[A kinetic study of hepatitis B virus pre-C gene mutation]

The point mutation in the precore region of hepatitis B viral genome (nt83) was tested with the method of mispairing PCR-RFLP in 54 chronic hepatitis B patients all confirmed by liver biopsy. The over all detection rate of pre-C mutation was 66.7% and the detection rate of pre-C mutation in chronic active hepatitis patients was as high as 80.0%, being significantly higher than that in chronic persistent hepatitis (46.7%). The detection rate of pre-C mutation was 41.2% in hepatitis B e antigen (HBeAg) positive group and 63.3% in anti-HBe(+) group respectively. The detection rate in anti-HBe(+) patients with normal alanine transaminase activity was as high as 82.4%. During the period of follow up it was found that pre-C mutation may appear and disappear or may persist continually. The results suggested that pre-C mutation was extremely common in chronic hepatitis B virus (HBV) infection. The coexistence of the mutant type and wild type in the patients may be considered as the natural course of HBV chronic infection. Further study on the cause and effect relation between pre-C mutation and genesis of chronic active hepatitis and liver cirrhosis is urgently needed.