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

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.

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, were evaluated. Cox proportional hazards analysis was used to calculate the hazard ratios for factors that were associated with mortality or liver transplantation.

Among the 158 patients, baseline measurements showed decreased serum BCAA concentrations for 59 patients (37.3%), elevated serum tyrosine concentrations for 80 patients (50.6%), and a decreased BCAA-to-tyrosine ratio for 114 patients (72.2%). During a median follow-up period of 3.0 years, death or liver transplantation occurred at a rate of 0.136 cases/1 person-year. Multivariable analysis showed 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 showed that a serum tyrosine concentration of >110 µmol/L was the optimal cut-off value for predicting transplant-free survival (adjusted hazard ratio 1.89, 95% confidence interval 1.15-3.11, p = 0.012). Kaplan-Meier analysis showed 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).

Elevated serum tyrosine concentration, but not changes in serum BCAA concentration or the BCAA-to-tyrosine ratio, may indicate a high risk of death or liver transplantation for patients with liver cirrhosis.