title: Analysis of the core gene of hepatitis B virus in Korean patients.
abstract: OBJECTIVE
  As the core gene of hepatitis B virus (HBV) is a major immunological target, its mutation may evoke or evade immune clearance. We investigated the frequency and location of HBV core gene substitutions according to hepatitis B e antigen (HBeAg) status and viral replication status, and evaluated the association of these substitutions with the different stages of chronic HBV infection in Korean patients.
  
  
  METHODS
  The study population included 45 HBeAg-positive/DNA-positive patients (group I), 49 HBeAg-negative/DNA-positive patients (II) and 50 HBeAg-negative/DNA-negative patients (III). The HBV core gene was analysed by polymerase chain reaction (PCR) and sequencing.
  
  
  RESULTS
  The frequency of core gene substitutions increased from group I to group III. Substitutions were commonly detected at codons 87, 97, 112 and 130. The frequency of substitutions at codons 87 and 112 was higher in groups II/III than in group I. The frequency of the codon I97F substitutions was the highest in group III. However, the codon 130 substitution was more frequently found in groups I/II than in group III.
  
  
  CONCLUSIONS
  Core gene substitutions were more frequently detected in HBeAg-negative and/or HBV DNA-negative patients. The substitutional hot spots were codons 87, 97, 112 and 130; substitutions at these codons might play a role in immune-modulation during the course of chronic HBV infection.
authors.affiliation: Department of Internal Medicine, Chung Ang University Hospital, Seoul, South Korea.
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Kim
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Lee
authors.forename: Geum-Youn
authors.initials: GY
authors.lastname: Gwak
authors.forename: Moon Seok
authors.initials: MS
authors.lastname: Choi
authors.forename: Joon Hyeok
authors.initials: JH
authors.lastname: Lee
authors.forename: Kwang Cheol
authors.initials: KC
authors.lastname: Koh
authors.forename: Seung Woon
authors.initials: SW
authors.lastname: Paik
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Yoo
mesh_terms: D000328:Adult; D000368:Aged; D019943:Amino Acid Substitution / Q000235:genetics*; D044466:Asian People; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000097:blood*; D005260:Female; D005814:Genes, Viral; D006513:Hepatitis B e Antigens / Q000097:blood*; D006515:Hepatitis B virus / Q000235:genetics* / Q000502:physiology; D019694:Hepatitis B, Chronic / Q000208:ethnology / Q000276:immunology / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D006513:Hepatitis B e Antigens