Abstract
BACKGROUND: A high prevalence of reactivation of hepatitis B has been documented among immunosuppressed individuals in the inactive phase of chronic hepatitis B; However, the proportion of and the risk factors for reactivation are largely unknown among non-immunosuppressed persons. OBJECTIVES: Estimate the incidence rate of and risk factors for hepatitis B reactivation in a population-based cohort of persons in the inactive phase of chronic hepatitis B in Alaska. STUDY DESIGN: A cohort of 414 Alaska Native Persons in the inactive phase of hepatitis B (HBV DNA<2000 IU/mL and normal alanine aminotransferase (ALT) for 12 months) was followed-up for 10 years. Reactivation of hepatitis B was defined as HBV DNA≥2000 IU/mL and ALT≥40 IU/L. Cox-proportional hazards regression models were used to identify factors associated with reactivation. RESULTS: A total of 36 (9%) persons had reactivation during 2984 person-years of follow-up, with an annual incidence of 1.2%. Persons aged ≥50 years (1.8%) at study entry had the highest incidence rates of reactivation although incidence rates were not significantly different by age group. Risk factors for hepatitis B reactivation were male sex (Hazard Ratio (HR)=2.41; 95% Confidence Interval (CI): 1.17-4.96), HBV DNA≥1000 IU/mL at study entry (HR=7.61; 95% CI: 2.81-20.6), and HBV genotype B (HR=6.08; 95% CI: 1.32-28.0). CONCLUSIONS: The incidence of hepatitis B reactivation was low during the 10 years of follow-up. However, given the higher risk of reactivation than their counterparts, males, and those with HBV DNA≥1000 IU/mL need to be followed-up more frequently.