title: The C-caffeine breath test distinguishes significant fibrosis in chronic hepatitis B and reflects response to lamivudine therapy.
abstract: BACKGROUND
  The 13C-caffeine breath test is a non-invasive, quantitative test of liver function.
  
  
  OBJECTIVE
  To determine the utility of the 13C-caffeine breath test in chronic hepatitis B virus and its ability to monitor response to lamivudine.
  
  
  METHODS
  Forty-eight chronic hepatitis B virus patients and 24 controls underwent the 13C-caffeine breath test. In 28 patients commenced on lamivudine, 13C-caffeine breath tests were performed at 1 week (n = 12) and after 1 year of therapy.
  
  
  RESULTS
  Patients with Metavir F0-1 fibrosis (2.30 +/- 1.02 Delta per thousand per 100 mg caffeine) had a 13C-caffeine breath test similar to controls (2.31 +/- 0.85, P = 0.96). However, patients with F2-3 fibrosis (1.59 +/- 0.78, P = 0.047) and cirrhotic patients (0.99 +/- 0.33, P = 0.001) had a decreased 13C-caffeine breath test. Fibrosis correlated best with the 13C-caffeine breath test (r(s) = -0.62, P < 0.001). The 13C-caffeine breath test independently predicted significant (F > or = 2) and advanced (F > or = 3) fibrosis and yielded the greatest area under the receiver operating characteristic curve (0.91 +/- 0.04) for predicting advanced fibrosis. The 13C-caffeine breath test was unaltered by 1 week of lamivudine but improved by 61% (P < 0.001) in responders to long-term lamivudine, whereas in those with viraemia and elevated alanine aminotransferase, values remained stable or deteriorated.
  
  
  CONCLUSIONS
  The 13C-caffeine breath test distinguishes chronic hepatitis B virus-related fibrosis and detects improvement in liver function in response to long-term lamivudine.
authors.affiliation: Department of Gastroenterology and Hepatology, The University of Sydney, Concord Hospital, Concord, NSW, Australia. gpark@med.usyd.edu.au
authors.forename: G J-H
authors.initials: GJ
authors.lastname: Park
authors.forename: P H
authors.initials: PH
authors.lastname: Katelaris
authors.forename: D B
authors.initials: DB
authors.lastname: Jones
authors.forename: F
authors.initials: F
authors.lastname: Seow
authors.forename: B P C
authors.initials: BP
authors.lastname: Lin
authors.forename: D G
authors.initials: DG
authors.lastname: Le Couteur
authors.forename: M C
authors.initials: MC
authors.lastname: Ngu
mesh_terms: D000328:Adult; D001944:Breath Tests / Q000379:methods*; D002110:Caffeine / Q000032:analysis*; D005260:Female; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008103:Liver Cirrhosis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine; D002110:Caffeine