title: Prevalence of genotype D in chronic liver disease patients with occult HBV infection in northern region of India.
abstract: BACKGROUND
  Etiology of nearly 30% cases of chronic viral hepatitis remains undetected. Occult HBV infection (OBI) has emerged as an important clinical entity in this scenario. Apart from prevalence and clinical outcome of OBI patients genotype was determined in northern region of India.
  
  
  METHODS
  A total of 847 patients with chronic liver disease (CLD) were screened for common viral etiologies and others serological markers of HBV. Amplification of surface, precore and polymerase genes of HBV was performed in patients negative for other etiologies. Genotyping and sequencing of the precore region was performed for OBI cases.
  
  
  RESULTS
  Twenty-nine (7.61%) cases of OBI were identifiedof which 9 had chronic liver disease (CHD), 11 liver cirrhosis (LC) and 9 hepatocellular carcinoma (HCC). Majority of OBI cases were detected by amplification of surface gene 26 (89.6%), followed by pre-core gene 12 (41.3%). Their liver functions tests were significantly deranged in comparison to overt HBV cases. IgG anti HBc was present in 8 (27.6%) OBI cases. Mutation was observed in 8 (32%) in pre-core region at nt. 1896 of overt HBV cases. Genotype D was the predominant genotype.
  
  
  CONCLUSIONS
  OBI in our study was characterized by predominance of genotype D and more severe clinical and biochemical profile in comparison to overt HBV. IgG anti HBc positivity could be utilized as a marker of OBI. We recommend use of sensitive nested PCR for diagnosis of OBI, amplifying at least surface and precore gene.
authors.forename: Meher
authors.initials: M
authors.lastname: Rizvi
authors.forename: Mohd
authors.initials: M
authors.lastname: Azam
authors.affiliation: Department of Microbiology, Jawaharlal Nehru Medical College and Hospital, Aligarh Muslim University (AMU), Aligarh, Uttar Pradesh, India.
authors.forename: Asfia
authors.initials: A
authors.lastname: Sultan
authors.forename: Indu
authors.initials: I
authors.lastname: Shukla
authors.forename: Abida
authors.initials: A
authors.lastname: Malik
authors.forename: Masihur Reman
authors.initials: MR
authors.lastname: Ajmal
authors.forename: Fatima
authors.initials: F
authors.lastname: Khan
authors.forename: Hiba
authors.initials: H
authors.lastname: Sami
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D058345:Asymptomatic Infections; D001483:Base Sequence; D001774:Blood Chemical Analysis; D006528:Carcinoma, Hepatocellular / Q000821:virology; D004279:DNA, Viral / Q000235:genetics; D005260:Female; D006512:Hepatitis B Core Antigens / Q000235:genetics; D006514:Hepatitis B Surface Antigens / Q000097:blood* / Q000235:genetics; D006513:Hepatitis B e Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000175:diagnosis* / Q000821:virology; D006801:Humans; D007194:India; D008111:Liver Function Tests; D008113:Liver Neoplasms / Q000821:virology; D008297:Male; D008875:Middle Aged; D017422:Sequence Analysis, DNA; D014758:Viral Core Proteins / Q000235:genetics
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; D014758:Viral Core Proteins