the formation of a covalently closed circular DNA (cccDNA), which is organized into a minichromosome that is the template for the synthesis of viral mRNA. HBV DNA (double-stranded linear form) can also integrate into the host genome, ensuring lifelong persistence of the virus. To date, despite great advances in therapeutics, once HBV is chronically established, it is incurable. This is by virtue of many aspects of its virological structure and viral life cycle. In this review, we aim to discuss important aspects of the virology of HBV with a focus on clinical implications.

The Envelope Gene of Hepatitis B Virus Is Implicated in Both Differential Virion Secretion and Genome Replication Capacities between Genotype B and Genotype C Isolates

Chronic infection by hepatitis B virus (HBV) genotype C is associated with a prolonged replicative phase and an increased risk of liver cancer, compared with genotype B infection. We previously found lower replication capacity but more efficient virion secretion by genotype C than genotype B isolates. Virion secretion requires interaction between core particles and ENVELOPE proteins. In the present study, chimeric constructs between genotype B and genotype C clones were generated to identify the structural basis for differential virion secretion. In addition to dimeric constructs, we also employed 1.1mer constructs, where the cytomegalovirus (CMV) promoter drove pregenomic RNA transcription. Through transient transfection experiments in Huh7 cells, we found that exchanging the entire envelope gene or just its S region could enhance virion secretion by genotype B clones while diminishing virion secretion by genotype C. Site-directed mutagenesis established the contribution of genotype-specific divergence at codons 108 and 115 in the preS1 region, as well as codon 126 in the S region, to differential virion secretion. Surprisingly, exchanging the envelope gene or just its S region, but not the core gene or 3′ S region, could markedly increase intracellular replicative DNA for genotype C clones but diminish that for genotype B, although the underlying mechanism remains to be clarified.

Differential regulation of hepatitis B virus core protein expression and genome replication by a small upstream open reading frame and naturally occurring mutations in the precore region

Hepatitis B virus (HBV) transcribes two subsets of 3.5-kb RNAs: precore RNA for hepatitis B e antigen (HBeAg) expression, and pregenomic RNA for core and P protein translation as well as genome replication. HBeAg expression could be prevented by mutations in the precore region, while an upstream open reading frame (uORF) has been proposed as a negative regulator of core protein translation. We employed replication competent HBV DNA constructs and transient transfection experiments in Huh7 cells to verify the uORF effect and to explore the alternative function of precore RNA. Optimized Kozak sequence for the uORF or extra ATG codons as present in some HBV genotypes reduced core protein expression. G1896A nonsense mutation promoted more efficient core protein expression than mutated precore ATG, while a +1 frameshift mutation was ineffective. In conclusion, various HBeAg-negative precore mutations and mutations affecting uORF differentially regulate core protein expression and genome replication.

Clinical Features of Chronic Hepatitis B in Treatment-naive Asian Patients With Positive HBeAg and Coexisting Precore and/or Basal Core Promoter Mutations

BACKGROUND

Precore or/and basal core promoter (PC/BCP) mutations are frequently detected in hepatitis B e antigen (HBeAg)-negative patients, but little is known about their clinical significance in HBeAg-positive patients.

AIM

To characterize and report the clinical features of treatment-naive chronic hepatitis B patients who are HBeAg positive and harbor PC and/or BCP mutations.

PATIENTS AND METHODS

Consecutive treatment-naive patients with chronic hepatitis B between 2004 and 2014 were enrolled. Clinical characteristics were compared based on the stratification of HBeAg status and the presence of PC/BCP mutations. In addition, subset analysis in HBeAg-positive cohort was performed to compare clinical features of patients with and without PC/BCP mutations RESULTS:: Of the 267 patients enrolled from 3 centers, 177 were HBeAg positive and 90 HBeAg negative. When compared with HBeAg-negative patients, HBeAg-positive patients were significantly younger in mean age (37.93 vs. 44.40; P<0.001), had higher levels of median ALT (51 vs. 30.5 U/mL; P<0.001), higher levels of mean HBV DNA (7.50±1.48 vs. 5.10±1.44 log10 copies/mL; P<0.001), and lower frequency of detectable PC/BCP mutations (60.45% vs. 93.33%; P<0.001), but had significantly higher frequency of BCP when mutations were detected (37.85% vs. 22.22%; P=0.013). Among HBeAg-positive patients, when compared with patients with wild type, those with PC/BCP mutations were significantly older (30.63 vs. 42.71; P<0.001), had higher median ALT levels (29.5 vs. 73 U/mL; P<0.001), but there was no significant association with mean HBV DNA levels (7.96 vs. 7.20 log10 copies/mL; P=0.865) or HBV genotype (P=1.000). In the multivariate analysis, only age and ALT were independently associated with PC/BCP mutations in HBeAg-positive patients, but there was no association with HBV genotype or DNA.

CONCLUSIONS

PC/BCP mutants were frequent (up to 60%) in treatment-naive HBeAg-positive patients and were associated with distinct clinical characteristics when compared with patients with wild type or HBeAg negative. Future large studies are needed to substantiate the long-term clinical outcomes when PC/BCP mutations are detected in HBeAg-positive patients as it may impact the natural history or treatment response in such patients.

A noninvasive model to predict liver histology in HBeAg-positive chronic hepatitis B with alanine aminotransferase ≤ 2upper limit of normal

BACKGROUND AND AIM

Liver biopsy remains the gold standard to evaluate liver histology. However, it has several limitations. This study aims to construct a noninvasive model to predict liver histology for commencing antiviral therapy in HBeAg-positive chronic hepatitis B (CHB) with aminotransferase (ALT) ≤ 2 upper limit of normal (ULN).

METHODS

Two hundred and ninety-eight patients with HBeAg-positive CHB, ALT ≤ 2ULN and HBV-DNA ≥20 000 IU/ml were enrolled and randomly divided into a training group and a validation group. A noninvasive model was constructed in the training group to predict significant liver histological change [necroinflammatory activity grade (G) ≥ 2 or fibrosis stage (S) ≥ 2] and then validated in the validation group.

RESULTS

Aspartate aminotransferase, HBsAg, platelet, and albumin were identified as independent predictors. A model was constructed by them. It had an area under the receiver operating characteristic curve of 0.875 in the training group, 0.858 in the validation group and 0.868 in the entire cohort. Using a cut-off point of -0.96, it showed 93% sensitivity, 90% negative predictive value (NPV) in the training group and 95% sensitivity, 94% NPV in the validation group. Using a cut-off point of 0.96, it showed 95% specificity, 91% positive predictive value (PPV) in the training group and 89% specificity, 80% PPV in the validation group.

CONCLUSIONS

This study constructed a noninvasive model to predict liver histology in HBeAg-positive CHB with ALT ≤ 2ULN, which might reduce the clinical need for liver biopsy.

Generation of Replication-Competent Hepatitis B Virus Genome from Blood Samples for Functional Characterization

Hepatitis B virus (HBV) infection can be associated with a spectrum of clinical outcomes. Transient transfection of the clinical HBV isolates in human hepatoma cell lines can establish their biological properties to shed light on their different pathogenic potentials, yet very few clinical HBV isolates have been functionally characterized so far. The technical challenges include faithful amplification of the full-length HBV genome from clinical samples and conversion into a replication-competent form. We have improved a published method to amplify the full-length HBV genome from blood samples. Two alternative approaches are used to render the cloned HBV genome replication competent: release and circularization of the 3.2-kb HBV genome prior to each transfection experiment or conversion of the monomeric clone into a tandem dimer version.

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.