RESUMEN
<p><b>OBJECTIVE</b>To explore the dynamics of hepatitis B virus covalently closed circular DNA (cccDNA) and optimal duration of treatment after serum virology response.</p><p><b>METHODS</b>HBV cccDNA in liver biopsies and the serum HBV DNA were quantified by real time PCR, the serum makers were detected by enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>(1) The cccDNA in biopsy samples continued to decrease after serum virology responded. (2) The longer the treatment after serum virology response, the lower the cccDNA level in liver tissue. (3) Anti-HBe positive patients had lower cccDNA in liver tissue than anti-HBe negative patients. (4) cccDNA in liver tissue was undetectable in 12 out of the 18 case anti-HBe(+) patients. Serum virology response lasted 35 months and anti-HBe(+) lasted 30 months.</p><p><b>CONCLUSION</b>After serum virology responded, the longer the treatment, the lower the liver cccDNA. The cccDNA is undetectable in about 2/3 of the patients if the serum virological clearance lasts more than 35 months and anti-HBe lasts more than 30 months.</p>