BACKGROUND/AIMS Occult HBV infection can persist following HBsAg loss and be transmitted, but the virological features are not well defined. METHODS Here we investigated 25 Korean patients who lost HBsAg during follow up, either spontaneously or subsequent to therapy. RESULTS Whereas subtype adr (genotype C) was found in 96% of HBsAg positive patients, 75 % of patients who lost HBsAg sponta...

Background: The antibody response to hepatitis B surface antigen (HBsAg) controls hepatitis B virus infection. The "a" determinant of HBsAg is the most important target for protective antibody response, diagnosis and immunoprophylaxis. Mutations in this area may induce immune escape mutants and affect the performance of HBsAg assays. Objectives: To construct clinically relevant recombinant muta...

A method has been developed for the analysis of hepatitis B surface antigen (HBsAg) antigenic structure at the molecular level that creates "fingerprints" or "signatures" of various hepatitis B viral (HBV) strains. This technique employs high affinity IgM and IgG monoclonal antibodies (anti-HBs) directed against distinct and separate determinants on HBsAg. In performing this antigenic structura...

Thermal stability of hepatitis B surface antigen (HBsAg) has been studied by analyzing alterations in the native secondary structure and the antigenic activity. After heating for 19 h, circular dichrosim showed a cooperative transition with a midpoint at 49 degrees C. The conformational changes induced by temperature reduced the helical content of HBsAg S proteins from 49% at 23 degrees C to 26...

BACKGROUND The association between mutations in the hepatitis B surface antigen (HBsAg) gene and the occurrence of occult HBV (OBI) in patients has not been studied adequately to determine if the two are correlated. The current study was aimed to investigate HBsAg mutations, the genotype of HBV and co-infection with HCV in OBI in the central part of Iran to determine any possible associations. ...

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, ...

Coexistence of hepatitis B surface antigen (HBsAg) and antibody against HBsAg (anti-HBs) comprises an atypical serological profile in patients with chronic hepatitis B virus (HBV) infection. In this study, in total 94 patients with coexisting HBsAg and anti-HBs and 94 age- and sex-matched patients with positive HBsAg were characterized by quantitatively measuring HBsAg and HBV DNA, sequencing l...

Disappearance of hepatitis B surface antigens (HBsAg) in chronic hepatitis B usually indicates clearance of hepatitis B virus (HBV) infection. However, false HBsAg negativity with mutations in pre-S2 and 'a' determinant has been reported. It is also known that YMDD mutations decrease the production of HBV and escape detection of serum HBsAg. Here, we report overlapping gene mutations in a patie...

BACKGROUND Many studies have identified mutations in the hepatitis B surface antigen (HBsAg) as important factors limiting the ability of commercial serological assays to detect this viral antigen. However, an association between mutations in the HBsAg gene and the occurrence of occult HBV infection (OBI) in patients has not been established. OBJECTIVES To detect hepatitis B virus (HBV) DNA i...

Background: The leading cause of mutations in the hepatitis B virus (HBV) genome is high rate nucleotide misincorporation during reverse transcription. Most were found within “a” determinant S gene’s major hydrophilic region (MHR). They resulted escape mutants due to amino acid changes MHR. However, outside MHR can also trigger mutants. Objectives: This study focused on further molecular studie...