Tenofovir disoproxil fumarate (TDF) is an acyclic nucleotide reverse transcriptase inhibitor used as antiviral therapeutic drug in hepatitis B virus (HBV) infection treatment. We investigated whether HBV itself or TDF could enhance genotoxicity in HBV infected patients. A total of 30 HBV-infected patients were included in this study: 10 were untreated, 10 took therapy for 6 months, 10 took therapy for 12 months and a further 15 were control group. We used the micronucleus test (MN) and mitotic index (MI) to assess the genotoxic effects of TDF. MN and MI frequency were significantly increased in all the HBV-infected patient groups when compared to control. However, significant differences were not found between different time points within the therapy groups. The current data indicate that chronic HBV infection without treatment has an effect on MN and MI. TDF administration at therapeutic doses for 12 months also did not reduce the MI and MN, suggesting its protective action against HBV induced genotoxic damage. Larger-scale and longtime studies are required for a better understanding of the genotoxicity of TDF.
Tenofovir disoproxil fumarate;hepatitis B;micronuclei;genotoxicity