title: A case-control study of response to lamivudine therapy for 2 years in Japanese and Chinese patients chronically infected with hepatitis B virus of genotypes Bj, Ba and C.
abstract: OBJECTIVE
  In eastern Asian countries, hepatitis B virus (HBV) genotype Ba (HBV/Ba), HBV/Bj and HBV/C are prevalent. The aim was to investigate the response or resistance to lamivudine therapy among patients with different HBV genotypes.
  
  
  METHODS
  Of 67 Japanese and Chinese patients with chronic hepatitis B, 18 patients with HBV/Bj, 15 with HBV/Ba and 34 with HBV/C were selected for a case-control study matched according to gender and age. All the patients were treated with lamivudine for 2 years and evaluated the response or emergence of the YMDD mutation at year 2 during the treatment. HBV genotypes were detected by the restriction fragment length polymorphism. The YMDD mutation was detected by the direct sequencing after amplification by PCR.
  
  
  RESULTS
  At year 2 during therapy, 44.8% of the patients showed normalization of ALT and undetectable HBV DNA (favorable response), 35.8% developed the YMDD mutation. There was no significant difference of response to the therapy among the three genotype groups. The emergence of the YMDD mutation was associated with HBV/C. By the multiple logistic regression analysis, however, the significant factor of a favorable response was a higher pretreatment ALT level and negative HBeAg status and the significant factor of the emergence of the YMDD mutation was HBV/C.
  
  
  CONCLUSIONS
  Higher pretreatment ALT level, HBeAg status or HBV genotype may affect the response or resistance to lamivudine therapy.
authors.affiliation: Department of Internal Medicine and Molecular Science, Nagoya City University Graduate School of Medical Sciences, Kawasumi 1, Mizuho, Nagoya 467-8601, Japan.
authors.forename: Etsuro
authors.initials: E
authors.lastname: Orito
authors.forename: Kei
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Man-Fung
authors.initials: MF
authors.lastname: Yuen
authors.forename: Ching-Lung
authors.initials: CL
authors.lastname: Lai
authors.forename: Takanobu
authors.initials: T
authors.lastname: Kato
authors.forename: Fuminaka
authors.initials: F
authors.lastname: Sugauchi
authors.forename: Atsunori
authors.initials: A
authors.lastname: Kusakabe
authors.forename: Michio
authors.initials: M
authors.lastname: Sata
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okanoue
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Niitsuma
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakugawa
authors.forename: Izumi
authors.initials: I
authors.lastname: Hasegawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami