AIM To investigate the characteristic features of hepatitis B surface antigen (HBsAg) seroclearance among Korean hepatitis B virus (HBV) carriers. METHODS Carriers with HBsAg seroclearance were selected by analyzing longitudinal data collected from 2003 to 2015. The period of time from enrollment to the negative conversion of HBsAg (HBsAg-NC) was compared by stratifying various factors, inclu...

We modified and automated a highly sensitive chemiluminescent enzyme immunoassay (CLEIA) for surface antigen (HBsAg) detection using a combination of monoclonal antibodies, each for a specific epitope of HBsAg, and by improving an earlier conjugation technique. Of 471 hepatitis B virus (HBV) carriers seen in our hospital between 2009 and 2012, 26 were HBsAg seronegative as determined by the Abb...

BACKGROUND Possible serologic activity after hepatitis B surface antigen (HBsAg) seroclearance documented by conventional assays in chronic hepatitis B (CHB) has not been thoroughly investigated. METHODS We determined the levels of serum hepatitis B virus (HBV) DNA, hepatitis B core-related antigen (HBcrAg), and linearized HBsAg (CLEIA prototype) in 329 CHB patients (72.0% male) after HBsAg s...

BACKGROUND We investigated the differences in HBsAg kinetics at different levels of viremia in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB). METHODS We compared HBsAg levels among HBeAg-negative CHB patients with persistently undetectable HBV DNA (≤20 IU/mL; Group A, n = 100), HBV DNA 20-2,000 IU/mL (Group B, n = 100), and HBV DNA >2,000 IU/mL (Group C, n = 100). HBsAg and...

South East Asia has some of the highest prevalence rates of hepatitis B virus (HBV) infection (>or=8%) in the world, and the emergence of hepatitis B surface antigen (HBsAg) mutant strains is a growing problem. Assays with the highest levels of sensitivity, including mutant detection, should be used for routine HBsAg screening. In this large multicenter study, the clinical and technical perform...

A new rapid immunochromatographic assay based on the signal amplification system (SAS) has been developed by Diagnostics for the Real World (Europe) Ltd. for the detection of hepatitis B virus surface antigen (HBsAg) in plasma or serum specimens. The SAS format features enhanced sensitivity as a result of an increased binding valence of the detector molecules. We have now evaluated the performa...

Recombinant Oka (ROka) varicella vaccine expressing hepatitis B surface antigen (HBsAg) and subunit HBsAg vaccine (SHV) were used as primary and booster HBsAg vaccines in 3 combinations (SHV-SHV, SHV-ROka, and ROka-SHV) in guinea pigs. Immune responses to HBsAg and varicella-zoster virus gE:gI were evaluated. The 3 combinations induced similar levels of the lymphocyte proliferation response to ...

Small hepatitis B virus surface protein (S-HBsAg) variant Y100C has been associated with HBsAg-negative phenotype. To determine whether Y100C substitution yields impaired HBsAg or small amounts of HBsAg that may reduce HBsAg detection by commercial anti-HBsAg antibodies, two eukaryotic expression plasmids, one containing a wild-type S and the other an S gene from a Y100C variant, were construct...

T lymphocytes from 7 (21%) of 34 patients with chronic hepatitis showed positive cytotoxicity against HBsAg-coated Chang cells. This positivity was observed in HBsAg-negative patients having positive blast transformation responses to HBsAg, as well as in patients convalescing and recovered from acute B hepatitis. Levels of S-GPT in these patients were not different from those showing no cytotox...