[Etiology and clinical consequence of spontaneous acute exacerbation of chronic hepatitis B]

Acute exacerbation (AE) of chronic hepatitis B (CHB) can occur spontaneously, and may be followed by HBeAg clearance. HBeAg seroconversion often coincides with the normalization of liver biochemical tests and clinical remission. The purpose of this study was to identify the etiology and the clinical consequence of severe AE in Korean patients with CHB.

The medical records of CHB patients with severe AE (defined by the sudden increase of ALT above 400 IU/L) who were admitted to Kyung Hee University Hospital between January 1992 and December 2001, were reviewed retrospectively. Forty-four patients were included in the severe AE group.

The most common etiology of severe AE was spontaneous exacerbation (77%). Drugs (16%), alcohol (5%), and HCV coinfection (2%) were suspected of causing AE in the remaining patients. HBeAg seroconversion at 12, 18, and 24 months following severe spontaneous AE was 18.5%, 40.7%, and 48.1%, respectively. These were significantly higher compared to CHB patients without AE (4.3%, 4.3%, and 10.9%, respectively). Seroconversion within 3 months, however, occurred in only 15% of CHB patients with AE. There was a tendency to progress to liver cirrhosis more frequently in the patients with AE as compared to the patients without AE (17.6% vs. 5.5%, P<0.08).

Severe AE in patients with CHB is mainly caused by spontaneous exacerbation. Although HBeAg seroconversion occurs frequently in these patients, the rates are relatively low compared to those reported in other countries and early seroconversion is expected only in a small proportion. Further studies will be warranted to determine the efficacy of the early use of antiviral agents at the time of AE.