title: Absence of pretreatment markers that predict the emergence of YMDD mutants during lamivudine treatment--the results of a prospective multi-center study.
abstract: OBJECTIVE
  The emergence of YMDD mutants in patients who are treated with lamivudine may determine the clinical prognosis. However, currently there are no clinical or virological factors that predict specifically the emergence of the mutants.
  
  
  METHODS
  To define these factors, we analyzed 69 patients with chronic hepatitis B infection who were treated with lamivudine (LAM) and followed prospectively for at least 12 months.
  
  
  RESULTS
  Of the 69 patients, 12 (17.4%) developed YMDD mutants up to 12 months after the start of LAM. The incidence of YMDD mutants was slightly higher in those who were younger, had higher HBV DNA titers, lower ALT levels, genotype C, and mutations in the core promoter before treatment. However, we could not find any significant factors that correlated with the appearance of the mutants.
  
  
  CONCLUSIONS
  Currently, using conventional virological assays, it is difficult to predict the development of mutants before LAM treatment. Management of flare-ups of hepatitis, due to the appearance of mutants, should always be envisaged when LAM treatment is started.
authors.affiliation: Gastroenterology Division, Graduate School of Niigata University, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Yano
authors.forename: Shogo
authors.initials: S
authors.lastname: Ohkoshi
authors.forename: Kenta
authors.initials: K
authors.lastname: Suzuki
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Ito
authors.forename: Hiroto
authors.initials: H
authors.lastname: Wakabayashi
authors.forename: Motoya
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Hironobu
authors.initials: H
authors.lastname: Maeda
authors.forename: Shige-aki
authors.initials: SA
authors.lastname: Hatakeyama
authors.forename: Tohru
authors.initials: T
authors.lastname: Hatano
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Takei
authors.forename: Hata
authors.initials: H
authors.lastname: Kohjiro
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Tsuboi
authors.forename: Tohru
authors.initials: T
authors.lastname: Takahashi
authors.forename: Tohru
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Tomoteru
authors.initials: T
authors.lastname: Kamimura
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ichida
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Aoyagi
mesh_terms: D000328:Adult; D020816:Amino Acid Motifs / Q000235:genetics*; D005260:Female; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*
chemical_list: D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine