Elevated serum tyrosine concentration is associated with a poor prognosis among patients with liver cirrhosis.

AIM Chronic liver insufficiency is often associated with changes in amino acid metabolism. We evaluated whether change in serum amino acid concentrations had prognostic value among patients with liver cirrhosis. METHODS This retrospective study evaluated 158 patients who had been hospitalized with cirrhosis. Baseline serum concentrations of branched-chain amino acids (BCAAs) and tyrosine, as well as the BCAA-to-tyrosine ratio (BTR), were evaluated. Cox proportional hazards analysis was used to calculate the hazard ratios (HRs) for factors that were associated with mortality or liver transplantation. RESULTS Among the 158 patients, baseline measurements revealed decreased serum BCAA concentrations for 59 patients (37.3%), elevated serum tyrosine concentrations for 80 patients (50.6%), and a decreased BTR for 114 patients (72.2%). During a median follow-up of 3.0 years, death or liver transplantation occurred at a rate of 0.136 cases/1 person-year. Multivariable analysis revealed that transplant-free survival was independently predicted by older age, male sex, comorbid hepatocellular carcinoma, Child-Turcotte-Pugh score, and serum tyrosine concentration. Receiver operating characteristic curve analysis revealed that a serum tyrosine concentration of >110 µmol/L was the optimal cut-off value for predicting transplant-free survival (adjusted HR: 1.89, 95% confidence interval: 1.15-3.11, P = 0.012). Kaplan-Meier analysis revealed a significant difference in the 5-year transplant-free survival probability between patients with high and low serum tyrosine concentrations (42.1% vs. 60.7%, P < 0.001). CONCLUSIONS Elevated serum tyrosine concentration, but not changes in serum BCAA concentration or the BTR, may indicate a high risk of death or liver transplantation for patients with liver cirrhosis. This article is protected by copyright. All rights reserved.