Characterization of Hepatitis B virus based complete genome analysis improves molecular surveillance and enables identification of a recombinant C/D strain in the Netherlands

Hepatitis B Virus (HBV) is classified into 10 HBV genotypes (A-J) based a >7.5 % divergence within the complete genome or a >4 % divergence in the S-gene. In addition, recombinant strains with common breakpoints at the gene boundaries of the preS1/preS2/S- and preC/C-gene are often identified. Analysis of HBV based on the complete genome is essential for public health surveillance as it provides higher genetic resolution to conduct accurate characterization and phylogenetic analysis of circulating strains and identify possible recombinants. Currently two separate assays are used for HBV-surveillance; the S-gene for typing, and due to the higher genetic variation, the C-gene to gain insight in transmission patterns. The aim of the study was to develop a complete genome PCR-assay and evaluate the characterization and circulation of HBV strains through the use of the S-gene, C-gene and complete genome. For this HBV positive samples collected in the period 2017 through 2019 were selected. Analysis of the complete genome showed that complete genome analysis portrays a high genetic resolution that provided accurate characterization and analysis of the different circulating types in the Netherlands and enabled identification and characterization of a recombinant CD strain.

Insights From Deep Sequencing of the HBV Genome-Unique, Tiny, and Misunderstood

Hepatitis B virus (HBV) is a unique, tiny, partially double-stranded, reverse-transcribing DNA virus with proteins encoded by multiple overlapping reading frames. The substitution rate is surprisingly high for a DNA virus, but lower than that of other reverse transcribing organisms. More than 260 million people worldwide have chronic HBV infection, which causes 0.8 million deaths a year. Because of the high burden of disease, international health agencies have set the goal of eliminating HBV infection by 2030. Nonetheless, the intriguing HBV genome has not been well characterized. We summarize data on the HBV genome structure and replication cycle, explain and quantify diversity within and among infected individuals, and discuss advances that can be offered by application of next-generation sequencing technology. In-depth HBV genome analyses could increase our understanding of disease pathogenesis and allow us to better predict patient outcomes, optimize treatment, and develop new therapeutics.

Lamivudine plus tenofovir combination therapy versus lamivudine monotherapy for HBV/HIV coinfection: a meta-analysis

BACKGROUND

Currently, there is no consensus on the efficacy and safety of lamivudine (LAM) plus tenofovir disoproxil fumarate (TDF) combination therapy versus lamivudine monotherapy in HBV/HIV coinfected patients.

METHODS

A comprehensive literature search was performed in English and Chinese databases. Both relevant dichotomous and continuous variables were extracted, and the combined outcomes were expressed as a risk ratio (RR) or a standard mean difference (SMD).

RESULTS

Eleven eligible studies were included in our analysis. For HBV-relevant outcomes, the proportion of patients with undetectable HBV, the rates of serum alanine aminotransferase (ALT) normalization and hepatitis B e antigen (HBeAg) loss were higher in the combination therapy group than the monotherapy group (RR = 1.42, 95% CI: 1.14-1.76, P = 0.002; RR = 1.36, 95% CI: 1.17-1.58, P < 0.0001; RR = 2.74, 95% CI: 1.20-6.22, P = 0.02). In addition, the rate of HIV RNA-negative conversion was higher in the combination therapy group than the monotherapy group (RR = 1.26, 95% CI: 1.11-1.42, P = 0.0003).

CONCLUSION

LAM plus TDF combination therapy was more efficacious than LAM monotherapy in HBV/HIV coinfected patients. As time passes, this difference becomes more pronounced.

Novel HBV recombinants between genotypes B and C in 3'-terminal reverse transcriptase (RT) sequences are associated with enhanced viral DNA load, higher RT point mutation rates and place of birth among Chinese patients

As one of the major global public health concerns, hepatitis B virus (HBV) can be divided into at least eight genotypes, which may be related to disease severity and treatment response. We previously demonstrated that genotypes B and C HBV, with distinct geographical distribution in China, had divergent genotype-dependent amino acid polymorphisms and variations in reverse transcriptase (RT) gene region, a target of antiviral therapy using nucleos(t)ide analogues. Recently recombination between HBV genotypes B and C was reported to occur in the RT region. However, their frequency and clinical significance is poorly understood. Here full-length HBV RT sequences from 201 Chinese chronic hepatitis B (CHB) patients were amplified and sequenced, among which 31.34% (63/201) were genotype B whereas 68.66% (138/201) genotype C. Although no intergenotypic recombination was detected among C-genotype HBV, 38.10% (24/63) of B-genotype HBV had recombination with genotype C in the 3'-terminal RT sequences. The patients with B/C intergenotypic recombinants had significantly (P<0.05) higher serum HBV DNA level than the "pure" B-genotype cohort did. Moreover, the B/C intergenotypic recombinants were prone to more substitutions at several specific residues in the RT region than genotype B or C. Besides, unlike their parental genotypes, the recombinant HBV appeared to display an altered geographic distribution feature in China. Our findings provide novel insight into the virological, clinical and epidemiological features of new HBV B/C intergenotypic recombinants at the 3' end of RT sequences among Chinese CHB patients. The highly complex genetic background of the novel recombinant HBV carrying new mutations affecting RT protein may contribute to an enhanced heterogeneity in treatment response or prognosis among CHB patients.

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.

Proteome Differences between Hepatitis B Virus Genotype-B- and Genotype-C-Induced Hepatocellular Carcinoma Revealed by iTRAQ-Based Quantitative Proteomics

Hepatitis B virus (HBV) is the main cause of hepatocellular carcinoma (HCC) in southeast Asia where HBV genotype B and genotype C are the most prevalent. Viral genotypes have been reported to significantly affect the clinical outcomes of HCC. However, the underlying molecular differences among different genotypes of HBV virus infected HCC have not been revealed. Here, we applied isobaric tags for relative and absolute quantitation (iTRAQ) technology integrated with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to identify the proteome differences between the HBV genotypes B- and C-induced HCC. In brief, a total of 83 proteins in the surrounding noncancerous tissues and 136 proteins in the cancerous tissues between HBV genotype-B- and genotype-C-induced HCC were identified, respectively. This information revealed that there might be different molecular mechanisms of the tumorigenesis and development of HBV genotypes B- and C-induced HCC. Furthermore, our results indicate that the two proteins ARFIP2 and ANXA1 might be potential biomarkers for distinguishing the HBV genotypes B- and C-induced HCC. Thus, the quantitative proteomic analysis revealed molecular differences between the HBV genotypes B- and C-induced HCC, and might provide fundamental information for further deep study.

Distribution of hepatitis B virus genotypes in azerbaijani patients with chronic hepatitis B infection

BACKGROUND

Hepatitis B virus (HBV) has been classified into ten genotypes (A-J) based on genome sequence divergence, which is very important for etiological and clinical investigations. HBV genotypes have distinct geographical distributions worldwide.

OBJECTIVES

The aim of this study was to investigate the distribution of HBV genotypes among Azerbaijani patients with chronic hepatitis B, came from the Republic of Azerbaijan country to Iran to receive medical care.

PATIENTS AND METHODS

One hundred and three patients with chronic HBV infection, referred to hospitals related to Iran University of Medical Sciences and Tehran Hepatitis Center from August 2011 to July 2014, were enrolled in this cross sectional study. About 3-milliliter of peripheral blood was taken from each patient. After viral DNA extraction, HBV genotypes were tested using the INNO-LiPA™ HBV kit (Innogenetics, Ghent, Belgium). HBV genotyping was confirmed using sequencing of hepatitis B surface antigen (HBsAg) and polymerase (pol) regions of HBV.

RESULTS

The mean age of patients was 35.9 ± 11.7 years (19-66). Of 103 patients, 72 (69.9%) were male. In the present study, the predominant HBV genotype was D (93.2%) followed by genotype A (5.8%) and concurrent infection with A and D genotypes (0.97%).

CONCLUSIONS

The main and frequent HBV genotype among Azerbaijani patients with chronic hepatitis B virus infection was genotype D followed by genotype A.

Hepatitis B virus genotypes in chronic liver disease patients from New Delhi, India

AIM

To study the Hepatitis B virus (HBV) genotypes and their effect on the progression and outcome in patients with chronic liver diseases from New Delhi, India.

METHODS

Sera from 100 HBV-related chronic liver disease (CLDB) cases were tested for HBV genotype using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and Type-specific primers-based PCR (TSP-PCR) targeting to the surface (S) gene encoding hepatitis B surface antigen.

RESULTS

Only genotypes A and D were present and genotype D was dominant. Genotype D was present in all CLDB patient categories. The genotype distribution for the 100 patients with CLDB was as follows: genotype A, 16/100 (16%) (7/40- 17% chronic hepatitis B (CHB); 8/47, 17%, HBV-related cirrhosis (CRB); 1/13, 7.6%, HBV-related hepatocellular carcinoma (HCCB); genotype D- 84/100 (84%) (32/40- 80% CHB; 38/47- 81%, CRB; 11/13, 85%, HCCB); genotype A+D, 3/100 (3%) (1/40- 3% CHB; 1/47- 2%, CRB; 1/13, 7.6%, HCCB); C, 0; B, 0; E, 0; F, 0; G 0, H 0; (P<0.01, genotype D vs A).

CONCLUSION

Only HBV genotypes A and D were present in patients with CLDB from New Delhi, India. Compared with genotype D, genotype A patients had no significant clinical or biochemical differences (P>0.05). Mixed infection with genotype A and D were seen in 3% of the cases. Genotype D was the dominant genotype prevalent in all patient categories.