Sulphur amino acid pattern in chronic liver disease

The metabolism of sulphur-containing amino acids is impaired in patients with advanced liver disease, but very few data are available in less severe chronic liver disease. We measured fasting plasma levels of methionine, cystine and taurine in 10 healthy subjects and 50 patients with biopsy proven liver disease: chronic persistent/active hepatitis (30 cases), compensated cirrhosis (10 cases) and decompensated cirrhosis (10 cases). Hypermethioninemia (up to 10 times control values) was present only in decompensated cirrhosis. Cystine was markedly reduced in patients with compensated chronic liver disease, while in advanced cirrhosis its concentration was within the normal range. No differences in taurine plasma levels were observed between the various groups. This study suggests that a derangement in sulphur amino acid metabolism, possibly located at various steps along the trans-sulphuration pathway, is also present in mild forms of chronic liver disease.