Changes in HBV DNA determined by ultra-sensitive quantitative method in chronic hepatitis B patients treated with long-term lamivudine

This study on patients with hepatitis B treated with long-term lamivudine (LAM) aimed to predict the time of relapse of hepatitis accompanying the emergence of LAM-resistant strain and to determine the time of discontinuation of treatment. The changes in hepatitis B virus (HBV) DNA were determined using sensitive quantitative methods. Eight HBV DNA-positive patients with chronic active hepatitis (seven males, aged 35 to 59 years, F3 in four cases, HBe antigen positive in three cases, genotype C in all cases, core promoter mutation in all cases) who were treated with LAM continuously for 24 months or longer were studied. HBV DNA was determined quantitatively by TMA-HPA method, Amplicor HBV monitor method and ultra-sensitive HBV RTD-PCR direct (DIRECT) method. In four cases, the DNA quantity showed another increase and YMDD mutant emerged after a long period, however all four cases showed a slight increase in DNA quantity during LAM treatment. In one case, such course was caught only by DIRECT method. In conclusion, it was suggested that the DIRECT method was useful to follow the changes in HBV DNA in patients treated with LAM.