Hepatitis B virus (HBV) reactivation has been reported during antihepatitis C treatment in patients with hepatitis C virus (HCV) and HBV
co-infection. We aimed to evaluate the frequency and risk factors of HBV reactivation during anti-HCV
therapy and compared those between
interferon (IFN)-free direct-acting
antiviral (DAA)
therapies and IFN-based
therapies. Three hundred and twenty-two patients with HCV
infection receiving anti-HCV
therapy were retrospectively screened. The baseline HBV
infection statuses of all eligible patients and the HBV-
DNA level of all patients with current or previous HBV
infection were examined at the end of treatment. In patients with baseline anti-HBs positivity, changes in anti-HBs titre were evaluated. Of 287 patients who met the inclusion criteria, 157 had current (n=4) or previous (n=153) HBV
infection; 85 were treated with IFN-free DAA
therapies and 72 were treated with IFN-based
therapies. Six patients experienced HBV reactivation (n=2) or HBV reappearance (n=4) after IFN-free DAA
therapies, while no patient developed HBV reactivation after IFN-based
therapies. The risk factors of HBV reactivation or reappearance were DAA
therapies and a reduction in anti-HBs titre to <12 mIU mL-1 by the end of treatment. The decline changes of anti-HBs titre were significantly higher in patients treated with DAA
therapies. Although HBV reactivation
hepatitis was not observed, three of four patients with HBV reactivation or reappearance after achieving HCV eradication had
viremia 8 weeks after completion of
therapy. A significant proportion of patients develop HBV reactivation or reappearance without
hepatitis after IFN-free DAA
therapies. Low levels of anti-HBs and their decrease to <12 mIU mL-1
after treatment are significant risk factors for HBV reactivation or reappearance.