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

Summary Background Hepatitis B surface antigen ( HB sAg) positivity is associated with increased risk for cirrhosis and hepatocellular carcinoma ( HCC ). HB sAg seroclearance is thought to be rare in general, but cohort data from US patients are limited. Aim To determine the incidence of HB sAg seroclearance in a real‐life US cohort. Methods In 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 HB sAg seropositivity. Persistent HB sAg was confirmed by direct serology or by proxy with positive hepatitis B e‐antigen ( HB eAg) or HBV DNA levels. Results HB sAg 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 HB sAg 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. Conclusion HB sAg 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.