title: Efficacy of lamivudine therapy and factors associated with emergence of resistance in chronic hepatitis B virus infection in Japan.
abstract: OBJECTIVE
  Several reports have examined the efficacy of long-term lamivudine therapy and the risk factors involved in emergence of viral resistance in Japanese patients with hepatitis B virus (HBV) infection. However, the patient cohorts in such studies are relatively small.
  
  
  METHODS
  We analyzed 234 chronically HBV-infected Japanese patients who were treated with lamivudine for more than 12 months. They comprised patients with HBV genotype A (n = 8), genotype B (n = 21), genotype C (n = 203) and other HBV genotypes (n = 2).
  
  
  RESULTS
  In most patients, lamivudine resulted in normalization of alanine transaminase (ALT) levels at 6 and 12 months, and suppression of serum HBV DNA to undetectable levels by the branched chain DNA probe assay (bDNA). Rates of ALT normalization and non-detection of HBV DNA were higher among patients with genotype B than genotype C disease. The proportions of patients who achieved HBeAg loss were 27, 42 and 45% after 6 months, 1 year and 2 years, respectively. The emergence of mutations was not different among genotypes A, B and C by the Kaplan-Meier method. Multivariate analyses identified high HBV DNA level (bDNA >or=100 MEq/ml) as an independent factor associated with emergence of the YMDD motif mutation in all patients. Among patients with genotype C disease, which is the predominant HBV genotype in Japan, multivariate analysis also identified high HBV DNA level and HBeAg positivity as factors associated with emergence of resistance.
  
  
  CONCLUSIONS
  Patients exhibiting these factors at the commencement of lamivudine treatment must be monitored carefully at regular intervals for emergence of viral resistance.
authors.affiliation: Department of Gastroenterology, Toranomon Hospital, Tokyo, Japan. fumitakas@toranomon.gr.jp
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Suzuki
authors.forename: Akihito
authors.initials: A
authors.lastname: Tsubota
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Arase
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Norio
authors.initials: N
authors.lastname: Akuta
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hosaka
authors.forename: Takashi
authors.initials: T
authors.lastname: Someya
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Saitoh
authors.forename: Kenji
authors.initials: K
authors.lastname: Ikeda
authors.forename: Mariko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Marie
authors.initials: M
authors.lastname: Matsuda
authors.forename: Junko
authors.initials: J
authors.lastname: Satoh
authors.forename: Kimiko
authors.initials: K
authors.lastname: Takagi
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Kumada
mesh_terms: D000328:Adult; D000368:Aged; D004279:DNA, Viral / Q000097:blood; D024882:Drug Resistance, Viral; D005260:Female; D005838:Genotype; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000187:drug effects* / Q000235:genetics; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000453:epidemiology / Q000821:virology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D019259:Lamivudine / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D004279:DNA, Viral; D006513:Hepatitis B e Antigens; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine