Serum viral load at the virological relapse predicts subsequent clinical flares in chronic hepatitis B patients off entecavir therapy.

Background and Aim: Therapeutic duration of nucleos(t)ide analogues for chronic hepatitis B (CHB) is not indefinite in many parts of the world. Viral reactivation is common off therapy, but the risk of subsequent clinical outcome remains unclear and unpredictable. We aimed to quantify the incidence of and explore the predictors for clinical flare following virological relapse in CHB patients who discontinue entecavir therapy. Methods: This multicenter cohort study prospectively monitored 133 CHB patients who were HBeAg-negative and viral DNA-undetectable when discontinuing entecavir after at least 3 years on therapy. Following virological relapse (viral DNA >2,000 IU/mL) that occurred in 92 patients, the incidences of subsequent clinical flare and persistent (unremittent for 3 months) or severe hepatitis (with jaundice or coagulopathy) were determined, and risk factors were explored. Patients did not resume antiviral therapy until occurrence of persistent or severe hepatitis. Results: The cumulative incidence of clinical hepatitis 2 years after virological relapse was 61.0% (95% confidence interval [CI], 49.9-72.3%) and that of persistent or severe hepatitis was 53.0% (95% CI, 40.9-66.2%). Serum viral load at the virological relapse was associated with both clinical hepatitis (adjusted hazard ratio [HR], 1.31 per log IU/mL; 95% CI, 1.07-1.60) and persistent or severe hepatitis (adjusted HR, 1.63 per log IU/mL; 95% CI, 1.27-2.10), after adjustment for serum aminotransferase and alfa-fetoprotein levels in the multivariate analysis. Viral DNA >100 000 IU/mL predicted a nearly inevitable occurrence of clinical flare (P<0.0001). Conclusions: A high viral load at the virological relapse predicts subsequent clinical hepatitis in CHB patients who discontinue entecavir.