title: Occult HBV infection in cryptogenic liver cirrhosis in an area with high prevalence of HBV infection.
abstract: OBJECTIVE
  Hepatitis B surface antigen (HBsAg) is often used as the serological marker to screen for hepatitis B virus (HBV) infection in the investigation of liver cirrhosis. In Hong Kong, where HBV infection is endemic, some patients may have persistent viral infection after the loss of HBsAg. We aimed to investigate 1) the prevalence of occult HBV infection in cryptogenic liver cirrhosis in Hong Kong and 2) the role of HBV "a" determinant mutations among these patients.
  
  
  METHODS
  Twenty-eight patients with cryptogenic liver cirrhosis (group I), 49 subjects with no liver disease (group II), and 26 patients with HBV-related cirrhosis (group III) were studied. HBV DNA was determined by the cross-linking assay (sensitivity = 0.5 mEq/ml) and polymerase chain reaction (PCR). Occult HBV infection was defined as HBV DNA detectable by PCR among patients with negative HBsAg.
  
  
  RESULTS
  Eighty-nine percent and 92% of patients in groups I and II, respectively, had positive anti-HBs and/or anti-hepatitis B core. Nine (32%), no (0%), and 14 (54%) patients in groups I, II, and III, respectively, had detectable HBV DNA by PCR (group I vs group II, p < 0.001; group I vs group III, p = 0.36). Four patients in group I had HBV DNA detectable by the cross-linking assay (median = 5.98 mEq/ml, range = 3.1-8.01). "a" determinant mutations were detected in two patients in group I (K122N and G145R, C125A) and one patient in group II (1126N).
  
  
  CONCLUSIONS
  Occult HBV infection is common among patients with cryptogenic liver cirrhosis, and it cannot be explained by mutations in the HBV "a" determinant.
authors.affiliation: Department of Medicine & Therapeutics and Microbiology, the Chinese University of Hong Kong, Shatin.
authors.forename: Henry Lik-Yuen
authors.initials: HL
authors.lastname: Chan
authors.forename: Steven Woon-Choi
authors.initials: SW
authors.lastname: Tsang
authors.forename: Nancy Wai-Yee
authors.initials: NW
authors.lastname: Leung
authors.forename: Chi-Hang
authors.initials: CH
authors.lastname: Tse
authors.forename: Yui
authors.initials: Y
authors.lastname: Hui
authors.forename: John Siu-Lun
authors.initials: JS
authors.lastname: Tam
authors.forename: Francis Ka-Leung
authors.initials: FK
authors.lastname: Chan
authors.forename: Joseph Jao-Yiu
authors.initials: JJ
authors.lastname: Sung
mesh_terms: D000368:Aged; D015331:Cohort Studies; D004279:DNA, Viral / Q000032:analysis; D019353:Endemic Diseases; D005260:Female; D006509:Hepatitis B / Q000150:complications* / Q000453:epidemiology* / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006515:Hepatitis B virus / Q000235:genetics; D006723:Hong Kong; D006801:Humans; D008103:Liver Cirrhosis / Q000821:virology*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D015995:Prevalence; D012016:Reference Values
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens