title: Mutations in the S gene and in the overlapping reverse transcriptase region in chronic hepatitis B Chinese patients with coexistence of HBsAg and anti-HBs.
abstract: BACKGROUND
  The mechanism underlying the coexistence of hepatitis B surface antigen and antibodies to HBsAg in chronic hepatitis B patients remains unknown.
  
  
  OBJECTIVE
  This research aimed to determine the clinical and virological features of the rare pattern.
  
  
  METHODS
  A total of 32 chronic hepatitis B patients infected by HBV genotype C were included: 15 carrying both HBsAg and anti-HBs (group I) and 17 solely positive for HBsAg (group II). S gene and reverse transcriptase region sequences were amplified, sequenced and compared with the reference sequences.
  
  
  RESULTS
  The amino acid variability within major hydrophilic region, especially the "a" determinant region, and within reverse transcriptase for regions overlapping the major hydrophilic region in group I is significantly higher than those in group II. Mutation sI126S/T within the "a" determinant was the most frequent change, and only patients from group I had the sQ129R, sG130N, sF134I, sG145R amino acid changes, which are known to alter immunogenicity.
  
  
  CONCLUSIONS
  In chronic patients, the concurrent HBsAg/anti-HBs serological profile is associated with an increased aa variability in several key areas of HBV genome. Additional research on these genetic mutants are needed to clarify their biological significance for viral persistence.
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University, Hubei Province, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Ding
authors.affiliation: Department of Clinical Laboratory, Puai Hospital Affiliated to Tongji Medical College of Huazhong University of Science & Technology, Hubei Province, PR China.
authors.forename: Xi-Li
authors.initials: XL
authors.lastname: Miao
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University, Hubei Province, PR China.
authors.forename: Yan-Xia
authors.initials: YX
authors.lastname: Li
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University, Hubei Province, PR China.
authors.forename: Jin-Fen
authors.initials: JF
authors.lastname: Dai
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University, Hubei Province, PR China; Institute for Gastroenterology and Hepatology, Wuhan University Medical School, Hubei Province, PR China. Electronic address: yuhonggang@yahoo.com.
authors.forename: Hong-Gang
authors.initials: HG
authors.lastname: Yu
mesh_terms: D000328:Adult; D002681:China; D004279:DNA, Viral; D005260:Female; D005838:Genotype; D006510:Hepatitis B Antibodies / Q000097:blood*; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D008297:Male; D009154:Mutation; D016133:Polymerase Chain Reaction; D012194:RNA-Directed DNA Polymerase / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014759:Viral Envelope Proteins / Q000235:genetics*; D055815:Young Adult
chemical_list: D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; C118669:S envelope protein, hepatitis B virus; D014759:Viral Envelope Proteins; D012194:RNA-Directed DNA Polymerase
keywords: Chronic hepatitis B; Coexistence of HBsAg and anti-HBs; Reverse transcriptase; S gene