Objective. Currently, five nucleos(t)ide analogues (NUCs) are available for the treatment of chronic hepatitis B in the world. We examined the prevalence of hepatitis B virus (HBV) DNA and alanine aminotransferase normalization in patients receiving entecavir (ETV) and the frequency of ETV-resistant mutations during an approximately 27-month use of ETV in chronic hepatitis B patients in an urban hospital in Japan.
Materials and methods. A retrospective analysis of 81 NUC-naive chronic hepatitis B patients who received 0.5 mg of ETV daily was performed. HBV DNA was measured and sequence analysis of HBV DNA was performed in virological breakthrough patients. Results. Hepatitis B e antigen (HBeAg)-positive patients with HBV DNA 5.0-7.0 log IU/mL group and all HBeAg-negative patients achieved serum HBV DNA negativity by 12 months. Four patients experienced virological breakthrough during ETV therapy. Two patients had no genotypic mutations, and medical interviews revealed that they had poor adherence to ETV.
Conclusions. We found that some of the HBV virological breakthroughs during ETV treatment were related to poor adherence to medication, highlighting that clinicians should pay attention to the emergence of resistant mutants as well as adherence to ETV.