title: Prognostic value of (13)C-phenylalanine breath test on predicting survival in patients with chronic liver failure.
abstract: OBJECTIVE
  To evaluate the prognostic value of percentage of (13)C-phenylalanine oxidation ((13)C-PheOx) obtained by (13)C-phenylalanine breath test ((13)C-PheBT) on the survival of patients with chronic liver failure.
  
  
  METHODS
  The hepatic function was determined by standard liver blood tests and the percentage of (13)C-PheOx in 118 chronic liver failure patients. The follow-up period was of 64 mo. Survival analysis was performed by the Kaplan-Meier method and variables that were significant (P < 0.10) in univariate analysis and subsequently introduced in a multivariate analysis according to the hazard model proposed by Cox.
  
  
  RESULTS
  Forty-one patients died due to progressive liver failure during the follow-up period. The probability of survival at 12, 24, 36, 48 and 64 mo was 0.88, 0.78, 0.66, 0.57 and 0.19, respectively. Multivariate analysis demonstrated that Child-Pugh classes, age, creatinine and the percentage of (13)C-PheOx (HR 0.338, 95% CI: 0.150-0.762, P = 0.009) were independent predictors of survival. When Child-Pugh classes were replaced by all the parameters of the score, only albumin, bilirubin, creatinine, age and the percentage of (13)C-PheOx (HR 0.449, 95% CI: 0.206-0.979, P = 0.034) were found to be independent predictors of survival.
  
  
  CONCLUSIONS
  Percentage of (13)C-PheOx obtained by (13)C-PheBT is a strong predictor of survival in patients with chronic liver disease.
authors.affiliation: Laboratory of Gastrohepatology Research, Hospital de Pediatria, CMN, Siglo XXI, IMSS. Av Cuauhtemoc 330, Colonia Doctores, Delegacion Cuauhtemoc, Mexico.
authors.forename: I
authors.initials: I
authors.lastname: Gallardo-Wong
authors.forename: S
authors.initials: S
authors.lastname: Morán
authors.forename: G
authors.initials: G
authors.lastname: Rodríguez-Leal
authors.forename: B
authors.initials: B
authors.lastname: Castañeda-Romero
authors.forename: R
authors.initials: R
authors.lastname: Mera
authors.forename: J
authors.initials: J
authors.lastname: Poo
authors.forename: M
authors.initials: M
authors.lastname: Uribe
authors.forename: M
authors.initials: M
authors.lastname: Dehesa
mesh_terms: D000328:Adult; D000367:Age Factors; D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D017093:Liver Failure / Q000097:blood / Q000175:diagnosis / Q000401:mortality*; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D010649:Phenylalanine / Q000032:analysis*; D011379:Prognosis; D016016:Proportional Hazards Models; D012372:ROC Curve; D015203:Reproducibility of Results; D018570:Risk Assessment; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D010649:Phenylalanine