Abstract:

Objective To determine the value of serum total bile acid and γ-glutamyl-transferase (γ-GT) in the determination of etiology and prediction of prognosis of prolonged jaundice. Methods Ninety-five infants with prolonged jaundice were divided into infantile hepatitis syndrome group (n=35), biliary atresia group (n=30) and elevated indirect bilirubin group (n=30) according to the bilirubin levels. Besides, 30 age-matched hospitalized infants without jaundice and liver function injury were served as controls. The liver function parameters were measured before and after treatment, the diagnosis value of serum total bile acid and γ-GT was determined with receiver operator characteristic (ROC) curve, and the correlation of liver function parameters after treatment was analysed. Results The serum γ-GT level in biliary atresia group was significantly higher than those in the other groups (P<0.01), and the serum total bile acid levels in infantile hepatitis syndrome group and biliary atresia group were significantly higher than those in elevated indirect bilirubin group and control group (P<0.05). ROC curve analysis indicated that serum total bile acid had lower diagnostic efficiency for infantile hepatitis syndrome and biliary atresia, and γ-GT had definite diagnostic value for biliary atresia. When serum total bile acid level was 88.35 μmol/L and γ-GT was 250.5 U/L, the sensitivity of diagnosis of biliary atresia was 97.9% in a parallel trial, and the specificity was 90.5% in a serial test. Correlation analysis revealed that the changes of serum bilirubin were related to direct bilirubin, alanine aminotransferase and bile acid in infantile hepatitis syndrome group. Conclusion In the prolonged jaundice with an elevated indirect bilirubin, total bile acid and γ-GT are not significantly elevated, and the prognosis is favorable. In the prolonged jaundice with an elevated direct bilirubin, when total bile acid and γ-GT are significantly elevated, the diagnosis may tend to be biliary atresia. In the prolonged jaundice with an elevated direct bilirubin,when total bile acid is significantly increased, while γ-GT is not, the diagnosis may tend to be infantile hepatitis syndrome.

Key words: total bile acid, γ-glutamyl-transferase, prolonged jaundice, infantile hepatitis syndrome, biliary atresia