Rebound of HBV DNA after cessation of nucleos/tide analogues in chronic hepatitis B patients with undetectable covalently closed circular DNA

Background & Aims: Nucleos(t)ide analogues (NUCs) effectively suppress serum HBV DNA. Previously, we have identified 21 patients with undetectable covalently closed circular DNA (cccDNA) upon long-term NUC therapy. This study investigated the effect of NUC withdrawal in patients with undetectable cccDNA. Methods: Nineteen patients on long term NUCs (median 13.4 years) were recruited: 13 were randomized to discontinue NUCs; 6 to continue taking NUCs. All had undetectable cccDNA at the time of last liver biopsy (median time 2.9 years prior to randomization). Serum HBV DNA, hepatitis B surface antigen (HBsAg), hepatitis B core-related antigen (HBcrAg), liver biochemistry, and serum HBV RNA were monitored. Results: At the time of randomization, all patients had undetectable serum HBV DNA and HBV RNA. Twelve of the 13 patients had HBV DNA rebound to 100 IU/ml within 20 weeks of NUC discontinuation. The thirteenth patient had HBV DNA rebound at week 70. Three patients experienced biochemical flares after re-treatment which subsequently resolved. There was no significant association between the time of HBV DNA rebound and baseline HBsAg, HBcrAg and alanine aminotransferase, duration of treatment, and age at which treatment was stopped (all p >0.05). At the time of HBV DNA rebound, HBV DNA levels correlated with HBcrAg levels (p = 0.003), but not with HBsAg levels (p = 0.262). Conclusions: In patients with undetectable intrahepatic cccDNA, virologic rebound still occurred after NUC cessation. At the rebound of HBV DNA, the kinetics of HBsAg production were independent of those of viral DNA replication. Additional studies are required to determine the factors that may predict virologic rebound and when NUCs can be discontinued in HBsAg-positive patients with chronic hepatitis B. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of European Association for the Study of the Liver (EASL).