Abstract
BACKGROUND/AIMS: The notion that acute hepatitis A superimposed on chronic hepatitis B infection leads to a worse outcome than acute hepatitis A alone remains controversial. The aim of this study was to determine the influence of the presence of hepatitis B surface antigen (HBsAg) on the severity of acute hepatitis A. METHODS: We retrospectively analyzed 449 patients hospitalized for acute hepatitis A from January 2000 to February 2010 and compared clinical outcomes based on the presence of HBsAg. RESULTS: Of the 449 patients, 30 patients were in the HBsAg-positive group and 419 in the HBsAg-negative group. The HBsAg-positive group was older than the HBsAg-negative group (36.1±8.3 vs 31.8±8.5 years, p=0.004); however, other baseline characteristics were similar between the 2 groups. Mean peak values of prothrombin time, serum total bilirubin, and serum creatinine at admission were significantly higher in the HBsAg-positive group. When comparing clinical outcomes between the 2 groups, gastrointestinal bleeding, acute renal failure, and acute liver failure were more frequently observed in the HBsAg-positive group. In particular, the incidence of acute liver failure was approximately 9-fold higher in the HBsAg-positive group than in the HBsAg-negative group (23.3% vs 3.3%; odds ratio [OR], 8.80; p<0.001). Multivariate analysis showed that HBsAg (OR, 7.43; 95% confidence interval [CI], 2.56 to 21.57) and age (OR, 1.07; 95% CI, 1.02 to 1.13) were independent risk factors for the occurrence of acute liver failure. CONCLUSIONS: In patients with chronic hepatitis B infection, acute hepatitis A is associated with more severe clinical outcomes, including acute liver failure, compared with patients with acute hepatitis A alone.