The role of hepatitis B virus core‐related antigen in predicting hepatitis B virus relapse after cessation of entecavir in hepatitis B e antigen‐negative patients

This study investigated the ability of hepatitis B core-related antigen (HBcrAg) to predict hepatitis B virus (HBV) relapse in HBeAg-negative patients after cessation of entecavir therapy. A total of 301 HBeAg-negative patients without cirrhosis who had stopped entecavir therapy for at least 12 months were recruited. All patients fulfilled the stopping criteria proposed by the APASL 2012 guidelines. The five-year cumulative rates of virological relapse, clinical relapse and HBsAg loss were 71.6%, 57.3% and 18.7%, respectively. Serum HBsAg at end of treatment (EOT) was an independent predictor of virological relapse, clinical relapse and HBsAg loss; an EOT HBsAg of 150 IU/ml was the optimal cut-off value. The 5-year virological relapse rates for patients with <150 and ≥150 IU/ml HBsAg at EOT were 43.3% and 82.2% (p < 0.001), clinical relapse rates were 32.3% and 66.3% (p < 0.001), and HBsAg loss rates were 46.1% and 5.2% (p < 0.001), respectively. A baseline HBcrAg of 4 IU/ml was the optimal cut-off value for predicting HBV relapse. Among patients with an EOT HBsAg <150 IU/ml, the five-year virological relapse rates for patients with baseline HBcrAg levels ≤4 and >4 log U/ml were 27.9% and 59.1% (p = 0.006) and the clinical relapse rates were 18% and 48.1% (p = 0.014), respectively. EOT HBcrAg was not a significant predictor of virological or clinical relapse after cessation of entecavir. In conclusion, the combination of an EOT HBsAg of 150 IU/ml and baseline HBcrAg of 4 log U/ml can effectively predict the risk of HBV relapse after stopping entecavir therapy.