Clinical evaluation of serum levels of tryptophan in hepatobiliary disease.

Fasting serum levels of total and free tryptophan, and free fatty acids and albumin, were measured and compared by blood biochemical analysis in patients with hepatobiliary disease and neuropsychiatric symptoms. The serum total tryptophan level tended to be elevated in patients with chronic active hepatitis, hepatic coma and obstructive jaundice, but not significantly. The serum free tryptophan level was significantly elevated in patients with chronic active hepatitis, liver cirrhosis, primary hepatocellular carcinoma and obstructive jaundice. The free tryptophan level was related to the decreased serum albumin level and elevated serum free fatty acid levels, which seems to indicate a connection with liver parenchymal function. The level, however, seemed not to correlate with neuropsychiatric symptoms.