HBs protein is encoded by the pre-S and S genome, and the detection of HBs antigen (HBsAg) in sera is an initial step for the diagnosis of hepatitis B virus (HBV) infection. The “a” determinant region (amino acid residues 124–147) is the main epitope for inducing a protective immune response. Mutations in the “a” determinant region, known as escape mutants, affect antigenicity and hinder attemp...

Hepatitis B virus L protein is retained intracellularly, and trans-inhibits secretion of the related S and M proteins, as particulate HBsAg, at high L/S-M ratios. Comparison of equivalent A and D strain mutants suggested that the retention mechanism does not vary with genotype. Contrary to an earlier suggestion, the N-terminal extension specific for A-C strains was found to be inactive as a ret...

Hepatitis B virus infection is a serious health problem worldwide, and more than 350 million people are chronic carriers, constituting a major global threat. Southeast Asia and the Western Pacific have the highest levels of endemicity in the world, with an estimated seroprevalence ranging between 2% and 31%. Mutations in the hepatitis B surface antigen (HBsAg) have been reported in many parts o...

In recent years the diagnostic industry has developed new automated immunoassays for the qualitative detection of hepatitis B virus (HBV) surface antigen (HBsAg) in serum and plasma samples that are performed on analyzers that permit a high-speed throughput, random access, and primary tube sampling. The aim of the present study was the evaluation of two new automated HBsAg screening assays, IMM...

Occult hepatitis B virus (HBV) infection is defined as presence of HBV DNA in the liver regardless of serum HBV DNA detectability in HBsAg-negative patients. Occult HBV infection is not uncommon in Korea because the prevalence of occult HBV infection depends on the HBsAg carrier rate. The underlying mechanisms for occult HBV infection is not fully understood yet, but both viral and host factors...

Objective (s):The aim of this study was to determine the correlation between vaccine therapy and appearance of mutations in hepatitis B surface antigen (HBsAg)-positive chronic hepatitis B virus (HBV) patients. Materials and Methods: 16 patients received the HBV vaccine and another 16 individuals from the control group did not. The surface gene was amplified and directly sequenced from samples...

Hepatitis delta virus (HDV) encodes two proteins, the small delta antigen (SHDAg) and large delta antigen (LHDAg). The latter is identical to the former except for the presence of additional 19 amino acids at the C terminus. While SHDAg is required for HDV replication, LHDAg inhibits replication and, together with hepatitis B surface antigen (HBsAg), is required for the assembly of HDV. The las...

Occult HBV infection (OBI) is a threat for the safety of blood-supply, and has been associated with the onset of HBV-related hepatocellular carcinoma and lymphomagenesis. Nevertheless, genetic markers in HBsAg (particularly in D-genotype, the most common in Europe) significantly associated with OBI in vivo are missing. Thus, the goal of this study is to define: (i) prevalence and clinical profi...

BACKGROUND AND AIMS Occult hepatitis B virus infection (OBI) poses a challenge to the safety of blood donation. The prevalence of OBI is not well documented in Indonesia, although this information in such an endemic country is needed. This study was aimed to evaluate the prevalence of occult hepatitis B in blood donors from two cities of Indonesia, and to study the genetic variation and its eff...