Rates and risk factors for hepatitis B reactivation in a cohort of persons in the inactive phase of chronic hepatitis B-Alaska, 2001-2010

Background: A high prevalence of reactivation of hepatitis B has been documented among immuno-suppressed 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. Published by Elsevier B.V.