Institute for Digestive Research, Department of Internal Medicine, Soonchunhyang University Hospital, Seoul, Korea.

Background/Aims: Sustained HBV DNA reduction is necessary for biochemical remission, histological improvement, and prevention of complications. We analyzed the time taken from HBV DNA loss to viral breakthrough after antiviral treatment in patients with chronic hepatitis B (CHB). The early fall of the HBV DNA level to undetectable levels assessed really whether it is related to late breakthrough.

Methods: A total of 91 patients whose HBV DNA levels dropped below undetectable levels were chosen from lamivudine-treated 306 patients and were analyzed retrospectively. The patients were divided into 4 groups (A48 wk) according to the time taken for the HBV DNA to decrease below undetectable levels. HBV DNA level was determined every 3 months.

Results: The mean time taken for loss of HBV DNA was 34±28 wk. The baseline ALT differed significantly among groups (A: 382±274, B: 340±30, C: 166±92, D: 54±100 IU/L) (p=0.007). Fifty nine of the 91 patients (64.8%) experienced viral breakthrough. The mean interval between HBV DNA loss and viral breakthrough was 65±40 wk and differed significantly between group A, B (82±43 wk) and group C, D (56±28 wk) (p=0.015). In multivariate analysis, only HBV DNA loss within 24 wk, was found to be independently associated with late viral breakthrough (p=0.035). Undetectable HBV DNA after 24 wk was associated with high odd ratio of 3.24 (95% CI, 1.09-9.67).

Conclusions: HBV DNA loss within 24 wk after antiviral treatment could predict the late breakthrough.