Hepatitis B Virus Infection, MicroRNAs and Liver Disease

Hepatitis B virus (HBV) attacks the liver and can cause both acute as well as chronic liver diseases which might lead to liver cirrhosis and hepatocellular carcinoma. Regardless of the availability of a vaccine and numerous treatment options, HBV is a major cause of morbidity and mortality across the world. Recently,microRNAs (miRNAs) have emerged as important modulators of gene function. Studies on the role of miRNA in the regulation of hepatitis B virus gene expression have been the focus of modern antiviral research. miRNAs can regulate viral replication and pathogenesis in a number of different ways, which includefacilitation, direct or indirect inhibition, activation of immune response, epigenetic modulation, etc. Nevertheless, these mechanisms can appropriately be used with a diagnosticand/or therapeutic approach. The present review is an attempt to classify specific miRNAs that are reported to be associated with various aspects of hepatitis B biology, in order to precisely present the participation of individual miRNAs in multiple aspects relating to HBV

Characterization of treatment-naive HIV/HBV co-infected patients attending ART clinic of a tertiary healthcare centre in eastern India.

OBJECTIVE: The study was designed to assess the hepatitis B virus (HBV) and hepatitis C virus (HCV) co-infection scenario among the human immunodeficiency virus (HIV) infected patients attending a tertiary healthcare unit in eastern India. Additionally, clinical and virological characterization of these viruses, prior to antiretroviral therapy (ART) initiation was also done for better understanding of the disease profile. METHODS: Pool of ART-naive HIV/HBV co-infected and HIV mono-infected patients, participating in two different studies, were included in this study. HBV DNA was detected by nested-PCR amplification followed by HBV genotype determination and HBV reverse transcriptase (RT) region amplification and direct sequencing for detecting drug resistance. RESULTS: The prevalence of HBsAg (11.3%) was higher compared to anti-HCV (1.9%) among the HIV infected ART-naive patients. Moreover, majority of the HBeAg positive HIV/HBV co-infected patients (87.7%) had HBV DNA ≥20,000 IU/ml with median HBV DNA significantly higher than that of HBeAg negative subjects (5.7 log10 IU/ml vs. 4.2 log10 IU/ml; p<0.0001). Multivariate analysis also showed that HBeAg-positive status was independently associated with higher HBV DNA level (p = <0.001). Notably, 60.9% of the HBeAg negative co-infected subjects had HBV DNA ≥2,000 IU/ml of which 37.0% had HBV DNA ≥20,000 IU/ml. Genotype HBV/D (68.2%) was the predominant genotype followed by HBV/A (24.3%) and HBV/C (7.5%). Anti-HBV drug resistant mutations were detected in two (3.8%) of the ART-naive patients. CONCLUSION: The prevalence of HIV/HBV co-infection was relatively higher in our study subjects. HBeAg testing might provide clue for early treatment initiation. Furthermore, HBeAg negative patients are also associated with high HBV DNA levels and therefore require appropriate medical attention. Pre-treatment screening for anti-HBV drug resistant mutations is not necessary before ART initiation

Virological Characteristics of Acute Hepatitis B in Eastern India: Critical Differences with Chronic Infection.

Hepatitis B Virus (HBV) manifests high genetic variability and is classifiable into ten genotypes (A-J). HBV infection can lead to variable clinical outcomes, ranging from self-limiting acute hepatitis to active chronic hepatitis, cirrhosis and hepatocellular carcinoma. The present study characterizes HBV strains circulating among patients with acute (AHB) and chronic HBV infection (CHB). Among a total of 653 HBsAg positive cases, 40 manifested acute infection. After sequencing the surface(S), basal core promoter/pre-core(BCP/PC) and the X gene regions, phylogenetic tree was constructed using MEGA4 by neighbor-joining method. Statistical robustness was established with bootstrap analysis. Nucleotide diversity was determined by Shannon entropy per site using the Entropy program of the Los Alamos National Laboratories. Analyses of acute patients revealed that HBV/D2 is the major circulating sub-genotype and commonly associated with sexual promiscuity and the age group between15-30 years. Comparison of AHB and CHB patients revealed that HBeAg positivity, ALT levels and genotype D were significantly high in AHB, whereas CHB patients were predominantly male, had a high viral load, and were commonly associated with genotype C. The frequencies of mutations in the S, BCP/PC, and X gene were low in AHB as compared to CHB. Drug resistant mutations were not detectable in the polymerase gene of AHB. Average nucleotide diversity in AHB was considerably low as compared to CHB. Further, the highest average ΔH (average difference in entropy between chronic and acute infection) was observed in the BCP/PC region implying that this region was most vulnerable to mutations upon HBV persistence, especially in case of genotype C. Additionally, among all substitutions, the A1762T and G1764A BCP mutations were the strongest indicators of chronicity. In conclusion, the study exhibits a general portrait of HBV strains circulating among acute hepatitis B patients in Eastern India and their intricate differences with chronic patients which should be useful from the clinical point of view

Occult hepatitis B virus infection in HIV positive patients at a tertiary healthcare unit in eastern India.

Occult HBV infection (OBI), defined by the presence of HBV DNA in absence of hepatitis B surface antigen (HBsAg), is a significant concern in the HIV-infected population. Of 441 HIV+/HBsAg- patients analyzed, the overall prevalence of OBI was 6.3% (28/441). OBI was identified in 21 anti-HBc positives (17.8%), as well as among those who lacked any HBV-specific serological markers (2.2%). Comparison with HIV/HBV co-infection revealed that the levels of CD4, ALT, and HBV DNA were significantly lower during occult infection. Discrete differences were also observed with respect to quasispecies divergence. Additionally, subgenotype D1 was most frequent in occult infection, while D2 was widespread during chronic infection. The majority (~90%) of occult D1 sequences had the sQ129R mutation in the surface gene. This study highlights several distinct features of OBI in India and underscores the need for additional HBV DNA screening in HIV-positive individuals

Phylogenetic analysis of the HBV isolates circulating among the HIV/HBV co-infected population of eastern India.

<p>The phylogenetic tree was constructed based on the complete small S region (nucleotide 155–835 from <i>EcoR</i>I site) of the HBV genome using the neighbor-joining method and bootstrap value of 1000 replicates. The 39 isolates (denoted by EICIS) were analyzed with respect to 42 reference sequences retrieved from the GenBank which are designated by their respective accession numbers along with their HBV genotypes/subgenotypes and country of origin. • represents isolates belonging to HBV/A, ▪ represents HBV/C whereas ▴ represents HBV/D.</p

Frequency of subjects with HBV DNA ≥20,000 IU/ml (HBeAg⁺) and ≥2,000 IU/ml (HBeAg⁻) by CD4+ T-cell count.

<p>There was no significant difference in the percentage of HBeAg positive patients with HBV DNA ≥20,000 IU/ml between the two CD4+ T-cell count categories (p = 0.47). This indicates the higher association of HBeAg positive subjects with greater HBV viremia, irrespective of CD4+ T-cell count. Similarly, for the HBeAg negative patients, no distinct variation was observed (p = 0.23).</p

List of primers used to amplify the different regions of the HBV genome and their respective thermal profile are presented here.

<p>List of primers used to amplify the different regions of the HBV genome and their respective thermal profile are presented here.</p

Baseline characteristics of all the participating HIV/HBV co-infected individuals belonging to different HBV genotypes.

<p>Baseline characteristics of all the participating HIV/HBV co-infected individuals belonging to different HBV genotypes.</p

Schematic representation of the PreS deletions and the mutations in the small surface gene of the HBV strains isolated from the HIV/HBV co-infected patients of eastern India.

<p>(A) The PreS deletions are indicated by dashed lines (–). The numbers ahead of each deletion indicates the starting point of the respective amino acid deletions whereas the numbers besides the triangle (▴) indicates the length of each deletion observed in the co-infected individuals. (B) The major mutations occurring frequently within the small surface gene of HBV are shown here. The substitutions marked with a star (*) are mainly contributed due to the presence of the HBV/D2 sequences.</p