BackgroundSevere acute exacerbation of chronic hepatitis B can sometimes occur and lead to hepatic failure and death. The objective of this study was to elucidate the predictors of progression to hepatic decompensation during severe acute exacerbation.MethodsWe prospectively analyzed 37 consecutive patients with acute exacerbation of chronic hepatitis B (accompanied by jaundice and coagulopathy) for clinical outcome and factors that influenced the development of severe acute exacerbation, including viral kinetics.ResultsFourteen (37.8%) patients progressed to severe acute exacerbation (accompanied by encephalopathy). Multivariate analysis identified serum bilirubin (>5 mg/dl, P = 0.002) as a significant determinant of progression to hepatic failure and prothrombin activity (<45%, P = 0.028) and as a determinant of liver-related death. The hepatitis B virus (HBV) DNA level before therapy was measured in 25 patients. HBV DNA levels increased or did not change from before commencement of treatment in all 11 patients who progressed to severe acute exacerbation. On the other hand, HBV DNA levels did not change or increased in 8 of 14 patients (57%) with acute exacerbation (P = 0.02).ConclusionsSerum bilirubin and prothrombin activities were significant predictors of clinical outcome in patients with severe acute exacerbation of chronic hepatitis B. Viral kinetics until commencement of therapy can predict the severity of acute exacerbation of chronic hepatitis B.