title: Subgenotype and genetic variability in the precore/core regions of hepatitis B virus in Korean patients with chronic liver disease.
abstract: OBJECTIVE
  The aim of this study was to determine the prevalence of hepatitis B virus (HBV) subgenotypes, the spectrum of mutations in the precore/core region through phylogenetic analysis, and the relevance of viral characteristics in disease progression in Korean patients.
  
  
  METHODS
  133 patients with chronic HBV infection were enrolled. The precore and core region of HBV was amplified and sequenced. Phylogenetic analysis was performed for subgenotyping and the changes of nucleotides and amino acid were compared in liver disease stages.
  
  
  RESULTS
  HBV/C2 subgenotype was predominant in chronic HBV carriers (98.5%), followed by HBV/A2 (0.75%) and HBV/C7 (0.75%). The mutations of the precore region were not different between liver disease stages. However, amino acid changes in the cytotoxic T lymphocyte epitope (p < 0.020), CD4+ T cell epitope (p < 0.027), or B cell epitope (p < 0.029) were significantly higher in liver cirrhosis patients than in chronic hepatitis patients, but not in hepatocellular carcinoma patients.
  
  
  CONCLUSIONS
  HBV/C2 is the most prevalent subgenotype in Korea, and HBV/C7 subgenotype found in the Philippines was first identified in the Korean population. Mutations in immune epitopes within the core gene were significantly associated with disease progression.
authors.affiliation: Department of Internal Medicine and WHO Collaborating Center on Viral Hepatitis, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Kwang Soo
authors.initials: KS
authors.lastname: Lyoo
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Hong
authors.forename: Myeong Jun
authors.initials: MJ
authors.lastname: Song
authors.forename: Wonhee
authors.initials: W
authors.lastname: Hur
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Choi
authors.forename: Lian-Shu
authors.initials: LS
authors.lastname: Piao
authors.forename: Jeong Won
authors.initials: JW
authors.lastname: Jang
authors.forename: Si Hyun
authors.initials: SH
authors.lastname: Bae
authors.forename: Jong Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Jung Wha
authors.initials: JW
authors.lastname: Park
authors.forename: Sang Wook
authors.initials: SW
authors.lastname: Choi
authors.forename: Seung Kew
authors.initials: SK
authors.lastname: Yoon
mesh_terms: D000328:Adult; D006528:Carcinoma, Hepatocellular / Q000821:virology; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000821:virology*; D006801:Humans; D007723:Korea; D008103:Liver Cirrhosis / Q000821:virology; D008113:Liver Neoplasms / Q000821:virology; D008297:Male; D008875:Middle Aged; D058889:Molecular Typing; D020125:Mutation, Missense; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D014758:Viral Core Proteins / Q000235:genetics*
chemical_list: D014758:Viral Core Proteins