title: [Correlation of HBV DNA level and viral breakthrough during lamivudine therapy for chronic hepatitis B].
abstract: OBJECTIVE
  Lamivudine is an effective therapy in chronic hepatitis B patients, but the emergence of resistant hepatitis B virus (HBV) mutants is a major concern. This study was performed to investigate whether serum viral DNA levels during lamivudine therapy are related with viral breakthrough in patients with chronic HBV infection.
  
  
  METHODS
  This study consisting of 103 patients was performed retrospectively and prospectively. Follow-up duration was 24 months after lamivudine therapy. Serum HBV DNA levels were quantified by PCR-based assay every 6 months.
  
  
  RESULTS
  Cumulative rate of viral breakthrough was 0%, 19.4%, 36%, and 48.5% in 6, 12, 18, and 24 months respectively. The rate of viral breakthrough in 24 months increased as serum HBV DNA levels increased at 6 months. When serum HBV DNA levels were 2-3 log10, 3-4 log10, 4-5 log10, and 5 log10 copies/mL or more, the breakthrough rates were significantly higher than that of the HBV DNA level less than 2 log10 copies/mL. The relative risks were 1.10, 1.93, 2.69, 3.21 respectively (P<0.001). The viral breakthrough rate also increased as serum HBV DNA levels at 12 months increased. When the HBV DNA levels were 2-3 log10, 3-4 log10, 4-5 log10, and 5 log10 copies/ mL or more, the breakthrough rate were significantly higher than those of HBV DNA level less than 2 log10 copies/mL. The relative risks were 2.42, 4.35, 3.73, 2.61, respectively (P=0.002).
  
  
  CONCLUSIONS
  The serum HBV DNA levels at 6 months and 12 months during lamivudine therapy can be closely correlated with the rate of viral breakthrough in 24 months.
authors.affiliation: Department of Internal Medicine, Pusan National University, School of Medicine, Busan, Korea.
authors.forename: Hee Seung
authors.initials: HS
authors.lastname: Park
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Lee
authors.forename: Jeong
authors.initials: J
authors.lastname: Heo
authors.forename: Gwang Ha
authors.initials: GH
authors.lastname: Kim
authors.forename: Dae Hwan
authors.initials: DH
authors.lastname: Kang
authors.forename: Geun Am
authors.initials: GA
authors.lastname: Song
authors.forename: Mong
authors.initials: M
authors.lastname: Cho
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood; D005260:Female; D006515:Hepatitis B virus / Q000302:isolation & purification*; D019694:Hepatitis B, Chronic / Q000188:drug therapy / Q000821:virology*; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D019259:Lamivudine