Urinary sulfated bile acids: a new simple urine test for cholestasis in infants and children.

BACKGROUND/PURPOSE: Measurement of urinary sulfated bile acid (USBA) has been reported as a simple urine test that reflects the degree of cholestasis. The authors report the diagnostic value of this new laboratory test in various cholestatic conditions affecting infants and children.

METHODS

A urine sample was collected from 4 surgical neonates with parenteral nutrition-induced cholestasis and 48 patients with biliary atresia (BA). USBA was measured by direct enzymatic assay.

RESULTS

In 3 patients receiving parenteral nutrition, USBA increased with caloric gains. For one surgical patient, a decrease in calories because of liver dysfunction resulted in a decrease of USBA, closely reflecting the fluctuations of caloric intake. In patients with BA, a significant positive correlation was noted between serum bile acid and USBA (r = 0.85; P <.01). Ten of 14 febrile episodes in 6 patients with liver dysfunction and increased C-reactive protein showed elevated USBA, thus diagnosed as cholangitis. Four febrile episodes caused by viral infection showed no elevation of USBA.

CONCLUSIONS

USBA is a simple and sensitive noninvasive test reflecting the degree of cholestasis in infants and children. USBA correlated highly with serum bile acid levels and may be helpful in diagnosis of cholestasis caused by cholangitis without blood sampling.