conclusions the distribution of amino acid mutations as well as the ratio between missense and silent nucleotide mutations (dn/ds) showed that a narrowly focused immune pressure had already been on the surface protein (especially ctl epitopes) which led to the emergence of escape mutants in these patients who were in tolerance phase of chronicity. materials and methods the surface genes from 17...

background and aims: the aim of this study was to determine the correlation between the hepatitis b virus surface ag (hbsag) genotypes and variations in the clinical/serological pictures among hbsag positive chronic patients from south khorasan province of iran. methods: twenty-five patients were enrolled in this study. the hbs ag gene was amplified and was directly sequenced. genotypes and nuc...

abstract mutations have been described in all of the four open reading frames of the hepatitis b virus (hbv), however, from a clinical perspective the surface escape mutant is the most troublesome. hepatitis b surface antigen (hbsag) variants may impair diagnosis, or allow the virus to escape vaccine-induced immunity or passive immunoglobulin therapy. hbv mutants with amino acid substitutions, ...

Occult hepatitis B virus infection (HBV) is characterized by HBV DNA positivity but HBV surface antigen (HBsAg) negativity. Occult HBV infection is associated with a risk of HBV transmission through blood transfusion, hemodialysis, and liver transplantation. Furthermore, occult HBV infection contributes to the development of cirrhosis and hepatocellular carcinoma. We recently reported the chara...

BACKGROUND AND OBJECTIVES This study was conducted by the International Consortium for Blood Safety (ICBS) to identify high-quality test kits for detection of hepatitis B virus (HBV) surface antigen (HBsAg) for the benefit of developing countries. MATERIALS AND METHODS The 70 HBsAg test kits from around the world were evaluated comparatively for their clinical sensitivity, analytical sensitiv...

Quasispecies of hepatitis B virus (HBV) with variations in the major hydrophilic region (MHR) of the HBV surface antigen (HBsAg) can evolve during infection, allowing HBV to evade neutralizing antibodies. These escape variants may contribute to chronic infections. In this study, we looked for MHR variants in HBV quasispecies using ultradeep sequencing and evaluated the relationship between thes...

HBV is a member of Hepadnavirus genus. HBV is a DNA virus with a diameter of 42 nm consisting of an outer lipid envelope which contains proteins HBsAg, pre-S1 and pre-S2. HBsAg is a product of ‘s’ gen. The s geneinvolves ‘a’ epitope124. -147. codones and this region is the affecting region for anti-HBs antibody binding. Vaccine /Immunglobulin escape mutations occur at HBV DNA s gene’s ‘a determ...

BACKGROUND Presence at the same time of HBsAg and anti-HBs antibodies (HBsAg/Ab) is an entity sometimes encountered in chronic hepatitis B (CHB) carriers. OBJECTIVES This study was designed to characterize such serological profiles and to assess the reliability of serological marker quantification by three commercially available assays in this setting. STUDY DESIGN Among 2578 CHB identified...

Universal infantile hepatitis B virus (HBV) vaccination may lead to an increase in vaccine escape variants, which may pose a threat to the long-term success of massive vaccination. To determine the prevalence of occult infections in Korean vaccinated individuals, 87 vaccinated subjects were screened for the presence of HBV DNA using both the nested PCR protocol and the VERSANT HBV DNA 3.0 assay...