Research ArticlePrevalence and causes of elevated serum aminotransferase levels in a population-based cohort of persons with chronic hepatitis B virus infection

Background & AimsInformation delineating the possible causes for elevated serum aminotransferase activity among persons with chronic hepatitis B virus (HBV) infection is limited.MethodsWe analysed data collected from a population-based cohort of persons with chronic HBV infection followed from 2001 to 2010 to determine the frequency and causes of elevated aminotransferase activity. Any elevation concurrent with an HBV DNA level ⩾2000 IU/ml was attributed to immune active hepatitis B. Participant medical charts were reviewed by expert clinical staff to determine the presence of additional or alternative attributable causes. For each participant, a serum aminotransferase elevation could be attributed to more than one cause.ResultsAmong 1090 persons with chronic HBV infection, the mean follow-up was 7.7 years and the median age in 2001 was 39 (range 19-96) years; 634 (58.2%) had ⩾1 elevated aminotransferase level during follow-up and 438 (69.1%) of persons with ⩾1 elevation had at least one cause assigned for the elevation. The most common causes of aminotransferase elevations were immune active hepatitis B (48.4%), alcohol consumption (30.8%), and non-alcoholic fatty liver disease (NAFLD) (24.7%). Among participants with HBV DNA levels persistently less than 2000 IU/ml, the most common causes were NAFLD or alcohol consumption.ConclusionsIn this population-based cohort of persons with chronic HBV infection, the prevalence of elevated aminotransferase activity was high and attributable to immune active chronic hepatitis B in approximately half of the cases; however, NAFLD or alcohol consumption were also common causes for enzyme elevations. These findings underscore the importance of monitoring HBV DNA levels, in addition to aminotransferase activity, among persons with chronic HBV infection so that appropriate interventions, including antiviral therapy, are utilised.