Evaluation of Occult Hepatitis B Infection in Individuals with Chronic Hepatitis C Before Treatment with Oral Direct-Acting Antivirals

Occult hepatitis B virus infection (OBI) is one of the most challenging entities in the field of viral hepatitis. The virological and clinical relevance of OBI in patients treated with novel direct-acting antivirals (DAA) for hepatitis C virus (HCV) infections is currently a topic of hot debate. In cases where hepatitis B surface antigen (HBsAg) is not detected, DAA treatment is often initiated without examining for the presence of hepatitis B virus (HBV) DNA. In this study, the incidence of OBI was investigated in 114 HCV patients prior to application of DAAs who did not respond to pegylated interferon and ribavirin (PEG-INF and RBV) treatment. Serum samples were screened for HBV serological markers (antibody to hepatitis B core antigen [anti-HBc] and HBsAg). Samples positive for antiHBc without HBsAg were further examined via real-time PCR (qPCR), nested PCR and S-gene mutational analyses. Overall, anti-HBc was detected in 37.7% chronic HCV patients and 2.6% had OBI with a baseline HBV DNA viral load < 2000 IU/mL before DAA therapy. One patient was identified as HBV genotype A1 withoutmutations in surface protein. Our collective data highlight the importance of clinicians being aware of potential anti-HBc positivity in patients with hepatitis C and the issues surrounding OBI screening before initiation of treatment with novel DAAs.