title: Measurement of hepatitis B virus core-related antigen is valuable for identifying patients who are at low risk of lamivudine resistance.
abstract: OBJECTIVE
  The clinical usefulness of hepatitis B virus core-related antigen (HBVcrAg) assay was compared with that of HBV DNA assay in predicting the occurrence of lamivudine resistance in patients with chronic hepatitis B.
  
  
  METHODS
  Of a total of 81 patients who were treated with lamivudine, 25 (31%) developed lamivudine resistance during a median follow-up period of 19.3 months.
  
  
  RESULTS
  The pretreatment positive rate of HBe antigen, or pretreatment levels of HBVcrAg or HBV DNA did not differ between patients with and without lamivudine resistance. Levels of both HBVcrAg and HBV DNA decreased after the initiation of lamivudine administration; however, the level of HBVcrAg decreased significantly more slowly than that of HBV DNA. The occurrence of lamivudine resistance was significantly less frequent in the 56 patients whose HBV DNA level was less than 2.6 log copy/ml at 6 months of treatment than in the remaining 25 patients. The cumulative rate of lamivudine resistance was as high as 70% within 2 years in the latter group, while it was only 28% in the former group. Lamivudine resistance did not occur during the follow-up period in the 19 patients whose HBVcrAg level was less than 4.6 log U/ml at 6 months of treatment, while it did occur in 50% of the remaining patients within 2 years.
  
  
  CONCLUSIONS
  These results suggest that measurement of HBV DNA is valuable for identifying patients who are at high risk of developing lamivudine resistance, and that, conversely, measurement of HBVcrAg is valuable for identifying those who are at low risk of lamivudine resistance.
authors.affiliation: Department of Medicine, Shinshu University School of Medicine, Matsumoto, Japan. etanaka@hsp.md.shinshu-u.ac.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
authors.forename: Akihiro
authors.initials: A
authors.lastname: Matsumoto
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Suzuki
authors.forename: Mariko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okanoue
authors.forename: Masahito
authors.initials: M
authors.lastname: Minami
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
authors.forename: Michio
authors.initials: M
authors.lastname: Imamura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yatsuhashi
authors.forename: Shinya
authors.initials: S
authors.lastname: Nagaoka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yotsuyanagi
authors.forename: Sumio
authors.initials: S
authors.lastname: Kawata
authors.forename: Tatsuji
authors.initials: T
authors.lastname: Kimura
authors.forename: Noboru
authors.initials: N
authors.lastname: Maki
authors.forename: Shiro
authors.initials: S
authors.lastname: Iino
authors.forename: Kendo
authors.initials: K
authors.lastname: Kiyosawa
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004279:DNA, Viral / Q000032:analysis; D004351:Drug Resistance; D005260:Female; D006509:Hepatitis B / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D006513:Hepatitis B e Antigens / Q000032:analysis / Q000276:immunology*; D006515:Hepatitis B virus / Q000276:immunology*; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D014758:Viral Core Proteins / Q000187:drug effects / Q000276:immunology*
chemical_list: D004279:DNA, Viral; D006513:Hepatitis B e Antigens; D014758:Viral Core Proteins; D019259:Lamivudine