title: Virological differences between patients infected with subtypes Ba and Bj of hepatitis B virus genotype B.
abstract: BACKGROUND
  Hepatitis B virus (HBV) genotype B is classified into subtype Ba with the recombination with genotype C in the precore region plus core gene and subtype Bj without recombination. Virological and clinical differences between infections with subtypes Ba and Bj, however, are yet to be determined.
  
  
  METHODS
  During 1976 through 2001, 224 patients visited Toranomon Hospital in Tokyo, Japan who were infected with HBV genotype B. Subtypes of genotype B were determined by sequencing HBV-DNA recovered from sera for detecting recombination with genotype C.
  
  
  RESULTS
  Subtype Ba was detected in 53 patients (24%) and Bj in 167 (75%); subtypes were not able to be determined in the remaining four (1%). The only virological difference was that detection of hepatitis B e antigen at the presentation was more frequent in the patients infected with subtype Ba than those with Bj (63% vs 33%, P = 0.016). There were no differences in the distribution of liver disease of various forms between the patients infected with subtypes Ba and Bj at presentation. No differences were noted, either, in the development of liver cirrhosis or hepatocellular carcinoma, or the loss of hepatitis B surface antigen from serum, between the patients infected with subtypes Ba and Bj during follow up of up to 26 years.
  
  
  CONCLUSIONS
  Although there were some virological differences between the patients infected with subtypes Ba and Bj of HBV genotype B, they do not seem to influence the long-term clinical outcome.
authors.affiliation: Research Institute for Hepatology, Toranomon Hospital, Tokyo, Japan. vj7m-kbys@asahi-net.or.jp
authors.forename: Mariko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Suzuki
authors.forename: Norio
authors.initials: N
authors.lastname: Akuta
authors.forename: Akihito
authors.initials: A
authors.lastname: Tsubota
authors.forename: Kenji
authors.initials: K
authors.lastname: Ikeda
authors.forename: Yasuji
authors.initials: Y
authors.lastname: Arase
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Saitoh
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hosaka
authors.forename: Takashi
authors.initials: T
authors.lastname: Someya
authors.forename: Marie
authors.initials: M
authors.lastname: Matsuda
authors.forename: Junko
authors.initials: J
authors.lastname: Sato
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Miyakawa
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Kumada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000956:Antigens, Viral / Q000235:genetics*; D016009:Chi-Square Distribution; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005838:Genotype; D006509:Hepatitis B / Q000821:virology*; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric
chemical_list: D000956:Antigens, Viral