Clinical relevance and public health significance of hepatitis B virus genomic variations

The impact of HBx protein on mitochondrial dynamics and associated signaling pathways strongly depends on the hepatitis B virus genotype

Chronic hepatitis B virus (HBV) infections are strongly associated with liver cirrhosis, inflammation, and hepatocellular carcinoma. In this context, the viral HBx protein is considered as a major factor influencing HBV-associated pathogenesis through deregulation of multiple cellular signaling pathways and is therefore a potential target for prognostic and therapeutic applications. However, HBV-associated pathogenesis differs significantly between genotypes, with the relevant factors and in particular the contribution of the genetic diversity of HBx being largely unknown. To address this question, we studied the specific genotype-dependent impact of HBx on cellular signaling pathways, focusing in particular on morphological and functional parameters of mitochondria. To exclusively investigate the impact of HBx of different genotypes on integrity and function of mitochondria in the absence of additional viral factors, we overexpressed HBx in Huh7 or HepG2 cells. Key signaling pathways were profiled by kinome analysis and correlated with expression levels of mitochondrial and pathogenic markers. Conclusively, HBx of genotypes A and G caused strong disruption of mitochondrial morphology alongside an induction of PTEN-induced putative kinase 1/Parkin-mediated mitophagy. These effects were only moderately dysregulated by genotypes B and E, whereas genotypes C and D exhibit an intermediate effect in this regard. Accordingly, changes in mitochondrial membrane potential and elevated reactive oxygen species production were associated with the HBx-mediated dysfunction among different genotypes. Also, genotype-related differences in mitophagy induction were identified and indicated that HBx-mediated changes in the mitochondria morphology and function strongly depend on the genotype. This indicates a relevant role of HBx in the process of genotype-dependent liver pathogenesis of HBV infections and reveals underlying mechanisms.IMPORTANCEThe hepatitis B virus is the main cause of chronic liver disease worldwide and differs in terms of pathogenesis and clinical outcome among the different genotypes. Furthermore, the viral HBx protein is a known factor in the progression of liver injury by inducing aberrant mitochondrial structures and functions. Consequently, the selective removal of dysfunctional mitochondria is essential to maintain overall cellular homeostasis and cell survival. Consistent with the intergenotypic difference of HBV, our data reveal significant differences regarding the impact of HBx of different genotypes on mitochondrial dynamic and function and thereby on radical oxygen stress levels within the cell. We subsequently observed that the induction of mitophagy differs significantly across the heterogenetic HBx proteins. Therefore, this study provides evidence that HBx-mediated changes in the mitochondria dynamics and functionality strongly depend on the genotype of HBx. This highlights an important contribution of HBx in the process of genotype-dependent liver pathogenesis.

A hepatitis B virus (HBV) sequence variation graph improves alignment and sample-specific consensus sequence construction

Nearly 300 million individuals live with chronic hepatitis B virus (HBV) infection (CHB), for which no curative therapy is available. As viral diversity is associated with pathogenesis and immunological control of infection, improved methods to characterize this diversity could aid drug development efforts. Conventionally, viral sequencing data are mapped/aligned to a reference genome, and only the aligned sequences are retained for analysis. Thus, reference selection is critical, yet selecting the most representative reference a priori remains difficult. We investigate an alternative pangenome approach which can combine multiple reference sequences into a graph which can be used during alignment. Using simulated short-read sequencing data generated from publicly available HBV genomes and real sequencing data from an individual living with CHB, we demonstrate alignment to a phylogenetically representative 'genome graph' can improve alignment, avoid issues of reference ambiguity, and facilitate the construction of sample-specific consensus sequences more genetically similar to the individual's infection. Graph-based methods can, therefore, improve efforts to characterize the genetics of viral pathogens, including HBV, and have broader implications in host-pathogen research.

Host immunity and HBV S gene mutation in HBsAg-negative HBV-infected patients

Background

Clinically, some patients whose HBsAg becomes negative owing to antiviral therapy or spontaneously still show a low level of HBV DNA persistence in serum. T-lymphocyte subsets, cytokine levels and HBV S gene sequences were analyzed in this study.

Methods

A total of 52 HBsAg-negative and HBV DNA-positive patients(HBsAg-/HBV DNA+ patients), 52 persistently HBsAg-positive patients(HBsAg+/HBV DNA+ patients) and 16 healthy people were evaluated. T-lymphocyte subsets of these patients were detected by flow cytometry, serum cytokines and chemokines were detected by the Luminex technique, and the HBV S region was evaluated by Sanger sequencing. T%, T-lymphocyte, CD8+ and CD4+T lymphocyte were lower in the HBsAg-negative group than in the HC group. Compared with the HBsAg-positive group, the HBsAg-negative group had lower levels in T lymphocyte %, CD8+T lymphocyte %, CD8+T lymphocyte and CD4/CD8. These difference were statistically significant (P<0.05). Serum IFN-γ, IFN-α and FLT-3L levels were significantly higher in the HBsAg-negative group than in the HBsAg-positive group (P<0.05). However, levels of many cytokines related to inflammation (i.e., IL-6, IL-8, IL10, IL-12, IL-17A) were lower in the HBsAg-negative group. Fifty-two HBsAg-negative samples were sequenced, revealing high-frequency amino acid substitution sites in the HBV S protein, including immune escape mutations (i.e., Y100C, S114T, C124Y, P127L, G130R, T131N, M133T, C137S, G145A) and TMD region substitutions (i.e., E2K/R/D, G7D/R, G10D, A17R, F20L/S, L21V, L22V).

Conclusions

According to the results of T-lymphocyte subsets and serum cytokines, it can be deduced that the cellular immune function of HBsAg-negative patients is superior to that of HBsAg-positive patients, with attenuation of liver inflammation. HBsAg-negative patients may show a variety of mutations and amino acid replacement sites at high frequency in the HBV S region, and these mutations may lead to undetectable HBsAg, HBsAg antigenic changes or secretion inhibition.

Circulation of multiple hepatitis B virus genotypes in individual pregnant women seeking antenatal care in northern Ghana

BACKGROUND

Identification and monitoring of HBV genotype variations is important, since that can help forecast the likelihood of developing serious liver disease and how well patients respond to antiviral medication. Given that HBV genotyping tests are not widely available in our healthcare system, this study characterized HBV genotypes in pregnant women seeking prenatal treatment in northern Ghana.

METHOD

By a cross-sectional approach, 2071 pregnant women seeking antenatal care in health facilities in northern Ghana were screened for HBV infection using hepatitis B surface antigen (HBsAg) rapid diagnostic test kit. The women were aged between 17 and 41 years, were of varying gravidae (primigravidae and multigravidae) and gestational age (first, second and third trimesters). A confirmatory PCR assay was used to detect HBsAg, and the distribution of HBV genotypes was determined using a nested PCR assay.

RESULTS

Three HBV genotypes (A, D and E) were detected among the pregnant women, of which 175 (91.6%) had genotype E, 9 (4.7%) had mixed genotypes A and E, 5 (2.6%) had mixed genotypes D and E, and 2 (1.1) had mixed genotypes A, D and E. The proportions of women with the different HBV genotypes were independent of age (p = 0.925), gravidity (p = 0.193, χ2 = 4.729) and gestational age (p = 0.227, χ2 = 8.152).

CONCLUSION

This study for the first-time characterized circulating HBV genotypes in pregnant women in northern Ghana, which reveals genotypes A and D are found in mixed infections with genotype E. The findings have clinical implications on the management of chronic HBV infection among pregnant women in northern Ghana.

A Recent Prevalence of Hepatitis B Virus (HBV) Genotypes and Subtypes in Asia: A Systematic Review and Meta-Analysis

Background and Aim: Despite introducing the hepatitis B virus (HBV) vaccine, the incidence of the Hepatitis B virus globally is still a major health concern. This systematic review and meta-analysis were conducted to provide detailed information on the prevalence of HBV genotypes and subtypes in circulation in Asia. Methods: A systematic search for articles describing the prevalence of HBV genotypes and subtypes in Asia was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Results: Our search returned 207 eligible articles involving 49,279 genotypes and 7457 subtypes representing 28 Asian countries. A meta-analysis was performed on our eligible studies using the Random effect Model. The pooled prevalence of HBV genotypes showed that genotype C (30.9%) (95% CI, 27.5–34.5%; I2 = 97.57%; p < 0.001) was the most common HBV genotype in Asia, followed by genotype B (17.8%) (95% CI, 15.5–20.4%; I2 = 97.26%; p < 0.001) and genotype D (15.4%) (95% CI, 11.8–19.8%). Vietnam had the highest prevalence of genotype B, Lebanon had the highest prevalence of genotypes C, and Jordan had the highest prevalence of genotype D. There was variation in genotypic prevalence with respect to the target genes for HBV genotyping. Reverse dot blot hybridization had the highest estimate of genotypes B and C. HBV subtype C2 (40.0%) (95% CI, 33.3–47.0) is the most prevalent HBV subtype. Conclusion: Evidence from this study reveals that HBV genotypes C and B are the most dominant HBV genotypes in Asia, and HBV subtype C2 is more endemic in Asia.

A hepatitis B virus (HBV) sequence variation graph improves sequence alignment and sample-specific consensus sequence construction for genetic analysis of HBV

Hepatitis B virus (HBV) remains a global public health concern, with over 250 million individuals living with chronic HBV infection (CHB) and no curative therapy currently available. Viral diversity is associated with CHB pathogenesis and immunological control of infection. Improved methods to characterize the viral genome at both the population and intra-host level could aid drug development efforts. Conventionally, HBV sequencing data are aligned to a linear reference genome and only sequences capable of aligning to the reference are captured for analysis. Reference selection has additional consequences, including sample-specific 'consensus' sequence construction. It remains unclear how to select a reference from available sequences and whether a single reference is sufficient for genetic analyses. Using simulated short-read sequencing data generated from full-length publicly available HBV genome sequences and HBV sequencing data from a longitudinally sampled individual with CHB, we investigate alternative graph-based alignment approaches. We demonstrate that using a phylogenetically representative 'genome graph' for alignment, rather than linear reference sequences, avoids issues of reference ambiguity, improves alignment, and facilitates the construction of sample-specific consensus sequences genetically similar to an individual's infection. Graph-based methods can therefore improve efforts to characterize the genetics of viral pathogens, including HBV, and may have broad implications in host pathogen research.

Molecular diversity of hepatitis B virus among pregnant women in Amhara National Regional State, Ethiopia

Background

Despite the availability of effective vaccines and treatments for hepatitis B virus (HBV), it continues to be a major public health problem in sub-Saharan Africa including Ethiopia. Routine screening for HBV in pregnant women is widely recommended, but there is lack of screening for HBV during pregnancy in Ethiopia. Therefore, this study aimed to assess viral load, and genetic diversity among pregnant women in the Amhara National Regional State, Ethiopia.

Materials and methods

Hepatitis B surface antigen (HBsAg) testing was performed on 1846 pregnant women, 85 of who tested positive were included in this study. HBV DNA was isolated from 85 positive sera, and the partial surface/polymerase gene was amplified and sequenced. HBV genotypes, sub-genotypes, serotypes and mutations in surface genes and polymerase were studied.

Results

Out of 85 pregnant women`s HBsAg positive sera, 59(69.4%) had detectable viral DNA. The median viral load was 3.4 log IU/ml ranging from 2.6 to7.6 and 46 samples were successfully sequenced and genotyped. Genotypes A and D were identified in 39 (84.8%) and 7 (15.2%); respectively. All genotype A isolates were further classified into sub-genotype A1 and serotype adw2 (84.8%) whereas genotype D isolates were further classified into three sub genotypes; 2 (4.3%) D2, 1(2.2%) D4, and 4 (8.7%) D10 with serotypes ayw2 (10.9%), and ayw3 (4.3%). There were 19 (41.3%) surface gene mutations in the major hydrophilic region (MHR). Six (13.1%) of them were discovered in MHR`s `a’-determinant region. Six polymerase gene mutations (13%) were identified.

Conclusion

Genotype A was the predominant genotype in the Amhara National Regional State. The surface and polymerase gene mutations identified in this study may lead to immune therapy failure, diagnostics escape and drug resistance. Thus, the data generated in this study will contribute to the planning of HBV diagnosis, vaccination and treatment, and most importantly to the prevention of vertical transmission of HBV in Ethiopia. Therefore, further molecular studies on HBV are warranted and continuous surveillance is important for patient management and for the prevention and control of HBV infection in the country.

Molecular detection of hepatitis B virus genotype E with immune escape mutations in chronic hepatitis B patients on long-term antiviral therapy in Jos, Nigeria

Background

Previous studies in Nigeria have reported the presence of hepatitis B virus (HBV) genotype E and the availability of immune escape mutants. There is a paucity of data on chronic patients on long-term antiviral therapy for HBV infection.

Objective

This study assessed HBV genotypes and drug resistance variants among patients with chronic HBV infection receiving tenofovir in Jos, Nigeria.

Methods

This cross-sectional study consecutively enrolled 101 patients (51 with HIV/HBV co-infection and 50 with HBV infection only) on antiviral therapy from February 2018 to May 2019 at four hospitals in Jos, Nigeria. DNA quantification of HBV was performed on all samples; 30 samples with detectable viral load were selected for genotyping using Sanger sequencing by targeting the full-length sequences of reverse transcriptase gene of the HBV genome. Phylogenetic analysis was performed with reference sequences from GenBank. Escape mutant and drug resistance analysis were performed using HBV drug resistance interpretation and Geno2pheno.

Results

Only 30 (29.7%) of the 101 study participants had detectable HBV DNA. Of these, six (20.0%) isolates were successfully amplified and sequenced. The identified genotype was E, including escape mutations L127R (16.7%) and G145A (16.7%).

Conclusion

This study revealed exclusive dominance of genotype E in Nigeria. The S gene mutations G145A and L271R are known to be associated with modified antigenicity and impaired serologic assays, which may cause false negatives in the detection of anti-HBV surface antigen. The presence of mutants that are associated with vaccine immune escape may also have diagnostic and vaccine immune response implications.

Pathogenicity and virulence of Hepatitis B virus

Hepatitis B virus (HBV) is a hepatotropic virus and an important human pathogen. There are an estimated 296 million people in the world that are chronically infected by this virus, and many of them will develop severe liver diseases including hepatitis, cirrhosis and hepatocellular carcinoma (HCC). HBV is a small DNA virus that replicates via the reverse transcription pathway. In this review, we summarize the molecular pathways that govern the replication of HBV and its interactions with host cells. We also discuss viral and non-viral factors that are associated with HBV-induced carcinogenesis and pathogenesis, as well as the role of host immune responses in HBV persistence and liver pathogenesis.

Molecular and genetic characterization of hepatitis B virus among multitransfused thalassaemia patients in Islamabad, Pakistan

Background:

Hepatitis B virus (HBV) is the aetiological agent of transfusion-transmitted hepatitis globally. Beta thalassaemia major individuals are at greater risk of contracting HBV infection due to multiple blood transfusions required for the medical management of these patients. Based on HBV genetic variability, it is divided into 10 genotypes. The determination of HBV genotypes has significant implications for clinical management and treatment regimens.

Aim:

This study was performed to assess the HBV epidemiology and circulating genotypes in multi-transfused β-thalassemia major patients with the aim to be considered while formulating the treatment pattern taking into account particular needs of thalassaemia patients.

Materials and Methods:

This study was performed from September 2018 to June 2019, at the Department of Pathology and Transfusion Medicine, Shaheed Zulfiqar Ali Bhutto (SZAB) Medical University, Islamabad. A total of 2,260 thalassaemia patients were enrolled in the study. The study was endorsed by the Ethics Committee of the SZAB Medical University, Islamabad. The samples were serologically screened for HBsAg on the LIAISON® XL Murex HBsAg Quant assay (DiaSorin S.p.A., Italy) a chemiluminescence based immunoassay (CLIA). HBV quantitative PCR kit was used to measure the HBV DNA in serum samples. The HBV genotypes were determined using universal primers targeting the P1 and S1 region amplification.

Results:

Of 2,260 thalassaemia patients, 64.6% were males while 35.4% were females. The HBsAg was identified in 98 individuals (4.33%). The PCR analysis was done for these 98 patients and in this cohort, genotype D was 59.18% (n = 58), genotype A was 21.42% (n = 21) while genotype C was 19.38% (n = 19).

Conclusion:

The determination of HBV genotypes in the multi-transfused patients is key to the effective management of chronic HBV patients as the severity and course of the disease is dependent on a specific type of genotypes. Quality assured screening of donated blood will prevent the incidence of HBV in thalassaemia patients.

Prevalence of hepatocarcinoma-related hepatitis B virus mutants in patients in grey zone of treatment

BACKGROUND

Antiviral treatment of patients with chronic hepatitis B (CHB) in the grey zone of treatment comands risk management in order to optimize the health outcome. In this sense, the identification of HBV mutants related with an increased risk of hepatocellular carcinoma (HCC) could be useful to identify subpopulations with potential indication of antiviral treatment.

AIM

To analyze the prevalence/persistence of hepatitis B virus (HBV) preS and basal core promoter (BCP)/precore/core variants associated to HCC development in CHB patients in the grey zone.

METHODS

Work was designed as a longitudinal retrospective study, including 106 plasma samples from 31 patients with CHB in the grey zone of treatment: Hepatitis B e antigen negative, HBV-DNA levels between 12-20000 IU/mL, normal or discordant transaminase levels during follow up and mild/moderate necro-inflammatory activity in liver biopsy or Fibroscan (up to 9.5 kPa). Serum HBV-DNA was tested using the Abbott Real Time HBV Assay and the BCP/precore/core and the hepatitis B surface antigen (HBsAg) coding regions were analyzed in positive samples by PCR/bulk-sequencing to identify the HCC-related HBV mutants.

RESULTS

High-risk HCC related mutants were detected in 24 (77%) patients: 19 (61%) in the BCP/precore/core, and 7 (23%) in the HBsAg coding region (2 preS1 and 5 preS2 deletions). The prevalence of preS deletions was genotype-dependent: 3/5 (60%) patients with preS2 deletions and 1/2 with preS1 deletions were infected with the HBV-E genotype. Since HBV-E was the most prevalent in sub-Saharan patients, a correlation between preS deletions and ethnicity was also found: 6/8 (75%) sub-Saharan vs 1/19 (5%) Caucasian patients had preS deletions (P = 0.00016). Remarkably, this correlation was maintained in those patients infected with HBV-A, a minor genotype in sub-Saharan patients: 2/2 patients infected with HBV-A from West Africa vs 0/6 of Caucasian origin had preS deletions. The HCC related variants were the major strains and persisted over time (up to 48 mo). Patients with preS deletions had a significant higher prevalence of F2 fibrosis stage than the negatives (57% vs 10%, P = 0.0078).

CONCLUSION

HBV genetic analysis of selected populations, like sub-Saharans infected with HBV-E/A genotypes, will allow identification of subpopulations with risk of HCC development due to accumulation of high-risk HBV variants, thus commanding their increased clinical surveillance.

Hepatitis B Virus Mutant Infections in Hemodialysis Patients: A Case Series

Rationale & Objective

Hepatitis B virus (HBV) transmission in hemodialysis units has become a rare event since implementation of hemodialysis-specific infection control guidelines: performing hemodialysis for hepatitis B surface antigen (HBsAg)-positive patients in an HBV isolation room, vaccinating HBV-susceptible (HBV surface antibody and HBsAg negative) patients, and monthly HBsAg testing in HBV-susceptible patients. Mutations in HBsAg can result in false-negative HBsAg results, leading to failure to identify HBsAg seroconversion from negative to positive. We describe 4 unique cases of HBsAg seroconversion caused by mutant HBV infection or reactivation in hemodialysis patients.

Study Design

Following identification of a possible HBsAg seroconversion and mutant HBV infection, public health investigations were launched to conduct further HBV testing of case patients and potentially exposed patients. A case patient was defined as a hemodialysis patient with suspected mutant HBV infection because of false-negative HBsAg testing results. Confirmed case patients had HBV DNA sequences demonstrating S-gene mutations.

Setting & Participants

Case patients and patients potentially exposed to the case patient in the respective hemodialysis units in multiple US states.

Results

4 cases of mutant HBV infection in hemodialysis patients were identified; 3 cases were confirmed using molecular sequencing. Failure of some HBsAg testing platforms to detect HBV mutations led to delays in applying HBV isolation procedures. Testing of potentially exposed patients did not identify secondary transmissions.

Limitations

Lack of access to information on past HBsAg testing platforms and results led to challenges in ascertaining when HBsAg seroconversion occurred and identifying and testing all potentially exposed patients.

Conclusions

Mutant HBV infections should be suspected in patients who test HBsAg negative and concurrently test positive for HBV DNA at high levels. Dialysis providers should consider using HBsAg assays that can also detect mutant HBV strains for routine HBV testing.

HBx-K130M/V131I Promotes Liver Cancer in Transgenic Mice via AKT/FOXO1 Signaling Pathway and Arachidonic Acid Metabolism

Chronic hepatitis B viral (HBV) infection remains a high underlying cause for hepatocellular carcinoma (HCC) worldwide, while the genetic mechanisms behind this remain unclear. This study elucidated the mechanisms contributing to tumor development induced by the HBV X (HBx) gene of predominantly Asian genotype B HBV and its common HBx variants. To compare the potential tumorigenic effects of K130M/V131I (Mut) and wild-type (WT) HBx on HCC, the Sleeping Beauty (SB) transposon system was used to deliver HBx Mut and WT into the livers of fumarylacetoacetate hydrolase (Fah)-deficient mice and in the context of transformation related protein 53 (Trp53) deficiency. From our results, HBx Mut had a stronger tumorigenic effect than its WT variant. Also, inflammation, necrosis, and fibrosis were evident in HBx experimental animals. Reduction of forkhead box O1 (FOXO1) with increased phosphorylation of upstream serine/threonine kinase (AKT) was detected under HBx Mut overexpression. Thus, it is proposed that HBx Mut enhances disease progression by reducing FOXO1 via phosphorylation of AKT. At the metabolomic level, HBx altered the expression of genes that participated in arachidonic acid (AA) metabolism, as a result of inflammation via accumulation of proinflammatory factors such as prostaglandins and leukotriene in liver. Taken together, the increased rate of HCC observed in chronic hepatitis B patients with K130M/V131I-mutated X protein, may be due to changes in AA metabolism and AKT/FOXO1 signaling. IMPLICATIONS: Our findings suggested that HBx-K130M/V131I-mutant variant promoted HCC progression by activating AKT/FOXO1 pathway and inducing stronger inflammation in liver via AA metabolism.

Variants of hepatitis B virus surface antigen observed during therapy with nucleic acid polymer REP 2139-Ca have no influence on treatment outcome and its detection by diagnostic assays

The treatment of patients suffering from HBeAg-positive chronic hepatitis B with REP 2139-Ca resulted in potent reductions in HBsAg and HBV DNA, seroconversion to anti-HBs and the establishment of functional control of infection. In this cohort of 12 patients, we investigated whether differences between HBsAg sequences might explain the lack of response to REP 2139-Ca observed in 3 of 12 patients. We also assessed if the reduction or complete loss of HBsAg in serum observed during therapy were caused by mutations in the "a" determinant preventing the detection of HBsAg by standard diagnostic assays. The complete pre-S/S open reading frame (ORF) was sequenced and pre-S1, pre-S2 and S amino acid sequences were analysed. We found no major differences between pre-S1, pre-S2 and S sequences in responders and nonresponders correlated with low reduction in HBsAg. In addition, we found no mutations in the "a" determinant that would significantly affect the reactivity of HBsAg in diagnostic assays. These results demonstrate that the amino acid sequence of complete pre-S/S ORF has no direct influence on response to REP 2139-Ca therapy.

Epidemiology of Hepatitis B Virus Infection in Bangladesh: Prevalence among General Population, Risk Groups and Genotype Distribution

Despite a considerable body of published research on hepatitis B in Bangladesh, researchers continue to lament the lack of reliable information about hepatitis B virus (HBV) infection epidemiology. The present review aims to provide a comprehensive survey of the literature with particular focus on a number of epidemiological questions, as well as a commentary on the trends of hepatitis B research as it has taken place in Bangladesh. The key themes to emerge from this review are: first, beyond noting a declining trend, it is difficult to provide conclusive estimates about HBV prevalence in the general population of Bangladesh. The majority of the studies, even the ones conducted on apparently healthy populations, fail to be adequately representative for the reasons explored in the article. Secondly, HBV infection in Bangladesh is sharply stratified across sociodemographic lines, which speaks to the role of awareness and risk exposure in HBV prevalence. Third, more research on occult infection rates is required to estimate the extent of risk posed by the current blood donation screening program, which relies exclusively on hepatitis B surface antigen as a biomarker. The same considerations apply for the comparative importance of vertical versus horizontal transmission and prevalence among particular risk groups like healthcare workers with high occupational exposure. Finally, while recent studies do allow us, albeit with some ambiguity, to draw conclusions about distribution of HBV genotypes in Bangladesh, there needs to be an added emphasis on molecular epidemiology. It is hoped that the present review, the first of its kind in Bangladesh, will serve as an up-to-date summary of the course HBV epidemiology research in Bangladesh has taken thus far, as well as crucial gaps to address going forward.

Detection of in vivo hepatitis B virus surface antigen mutations-A comparison of four routine screening assays

An important requirement for a state-of-the-art hepatitis B surface antigen (HBsAg) screening assay is reliable detection of mutated HBsAg. Currently, there is a striking shortage of data regarding the detection rates of in vivo HBsAg mutations for these clinically important assays. Therefore, we compared the detection rates of four commercial HBsAg screening assays using a global cohort of 1553 patients from four continents with known HBV genotypes. These samples, which represent the broadest spectrum of known and novel HBsAg major hydrophilic region (MHR) mutations to date, were analyzed for the presence of HBsAg using the Roche Elecsys^® HBsAg II Qualitative, Siemens ADVIA Centaur XP HBsAg II, Abbott Architect HBsAg Qualitative II and DiaSorin Liaison^® HBsAg Qualitative assays, respectively. Of the 1553 samples, 1391 samples could be sequenced; of these, 1013 (72.8%) carried at least one of the 345 currently known amino acid substitutions (distinct HBsAg mutation) in the HBsAg MHR. All 1553 patient samples were positive for HBsAg using the Elecsys^® HBsAg II Qual assay, with a sensitivity (95% confidence interval) of 99.94% (99.64%-100%), followed by the Abbott Architect 99.81% (99.44%-99.96%), Siemens ADVIA 99.81% (99.44%-99.96%) and DiaSorin Liaison^® 99.36% (98.82%-99.69%) assays, respectively. Our results indicate that the Elecsys^® HBsAg II Qual assay exhibits the highest sensitivity among the commercial HBsAg screening assays, and demonstrate that its capacity to detect HBV infection is not compromised by HBsAg MHR mutants.

Hepatocellular carcinoma among US and non-US-born patients with chronic hepatitis B: Risk factors and age at diagnosis

BACKGROUND

Risk factors for hepatocellular carcinoma (HCC) have not been well characterized among African immigrants with chronic hepatitis B virus (HBV) infection. We conducted a case-control study to identify demographic and clinical factors associated with HCC among a diverse cohort of patients with chronic HBV infection seen in a large academic health setting.

METHODS

We identified a total of 278 patients with HCC and chronic HBV seen at two medical centers in a 14-year span from January 2002 to December 2015. These cases were age- and sex-matched in a 1:3 ratio with 823 non-cancer control subjects with chronic HBV. Conditional logistic regression was used to estimate the odds of HCC by race, with black race stratified by African-born status, after adjusting for diabetes, HIV or HCV coinfection, alcohol misuse and cirrhosis.

RESULTS

Of the 278 HCC cases, 67% were 60 years of age or older, 78% were male, 87% had cirrhosis and 72% were Asian. HIV infection was present in 6% of cases. Only 7% (19 of 278) of HCC cases were black, of whom 14 were African immigrants. The median age at HCC diagnosis was 44 years in Africans. Notably, nearly all (93%) of the African-born patients with HCC were diagnosed at an age younger than 60 years compared with 52% of Asian cases (P<0.001). The main factors independently associated with greater odds of HCC overall were Asian race (adjusted odds ratio [aOR] 3.3, 95% confidence interval [CI] 1.9-5.5) and cirrhosis (aOR 19.7, 95% CI 12.2-31.8).

CONCLUSION

African immigrants accounted for a small proportion of HBV-associated HCC cases overall compared with Asians but appeared to have greater likelihood of early-onset HCC. Optimal strategies for HCC prevention in these key subroups with chronic HBV warrant further study.

viGEN: An Open Source Pipeline for the Detection and Quantification of Viral RNA in Human Tumors

An estimated 17% of cancers worldwide are associated with infectious causes. The extent and biological significance of viral presence/infection in actual tumor samples is generally unknown but could be measured using human transcriptome (RNA-seq) data from tumor samples. We present an open source bioinformatics pipeline viGEN, which allows for not only the detection and quantification of viral RNA, but also variants in the viral transcripts. The pipeline includes 4 major modules: The first module aligns and filter out human RNA sequences; the second module maps and count (remaining un-aligned) reads against reference genomes of all known and sequenced human viruses; the third module quantifies read counts at the individual viral-gene level thus allowing for downstream differential expression analysis of viral genes between case and controls groups. The fourth module calls variants in these viruses. To the best of our knowledge, there are no publicly available pipelines or packages that would provide this type of complete analysis in one open source package. In this paper, we applied the viGEN pipeline to two case studies. We first demonstrate the working of our pipeline on a large public dataset, the TCGA cervical cancer cohort. In the second case study, we performed an in-depth analysis on a small focused study of TCGA liver cancer patients. In the latter cohort, we performed viral-gene quantification, viral-variant extraction and survival analysis. This allowed us to find differentially expressed viral-transcripts and viral-variants between the groups of patients, and connect them to clinical outcome. From our analyses, we show that we were able to successfully detect the human papilloma virus among the TCGA cervical cancer patients. We compared the viGEN pipeline with two metagenomics tools and demonstrate similar sensitivity/specificity. We were also able to quantify viral-transcripts and extract viral-variants using the liver cancer dataset. The results presented corresponded with published literature in terms of rate of detection, and impact of several known variants of HBV genome. This pipeline is generalizable, and can be used to provide novel biological insights into microbial infections in complex diseases and tumorigeneses. Our viral pipeline could be used in conjunction with additional type of immuno-oncology analysis based on RNA-seq data of host RNA for cancer immunology applications. The source code, with example data and tutorial is available at: https://github.com/ICBI/viGEN/.

Efficacy and Safety of Entecavir 0. 5 mg in Treating Naive Chronic Hepatitis B Virus Patients in Egypt: Five Years of Real Life Experience

Background

The aim of the study was to evaluate the efficacy and safety of entecavir (ETV) among chronic hepatitis B (CHB) nucleos(t)ide-naive Egyptian patients.

Methods

Forty-eight CHB patients on ETV were included. Males comprised 83.3% (40 cases), while females comprised 16.7% (eight cases). Minimum age was 19 years, while maximum age was 64 years. Hepatitis B envelope antigen (HBeAg)-negative cases were 60.4%. HBeAg-positive cases were 39.6%. Factors including sex, positive HBeAg, baseline hepatitis B virus (HBV) DNA level, baseline alanine aminotransferase (ALT) and aspartate aminotransferase (AST), were evaluated in terms of their predictive role in treatment response, which was defined as a serum HBV DNA decrease of < 10 IU/mL.

Results

Mean age of patients was 38.2 years; males were 83.3% and females were 16.7%. HBeAg-negative cases were 60.4%, while HBeAg-positive cases were 39.6%. Mean baseline DNA level was 44 × 10⁶ IU/mL. Ultrasound results showed 14 cases had hepatomegaly, 10 cases had bright liver, seven cases had coarse liver, and eight cases had cirrhosis. Of the cases, 45.8% showed a negative PCR after the first 6 months of therapy to reach 64.6% by the end of the first year. HBV DNA undetectability reached 91.3% and 100% after 4 and 5 years, respectively for those who completed the study period. ALT reduction started after 6 months of treatment and reached 53.37% after 5 years. Similarly AST showed the same pattern of decline and reached 54.37% after 5 years. Only two cases achieved HBeAg seroconversion. Three patients experienced virological breakthrough and the three cases shared similar characteristics of being less than 40 years, with baseline HBV DNA of ≥ 10⁵ IU/mL and positive HBeAg. None of the cases showed hepatitis B surface antigen (HBsAg) seroconversion.

Conclusion

ETV proved to have a potent antiviral efficacy and safety in nucleoside/tide-naive Egyptian patients. Rate of HBV DNA undetectability was higher in patients above 40 years of age and in patients who initially had a low viral load. ETV was well tolerated during the treatment period with a good overall safety profile.

Hepatitis B virus DNA polymerase gene polymorphism based prediction of genotypes in chronic HBV patients from Western India

Background

Hepatitis B Virus (HBV) infection is one of the major causes of liver cirrhosis, hepatocellular carcinoma and deaths due to the acute or chronic consequences worldwide. HBV is distributed into various genotypes based on nucleic acid sequence variation.

Objectives

To develop a method of HBV genotyping and drug resistance interpretation using partial sequencing of polymerase gene.

Methods

This study was performed on 98 HBV infected patients' serum samples from Western India. A nested PCR protocol was designed for amplification of pol gene from HBV genome and Sanger's sequencing of the gene fragment. Sequences were aligned with HBV reference sequences for phylogenetic analysis and for characterization of genetic diversity. Drug resistance mutations were screened using HBVSeq program from Stanford University.

Results

Distribution of HBV genotypes showed predominance of genotype D, circulating in 76 (77.55%) patients (p < 0.05). Genotypes A and C were less prevalent and were identified in 4 (4.08%) and 18 (18.37%) patients, respectively. Anti-retroviral drug resistance mutations were not detected in any patient.

Conclusion

A method for determination of HBV genotypes using pol gene sequencing which simultaneously detects major drug resistance mutations has been established. HBV genetic diversity may play an important role in treatment decision.

Gamma-Glutamyl Transpeptidase-to-Platelet Ratio Predicts Significant Liver Fibrosis of Chronic Hepatitis B Patients in China

Background and Aims

We want to investigate whether a novel noninvasive marker is suitable for Chinese CHB patients.

Methods

A total of 160 treatment-naïve CHB patients who underwent liver biopsy were enrolled in our study, and we assessed the diagnostic accuracies of GPR, aspartate transaminase-to-platelet ratio index (APRI), and the fibrosis index based on 4 factors (FIB-4) in them.

Results

Of these 160 CHB patients, the numbers of F0, F1, F2, F3, and F4 are 34 (21.3%), 62 (38.8%), 18 (11.3%), 24 (15%), and 22 (13.8%), respectively. The area under the receiver operating characteristic curves (AUROC) of GPR for fibrosis (0.77 versus 0.70, P = 0.03), significant fibrosis (0.70 versus 0.63, P = 0.02), and extensive fibrosis (0.71 versus 0.64, P = 0.02) were significantly higher than those of APRI. The AUROCs of GPR and Fib-4 for fibrosis (0.77 versus 0.75, P = 0.14), significant fibrosis (0.70 versus 0.70, P = 0.22), extensive fibrosis (0.71 versus 0.68, P = 0.13), and cirrhosis (0.64 versus 0.67, P = 0.24) were comparable.

Conclusions

The GPR can be a routine laboratory marker to stage liver fibrosis in patients with CHB in China.

HBV infection in untreated HIV-infected adults in Maputo, Mozambique

Background

HIV/ HBV coinfected patients are at high risk of developing chronic HBV infection, liver cirrhosis and hepatocellular carcinoma. In Mozambique, where HIV prevalence is one of the highest in the world, HIV-infected patients are scarcely characterized in terms of HBV coinfection and 3TC-resistance mutations profile.

Methods

To characterize ART-naïve HIV-infected adults, with and without HBV coinfection, a cross-sectional study was conducted between May and November 2012 in two health centers from Maputo city, Mozambique. Subjects were consecutively enrolled in the study and, then, tested for hepatitis B surface antigen (HBsAg). Moreover, CD4⁺ T cells count, HBV DNA in plasma, HBV genotyping and 3TC-resistance mutations profile of HBV were assessed in HIV/HBV coinfected patients.

Results

In total, 518 patients were enrolled in the study. The median age was 33 years old and 66.8% were women. The median CD4⁺ T cells count was 361 cells/mm³ and 47 (9.1%) were coinfected with HBV. Out of 46 coinfected patients, 24 (55.2%) had HBV DNA ≥ 20 - < 20 000 and 12 (26.1%) had HBV-DNA ≥20 000. APRI > 2.0 was reported in 4.3% of coinfected and 1.7% of monoinfected patients (p = 0.228), while FIB-4 > 3.25 was reported in 4.4% of coinfected and 1.3% of monoinfected patients (p = 0.112). Genotype A was the most frequent, identified in 25/27 (92.6%) patients, whereas genotype E was present in 2/27 (7.4%) patients. No patient had 3TC-resistance mutations.

Conclusions

This study showed that HBV coinfection was prevalent among ART-naïve HIV-infected adults in Mozambique. Overall, these data highlight the importance of screening HBV coinfection as an integrated measure of HIV routine care to improve health conditions and treatment of HIV/HBV coinfected patients.

Mechanism and prediction of HCC development in HBV infection

Chronic hepatitis B virus (HBV) infection remains one of the leading causes of hepatocellular carcinoma (HCC) globally. Over the past few decades, the risk factors of HCC in patients with chronic hepatitis B have been well characterized, and can be divided into host and viral factors. A few groups have also derived and validated HCC prediction scores based on these risk factors. In general, the scores have high negative predictive value in identifying a low risk group who may not need HCC surveillance in the next 3-5 years. The scores have been tested originally in Asian patients, and results on their performance in the Caucasian population are conflicting. Furthermore, new research has identified genetic factors and new virological markers (e.g. hepatitis B surface antigen and core-related antigen levels) for HCC, but they are yet to be applied in routine clinical practice.

Interleukin-1 receptor antagonist expression is inversely associated with outcomes of hepatitis B-related acute-on-chronic liver failure

Interleukin-1 receptor antagonist (IL-1ra) is a naturally occurring anti-inflammatory antagonist of the proinflammatory cytokine IL-1, a critical factor in many inflammatory diseases. The aim of the present study was to investigate the role of IL-1ra in hepatitis B-related acute-on-chronic liver failure (HB-ACLF). Serum cytokine concentrations were measured using a Q-Plex array in 31 patients with HB-ACLF, 28 patients with acute hepatitis B (AHB), 31 patients with chronic hepatitis B (CHB) and 15 healthy control patients (HCs). Additionally, peripheral blood mononuclear cells (PBMCs) from patients with HB-ACLF were incubated with PBS or lipopolysaccharide and/or different concentrations of recombinant human IL-1ra (rhIL-1ra) in vitro. Cytokines in the supernatant were measured using a Q-Plex array. The median serum IL-1ra level in patients with HB-ACLF was 186.46 (350.22) pg/ml, which was significantly higher than all other groups (AHB, P=0.012; CHB, P<0.001; HCs, P<0.001). However, the ratio of IL-1ra/IL-1β was significantly lower in the HB-ACLF group compared with the AHB group (P=0.048). Median serum IL-1ra levels in patients with AHB were also significantly increased compared with those in the CHB (P<0.001) and HC (P<0.001) groups. Patients who succumbed to mortality within 3 months of the study were found to have significantly lower IL-1ra concentrations (P=0.02) and IL-1ra/IL-1β ratios (P=0.007) compared with surviving patients with HB-ACLF. Furthermore, serum IL-1ra concentrations were negatively associated with the Model for End-stage Liver Disease score (r=−0.870; P<0.001). Cytokine secretion by PBMCs in vitro was significantly inhibited in a dose-dependent manner by rhIL-1ra (125–500 ng/ml; all P<0.05). These results suggest that IL-1ra is associated with the development of liver inflammation, which is reduced in patients with HB-ACLF and inversely associated with disease severity.

Identification of Novel A2/C2 Inter-Genotype Recombinants of Hepatitis B Virus from a Korean Chronic Patient Co-Infected with Both Genotype A2 and C2

Nearly all cases of Hepatitis B virus (HBV) infections in South Korea have the C2 genotype. Here, we have identified a chronically infected patient who was co-infected with HBV of both the A2 and C2 genotypes by screening 135 Korean chronically infected patients using direct sequencing protocols targeting the 1032-bp polymerase reverse transcriptase (RT) region. Further polymerase chain reaction (PCR)-cloning analysis (22 clones) of the RT showed that this patient had genotype C2 (12 clones), genotype A2 (six clones) and A2/C2 inter-genotype HBV recombinants (four clones). BootScan analysis showed that three of the four recombinants have different types of recombination breakpoints in both the RT and overlapping hepatitis B surface antigen (HBsAg) region. Given the significance of HBsAg as a diagnostic or vaccination target against HBV infection, clinical implications of these identified recombinants should be studied in the future. To our knowledge, this is the first report on A2/C2 inter-genotype HBV recombinants.

High association of T1858-G1896 precore mutations with impaired base pairing and high hepatitis B virus DNA levels in HBeAg-negative chronically infected patients

The progression of liver disease in hepatitis B virus (HBV) infection is fostered by active virus replication. Mutations in the basal core promoter (BCP) and precore (PC) regions of the HBV genome are known to have an impact on viral replication. The aim of the present study was to assess the correlation of mutation profiles in the BCP and PC regions with the viral load in HBeAg-negative chronically infected patients. The HBV genotype, BCP/PC mutations, serum HBV DNA levels, and associated serological markers were analyzed in 92 HBeAg-negative chronically infected patients. Sequence analysis of the BCP and PC regions revealed variability of 19% and 24.1%, respectively. This variability was primarily associated with five critical positions (1753, 1762, 1764, 1896 and 1899). An elevated HBV viral load (>20,000 IU/ml) was classically correlated with F2-F4 liver fibrosis, elevated serum alanine aminotransferase levels, 1762/1764 and 1753 combination mutations, and surprisingly, with an 1858T-1896G double mutation that impairs base pairing at the base of the bulge in the ε encapsidation signal. An analysis of covariance confirmed the independent nature of the relationship between the 1858T-1896G double mutation and the HBV viral load. In conclusion, independently of conventional parameters, this study demonstrates that a high serum HBV DNA level was also associated with PC 1858-1896 mutations. These BCP/PC mutations may have important clinical implications as predictive factors for HBV DNA increase.

Hepatitis B virus full-length genomic mutations and quasispecies in hepatocellular carcinoma

BACKGROUND AND AIM

Hepatitis B virus (HBV) full-length genomic mutations and quasispecies characteristics in hepatocellular carcinoma (HCC) were investigated.

METHODS

Hepatitis B virus DNA was extracted from the tumor and non-tumor tissues of 16 HCC patients. Overlapping DNA fragments covering the entire HBV genome were amplified and sequenced. To study HBV sequence at the quasispecies level, the preS region was amplified and clonally sequenced. HBV mutation profiles, quasispecies complexity and diversity, and phylogenetic characteristics were assessed.

RESULTS

Fourteen patients had full-length HBV amplification. Hot-spot mutations at HBx aa130-131 and pre-S deletions were detected in 13 (93%) and 6 (43%) patients, respectively. Deletions in the X/preC/C regions were more frequently detected in the tumor than in the non-tumor tissues (P = 0.031). Compared with the non-tumor tissues, the tumor tissues had a lower quasispecies complexity (P = 0.014 and 0.043, at the nucleotide and amino acid levels, respectively) and diversity (P = 0.048 and 0.022, at the nucleotide and amino acid levels, respectively). Phylogenetic analysis showed that HBV sequences derived from tumor and non-tumor tissues were separately clustered, suggesting the occurrence of compartmentalization, which was confirmed by the correlation coefficient testing on both the number and length of branches of viral populations (all P < 0.02).

CONCLUSIONS

Hepatitis B virus mutation patterns in HCC tumor tissues and non-tumor tissues were different. HBV quasispecies within the preS region were compartmentalized, and tumor tissues had a lower genome complexity and diversity. Our study suggests HBV evolution is conditioned by the differential host cellular environment in HCC tumors.

Distribution and clinical significance of hepatitis B virus genotypes in Pakistan

Background

Hepatitis B virus (HBV) genotype and its role in disease progression and patients’ response to antiviral treatment, is not well studied in Pakistan. This comprehensive study was aimed to determine the distribution of HBV genotypes in Pakistan and their possible association with phases of HBV infection.

Methods

A total of 840 HBsAg positive samples was collected and tested for HBV DNA quantity. Samples below 100 IU/ml were excluded from the study. A total of 715 samples representing all the six parts of the country were genotyped by type specific primer PCR method. Clinical data of only 384 patients was compared as the remaining 332 were either receiving antiviral treatment or their infection phase was not confirmed.

Results

Genotype D was found in 509 samples (71.2 %), genotype A in 55 samples (7.7 %) and mixed infection with genotypes A and D in 124 samples (17.3 %). Genotypes B, C and E were identified in less than 1 % of the total samples. Genotype A, D and their mixture (A + D) were compared for severity of HBV infection. Significant differences were not found in distribution of HBV genotypes among different disease stages.

Conclusion

HBV genotype D was the predominant infection in all study areas of Pakistan followed by mixed genotypes infection (A + D) whereas genotype A has 10 times lower prevalence than genotype D. Genotypes B, C, E and F altogether make only 1.5 % of the prevalence. Genotype do not appears to show the severity of liver disease.

Single-Molecule Sequencing Reveals Complex Genome Variation of Hepatitis B Virus during 15 Years of Chronic Infection following Liver Transplantation

Chronic hepatitis B (CHB) is prevalent worldwide. The infectious agent, hepatitis B virus (HBV), replicates via an RNA intermediate and is error prone, leading to the rapid generation of closely related but not identical viral variants, including those that can escape host immune responses and antiviral treatments. The complexity of CHB can be further enhanced by the presence of HBV variants with large deletions in the genome generated via splicing (spHBV variants). Although spHBV variants are incapable of autonomous replication, their replication is rescued by wild-type HBV. spHBV variants have been shown to enhance wild-type virus replication, and their prevalence increases with liver disease progression. Single-molecule deep sequencing was performed on whole HBV genomes extracted from samples, including the liver explant, longitudinally collected from a subject with CHB over a 15-year period after liver transplantation. By employing novel bioinformatics methods, this analysis showed that the dynamics of the viral population across a period of changing treatment regimens was complex. The spHBV variants detected in the liver explant remained present posttransplantation, and a highly diverse novel spHBV population as well as variants with multiple deletions in the pre-S genes emerged. The identification of novel mutations outside the HBV reverse transcriptase gene that co-occurred with known drug resistance-associated mutations highlights the relevance of using full-genome deep sequencing and supports the hypothesis that drug resistance involves interactions across the full length of the HBV genome.

IMPORTANCE

Single-molecule sequencing allowed the characterization, in unprecedented detail, of the evolution of HBV populations and offered unique insights into the dynamics of defective and spHBV variants following liver transplantation and complex treatment regimens. This analysis also showed the rapid adaptation of HBV populations to treatment regimens with evolving drug resistance phenotypes and evidence of purifying selection across the whole genome. Finally, the new open-source bioinformatics tools with the capacity to easily identify potential spliced variants from deep sequencing data are freely available.

Molecular epidemiology of hepatitis B virus in Misiones, Argentina

Hepatitis B virus (HBV) infection is a major public health problem worldwide. The aims of this study were to describe the molecular epidemiology of HBV in the Province of Misiones, Argentina and estimate the phylodynamic of the main groups in a Bayesian coalescent framework. To this end, partial or complete genome sequences were obtained from 52 blood donor candidates. The phylogenetic analysis based on partial sequences of S/P region showed a predominance of genotype D (65.4%), followed by genotype F (30.8%) and genotype A as a minority (3.8%). At subgenotype level, the circulation of subgenotypes D3 (42.3%), D2 (13.5%), F1b (11.5%) and F4 (9.6%) was mainly identified. The Bayesian coalescent analysis of 29 complete genome sequences for the main groups revealed that the subgenotypes D2 and D3 had several introductions to the region, with ancestors dating back from 1921 to 1969 and diversification events until the late '70s. The genotype F in Misiones has a more recent history; subgenotype F4 isolates were intermixed with sequences from Argentina and neighboring countries and only one significant cluster dated back in 1994 was observed. Subgenotype F1b isolates exhibited low genetic distance and formed a closely related monophyletic cluster, suggesting a very recent introduction. In conclusion, the phylogenetic and coalescent analyses showed that the European genotype D has a higher circulation, a longer history of diversification and may be responsible for the largest proportion of chronic HBV infections in the Province of Misiones. Genotype F, especially subgenotype F1b, had a more recent introduction and its diversification in the last 20years might be related to its involvement in new transmission events.

The Gamma-Glutamyl-Transpeptidase to Platelet Ratio Does not Show Advantages than APRI and Fib-4 in Diagnosing Significant Fibrosis and Cirrhosis in Patients With Chronic Hepatitis B: A Retrospective Cohort Study in China

The gamma-glutamyl-transpeptidase to platelet ratio (GPR) is a new liver fibrosis model, which is reported to be more accurate than aspartate transaminase (AST) to platelet ratio index (APRI) and fibrosis index based on the four factors (Fib-4) for diagnosing significant fibrosis and cirrhosis in patients with chronic hepatitis B (CHB) in West Africa. The aim of this study is to assess the diagnostic accuracy of GPR for significant fibrosis and cirrhosis in Chinese CHB patients, and explore whether GPR deserves to be popularized in China. A total of 372 CHB patients who underwent liver biopsies and routine laboratory tests were retrospectively studied. The Scheuer scoring system was adopted as the pathological standard of liver fibrosis. Using liver histology as a gold standard, the diagnostic accuracies of GPR, APRI, and Fib-4 for significant fibrosis and cirrhosis are evaluated and compared by the receiver operating characteristic (ROC) curves and the area under the ROC curves (AUROCs). Of these 372 patients, 176 (47.3%), 129 (34.7%), and 72 (19.4%) were classified as having significant fibrosis (≥ S2), severe fibrosis (≥ S3), and cirrhosis (S4), respectively. The AUROCs of GPR for significant fibrosis (0.72 vs. 0.78; P = 0.01), severe fibrosis (0.75 vs. 0.80; P = 0.04), and cirrhosis (0.78 vs. 0.83; P = 0.02) were lower than those of APRI. The AUROCs of GPR and Fib-4 for diagnosing significant fibrosis (0.72 vs. 0.70; P = 0.29), severe fibrosis (0.75 vs. 0.73; P = 0.33), and cirrhosis (0.78 vs. 0.75; P = 0.38) were comparable. GPR is a new serum diagnostic model for liver fibrosis and cirrhosis, but does not show advantages than APRI and Fib-4 in identifying significant fibrosis, severe fibrosis, and cirrhosis in CHB patients in China.

Characterization of Occult Hepatitis B Infection Among Injecting Drug Users in Tehran, Iran

BACKGROUND

Hepatitis B virus (HBV) infection is a major health problem worldwide.

OBJECTIVES

The aim of this study was to investigate the frequency of occult hepatitis B infection (OBI) and its associated risk factors, together with the molecular characterization of the virus in injecting drug users of Tehran.

PATIENTS AND METHODS

The study consisted of 229 injecting drug users. Serum samples were collected and tested for the presence of hepatitis B core antibody (HBcAb) and hepatitis B surface antigen (HBsAg) by an enzyme-linked immunosorbent assay (ELISA). HBV B virus DNA was extracted from the serum samples, and a fragment of the S gene was amplified using the nested polymerase chain reaction. The genotype, subgenotypes, subtype, and S gene mutation of HBV were determined by direct sequencing. A phylogenetic tree was constructed using the neighbor-joining method.

RESULTS

Sixty-four (28%) participants were HBcAb positive, 59 cases were HBcAb positive and HBsAg negative, and 5 cases were HBsAg positive. Hepatitis B DNA was found in three HBsAg-positive cases. Thirteen of 59 (22%) individuals were hepatitis B DNA positive. The phylogenetic tree of hepatitis B DNA showed the existence of genotype D. The only significant correlation was between sharing a syringe and OBI.

CONCLUSIONS

In comparison with the rate of HBcAb positivity reported in other Iranian studies, the rate was higher in the present study. There were a few variations, genotypes, and subtypes among the infected injecting drug users. Further investigations are needed to unravel the molecular characterization of OBI.

Prevalence of genotypes and subtypes of hepatitis B viruses in Bangladeshi population

The genetic variability of hepatitis B virus (HBV) represents a challenge for the sensitivity of immunologic and molecular based assays. Based on sequence divergences in the entire genome of >8 %, HBV genomes have been classified into ten genotypes designated as A to J. The aim of this study was to determine HBV genotypes and subtype in samples of HBV infected patients in Bangladesh. The sera samples were collected from chronically infected HBV patients. At first the DNA positive HBV samples were screened by EIA in our laboratory and the 1063 bp region of surface gene was amplified, sequenced and genotyped by sequence analysis. The same sequences were also used for subtypes and mutational analyses. After that, genotyping was also carried out by nested PCR using genotype specific primers in the same region of HBV surface gene. A total of 39 samples were sequencing to find out the genotypes and subtypes. It was found that the prevalent genotype was genotype C (subgenotype C1) which accounted for 48.7 %. The other genotypes found were genotype A (23.1 %) and genotype D (28.2 %). Predominant subtypes in Bangladesh were adr (41 %) followed by subtype adw2 (28.2 %), ayw3 (25.6 %), and others. Additionally, genotyping was also done by nested PCR using type-specific primers. In this method, out of 17 samples 6 were found to be genotype C, followed by genotype D (4 of 17) and genotype A (3 of 17). In PCR-based genotyping system we also observed the mix genotypes; 3 samples contained both genotype A and D, and 2 samples contained both C and D. The genetic diversity of HBV and distribution of its genotypes and subtypes amongst Bangladeshi population were done in this study, which will help us to provide information regarding circulating genotypes in this region and also help physicians to prescribe proper antiviral/interferon therapy.

Overview of hepatitis B virus mutations and their implications in the management of infection

Hepatitis B virus (HBV) affects approximately two billion people worldwide and more than 240 million people in the world are currently chronic carrier that could develop serious complications in the future, like liver cirrhosis and hepatocellular carcinoma. Although an extended HBV immunization program is being carried out since the early ‘80s, representing effective preventive measure, leading to a dramatic reduction of HBV hepatitis incidence, globally HBV infection still represents a major public health problem. The HBV virus is a DNA virus belongs to the Hepadnaviridae family. The HBV-DNA is a circular, partial double strand genome. All coding information is on the minus DNA strand and it is organized into four open reading frames. Despite hepatitis B virus is a DNA virus, it has a high mutation rate due to its replicative strategy, that leads to the production of many non-identical variants at each cycle of replication. In fact, it contains a polymerase without the proofreading activity, and uses an RNA intermediate (pgRNA) during its replication, so error frequencies are comparable to those seen in retroviruses and other RNA viruses rather than in more stable DNA viruses. Due to the low fidelity of the polymerase, the high replication rate and the overlapping reading frames, mutations occur throughout the genome and they have been identified both in the structural and not structural gene. The arise of mutations being to develop of a whole of viral variants called “quasi-species” and the prevalent population, which favors virus replication, was selected by viral fitness, host’s immune pressure and external pressure, i.e., vaccination or antiviral therapy. Naturally occurring mutations were found both in acute and chronic subjects. In the present review we examine and discuss the most recent available data about HBV genetic variability and its significance.

Genetic variation of hepatitis B virus and its significance for pathogenesis

Hepatitis B virus (HBV) has a worldwide distribution and is endemic in many populations. Due to its unique life cycle which requires an error-prone reverse transcriptase for replication, it constantly evolves, resulting in tremendous genetic variation in the form of genotypes, sub-genotypes, and mutations. In recent years, there has been considerable research on the relationship between HBV genetic variation and HBV-related pathogenesis, which has profound implications in the natural history of HBV infection, viral detection, immune prevention, drug treatment and prognosis. In this review, we attempted to provide a brief account of the influence of HBV genotype on the pathogenesis of HBV infection and summarize our current knowledge on the effects of HBV mutations in different regions on HBV-associated pathogenesis, with an emphasis on mutations in the preS/S proteins in immune evasion, occult HBV infection and hepatocellular carcinoma (HCC), mutations in polymerase in relation to drug resistance, mutations in HBV core and e antigen in immune evasion, chronicalization of infection and hepatitis B-related acute-on-chronic liver failure, and finally mutations in HBV x proteins in HCC.

Genotyping of occult hepatitis B virus infection in Egyptian hemodialysis patients without hepatitis C virus infection

BACKGROUND

Occult hepatitis B viral infection is the presence of hepatitis B viral nucleic acids in the serum and/or liver in the absence of hepatitis B surface antigen.

AIM

The study aimed to determine the prevalence of occult hepatitis B virus infection among hepatitis C virus-negative hemodialysis patients and to identify their genotypes.

METHODS

of 144 patients on maintenance hemodialysis, 50 hepatitis B surface antigen and hepatitis C virus nucleic acid-negative patients were selected according to strict inclusion criteria to avoid the effect of confounding variables. The following investigations were done: serum AST and ALT; HBsAg; HBcAb; HCV-Ab; HCV-RNA; and HBV-DNA.

RESULTS

Positive hepatitis B viral nucleic acid was confirmed in 12/144 (8.3%) hemodialysis patients and 12/50 (24%) in our study group (occult infection). Mean hemodialysis periods for negative patients and occult hepatitis B virus patients were 27.3±18.8 and 38.4±8.14 months, respectively, and this difference was significant (p-value=0.02). Mean alanine transaminase levels were 20.27±5.5IU/L and 25.3±9.6 in negative patients and occult infection patients, respectively. This difference was non-significant. Aspartate transaminase levels were 21.4±10.2IU/L and 27.3±4.6IU/L, respectively, in negative patients and infected patients; this difference was significant (p-value=0.03). Half (6/12) of the positive samples belonged to genotype 'B', 33.3% (4/12) to 'C', and 16.6% (2/12) to genotype 'D'.

CONCLUSION

OBI is likely among hemodialysis patients even without HCV coinfection (24%). Genotype D cannot be the only genotype distributed in Upper Egypt, as the current study reported relatively new results that 50% of the patients with occult B carry genotype B, 33.3% carry genotype C and only 16.6% carry genotype D.

Molecular epidemiology and genetic diversity of hepatitis B virus in Ethiopia

Although hepatitis B virus (HBV) infection is hyperendemic in Ethiopia and constitutes a major public health problem, little is known about its genetic diversity, genotypes, and circulation. The aim of this study was to determine the molecular epidemiology and genetic diversity of HBV in Ethiopia, using 391 serum samples collected from HBsAg-positive blood donors living in five different geographic regions. The HBV S/pol gene was amplified, sequenced, and HBV genotypes, subgenotypes, serotypes, and major hydrophilic region (MHR) variants were determined. Phylogenetic analysis of 371 samples (95%) revealed the distribution of genotypes A (78%) and D (22%) in Ethiopia. Further phylogenetic analysis identified one subgenotype (A1) within genotype A, and 4 subgenotypes within genotype D (D1; 1.3%, D2; 55%, D4; 2.5%, and D6; 8.8%). Importantly, 24 isolates (30%) of genotype D formed a novel phylogenetic cluster, distinct from any known D subgenotypes, and two A/D recombinants. Analysis of predicted amino-acid sequences within the HBsAg revealed four serotypes: adw2 (79%), ayw1 (3.1%), ayw2 (7.8%), and ayw3 (11.6%). Subsequent examination of sequences showed that 51 HBV isolates (14%) had mutations in the MHR and 8 isolates (2.2%) in the reverse transcriptase known to confer antiviral resistance. This study provides the first description of HBV genetic diversity in Ethiopia with a predominance of subgenotypes A1 and D2, and also identified HBV isolates that could represent a novel subgenotype. Furthermore, a significant prevalence of HBsAg variants in Ethiopian population is revealed.

Hepatitis B virus genotype, mutations, human leukocyte antigen polymorphisms and their interactions in hepatocellular carcinoma: a multi-centre case-control study

Three genome-wide association studies (GWAS) have been conducted on the genetic susceptibility of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), two of which consistently identified tagging single nucleotide polymorphisms (SNPs) around HLA-DQ/DR. In contrast, large multi-centre association studies between HBV genotype, mutations and the risk of HCC are relatively rare, and their interactions with host variants are even less. We performed a multi-centre study of 1,507 HBV-related HCC cases and 1,560 HBV persistent carriers as controls to evaluate the effects of HBV genotype, mutations, GWAS-identified HLA-DQ/DR SNPs (rs9272105 and rs9275319) and their interactions on HCC risk. We found HBV genotype C was more frequent in HBV-related HCC. And 11 HBV hotspot mutations were independently and significantly associated with HCC risk. We also detected significant interactions of rs9272105 with both the HBV genotype and mutations. Through stepwise regression analysis, HBV genotype, the 11 mutations, HLA-DQ/DR SNPs, and the interaction of rs9272105 with mutation A1752G were all entered into the HCC prediction model, and the area under the curve for the panel including the HLA-DQ/DR SNPs, HBV genotype and mutations was 0.840. The HBV genotype, the mutations and the HLA-DQ/DR SNPs may serve as biomarkers for the surveillance of HBV persistent carriers.

Deep sequencing analysis of HBV genotype shift and correlation with antiviral efficiency during adefovir dipivoxil therapy

Background

Viral genotype shift in chronic hepatitis B (CHB) patients during antiviral therapy has been reported, but the underlying mechanism remains elusive.

Methods

38 CHB patients treated with ADV for one year were selected for studying genotype shift by both deep sequencing and Sanger sequencing method.

Results

Sanger sequencing method found that 7.9% patients showed mixed genotype before ADV therapy. In contrast, all 38 patients showed mixed genotype before ADV treatment by deep sequencing. 95.5% mixed genotype rate was also obtained from additional 200 treatment-naïve CHB patients. Of the 13 patients with genotype shift, the fraction of the minor genotype in 5 patients (38%) increased gradually during the course of ADV treatment. Furthermore, responses to ADV and HBeAg seroconversion were associated with the high rate of genotype shift, suggesting drug and immune pressure may be key factors to induce genotype shift. Interestingly, patients with genotype C had a significantly higher rate of genotype shift than genotype B. In genotype shift group, ADV treatment induced a marked enhancement of genotype B ratio accompanied by a reduction of genotype C ratio, suggesting genotype C may be more sensitive to ADV than genotype B. Moreover, patients with dominant genotype C may have a better therapeutic effect. Finally, genotype shifts was correlated with clinical improvement in terms of ALT.

Conclusions

Our findings provided a rational explanation for genotype shift among ADV-treated CHB patients. The genotype and genotype shift might be associated with antiviral efficiency.

Distribution of hepatitis B virus genotype and cancer predicting precore and basal core promoter mutations

BACKGROUND

Chronic hepatitis B (CHB) infection which is associated with an increased risk of developing liver disease including cirrhosis and hepatocellular carcinoma. Viral factors that may increase the risk for HCC development include HBV DNA level, genotypes, and naturally occurring mutations such as hepatitis B virus precore (PC) (G1896A) and basal core promoter (BCP) A1762T/G1764A double mutations. HBV genotypes and subgenotypes can significantly influence HBeAg seroconversion rates, viremia levels, mutational patterns that could significantly influence the heterogeneity in clinical manifestations and even response to antiviral therapy.

METHOD

94 CHB infected individuals with detectable serum HBV DNA levels were studied. HBsAg, HBeAg, anti-HBc IgM antibody estimations were done by ELISA. HBV DNA estimation was done. The HBV genotypes were determined by TSP-PCR and 10 samples randomly selected for DNA sequencing. PC and BCP mutations were determined by DNA sequence analysis of core region.

RESULT

Of 94 study participant samples with detectable serum HBV DNA levels, 75 were successfully genotyped and sequenced for BCP/PC region. 30/75 (40%) harbored PC and BCP mutations. The total Double mutations of BCP at A1762T/G1764A nucleotide positions, and PC mutation at G1896A nucleotide position were seen in 29.3% and 21.3%, respectively. All 75 isolates were subtype D using TSP-PCR. However, by sequencing 2/10 were subtype A, while 8 were subtype D.

CONCLUSION

Our study reinforces that D is the predominant genotype in Indian population. It reveals that Indian CHB subjects have increased prevalence of BCP & PC mutations, which possibly may lead to development of HCC.

Is mother-to-infant transmission the most important factor for persistent HBV infection?

Of the infants born to hepatitis B surface antigen (HBsAg)-positive mothers globally, 42.1% who did not receive hepatitis B virus (HBV) passive-active immunoprophylaxis and 2.9% of infants who received the immunoprophylaxis acquired HBV infection perinatally. Moreover, perinatal infection occurred in 84.2% (18.8%-100%) and 8.7% (0.0-21.0%) of infants born to hepatitis B e-antigen (HBeAg)-positive mothers who did not and did receive immunoprophylaxis, respectively; by contrast, the infection rates were 6.7% (0.0-15.4%) and 0.4% (0.0-2.5%) for infants born to HBeAg-negative-carrier mothers, respectively. The chronicity rates of HBV infection acquired perinatally were 28.2% (17.4%-33.9%) in infants born to HBeAg-negative mothers and 64.5% (53.5%-100%) in infants born to HBeAg-positive mothers. HBV mother-to-child transmission was more frequent in East Asia relative to other areas. In addition to differences in the endemic HBV genotype, the interchange of allelic dominance in genetic polymorphisms in HLA class II and NF-κB between the Chinese and European populations may explain why chronic HBV infection frequently affects the Chinese. The risk of progressing into chronic infection was inversely related to the age of children at the time of horizontal transmission. To further diminish HBV chronic infection, it is necessary to enforce antiviral treatment after the 28th week of gestation for HBeAg-positive mothers and to improve the health habits of carrier mothers and household sanitary conditions.

Hepatitis B virus genotypes and variants

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

Decaprenyl diphosphate synthase subunit 2 as a prognosis factor in hepatocellular carcinoma

AIM: To investigate the involvement of decaprenyl diphosphate synthase subunit 2 (PDSS2) in development and progression of human hepatocellular carcinoma (HCC).

METHODS: PDSS2 protein expression was examined in well- and poorly differentiated HCC tumor samples. The levels of PDSS2 expression were compared with clinical features and prognosis of HCC patients. The effects of PDSS2 on cell proliferation, cell cycle, apoptosis, cell migration, and invasion in HCC HepG2 cells were also investigated.

RESULTS: PDSS2 was downregulated in poorly differentiated cancer samples compared with well-differentiated tumor samples, and the expression level was markedly lower in HCC tissues than in histologically normal tissue adjacent to the cancer. Reduced protein expression was negatively associated with the status of HCC progression. In addition, overexpression of PDSS2 dramatically suppressed cell proliferation and colony formation, and induced apoptosis in HepG2 cells by inducing G1-phase cell-cycle arrest. The migration and invasion capabilities of HepG2 cells were significantly decreased following PDSS2 overexpression.

CONCLUSION: Decreased PDSS2 expression is an unfavorable prognostic factor for HCC, and PDSS2 has potent anticancer activity in HCC tissues and HepG2 cells.

Somatic mutations, viral integration and epigenetic modification in the evolution of hepatitis B virus-induced hepatocellular carcinoma

Liver cancer in men is the second leading cause of cancer death and hepatocellular carcinoma (HCC) accounts for 70%-85% of the total liver cancer worldwide. Chronic infection with hepatitis B virus (HBV) is the major cause of HCC. Chronic, intermittently active inflammation provides “fertile field” for “mutation, selection, and adaptation” of HBV and the infected hepatocytes, a long-term evolutionary process during HBV-induced carcinogenesis. HBV mutations, which are positively selected by insufficient immunity, can promote and predict the occurrence of HCC. Recently, advanced sequencing technologies including whole genome sequencing, exome sequencing, and RNA sequencing provide opportunities to better under-stand the insight of how somatic mutations, structure variations, HBV integrations, and epigenetic modifications contribute to HCC development. Genomic variations of HCC caused by various etiological factors may be different, but the common driver mutations are important to elucidate the HCC evolutionary process. Genome-wide analyses of HBV integrations are helpful in clarifying the targeted genes of HBV in carcinogenesis and disease progression. RNA sequencing can identify key molecules whose expressions are epigenetically modified during HCC evolution. In this review, we summarized the current findings of next generation sequencings for HBV-HCC and proposed a theory framework of Cancer Evolution and Development based on the current knowledge of HBV-induced HCC to characterize and interpret evolutionary mechanisms of HCC and possible other cancers. Understanding the key viral and genomic variations involved in HCC evolution is essential for generating effective diagnostic, prognostic, and predictive biomarkers as well as therapeutic targets for the interventions of HBV-HCC.

S gene mutants occurrence among hepatitis B carriers in malaysia

BACKGROUND

The S gene region of the hepatitis B virus (HBV) codes for surface antigen (HBs Ag) and is responsible for classification of HBV strains.

OBJECTIVES

The current study aimed to identify important mutations in the S gene in Hepatitis B virus (HBV) isolated from Malaysian HBV carriers.

MATERIALS AND METHODS

Isolated HBV DNAs were subjected for PCR amplification and sequencing of HBV full genome.

RESULTS

A total of 76 HBV full genome and 17 partial genome sequences were obtained from the 93 sequenced sera samples Genotyping of the full genome sequences by HEPSEQ software revealed a distribution of 49.46%, 48.39% and 2.15% of genotypes C, B, and D, respectively; whereas phylogenetic and jumping profile Hidden Markov Model (jpHMM) analysis identified six (7.89%) recombinant B/C strains. The distribution of sub-genotypes were B2 (78.79%) and B3 (21.21%) for genotype B, sub genotype D2 (100%) for genotype D and sub genotype C1 (75.76%), C2 (15.15%), C3 (6.06%) and C5 (3.13%) for genotype C. Mutation analysis in the S gene demonstrated two significant mutations which were W182 stop codon and deletion at open reading frame (ORF) of pre-S1 with the frequency occurrence of 2.2% (2/93) and 5.4% (5/93), respectively. The two patients with W182 stop codon were both male, infected with HBV genotype C and one showed progression of liver disease to hepatocellular carcinoma (HCC).

CONCLUSIONS

Association with sex, genotype and clinical symptoms revealed that the pre-S1 ORF deletion occurred in 40% , 40%,and 20% of genotypes B,C, and D respectively, and 80% of the female population, of which all but one were diagnosed with chronic hepatitis B. Additionally, several mutations were found in the BCP region with the following incidence rate; C1653 T (8.6%), A1752 G (10.8%),1762 AGG--TGA 1764 (26.9%), C1766T(2.2%),T1768 A (10.8%), C1858 T (64.5%), G1896 A (25.8%).

A deep-sequencing method detects drug-resistant mutations in the hepatitis B virus in Indonesians

OBJECTIVE

The long-term administration of a nucleos(t)ide analogue (NA) for the treatment of chronic hepatitis B may encourage the emergence of viral mutations associated with drug resistance. Minor populations of viruses may exist before treatment, but are difficult to detect because of technological limitations. Identifying minor viral quasispecies should be useful in the clinical management of hepatitis B virus (HBV) infection.

METHODS

Six treatment-naïve Indonesian patients with chronic HBV infection participated in this study. The polymerase region of the HBV genome, including regions with known drug-resistant mutations, was subjected to capillary sequencing and MiSeq sequencing (Illumina). Mutations were analyzed with Genomics Workbench software version 6.0.1 (CLC bio).

RESULTS

The mean mapping reads for the six samples was 745,654, and the mean number of amplified fragments ranged from 17,926 to 25,336 DNA reads. Several known drug-resistant mutations in the reverse transcriptase region were identified in all patients, although the frequencies were low (0.12-1.06%). The proportions of the total number of reads containing mutations I169L/M, S202R, M204I/L or N236S were >1.0%.

CONCLUSION

Several known NA-resistant mutations were detected in treatment-naïve patients in Indonesia using deep sequencing. Careful management of such patients is essential to prevent drug-resistant mutations from spreading to other patients.

Distinct distribution pattern of hepatitis B virus genotype C and D in liver tissue and serum of dual genotype infected liver cirrhosis and hepatocellular carcinoma patients

Aims

The impact of co-infection of several hepatitis B virus (HBV) genotypes on the clinical outcome remains controversial. This study has for the first time investigated the distribution of HBV genotypes in the serum and in the intrahepatic tissue of liver cirrhotic (LC) and hepatocellular carcinoma (HCC) patients from India. In addition, the genotype-genotype interplay and plausible mechanism of development of HCC has also been explored.

Methods

The assessment of HBV genotypes was performed by nested PCR using either surface or HBx specific primers from both the circulating virus in the serum and replicative virus that includes covalently closed circular DNA (cccDNA) and relaxed circular DNA (rcDNA) of HBV from the intrahepatic tissue. The integrated virus within the host chromosome was genotyped by Alu-PCR method. Each PCR products were cloned and sequences of five randomly selected clones were subsequently analysed.

Results

HBV/genotype D was detected in the serum of all LC and HCC patients whereas the sequences of the replicative HBV DNA (cccDNA and rcDNA) from the intrahepatic tissue of the same patients revealed the presence of both HBV/genotype C and D. The sequences of the integrated viruses exhibited the solo presence of HBV/genotype C in the majority of LC and HCC tissues while both HBV/genotype C and D clones were found in few patients in which HBV/genotype C was predominated. Moreover, compared to HBV/genotype D, genotype C had higher propensity to generate double strand breaks, ER stress and reactive oxygen species and it had also showed higher cellular homologous-recombination efficiency that engendered more chromosomal rearrangements, which ultimately led to development of HCC.

Conclusions

Our study highlights the necessity of routine analysis of HBV genotype from the liver tissue of each chronic HBV infected patient in clinical practice to understand the disease prognosis and also to select therapeutic strategy.