title: 13C-phenylalanine and 13C-methacetin breath test to evaluate functional capacity of hepatocyte in chronic liver disease.
abstract: BACKGROUND
  To grade liver damage, Child-Pugh classification is used but these tests do not reflect the quantitative functional hepatic reserve.
  
  
  OBJECTIVE
  13C-Phenylalanine Breath Test and 13C-Methacetin Breath Test are evaluated as possible tools, being both safe and easy to perform, to quantify functional hepatic reserve in chronic liver disease patients.
  
  
  METHODS
  Both tests were performed in 48 healthy volunteers and 48 chronic liver disease patients.
  
  
  METHODS
  Breath samples were collected after taking 13C-Phenylalanine (100 mg) and 13C-Methacetin (75 mg). 13CO2 enrichment was measured using mass spectrometry
  
  
  RESULTS
  Both tests discriminated the hepatic function, decreasing results of the 13CO2 enrichment agreeing with the increasing severity of the hepatic patient (13C-Phenylalanine Breath Test multiple correlation coefficient: 0.72, global p<0.001; Methacetin Breath Test: 0.73, p<0.001). Correlation between 13C-Phenylalanine Breath Test and Methacetin Breath Test was 0.63, p<0.001. If both tests were pathological, the sensitivity for the diagnosis of hepatic dysfunction was high (98%), although the specificity decreased to 60%. Best results were obtained at 30 minutes with 13C-Phenylalanine Breath Test and at 10 minutes with Methacetin Breath Test.
  
  
  CONCLUSIONS
  Both 13C-Phenylalanine Breath Test and Methacetin Breath Test are safe and easy tests to perform and both are able to discriminate the hepatic functional capacity between the different groups studied.
authors.affiliation: Department of Clinical Analysis, Hospital de la Princesa, Universidad Autónoma, Madrid, Spain. jvalle@intersep.org
authors.forename: S
authors.initials: S
authors.lastname: Lara Baruque
authors.forename: M
authors.initials: M
authors.lastname: Razquin
authors.forename: I
authors.initials: I
authors.lastname: Jimenez
authors.forename: A
authors.initials: A
authors.lastname: Vazquez
authors.forename: J P
authors.initials: JP
authors.lastname: Gisbert
authors.forename: J M
authors.initials: JM
authors.lastname: Pajares
mesh_terms: D000081:Acetamides; D000328:Adult; D001944:Breath Tests; D002247:Carbon Isotopes; D002908:Chronic Disease; D005260:Female; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D008107:Liver Diseases / Q000175:diagnosis* / Q000378:metabolism; D008111:Liver Function Tests / Q000379:methods*; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D010649:Phenylalanine; D011379:Prognosis; D012720:Severity of Illness Index
chemical_list: D000081:Acetamides; D002247:Carbon Isotopes; C035495:methacetin; D010649:Phenylalanine