Ethnic differences in incidence of hepatitis B surface antigen seroclearance in a real-life multicenter clinical cohort of 4737 patients with chronic hepatitis B infection

BackgroundHepatitis B surface antigen (HBsAg) positivity is associated with increased risk for cirrhosis and hepatocellular carcinoma (HCC). HBsAg seroclearance is thought to be rare in general, but cohort data from US patients are limited. AimTo determine the incidence of HBsAg seroclearance in a real-life US cohort. MethodsIn total, 4737 patients with chronic hepatitis B from five primary care, gastroenterology and multispecialty centres, and a university medical centre were retrospectively enrolled between 2001 and 2014 with data obtained by manual review of individual patient medical records. Seroclearance was determined by loss of HBsAg seropositivity. Persistent HBsAg was confirmed by direct serology or by proxy with positive hepatitis B e-antigen (HBeAg) or HBV DNA levels. ResultsHBsAg seroclearance occurred in 52 patients over 16 844 person-years (0.31% annually, 1.2% overall). Median follow-up was 32 months, and mean age 45 14 years. Incidence of HBsAg seroclearance was higher in non-Asians, age >45, males, and those with baseline HBV DNA 10 000 IU/mL. On multivariate Cox proportional modelling, non-Asian ethnicity (HR 2.8), male sex (HR 2.1), baseline HBVDNA 10 000 (HR 2.0) and age >45 (HR 1.8) were significant independent predictors of seroclearance. ConclusionHBsAg seroclearance rates were lower than previously described in this real-life cohort of patients with chronic hepatitis B, especially among Asian, female and younger patients.