BACKGROUND/AIMS: It is controversial whether hepatitis B or C viruses induce liver cancer through non-specific mechanisms (inflammation and cell renewal) or direct genotoxicity. Considering that both viruses infect peripheral lymphocytes, studying sister chromatid exchange frequency and mitotic index in peripheral lymphocytes is a reasonable experimental approach to investigate their genotoxic potential separately. In the present study we investigated sister chromatid exchange frequency and mitotic index in the peripheral lymphocytes of patients with cirrhosis and chronic carriers with positive serology for HBV or HCV infections. METHODOLOGY: The study population consisted of 3 groups: group I involved 23 HBsAg positive chronic carriers; group II involved 30 HBsAg positive patients with cirrhosis and group III involved 9 HCV-positive patients with cirrhosis. The control group involved 30 healthy individuals. RESULTS: Sister chromatid exchange frequency was significantly higher in all the study groups than the control group (p < 0.05). The mitotic index was significantly lower in all the study groups than the control group (p < 0.05). CONCLUSIONS: The increased sister chromatid exchange frequency and low mitotic index may be reflecting a direct genotoxic effect of HBV and HCV in peripheral lymphocytes. We suggest that the same genotoxicity may also operate in the liver and contribute to hepatocarcinogenesis.
BACKGROUND/AIMS: It is controversial whether hepatitis B or C viruses induce liver cancer through non-specific mechanisms (inflammation and cell renewal) or direct genotoxicity. Considering that both viruses infect peripheral lymphocytes, studying sister chromatid exchange frequency and mitotic index in peripheral lymphocytes is a reasonable experimental approach to investigate their genotoxic potential separately. In the present study we investigated sister chromatid exchange frequency and mitotic index in the peripheral lymphocytes of patients with cirrhosis and chronic carriers with positive serology for HBV or HCV infections. METHODOLOGY: The study population consisted of 3 groups: group I involved 23 HBsAg positive chronic carriers; group II involved 30 HBsAg positive patients with cirrhosis and group III involved 9 HCV-positive patients with cirrhosis. The control group involved 30 healthy individuals. RESULTS: Sister chromatid exchange frequency was significantly higher in all the study groups than the control group (p < 0.05). The mitotic index was significantly lower in all the study groups than the control group (p < 0.05). CONCLUSIONS: The increased sister chromatid exchange frequency and low mitotic index may be reflecting a direct genotoxic effect of HBV and HCV in peripheral lymphocytes. We suggest that the same genotoxicity may also operate in the liver and contribute to hepatocarcinogenesis.
Authors: Marcia R Nagaoka; Luciana Le Sueur-Maluf; Odair Aguiar; Glaucia M Castro; Regina C Spadari-Bratfisch; Daniel A Ribeiro Journal: Hepatol Int Date: 2011-01-06 Impact factor: 6.047