Recombinant HBV Surface Antigen (subtype adw)

INTRODUCTION: Spontaneous hepatitis B surface antigen (HBsAg) seroclearance, the functional cure of hepatitis B infection, occurs rarely. Prior original studies are limited by insufficient sample size and/or follow-up, and recent meta-analyses are limited by inclusion of only study-level data and lack of adjustment for confounders to investigate HBsAg seroclearance rates in most relevant subgroups. Using a cohort with detailed individual patient data, we estimated spontaneous HBsAg seroclearance rates through patient and virologic characteristics. METHODS: We analyzed 11,264 untreated patients with chronic hepatitis B with serial HBsAg data from 4 North American and 8 Asian Pacific centers, with 1,393 patients with HBsAg seroclearance (>= 2 undetectable HBsAg >= 6 months apart) during 106,192 person-years. The annual seroclearance rate with detailed categorization by infection phase, further stratified by hepatitis B e antigen (HBeAg) status, sex, age, and quantitative HBsAg (qHBsAg), was performed. RESULTS: The annual seroclearance rate was 1.31% (95% confidence interval: 1.25-1.38) and over 7% in immune inactive patients aged >= 55 years and with qHBsAg <100 IU/mL. The 5-, 10-, 15-, and 20-year cumulative rates were 4.74%, 10.72%, 18.80%, and 24.79%, respectively. On multivariable analysis, male (adjusted hazard ratio [aHR] = 1.66), older age (41-55 years: aHR = 1.16; >55 years: aHR = 1.21), negative HBeAg (aHR = 6.34), and genotype C (aHR = 1.82) predicted higher seroclearance rates, as did lower hepatitis B virus DNA and lower qHBsAg (P< 0.05 for all), and inactive carrier state. DISCUSSION: The spontaneous annual HBsAg seroclearance rate was 1.31%, but varied from close to zero to about 5% among most chronic hepatitis B subgroups, with older, male, HBeAg-negative, and genotype C patients with lower alanine aminotransferase and hepatitis B virus DNA, and qHBsAg independently associated with higher rates (see Visual Abstract, Supplementary Digital Content 2, http://links.lww.com/CTG/A367).

Background and Aims A dichotomous separation of hepatitis B viral DNA and hepatitis B surface antigen (HBsAg) concentrations occurs during the natural history and treatment of chronic hepatitis B. We have evaluated the ability of hepatitis B virus (HBV) RNA and hepatitis B core-related antigen (HBcrAg) as surrogates of silencing of covalently closed circular DNA (cccDNA), to characterize this dissociation, and virological outcomes. Approach and Results Three cohorts of hepatitis B e antigen (HBeAg)-negative patients were studied: cohort A: 66 HBeAg-negative patients on long-term nucleos(t)ide analogue (NA) therapy; cohort B: 23 antibodies against hepatitis B e antigen (anti-HBe)-positive patients who stopped treatment; and Cohort C: 19 anti-HBe-positive patients on long-term NA treatment who achieved HBsAg loss and in whom treatment was withdrawn. Concentrations of HBV serological/virological biomarkers (HBV DNA, HBsAg, HBcrAg, and HBV RNA) were measured in sequential samples at different time points on/off therapy. Cohort A: After 3 years of antiviral therapy, 33% and 30% had detectable HBcrAg and HBV RNA, respectively, despite all being HBV-DNA negative. After 5 years' therapy with NA, 27% and 14% had detectable HBcrAg and HBV RNA. Detectable HBcrAg and HBV RNA at the time of treatment withdrawal was only observed in those patients who developed a severe aminotransferase flare. Only those patients with HBV reactivation in cohort C had detectable HBV RNA at treatment withdrawal, but HBcrAg and HBV DNA were not detected. Conclusions HBcrAg and HBV RNA are sensitive biomarkers of continued transcription of cccDNA in HBeAg-negative patients despite marked HBV-DNA suppression by NA. These markers were predictors of severe alanine transaminase flares, after treatment withdrawal, and HBV-DNA reactivation. Their measurement during the natural history of hepatitis B, and on treatment with current and new agents, could characterize residual HBV-RNA transcription from cccDNA and assist drug development and disease management.