1 Saint Louis University Liver Center, Saint Louis University.
2 Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh.
3 Washington University.
4 University of California at San Francisco.
5 Toronto Centre for Liver Disease, Toronto General Hospital, University of Toronto.
6 Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases.
7 Beth Israel, Deaconess Medical Center.
8 University of Texas, Southwestern Medical Center.
9 California Pacific Medical Center.
10 Johns Hopkins University School of Medicine.
11 Virginia Commonwealth University.
Hepatitis B e antigen (HBeAg) is an important serological marker of hepatitis B virus (HBV) infection and is associated with higher levels of viremia, increased risk of infectivity to others and increased risk of hepatocellular carcinoma. We analyzed HBeAg status in a large cohort of adults and children enrolled in Cohort Studies of the Hepatitis B Research Network, long-term natural history studies of chronic HBV infection. A cross sectional analysis examined factors associated with HBeAg positivity, including demographic and virologic data, across the age spectrum. Among 2,241 enrolled participants who met criteria for this analysis, 825 (37%) were seropositive for HBeAg. The prevalence of HBeAg was lower in those with older age, ranging from 85% among up to 10 years of age to only 12% among those older than 50 years. In addition to age, both race and HBV genotype were independently associated with HBeAg positivity. There was a significant interaction between age and race; prevalence of HBeAg was significantly higher among Asians >10-30 years old vs. whites or blacks who were >10 to 30 years old, and those infected with HBV genotype C. Conversely, the presence of the basal core promoter and pre-core variants were associated with significantly lower prevalence of HBeAg, even when adjusted for age, race and genotype. These data will provide a better understanding of factors associated with seropositivity for HBeAg and may lead to better strategies for preventing HBV infection and broader indications for antiviral therapy.