title: Retrospective study of the prevalence and clinical significance of hepatitis B virus precore and basal core promoter variants.
abstract: BACKGROUND
  Hepatitis B virus (HBV) precore (PC) and basal core promoter (BCP) variants are well known; however, their prevalence in North America is unclear, especially among hepatitis B e antigen-negative patients.
  
  
  OBJECTIVE
  To investigate the prevalence of PC⁄BCP mutations and their clinical significance.
  
  
  METHODS
  One hundred twenty-eight patients positive for both hepatitis B surface antigen and hepatitis B e antibody were selected, and PC⁄BCP mutations were identified using a line probe assay. The subjects' charts were reviewed for race⁄ethnicity, HBV genotype, HBV viral load, sex, liver enzyme levels, imaging and biopsy results up to 10 years before the study.
  
  
  RESULTS
  The prevalence of PC and BCP variants were 47.6% and 62.5%, respectively. Older age was associated with aspartate aminotransferase-to-platelet index ratio (APRI) ≥0.7 (P=0.011) and abnormal imaging⁄biopsy results (P=0.0008). Although the presence of BCP variant(s) was associated with APRI ≥0.7 (P=0.029), it was not associated with abnormal imaging⁄biopsy results. The combination of age ≥50 years and the presence of BCP variant(s) was associated with abnormal imaging⁄biopsy results, suggestive of either cirrhosis or hepatocellular carcinoma (not observed with PC mutation). Neither sex or genotype, or median HBV viral load showed significant influence on any of these outcomes.
  
  
  CONCLUSIONS
  The present study suggests that the prevalence of PC and BCP mutations are higher than what has been previously reported. One potential explanation would be increased immigration in the past decade. Considering the potential public health and clinical implications of these variants, long-term multicentre and prospective studies could further unravel the uncertainty around these variants.
authors.forename: Meaghan
authors.initials: M
authors.lastname: O'Brien
authors.forename: Adara
authors.initials: A
authors.lastname: Casselman
authors.forename: Gerry
authors.initials: G
authors.lastname: Smart
authors.forename: Ainsley
authors.initials: A
authors.lastname: Gretchen
authors.forename: Kelly
authors.initials: K
authors.lastname: Kaita
authors.forename: Kamran
authors.initials: K
authors.lastname: Kadkhoda
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000410:Alanine Transaminase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D005260:Female; D005838:Genotype; D006512:Hepatitis B Core Antigens / Q000235:genetics*; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000201:enzymology / Q000473:pathology / Q000821:virology*; D006801:Humans; D008099:Liver / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010976:Platelet Count; D011401:Promoter Regions, Genetic / Q000235:genetics; D012189:Retrospective Studies; D019562:Viral Load; D055815:Young Adult
chemical_list: D006512:Hepatitis B Core Antigens; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase