Measuring bile-salt concentrations lacks clinical value for detecting hepatic dysfunction in infants receiving parenteral nutrition.

Abstract

Concentrations of conjugated cholate, chenodeoxycholate, direct bilirubin, and alanine aminotransferase (ALT, EC 2.6.1.2) were measured in plasma of 122 low-birthweight infants receiving parenteral nutrition. Eighteen (15%) of them developed hepatic dysfunction. We observed two distinct biochemical patterns in these infants. In the Type A pattern (12 infants), concentrations of direct-reading bilirubin and bile salts increased with no change in ALT activity. In the Type B pattern (six infants), increases in the concentrations of bile salt and direct bilirubin were followed by increases in ALT activity. Hepatic dysfunction persisted significantly longer in infants who developed the Type B pattern. The two patterns did not differ significantly in the times at which values for bile salts or direct bilirubin in plasma became abnormal or became normal at resolution, nor did maximal concentrations of bile salts in plasma differ significantly. Maximal concentrations of direct bilirubin were higher in the Type B infants. We conclude that, in such infants, measurement of bile-salt concentrations in plasma offers no advantages for detecting hepatic dysfunction over the more conventional measurement of direct bilirubin in plasma.