Prevalence of HBV precore/core promoter variants in the United States

Hepatitis B Immunization Status in Children with Chronic Kidney Disease: Experience at a Single Center, Egypt

Background: Children with chronic kidney disease (CKD), particularly those who require hemodialysis (HD), are at high risk of hepatitis B virus (HBV) infection. The HBV vaccine non-/hypo-response rate among HD children remains high, and it is critical to investigate the influencing factors and their linkages. The aim of this study was to identify the pattern of HB vaccination response in HD children and to analyze the interference of various clinical and biomedical factors with the immunological response to HB vaccination. Methods: This cross-sectional study included 74 children on maintenance hemodialysis, aged between 3 and 18 years. These children were subjected to complete clinical examination and laboratory investigations. Results: Out of a total of 74 children with HD, 25 (33.8%) were positive for the HCV antibody. Regarding the immunological response to hepatitis B vaccine, 70% were non-/hypo-responders (≤100 IU/mL) and only 30% mounted a high-level response (more than 100 IU/mL). There was a significant relation between non-/hypo-response and sex, dialysis duration, and HCV infection. Being on dialysis for more than 5 years and being HCV Ab-positive were independent variables for non-/hypo-response to HB vaccine. Conclusions: Children with CKD on regular HD have poor seroconversion rates in response to the HBV vaccine, which were influenced by dialysis duration and HCV infection.

Regulatory function of interferon-inducible 44-like for hepatitis B virus covalently closed circular DNA in primary human hepatocytes

AIM

Curing hepatitis B virus (HBV) infection requires elimination of covalently closed circular DNA (cccDNA). Interferon (IFN)-γ has noncytolytic antiviral potential; however, elimination of cccDNA could not be achieved. To enhance the regulatory effect, we comprehensively analyzed the host factors associated with cccDNA amplification and IFN-γ and IFN-α effects using an in vitro HBV infection system showing various transcription levels.

METHODS

Primary human hepatocytes were infected with HBV using genomic plasmids carrying the basic core promoter mutation A1762T/G1764A and/or the precore mutation G1896A and treated with IFN-γ and IFN-α. Comprehensive and functional studies involving microarray and small interfering RNA analysis revealed the host factors related to cccDNA regulation.

RESULTS

The HBV infection system reproduced the HBV life cycle and showed various propagation levels. Microarray analysis revealed 53 genes correlated with the cccDNA levels. Of the 53 genes, expression of IFN-induced protein 44-like (IFI44L) was significantly upregulated by IFN-γ and IFN-α. The anti-HBV effect of IFI44L is exerted regardless of IFN-γ or IFN-α by inhibiting the activation of nuclear factor-κB and signal transducer and activator of transcription 1 pathways.

CONCLUSIONS

Using the in vitro HBV infection system, an IFN-inducible molecule, IFI44L, associated with cccDNA amplification, was identified. These results suggest an innovative molecular strategy for the regulation of HBV cccDNA by controlling a novel host factor, IFI44L.

Precore and Basal Core Promoter Hepatitis B Virus (HBV) Variants Are Present From a Young Age and Differ Across HBV Genotypes

BACKGROUND AND AIMS

Hepatitis B virus (HBV) precore (PC) and dual basal core promoter (BCP) mutations halt and down-regulate hepatitis B e antigen (HBeAg) production respectively. PC mutation is rarely associated with HBV genotype A. We sought to examine the association of these variants with HBV genotypes, age, and HBeAg status in a racially diverse population in North America. Prospective study included 1,036 (808 adults, 228 children) participants in the Hepatitis B Research Network. PC and BCP variants were determined by Sanger sequencing, and dominant HBV species (>50%) were reported.

APPROACH AND RESULTS

Median age was 36.3 years (range, 2-80), 44.6% HBeAg(+), 74.2% Asians, 13.3% black, and 9.7% white. The dominant PC variant was present in 29.4% participants, including 20 with subgenotype A1 or A2. Seventeen of 20 participants with genotype A and PC had a compensatory C1858T mutation. In the HBeAg(+) cohort, the prevalence of PC and/or BCP variants increased from 14.4% in the first two decades to 51% after 40 years of age. Among those aged 2-18, 52% and 83% with dominant PC and BCP variants were HBeAg(+) compared to 3.8% and 29% in the >40 years age group. HBeAg clearance rates were significantly higher for those with dominant PC or BCP variants: 24.4 and 15.0 per 100 person-years compared to 6.0 in wild-type HBV (P < 0.0001).

CONCLUSIONS

PC variants can be present in HBV genotype A and are usually associated with C1858T, which preserves the pregenome encapsidation sequence. Selection of PC and BCP variants occurred at a young age, with increasing prevalence across age groups. HBeAg(+) participants with dominant PC and BCP variants progressed to the HBeAg(-) phase of chronic HBV infection significantly faster. This finding has potential clinical and therapeutic implications.

The Occurrence of rtA194T Mutant After Long-Term Lamivudine Monotherapy Remains Sensitive to Tenofovir Disoproxil Fumarate: A Case Report

Tenofovir disoproxil fumarate (TDF) is recommended as first-line agents in chronic hepatitis B (CHB) patients for its high antiviral effects and high barrier to resistance. It is controversial whether the rtA194T mutation truly confers resistance against TDF. We present here a 62-year-old CHB patient who occurred rtL180M, rtM204V and rtA194T mutants after lamivudine (LAM) monotherapy for 9 years. TDF was introduced in replacement of LAM and led to Hepatitis B Virus (HBV) DNA undetectable in 1 month, maintained in the follow up of 52 weeks. These observations suggest that rtA194T mutation emerges under LAM monotherapy and remains sensitive to TDF.

Three Heads are Better than Two: HBcrAg as a New Predictor of HBV-related HCC

Patients with chronic hepatitis B virus (HBV) infection are at risk of developing hepatocellular carcinoma (HCC), and serum markers reflecting viral replication are potential predictors for HCC development. Besides the levels of serum HBV DNA and hepatitis B surface antigen (HBsAg), hepatitis B core-related antigen (HBcrAg) quantification is an emerging serological marker for viral replication. Unlike HBV DNA and HBsAg, HBcrAg is a covalently closed circular DNA-derived protein marker, consisting of hepatitis B e antigen (HBeAg), p22cr, and hepatitis B core antigen. In treatment-naïve HBV patients, higher HBcrAg levels are shown to be associated with an increased risk of HCC in several studies. More importantly, HBcrAg may complement HBV DNA level to predict HCC development. For example, an Asian treatment-naïve cohort study’s data showed that HBcrAg level of 4 log U/mL was effective to stratify HCC risk in HBeAg-negative patients with intermediate viral loads, who may not need antiviral therapy because of the low to moderate risk of HCC. In patients receiving prolonged nucleos(t)ide analogue with profound viral suppression, most data indicated that HBV DNA and HBsAg levels no longer serve as HCC predictors. However, several studies suggested on-treatment HBcrAg levels may remain as an HCC predictor. In summary, HBcrAg level can be a useful biomarker for treatment-naïve patients, but its value in on-treatment patients needs validation. The next challenge is how to combine HBcrAg with the other viral markers to construct a better HCC prediction model, optimizing the management of HBV patients.

The treatment outcome of chronic HBV infection among HBV/HIV co-infected and HBV mono-infected patients

The aim of this study was to analyze the treatment response of hepatitis B virus (HBV) to lamivudine and tenofovir disoproxil fumarate in HBV/HIV co-infected patients in comparison to HBV mono-infected patients. This study was conducted at the University Hospital for Infectious and Tropical Diseases in Belgrade from January 2000 until December 2017 and included all patients with chronic hepatitis B who received antiviral therapy. All patients initially treated with lamivudine were switched to tenofovir if lamivudine failure occurred. A patient was considered to have achieved a full treatment response if the level of HBV DNA was lower than 20 IU/ml or undetectable. HBs and HBe antigen loss and HBs seroconversion were also monitored. After a mean duration of lamivudine-containing antiretroviral therapy (ART) of 4.87 ± 3.48 years and lamivudine mono-therapy of 4 ± 2.52 years, failure was recorded in 82.1% and 79.3% of patients, respectively. HBV viral loads were 20 ± 32 IU/ml and 3 ± 13 IU/ml after 2.49 ± 1.56 years of tenofovir-containing ART and 1.9 ± 1.13 years of tenofovir mono-therapy, respectively. Overall mean treatment duration, taking both lamivudine- and tenofovir-based regimens into account, was 4.18 ± 2.72 and 6.17 ± 3.63 years in the mono- and co-infected patients, respectively ( p = 0.02).

HBV T1719G mutation reduced HBV replication through mutant Enh II and HBx protein in vitro

It was repeatedly reported that the hepatitis B virus (HBV) T1719G mutation was very common and related to progression and malignancy of liver disease. However, its effect on viral replication efficiency remains unclear. In this study, we aimed to evaluate the function and mechanisms of the T1719G mutation on viral replication capacity. Wild-type and T1719G mutation-bearing HBV1.2× plasmids were transfected into Huh7 and HepG2 cells, respectively, and HBV total RNA, 3.5 kb RNA and supernatant HBV DNA were assessed using real-time PCR, hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) levels were measured by time-resolved fluoroimmunoassay. In order to assess Enh II activity and the binding capacity of HNF3β to Enh II sequence, dual-luciferase assay and Chromatin immunoprecipitation (ChIP)-PCR were employed, respectively. Simultaneously, the HBx or HBx-mut (T1719G) plasmid was co-transfected to evaluate the effect of HBx on viral replication. Our results showed that the T1719G mutation impaired viral replication efficacy compared with the wild type both by reducing Enh II activity and binding capacity of HNF3β with Enh II. And such reduction caused by T1719G mutation could be rescued by HBx protein. Our results show that the T1719G mutation decreases HBV viral replication capacity possibly by mutant HBx protein and altered Enh II activity.

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.

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.

Naturally occurring hepatitis B virus reverse transcriptase mutations related to potential antiviral drug resistance and liver disease progression

The annual number of deaths caused by hepatitis B virus (HBV)-related disease, including cirrhosis and hepatocellular carcinoma (HCC), is estimated as 887000. The reported prevalence of HBV reverse transcriptase (RT) mutation prior to treatment is varied and the impact of preexisting mutations on the treatment of naïve patients remains controversial, and primarily depends on geographic factors, HBV genotypes, HBeAg serostatus, HBV viral loads, disease progression, intergenotypic recombination and co-infection with HIV. Different sensitivity of detection methodology used could also affect their prevalence results. Several genotype-dependent HBV RT positions that can affect the emergence of drug resistance have also been reported. Eight mutations in RT (rtL80I, rtD134N, rtN139K/T/H, rtY141F, rtM204I/V, rtF221Y, rtI224V, and rtM309K) are significantly associated with HCC progression. HBeAg-negative status, low viral load, and genotype C infection are significantly related to a higher frequency and prevalence of preexisting RT mutations. Preexisting mutations are most frequently found in the A-B interdomain of RT which overlaps with the HBsAg “a” determinant region, mutations of which can lead to simultaneous viral immune escape. In conclusion, the presence of baseline RT mutations can affect drug treatment outcomes and disease progression in HBV-infected populations via modulation of viral fitness and host-immune responses.

Hepatitis B virus e antigen-negative chronic infection. Treatment based on glutamic pyruvic transaminase and hepatitis B virus deoxyribonucleic acid cut-off values

OBJECTIVES

To identify glutamic pyruvic transaminase (GPT) and hepatitis B virus DNA (HBV-DNA) cut-off values at diagnosis in patients with hepatitis B virus e antigen-negative chronic infection (HBeAg(-)), which may be predictors of clinical course, prognosis and/or the need for antiviral therapy.

METHODS

A retrospective and observational cohort study of patients diagnosed with HBeAg(-) chronic infection (2005-2012). A normal GPT cut-off value at diagnosis that predicts abnormal GPT values in the clinical course of the infection, a baseline HBV-DNA cut-off value that predicts an increase in HBV-DNA above 2,000IU/ml, and GPT and HBV-DNA as predictors of the need for treatment were investigated using ROC curves.

RESULTS

126 patients were enrolled (follow-up: 42.1±21.5months), 93 of which had normal GPT levels at diagnosis. In the ROC curve analysis, 900IU/ml was found to be the HBV-DNA cut-off value that best predicted this value's increase above 2,000IU/ml (sensitivity: 90%; specificity: 88%; PPV: 79%; NPV: 100%; diagnostic precision: 89%), while 25mU/ml was the normal GPT cut-off value at diagnosis that best predicted subsequently elevated GPT levels (sensitivity: 95.4%; specificity: 81.6%; PPV: 67%; NPV: 96%; diagnostic precision: 80.6%). Patients with GPT 26-40mU/ml at diagnosis presented with more complications or required more treatment than subjects with GPT≤25mU/ml (P<.05). The combined GPT and HBV-DNA values that elicited the highest treatment need were 38mU/ml of GPT and 6,000IU/ml of HBV-DNA (sensitivity: 75%; specificity: 93.4%; PPV: 60%; NPV: 96.6%).

CONCLUSION

HBeAg(-) patients with GPT<25mU/ml and HBV-DNA<900IU/ml at diagnosis have positive outcomes and may not require such stringent follow-up in the first years after diagnosis.

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.

Hepatitis B virus sequencing and liver fibrosis evaluation in HIV/HBV co-infected Nigerians

OBJECTIVES

Molecular characteristics of hepatitis B virus (HBV), such as genotype and genomic mutations, may contribute to liver-related morbidity and mortality. The association of these characteristics with liver fibrosis severity in sub-Saharan Africa is uncertain. We aimed to characterise molecular HBV features in human immunodeficiency virus (HIV)/HBV co-infected Nigerians and evaluate associations between these characteristics and liver fibrosis severity before and after antiretroviral therapy (ART) initiation.

METHODS

HIV/HBV co-infected Nigerians underwent liver fibrosis estimation by transient elastography (TE) prior to and 36 months after ART initiation. Basal core promoter/precore (BCP/PC) and preS1/preS2/S regions of HBV were sequenced from baseline plasma samples. We evaluated associations between HBV mutations and liver fibrosis severity by univariate and multivariable regression.

RESULTS

At baseline, 94 patients underwent TE with median liver stiffness of 6.4 (IQR 4.7-8.7) kPa. Patients were predominantly infected with HBV genotype E (45/46) and HBe-antigen negative (75/94, 79.8%). We identified BCP A1762T/G1764A in 15/35 (43%), PC G1896A in 20/35 (57%), 'a' determinant mutations in 12/45 (26.7%) and preS2 deletions in 6/16 (37.5%). PreS2 mutations were associated with advanced fibrosis in multivariable analysis. At follow-up, median liver stiffness was 5.2 (IQR 4.1-6.6) kPa. No HBV molecular characteristics were associated with lack of fibrosis regression, although HIV virologic control, body mass index (BMI) and baseline CD4+ T-cell count were associated with a decline in fibrosis stage.

CONCLUSION

Frequent BCP/PC and preS1/preS2/S mutations were found in ART-naïve HIV/HBV co-infected Nigerians. Median liver stiffness declined after initiation of ART, regardless of pre-ART HBV mutational pattern or virologic characteristics.

A combination of different diagnostic tools allows identification of inactive hepatitis B virus carriers at a single time point evaluation

BACKGROUND & AIMS

Serial evaluation of hepatitis B virus (HBV) DNA and aminotransferase values is required for identification of inactive HBV carriers (ICs). Recently, HBV surface antigen quantification (qHBsAg) and liver stiffness measurement (LSM) have been proposed as diagnostic tools in chronic HBV infection. The aim of this study was to evaluate the efficacy of HBV DNA quantification, qHBsAg and LSM in diagnosing ICs at a single time point.

METHODS

Fifty-seven previously characterized ICs and 90 untreated HBsAg-/anti-HBe-positive patients [49 chronic hepatitis (CH), 41 cirrhosis] were enrolled. HBV DNA ≤2000 IU/mL, LSM ≤6.2 kPa and qHBsAg ≤1000 IU/mL were used as cut-offs to evaluate sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy (DA).

RESULTS

Combined HBV DNA quantification and qHBsAg correctly identified 30/57 (52.6%) ICs showing 94% sensitivity, 96% specificity, 98% PPV, 87% NPV and 95% DA. HBV DNA coupled with LSM identified 40/57 (70.2%) ICs showing 97% sensitivity, 97% specificity, 98% PPV, 95% NPV and 97% DA. Combined LSM and qHBsAg identified 33/57 (57.9%) ICs showing 95% sensitivity, 78% specificity, 89% PPV, 89% NPV and 89% DA. The evaluation of the three parameters altogether allowed the identification of 23/57 (40.3%) ICs showing 100% specificity, 96% sensitivity, 100% PPV, 92% NPV and 97% DA. Similar results were obtained when either CH or cirrhotic patients were excluded from the analysis.

CONCLUSIONS

Combined evaluation of HBV DNA amount with LSM and/or qHBsAg is a highly reliable tool allowing the identification of a considerable number of HBV ICs at a single time point evaluation.

Prevalence and Characteristics of Basal Core Promoter Mutations in Iran and its Correlation with Acute and Chronic Hepatitis B Infection

Introduction

Manifestations of HBV infection differ in chronic and acute phases. Therefore, identifying the determinants such as mutations has a vital role in the treatment of the disease. A dual transversion in the basal core promoter (BCP) region is common among HBV patients. Thus, the present study was conducted with the objective of determining the prevalence of basal core promoter (BCP) mutations and its correlation with the outcome of HBV infection.

Method

In this cross-sectional study, samples were obtained from 182 Iranian HBsAg positive patients who were admitted to the Bandar Abbas Blood Transfusion Organization in 2012 and 2013. They were screened by ELISA test using commercial kits to detect serological marker anti-HBc IgM for distinct chronic hepatitis from acute infection. Thereafter, the extracted DNA was used for determination of the BCP mutations by PCR-RFLP technique. Data analyses were performed with SPSS 12 by Mann–Whitney U test, Fisher’s exact probability test, and t-test.

Results

BCP mutations were observed in 15 samples (8.24%) of the study population, and serological tests determined that, among the BCP mutants, one sample (6.67%) was HBeAg positive, 14 samples (93.33%) were HBeAg negative, and four samples (2.2%) were positive for anti-HBc IgM test. Data analysis indicated a statistically significant association between BCP mutations and acute hepatitis (p=0.002). However, no relationship was detected between the prevalences of the BCP mutations and gender of subjects (p>0.567).

Conclusions

The prevalence of BCP variants was low in the south of Iran, and this mutation can lead to acute phase of viral hepatitis.

A novel hepatitis B virus subgenotype D10 circulating in Ethiopia

Hepatitis B virus (HBV) is genetically highly divergent and classified in ten genotypes and forty subgenotypes in distinct ethno-geographic populations worldwide. Ethiopia is a country with high HBV prevalence; however, little is known about the genetic variability of HBV strains that circulate. Here, we characterize the complete genome of 29 HBV strains originating from five Ethiopian regions, by 454 deep sequencing and Sanger sequencing. Phylogenetically, ten strains were classified as genotype A1 and nineteen as genotype D. Fifteen genotype D strains, provisionally named subgenotype D10, showed a novel distinct cluster supported by high bootstrap value and >4% nucleotide divergence from other known subgenotypes. In addition, the novel D10 strains harboured nine unique amino acid signatures in the surface, polymerase and X genes. Seventy-two per cent of the genotype D strains had the precore premature stop codon G1896A. In addition, 63% genotype A and 33% genotype D strains had the basal core promoter mutations, A1762T/G1764A. Furthermore, four pre-S deletion variants and two recombinants were identified in this study. In conclusion, we identified a novel HBV subgenotype D10 circulating in Ethiopia, underlining the high genetic variability of HBV strains in Africa.

The nucleotide changes within HBV core promoter/precore during the first 12weeks of nucleos(t)ide treatment might be associated with a better virological response

OBJECTIVES

We aimed to study the dynamic changes of hepatitis B virus (HBV) core promoter/precore (CP/preC) sequences during antiviral treatment and their associations with virological responses.

MATERIALS AND METHODS

The baseline and 12-week CP/preC sequences (nts 1655-2014) were obtained from 52 chronic hepatitis B patients with positive hepatitis B e antigen (HBeAg), who received a 104-week lamivudine and adefovir dipivoxil combination therapy. The mutations within the CP/preC were analyzed against genotype specific reference sequences. The nucleotide change rates in individuals during therapy were analyzed in a pairwise comparison manner.

RESULTS

There was no significant difference of the mutation rate at each nucleotide site between baseline and week 12 of treatment (P>0.05). The mutation rates of A1762T/G1764A and G1896A were found to decrease from 46.2% (24/52) at baseline to 36.5% (19/52) at week 12 (P=0.426) and from 28.8% (15/52) to 21.2% (11/52) (P=0.497), respectively. The nucleotide change rates varied from 0.0% - 7.8% in individuals [0.0% in Group 1 (N=26); 0.3% - 7.8% in Group 2 (N=26)] during the first 12-week treatment. HBV DNA levels in Group 2 were significantly lower than those in Group 1 throughout therapy (P<0.01) (e.g., 1.5±1.3log₁₀ IU/ml vs. 2.6±1.0log₁₀ IU/ml at week 104, P=0.001). At week 104 the rates of HBV DNA undetectable and HBeAg loss in Group 2 were significantly higher than those in Group 1 (P<0.05). Along with the increased nucleotide change rates, the rate of HBV DNA undetectable at week 104 tended to increase (odds ratio=0.323, 95% confidence interval=0.138-0.758, P<0.001).

CONCLUSION

Our findings suggested that the nucleotide changes within HBV CP/preC region during the first 12-week treatment might be associated with a better virological response.

Characteristics and course of chronic hepatitis B e antigen-negative infection

OBJECTIVE

To describe the epidemiological, analytical and histological characteristics and clinical course of hepatitis B virus (HBV) carriers with negative HBe antigen.

MATERIAL AND METHODS

Observational, retrospective cohort study of HBV carriers with negative HBe antigen (2005-2012), with no other causes of liver disease.

RESULTS

One hundred and thirty-eight patients were included, with mean age 40.5±12.2 years; 54% were women, and 38% were of foreign origin; the number of foreign patients significantly increased (P<.001) over the years. Transaminases were normal in nearly 75% and HBV-DNA was <2,000IU/ml in 56% of patients at diagnosis. There was a gradual decrease in HBV-DNA levels in inactive carriers over the study period. Fibrosis study was performed in 47% of patients by Fibroscan^® or liver biopsy: 55.4% normal histology and 6.1% cirrhosis. Just over three quarters of patients (77.77%) were inactive carriers. Treatment was required in 15.5% of patients (20% because of cirrhosis and 80% HBeAg-negative chronic hepatitis B). Five patients cleared HBsAg (annual rate .94%), all of whom presented HBV-DNA <2,000IU/ml at diagnosis. Five patients developed complications (3.6%), 4 of them hepatocellular carcinoma (HCC), of which only 2 had cirrhosis. There was 1 HBV-related death (.72%).

CONCLUSION

Among HBV carriers with negative HBe antigen, inactive HBs-Ag carriers are predominant. HBV-DNA gradually decreases in the first few years after diagnosis. Morbidity and mortality are low, especially if glutamic pyruvic transaminase (GPT) is normal and HBV-DNA levels are low at diagnosis. Treatment is needed in a considerable number of patients. HCC is the most frequent complication, even in the absence of cirrhosis.

Mutation Changes in the preC/Core Promoter in HBeAg-Positive Patients With Chronic Hepatitis B During Interferon Therapy

To study the changes in 3 mutations related with hepatitis B e antigen (HBeAg) in patients with HBeAg-positive chronic hepatitis B (CHB) during interferon therapy.HBeAg seroconversion is a major therapeutic milestone for patients with HBeAg-positive CHB. The precore mutation G1896A and the basal core promoter mutations A1762T/G1764A are 3 important mutations that affect the expression of HBeAg; however, the change of these 3 mutations in CHB patients during interferon therapy has not yet been evaluated.Sixty-four treatment-naive patients with HBeAg-positive CHB were treated with interferon for 48 weeks and followed up for 24 weeks. Serum samples were collected from all of the participants at different time points and then subjected to viral DNA extraction. The precore and basal core promoter sequences were determined using nested PCR and direct sequencing. The treatment outcomes were confirmed both at the end of therapy and the follow-up period, and the results were compared between patients with mutant and wild-type virus.No significant difference in HBeAg loss and HBeAg seroconversion was observed between patients with mutant versus wild-type virus although the portion of patients who achieved HBeAg loss/seroconversion with mutant virus was a little higher than in patients with wild-type virus. Once a mutation exists, it is not replaced with the wild-type sequence during interferon therapy and follow-up; moreover, our results show that mutants stably coexist with the wild-type virus during interferon therapy.This study shows the changes in 3 mutations affecting the expression of HBeAg during interferon therapy. However, additional studies with a larger sample size and more sensitive detection methods are needed to uncover the underlying mechanism and clinical significance of these results.

Hepatitis B: 50 years after the discovery of Australia antigen

It is an honour to be invited to recount the progress in our understanding and management of hepatitis B 50 years after the discovery of Australia antigen (Au Ag). During this half century, we have gone from identifying the causative agent--hepatitis B virus (HBV), understanding its biology and the disease it causes, to having vaccines that can prevent HBV infection and antiviral therapy that can suppress HBV replication and prevent progression of HBV-related liver disease. As a result of the progress, prevalence of HBV infection and morbidity and mortality from chronic HBV infection has declined.

Hepatitis B virus basal core promoter/precore mutants and association with liver cirrhosis in children with chronic hepatitis B virus infection

We investigated 168 children and analysed the virological characterization and association with disease progression in children with hepatitis B virus (HBV) basal core promoter/precore (BCP/PC) mutants. Among 168 patients with HBV infection (aged 0.5-18 years old, mean 10.1), 86 of them had HBV-related liver cirrhosis (LC) and 82 had HBV-related chronic hepatitis B (CHB). A direct sequencing method was employed to determine the HBV genotypes and the mutations in BCP/PC regions. In all, 133 of them were infected with genotype C viruses (79.17%); only 35 patients (20.83%) were infected with genotype B viruses. Both LC patients and CHB patients had significantly higher ratios of genotype C when compared with the ratios of genotype B (83.7%-16.3% versus 74.4%-25.6%). For patients with CHB, the prevalence of BCP/PC wild-type viruses was 52.4%; but this was only 4.7% in patients with LC. The C1653T, T1753C, A1762T/G1764A and G1896A mutations had a significantly higher prevalence in patients with LC. Among all the patients with genotype B viruses, those with LC had lower HBV DNA levels and higher G1899A mutation frequency than patients with CHB. Among all the patients with genotype C viruses, the patients with LC had higher prevalence of C1653T, A1762T/G1764A and G1896A mutation frequency, higher hepatitis B e antigen (HBeAg) -negative rates, lower viral load, lower elevated alanine aminotransferase and lower anti-HBe positive rates than CHB patients. The HBV BCP/PC variants were more common in HBeAg-negative LC patients than in the CHB group (BCP, 53.4% versus 15.6%; PC, 18.6% versus 3.7%, respectively, p < 0.001). Patients with HBV genotype C viruses, high viral load and C1653T, A1762T/G1764A, G1896A mutant viruses, were more susceptible to developing LC.

Enhanced hepatitis B virus (HBV) pre-genomic RNA levels and higher transcription efficiency of defective HBV genomes

Defective hepatitis B virus (dHBV) particles contain genomes corresponding to singly spliced HBV RNA. A limited number of studies show that dHBV is present in all chronically HBV-infected patients. Clinical studies have linked dHBV and dHBV gene products to high virus loads and liver damage. The replication characteristics of dHBV genomes remain poorly understood. We found that the splice donor/acceptor sites critical for the formation of dHBV genomes are conserved across HBV genotypes. We report a novel method to create dHBV constructs from corresponding wild-type (WT) HBV constructs. We assessed the transcriptional characteristics of the dHBV constructs with those of the corresponding WT construct using a cell culture model. Interestingly, dHBV constructs had higher pre-genomic RNA levels, transcription efficiency, HBV e antigen levels and intracellular HBV core antigen levels compared with the corresponding WT HBV constructs. Our findings highlight previously unrecognized fundamental molecular characteristics of dHBV genomes and their potential role in the pathogenesis of HBV infection.

Biological characteristics of the A1762T/G1764A mutant strain of hepatitis B virus in vivo

The double nucleotide, A1762T and G1764A exchange (TA mutation), in the hepatitis B virus (HBV) genome basal core promoter (BCP) region is a common viral mutation in patients with chronic HBV infection. This mutation is located in the binding site of hepatocyte nuclear factor 4 (HNF4), and a number of liver‑enriched transcription factors are involved in the regulation of HBV transcription and replication. The aim of the present study was to investigate the biological characteristics of the HBV strain with this mutation, and the effect of HNF4 inhibition on the replication of this strain in vivo. The results indicated that in vivo the HBV strain with the TA mutation supported a higher level of pregenomic RNA transcription and HBV DNA replication, compared with the wild‑type strain. Furthermore, the concentration of serum HBeAg in the TA mutant group was lower than that in the wild‑type strain. Following treatment of the mice with entecavir (ETV) or tenofovir disoproxil fumarate (TDF), the transcription and replication levels of wild‑type and mutant strains were reduced. In the groups treated with TDF, the inhibition effect was more marked. In hepatocytes in which HNF4 expression was specifically inhibited, the level of 3.5 kb mRNA of HBV was reduced compared with that in mouse cells with normal HNF4 expression, and HBV DNA replication levels were also reduced to a greater extent. Furthermore, following liver‑specific knockdown of HNF4, the reduction in variant virus expression was greater than that of the wild‑type virus. In conclusion, the replication capacity of HBV with the TA mutation was increased, and the mutation was associated with a reduction in serum HBeAg levels. This mutant strain remained sensitive to ETV and TDF, and HNF4 supported a higher replication level of TA mutant HBV in vivo.

Chronic hepatitis B: Virology, natural history, current management and a glimpse at future opportunities

The host immune system plays an important role in chronic hepatitis B (CHB), both in viral clearance and hepatocellular damage. Advances in our understanding of the natural history of the disease have led to redefining the major phases of infection, with the "high replicative, low inflammatory" phase now replacing what was formerly termed the "immune tolerant" phase, and the "nonreplicative phase" replacing what was formerly termed the "inactive carrier" phase. As opposed to the earlier view that HBV establishes chronic infection by exploiting the immaturity of the neonate's immune system, new findings on trained immunity show that the host is already somewhat "matured" following birth, and is actually very capable of responding immunologically, potentially altering future hepatitis B treatment strategies. While existing therapies are effective in reducing viral load and necroinflammation, often restoring the patient to near-normal health, they do not lead to a cure except in very rare cases and, in many patients, viremia rebounds after cessation of treatment. Researchers are now challenged to devise therapies that will eliminate infection, with a particular focus on eliminating the persistence of viral cccDNA in the nuclei of hepatocytes. In the context of chronic hepatitis B, new definitions of 'cure' are emerging, such as 'functional' and 'virological' cure, defined by stable off-therapy suppression of viremia and antigenemia, and the normalization of serum ALT and other liver-related laboratory tests. Continued advances in the understanding of the complex biology of chronic hepatitis B have resulted in the development of new, experimental therapies targeting viral and host factors and pathways previously not accessible to therapy, approaches which may lead to virological cures in the near term and functional cures upon long term follow-up. This article forms part of a symposium in Antiviral Research on "An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for hepatitis B."

Precore/basal core promoter mutants quantification throughout phases of hepatitis B virus infection by Simpleprobe

AIM: To investigate precore/basal core promoter (PC/BCP) mutants throughout hepatitis B virus (HBV) infection and to determine their relationship to hepatitis B early antigen (HBeAg) titers.

METHODS: We enrolled 191 patients in various stages of HBV infection at the Huashan Hospital and the Taizhou Municipal Hospital from 2010 to 2012. None of the patients received antiviral therapy. HBV DNA from serum, was quantified by real-time PCR. The HBV genotype was determined by direct sequencing of the S gene. We used the Simpleprobe ultrasensitive quantitative method to detect PC/BCP mutants in each patient. We compared the strain number, percentage, and the changes in PC/BCP mutants in different phases, and analyzed the relationship between PC/BCP mutants and HBeAg by multiple linear regression and logistic regression.

RESULTS: Patients with HBV infection (n = 191) were assigned to groups by phase: Immune tolerance (IT) = 55, Immune clearance (IC) = 67, Low-replicative (LR) = 49, and HBeAg-negative hepatitis (ENH) = 20. Of the patients (male, 112; female, 79) enrolled, 122 were HBeAg-positive and 69 were HBeAg-negative. The median age was 33 years (range: 18-78 years). PC and BCP mutation detection rates were 84.82% (162/191) and 96.86% (185/191), respectively. In five HBeAg-negative cases, we detected double mutation G1896A/G1899A. The logarithm value of PC mutant quantities (log₁₀ PC) significantly differed in IT, IC, and LR phases, as well as in the ENH phase (F = 49.350, P < 0.001). The logarithm value of BCP mutant quantities (log₁₀ BCP) also differed during the four phases (F = 25.530, P < 0.001). Log₁₀ PC and log₁₀ BCP values were high in the IT and IC phases, decreased in the LR phase, and increased in the ENH phase, although the absolute value at this point remained lower than that in the IT and IC phases. PC mutant quantity per total viral load (PC%) and BCP mutant quantity per total viral load (BCP%) differed between phases (F = 20.040, P < 0.001; F = 10.830, P < 0.001), with PC% and BCP% gradually increasing in successive phases. HBeAg titers negatively correlated with PC% (Spearman’s rho = -0.354, P < 0.001) and BCP% (Spearman’s rho = -0.395, P < 0.001). The negative correlation between PC% and HBeAg status was significant (B = -5.281, P = 0.001), but there was no such correlation between BCP% and HBeAg status (B = -0.523, P = 0.552).

CONCLUSION: PC/BCP mutants become predominant in a dynamic and continuous process. Log₁₀ PC, log₁₀ BCP, PC% and BCP% might be combined to evaluate disease progression. PC% determines HBeAg status.

Hepatitis B Virus Core Promoter A1762T/G1764A (TA)/T1753A/T1768A Mutations Contribute to Hepatocarcinogenesis by Deregulating Skp2 and P53

BACKGROUND AND AIM

Hepatitis B virus core promoter (CP) mutations can increase risk of hepatocellular carcinoma. The CP region overlaps with the HBV X (HBx) gene, which has been associated with hepatocarcinogenesis. The cyclin kinase inhibitor P53 is an important regulator of cell cycle progression. We determined whether HBx mutants that result from mutations in the CP deregulate P53.

METHODS

A HBx combination (combo) mutant with changes in the CP region that corresponded to A1762T/G1764A (TA), T1753A, and T1768A was constructed and expressed in L-02 and Hep3B cells. The effects of CP mutations on expression and degradation of P53, and the effects on cell cycle progression and proliferation were analyzed.

RESULTS

The combo mutant decreased levels of P53 and increased cyclin D1 expression, accelerated P53 degradation in L-02 cells, accelerated cell cycle progression, and increased expression of S-phase kinase-associated protein 2 (Skp2) in L-02 and Hep3B cells. Silencing of Skp2 abrogated the effects of CP mutations on P53 expression. The kinetics of P53 expression correlated with changes in cell cycle distribution.

CONCLUSIONS

The HBx mutant with a combination of CP mutations can up-regulate Skp2, which then down-regulates P53 via ubiquitin-mediated proteasomal degradation, increasing the risk of hepatocellular carcinoma.

Influence of the basal core promoter and precore mutation on replication of hepatitis B virus and antiviral susceptibility of different genotypes

Mutations in the basal core promoter (BCP) and precore (PC) regions of the hepatitis B virus (HBV) are more common in genotypes B and C than in genotype A, suggesting that these mutations might affect replication competency depending on genotype. The purpose of the study was to investigate the influence of these mutations on the capacity of HBV for replication and antiviral drug susceptibility according to genotype. Genotypes A, B, and C of HBV strains with a BCP mutation, PC mutation, or BCP + PC mutation were made by site-directed mutagenesis. Replication competency of each construct and susceptibility to nucleos(t) ide analogues were tested in an Huh7 cell line. In genotype A, the BCP and BCP + PC mutations increased the viral replication around 6.5 times compared with the wild type, and the PC mutation alone similarly increased the viral replication around three times. In genotypes B and C, all three mutant types increased viral replication to a similar extent, regardless of mutation pattern. Interestingly, the BCP mutation appeared to have a greater effect on viral replication in genotype A than in genotypes B and C. This finding was unexpected because the BCP mutation is more common in HBV genotypes B and C. Moreover, the BCP, PC, and BCP + PC mutations decreased the sensitivity of HBV to antiviral agents to various degrees (2- to 10-fold) regardless of genotype. In conclusion, BCP and PC mutations increased viral replication regardless of HBV genotype and decreased in vitro antiviral susceptibility to the nucleos(t) ide analogues.

Retrospective study of the prevalence and clinical significance of hepatitis B virus precore and basal core promoter variants

BACKGROUND

Hepatitis B virus (HBV) precore (PC) and basal core promoter (BCP) variants are well known; however, their prevalence in North America is unclear, especially among hepatitis B e antigen-negative patients.

OBJECTIVE

To investigate the prevalence of PC⁄BCP mutations and their clinical significance.

METHODS

One hundred twenty-eight patients positive for both hepatitis B surface antigen and hepatitis B e antibody were selected, and PC⁄BCP mutations were identified using a line probe assay. The subjects' charts were reviewed for race⁄ethnicity, HBV genotype, HBV viral load, sex, liver enzyme levels, imaging and biopsy results up to 10 years before the study.

RESULTS

The prevalence of PC and BCP variants were 47.6% and 62.5%, respectively. Older age was associated with aspartate aminotransferase-to-platelet index ratio (APRI) ≥0.7 (P=0.011) and abnormal imaging⁄biopsy results (P=0.0008). Although the presence of BCP variant(s) was associated with APRI ≥0.7 (P=0.029), it was not associated with abnormal imaging⁄biopsy results. The combination of age ≥50 years and the presence of BCP variant(s) was associated with abnormal imaging⁄biopsy results, suggestive of either cirrhosis or hepatocellular carcinoma (not observed with PC mutation). Neither sex or genotype, or median HBV viral load showed significant influence on any of these outcomes.

CONCLUSIONS

The present study suggests that the prevalence of PC and BCP mutations are higher than what has been previously reported. One potential explanation would be increased immigration in the past decade. Considering the potential public health and clinical implications of these variants, long-term multicentre and prospective studies could further unravel the uncertainty around these variants.

High rate of core promoter and precore mutations in patients with chronic hepatitis B

Background

The prevalence of precore (PC) and core promoter (CP) mutations in patients with chronic hepatitis B virus (HBV) infection (CHB) and their impact on liver disease is incompletely defined in the United States.

Methods

A retrospective chart review using a cross-sectional approach of 1,186 CHB patients was conducted.

Results

Of 926 patients tested for HBV e antigen (HBeAg), 37 % were HBeAg+. Of 194 patients tested for mutations, 80 % had PC or CP mutations or both; 89 % of HBeAg-negative and 56 % of HBeAg+ patients had PC or CP mutations or both (p < 0.001). The mean log₁₀ ALT was significantly lower in patients with both mutations compared to patients without mutations. The mean log₁₀ HBV DNA was significantly lower in patients with only PC mutations (4.82) compared to patients without mutations (5.71, p = 0.019). With the study population divided into four subgroups based on ALT level at time of diagnosis, cirrhosis incidence was significantly higher in patients with ALT 1–2 × ULN and ALT > 2 × ULN compared to patients with ALT ≤ 0.5 × ULN.

Conclusions

Our finding that PC and CP mutations may be associated with milder liver disease in some patients could serve as the basis for longitudinal studies to help delineate treatment need and duration in patients with these mutations. If confirmed, the finding of an association between ALT 1–2 × ULN and increased incidence of cirrhosis could call into question guidelines which only recommend treatment with ALT > 2 × ULN.

Viral hepatitis B: clinical and epidemiological characteristics

It is now 50 years since the discovery of the hepatitis B virus (HBV), and, despite the availability of a prophylactic vaccine for more than 20 years, HBV infection remains a disease of significant global health burden. It is estimated that more than 240 million people are chronically infected with HBV and, therefore, are at risk for the development of cirrhosis, hepatic decompensation, and hepatocellular carcinoma (HCC). The risk of clinical complications has traditionally been higher in older males with hepatitis B e antigen (HBeAg)-positive disease, high-grade liver necroinflammation, and progressive fibrosis. Recent advances in the understanding of the natural history of chronic HBV infection have identified an important role for plasma HBV DNA levels as a marker of risk for clinical outcomes. Among adults, persistent high-level HBV replication is associated with an increased risk of cirrhosis, as well as HCC development. This has led to the therapeutic focus on achieving sustained viral suppression. There is an emerging role for quantitative hepatitis B surface antigen (HBsAg) levels as a marker of natural history. Low levels of HBsAg have been associated with sustained immune control, HBsAg seroclearance, as well as lower risk of HCC. In this work, we review the natural history of HBV infection, with a focus on the determinants of clinical outcomes in patients with chronic hepatitis B (CHB) infection.

The Emergent Concern of Hepatitis B globally with special attention to Kingdom of Saudi Arabia

Chronic viral hepatitis is highly prevalent and creates a substantial burden to healthcare systems globally. The World Health Organization (WHO) estimates that over 350 and 250 million people worldwide are chronic carrier of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection respectively. These two diseases are the cause of significant global mortality and morbidity with approximately 1 million deaths each year attributable to them and their sequelae, liver disease and primary liver cancer. Although the efforts have been met with the long-lasting level of success and holds the promise for large reductions in disease burden in spite of the huge numbers of HBV infected population. The viral hepatitis has also been emerged as a leading public health concern and continues to be major disease burden in the Eastern Mediterranean. The WHO, estimates that approximately 4.3 million persons are infected with HBV in the Region each year. Saudi Arabia has been classified as a country with an intermediate prevalence of HBV showed up to 7% in Saudi children in late 1980s but declined to as low as 0.3% in 1997 since the introduction of universal vaccination of all Saudi children in 1989. In spite of this remarkable decline, the burden of decompensated liver disease secondary to hepatitis B is estimated to increase drastically in the next 40 years as the previously infected children start aging.

Novel point mutations and mutational complexes in the enhancer II, core promoter and precore regions of hepatitis B virus genotype D1 associated with hepatocellular carcinoma in Saudi Arabia

In this study, a cohort of 182 patients [55 hepatocellular carcinoma (HCC) and 127 non-HCC] infected with hepatitis B virus (HBV) in Saudi Arabia was investigated to study the relationship between sequence variation in the enhancer II (EnhII), basal core promoter (BCP) and precore regions of HBV genotype D (HBV/D) and the risk of HCC. HBV genotypes were determined by sequencing analysis and/or enzyme-linked immunosorbent assay. Variations in the EnhII, BCP and precore regions were compared between 107 non-HCC and 45 HCC patients infected with HBV/D, followed by age-matched analysis of 40 cases versus equal number of controls. Age and male gender were significantly associated with HCC (p = 0.0001 and p = 0.03, respectively). Serological markers such as aspartate aminotransferase, albumin and anti-HBe were significantly associated with HCC (p = 0.0001 for all), whereas HBeAg positivity was associated with non-HCC (p = 0.0001). The most prevalent HBV genotype was HBV/D (94%), followed by HBV/E (4%), HBV/A (1.6%) and HBV/C (0.5%). For HBV/D1, genomic mutations associated with HCC were T1673/G1679, G1727, C1741, C1761, A1757/T1764/G1766, T1773, T1773/G1775 and C1909. Age- and gender-adjusted stepwise logistic regression analysis indicated that mutations G1727 [odds ratio (OR) = 18.3; 95% confidence interval (CI) = 2.8-118.4; p = 0.002], A1757/T1764/G1766 (OR = 4.7; 95% CI = 1.3-17.2; p = 0.01) and T1773 (OR = 14.06; 95% CI = 2.3-84.8; p = 0.004) are independent predictors of HCC development. These results implicate novel individual and combination patterns of mutations in the X/precore region of HBV/D1 as predictors of HCC. Risk stratification based on these mutation complexes would be useful in determining high-risk patients and improving diagnostic and treatment strategies for HBV/D1.

Full genome ultra-deep pyrosequencing associates G-to-A hypermutation of the hepatitis B virus genome with the natural progression of hepatitis B

Human APOBEC3 (A3) cytosine deaminases are antiviral restriction factors capable of editing the genome the hepatitis B virus (HBV). Despite the importance of the human A3 protein family for the innate immune response little is known about the clinical relevance for hepatitis B. The aim of this study was to utilize ultra-deep pyrosequencing (UDPS) data to analyse the phenomenon of G-to-A hypermutation of the complete HBV genome and to relate it to fundamental characteristics of patients with chronic hepatitis B. By analysing the viral population of 80 treatment naïve patients (47 HBeAg-positive and 33 HBeAg-negative), we identified an unequal distribution of G-to-A hypermutations across the genome. Our data indicate that G-to-A hypermutation occurs predominantly in a region between nucleotide positions 600 and 1800 a region which is usually single stranded in matured HBV particles. This implies that A3 likely edits HBV in the virion. Hypermutation rates for HBeAg-negative patients were more than 10-fold higher than those of HBeAg-positive patients. For HBeAg-negative patients higher hypermutation rates were significantly associated with the degree of fibrosis. Additionally, we found that for HBeAg-positive chronic hepatitis G-to-A hypermutation rates were significantly associated with the relative prevalence of the G1764A mutation, which is related to HBeAg seroconversion. In total, our data imply an important association of hypermutation mediated by A3 deaminases with the natural progression of chronic hepatitis B infections both in terms of HBeAg seroconversion and disease progression towards cirrhosis.

Variability in the precore and core promoter region of the hepatitis B virus genome

There is increasing evidence that hepatitis B virus (HBV) infections with different genotypes and subgenotypes differ in response to treatment and long-term prognosis. The differences emerge from variability within the genomes that leads to structural deviations at the pregenomic level and to changes at the translational level. Naturally occurring HBV strains covering the four major genotypes A-D were obtained from 393 patients and part of the genome was amplified using polymerase chain reaction (PCR), sequenced, and analyzed for mutational differences in the precore and core promoter regions. The study confirmed that core promoter and precore mutations occur at key positions (A1762T, G1764A, G1896A, and G1899A), and that the proportions of strains with seroconvertion in patients differ between the four HBV genotypes. A rare double mutation (C1857T together with G1897A) was observed, and C1856T was found together with the emerging G1898A mutation, which itself was found to be more widespread geographically than previously described. We found a novel mutation (T1850C), never before observed in human HBV strains but known from woodchuck hepatitis virus (WHV). A novel association of mutation C1773T with G1764T, C1766A, and G1757A was also found within a site already suggested to be a putative binding site for HNF-3. This novel association is proposed by us to be of importance for additional binding of HNH-2 to this site and is a better indicator of the emergence of the double mutation G1764T and C1766A than the G1757A mutation proposed previously.

Distribution of hepatitis B virus subgenotype F2a in São Paulo, Brazil

Background

HBV genotype F is primarily found in indigenous populations from South America and is classified in four subgenotypes (F1 to F4). Subgenotype F2a is the most common in Brazil among genotype F cases. The aim of this study was to characterize HBV genotype F2a circulating in 16 patients from São Paulo, Brazil. Samples were collected between 2006 and 2012 and sent to Hospital Israelita Albert Einstein. A fragment of 1306 bp partially comprising HBsAg and DNA polymerase coding regions was amplified and sequenced. Viral sequences were genotyped by phylogenetic analysis using reference sequences from GenBank (n=198), including 80 classified as subgenotype F2a. Bayesian Markov chain Monte Carlo simulation implemented in BEAST v.1.5.4 was applied to obtain the best possible estimates using the model of nucleotide substitutions GTR+G+I.

Findings

It were identified three groups of sequences of subgenotype F2a: 1) 10 sequences from São Paulo state; 2) 3 sequences from Rio de Janeiro and one from São Paulo states; 3) 8 sequences from the West Amazon Basin.

Conclusions

These results showing for the first time the distribution of F2a subgenotype in Brazil. The spreading and the dynamic of subgenotype F2a in Brazil requires the study of a higher number of samples from different regions as it is unfold in almost all Brazilian populations studied so far. We cannot infer with certainty the origin of these different groups due to the lack of available sequences. Nevertheless, our data suggest that the common origin of these groups probably occurred a long time ago.

Characterization of hepatitis B virus genotypes and quantitative hepatitis B surface antigen titres in North American tertiary referral liver centres

BACKGROUND & AIMS

Hepatitis B virus (HBV) genotype and quantitative hepatitis B surface antigen (qHBsAg) have been related to clinical outcome. In this nationwide cross-sectional study, we aimed to investigate the epidemiology and clinical significance of HBV genotype and qHBsAg in patients with chronic hepatitis B (CHB).

METHODS

Six hundred and thirty patients with CHB were seen in four urban tertiary referral centres in Canada. HBV genotype was determined by line probe assay (INNO-LIPA) and HBV DNA quantified by commercial PCR (Roche TaqMan, sensitivity <55 IU/ml or AMPLICOR, sensitivity <60 IU/ml). Titres of qHBsAg were determined by an in-house assay based on the WHO standard (calibration range 0.24-62.5 IU/ml).

RESULTS

In 630 patients (57% male, 69% Asian, median age 42 years), 21% were hepatitis B e antigen positive and the median alanine aminotransferase was 29 U/L. The HBV genotype distribution was A (16%), B (29%), C (31%), D (16%), E (6%). HBV genotype was strongly associated with ethnicity, but neither genotype nor qHBsAg correlated with the degree of fibrosis. In the treatment-naïve patients, the baseline qHBsAg levels correlated with HBV DNA (r = 0.2517, P < 0.0008). The median qHBsAg levels were lowest in patients with genotype B (P < 0.0001), but no significant correlation was noted with all other HBV genotypes.

CONCLUSIONS

In this large North American HBV epidemiological study, genotypes B and C were the most common; however, all genotypes (A-E) were observed with varied distribution nationwide. Baseline qHBsAg significantly correlated with HBV DNA and with HBV genotype B, but not with liver fibrosis.

Distinct evolution and predictive value of hepatitis B virus precore and basal core promoter mutations in interferon-induced hepatitis B e antigen seroconversion

Precore (PC) (G1896A) and basal core promoter (BCP) (A1762T/G1764A) mutations of the hepatitis B virus (HBV) genome often emerge in chronic hepatitis B (CHB) patients. Their roles in hepatitis B e antigen (HBeAg) seroconversion induced by interferon (IFN) therapy remain controversial, partly because quantitative analysis for these mutants is lacking. This study aimed to develop a new assay to accurately quantify the PC and BCP mutant percentages and correlate their dynamic changes with IFN-induced HBeAg seroconversion in HBeAg-positive CHB patients. The PC and BCP mutant percentages were analyzed by polymerase chain reaction (PCR)-pyrosequencing. Our results showed that this quantitative assay for PC and BCP mutants achieved high accuracy (R(2) > 0.99) within a range between 10% and 90% mutants. We examined dynamic changes of the PC and BCP mutant percentages following IFN treatment in 203 HBeAg-positive CHB patients. By multiple logistic regression analysis, we found that the chance of HBeAg seroconversion increased by 2.2% (odds ratio [OR] = 1.022, 95% confidence interval [CI]: 1.009-1.034, P = 0.001) and 2.3% (OR = 1.023, 95% CI: 1.010-1.037, P = 0.001) per 1% increase of the pretreatment PC and BCP mutant percentages, respectively, after adjustment for other predictors. However, only the pretreatment PC mutation percentage was significantly associated with HBeAg seroconversion with HBV DNA < 2,000 IU/mL (OR = 1.030, 95% CI: 1.014-1.047, P < 0.001). Furthermore, the mutant percentage of PC, but not BCP, in patients achieving HBeAg seroclearance with HBV DNA < 20,000 IU/mL increased significantly during IFN treatment (P = 0.039). Interestingly, patients with HBeAg seroconversion who had a high PC mutant percentage at the end of IFN treatment tended to exhibit high viremia after seroconversion.

CONCLUSION

Quantitative analysis of PC and BCP mutants can predict IFN-induced HBeAg seroconversion and demonstrate their distinct evolution patterns during HBeAg seroconversion. (HEPATOLOGY 2013).

IL28B polymorphism correlates with active hepatitis in patients with HBeAg-negative chronic hepatitis B

BACKGROUND AIMS

The clinical relevance of single nucleotide polymorphisms (SNPs) near the IL28B gene is controversial in patients with hepatitis B virus (HBV) infection. This study aimed to investigate the role of viral and host factors, including IL28B genotypes, in the natural course of chronic hepatitis B (CHB).

METHODS

The study enrolled consecutive 115 treatment-naive CHB patients. HBV viral loads, genotypes, precore and basal core promotor mutations, serum hepatitis B surface antigen (HBsAg) and interferon-gamma inducible protein 10 (IP-10) levels as well as four SNPs of IL28B were determined. Serial alanine transaminase (ALT) levels in the previous one year before enrollment at an interval of three months were recorded. Factors associated with active hepatitis, defined as persistent ALT >2× upper limit of normal (ULN) or a peak ALT level >5× ULN, were evaluated.

RESULTS

The prevalence of rs8105790 TT, rs12979860 CC, rs8099917 TT, and rs10853728 CC genotypes were 88.3%, 87.4%, 88.4% and 70.9%, respectively. In HBeAg-positive patients (n = 48), HBV viral load correlated with active hepatitis, while in HBeAg-negative patients (n = 67), rs10853728 CC genotype (p = 0.032) and a trend of higher IP-10 levels (p = 0.092) were associated with active hepatitis. In multivariate analysis, high viral load (HBV DNA >10(8) IU/mL, p = 0.042, odds ratio = 3.946) was significantly associated with HBeAg-positive hepatitis, whereas rs10853728 CC genotype (p = 0.019, odds ratio = 3.927) was the only independent factor associated with active hepatitis in HBeAg-negative population.

CONCLUSIONS

HBV viral load and IL28B rs10853728 CC genotype correlated with hepatitis activity in HBeAg-positive and HBeAg-negative CHB, respectively. Both viral and host factors play roles in disease activity during different phases of CHB.

[Characteristics of patients with chronic hepatitis B virus infection. analysis of a series of 474 patients]

OBJECTIVE

To determine the clinical, laboratory, serological and histologic characteristics of chronic hepatitis B virus carriers in our environment.

MATERIAL AND METHODS

A retrospective cohort study was performed that included chronic AgHBs carriers aged more than 13 years attending our service since January 2000.

RESULTS

A total of 474 patients were included. At diagnosis, 55.49% were men, with a mean age of 41.05±13.93 years. Alanine aminotransferase (ALT) levels were within the normal range in 57.17% of the patients, and 87.76% were AgHBe(-). Hepatitis C and D virus coinfection was found in 3.62% and 1.86%, respectively. Liver biopsy was performed in 31.22%; varying grades of inflammation-fibrosis were found in 63.51% and cirrhosis was found in 12.84%. Compared with AgHBe(-) patients, those who were AgHBe(+) were younger and had greater disease activity. This difference was statistically significant. Patients in the immunotolerant phase were the least numerous (5.26%), while AgHBe(-) patients with chronic HBV infection were the most numerous (48.32%). Patients in the immunoreactive phase showed greater histological involvement (16.67% cirrhosis). A familial history of chronic HBV was found in 21.52%. The percentage of non-Spanish patients increased in the last few years and accounted for 18.78%.

CONCLUSION

Chronic HBV infection in our environment occurs mainly in middle-aged persons. GPT values are normal in more than 50%, most are AgHBe(-), and approximately half are inactive carriers. The incidence of chronic infection has increased in the non-Spanish population in recent years.

Etiological and molecular profile of hepatocellular cancer from India

Hepatocellular carcinoma (HCC) cases are underreported in India. Our study was designed to investigate the etiological profile of HCC cases in India and compare with global incidence. The study included 348 HCC and 375 chronic liver disease cases without HCC as controls. Samples were screened for hepatitis B virus (HBV)/hepatitis C virus (HCV) infections using enzyme-linked immunosorbent assay and polymerase chain reaction (PCR). HBV-DNA and HCV-RNA genotyping was performed by PCR-restriction fragment length polymorphism. All cases were also assessed for other possible risk factors of HCC. Among HCC cases, 62.6% were positive for HBV, 26.7% for HCV and 3.2% had coinfection. Around 17% of HCC cases had aflatoxin-B1 exposure. HBV genotype D (odds ratio, OR = 1.76) and mixed genotypes (OR = 6.86) had higher risk of HCC development. The risk of HCC was twofold (OR = 2.26) in patients with high HBV-DNA levels. Moreover, our findings were unable to establish a clear differential effect of HCV genotype (OR = 1.48) and high viral load (OR = 1.21) on HCC development. In India, HBV is the major risk factors, whereas alcohol, smoking and diabetes are nonsignificantly associated. Asian countries such as Hong Kong and Taiwan also had high incidence of HBV-related HCC. Contrarily, countries from Europe and USA reported HCV as predominant cause of HCC. Further, aflatoxin could be a possible risk of HCC in the population. However, in comparison to the countries such as China and Taiwan (high Aflatoxin exposure), the aflatoxin level is relatively low in our patients. High HBV-DNA levels and HBV/D increased the risk of HCC. However, neither genotype nor virus loads of HCV affected prognosis of HCC patients in our study.

Precore and basal core promoter mutations in Asian American patients with hepatitis B e antigen-positive chronic hepatitis B

BACKGROUND

Prior studies have shown that precore mutations abolish and basal core promoter (BCP) mutations down-regulate hepatitis B e antigen (HBeAg) production. Thus, the presence of precore and BCP mutations in HBeAg-positive patients indicates an infection with a mixed viral population of wild-type and precore and/or BCP mutant hepatitis B virus (HBV). To date, there has been limited study of the prevalence and clinical significance of precore and BCP mutations in patients with HBeAg-positive chronic hepatitis B.

AIM

To determine the prevalence, predictors and clinical characteristics of mixed wild-type and precore/BCP HBV infection, through a cross-sectional study, in a US cohort of patients with chronic hepatitis B.

METHODS

We conducted a retrospective study of 828 chronic hepatitis B patients with HBV genotype and mutation panel testing seen at three US gastroenterology and liver clinics from June 2005 to September 2009.

RESULTS

A majority of our patients (92.3%) were either Vietnamese or Chinese American. In the HBeAg-positive cohort, 17% of patients had precore mutations only, 28% had BCP mutations only and 5% had both BCP and precore mutations. On multivariate analyses, HBV genotype C, increasing age, lower HBV DNA level and an ALT quotient >2 were independent predictors for the presence of precore and/or BCP mutations.

CONCLUSIONS

The current distinction and management recommendations for HBeAg-positive vs. HBeAg-negative patients with chronic hepatitis B should be reassessed. Additional biomarkers and treatment endpoints should be studied for their usefulness in predicting continued viral suppression after treatment discontinuation.

High frequency of genotype D and spontaneous hepatitis B virus genomic mutations among Haitians in a multiethnic North American population

GOALS/BACKGROUND

The importance of hepatitis B virus (HBV) genotype and mutations has been increasingly recognized. We aimed to determine HBV genotype, precore (PC), and basal core promoter region (BCP) mutations in a HBV multiethnic South Florida population.

STUDY

Samples from 213 patients were tested for HBV-DNA using Abbott RealTime HBV IUO assay, and for mutations using INNO-LiPA assay.

RESULTS

Patients were predominantly male (67%); 61 (31%) were African American, 60 (28%) Hispanic, 37 (17%) Haitian, 27 (19%) white non-Hispanic, and 14 (6.6%) Asian. Genotype A was found in 101 (69%), D in 25 (17%), F in 9 (6%), G in 7 (5%), C and E in 6 (4%) each, B in 4 (3%), and H in 2 (1%) patients. Mixed genotypes were detected in 11 patients. Genotype A was more prevalent in all ethnicities except for Asian. Among hepatitis B e antigen (HBeAg)-negative patients (59%), BCP, PC, and combined BCP/PC mutations were found in 30 (37.5%), 13 (16.3%), and 14 (17.5%), respectively. Genotype D was associated with higher frequency of HBeAg-negative status [18/24 (75%) vs. 62/121 (51%) P=0.03] and mutations [16/19 (84%) vs. 40/67 (60%) P=0.04] compared with others. Genotype A was negatively associated with mutations [26/31 (84%) vs. 30/55 (55%), P=0.009]. PC mutations were more common in genotype D (14/19, 73%) compared with genotype A (7/54, 13%, P<0.0001). One-hundred percent and 79% of Asians and Haitians had spontaneous mutations, respectively. All Haitians with genotype D had PC mutations and 3 (50%) had BCP/PC.

CONCLUSIONS

The present study shows that HBeAg-negative status and spontaneous mutations were more common with genotype D; the presence of genotype D in Haitians was always associated with spontaneous mutations.