Pre‐operative time course changes in liver function tests in biliary atresia: Its usefulness in the discrimination of biliary atresia in early infancy

In order to investigate the possibility of early discrimination of extrahepatic biliary atresia from other cholestatic diseases, a series of results of liver function tests in infants with cholestatic diseases were reviewed. The results of routine liver function tests (LFT) recorded in patients' charts were reviewed within 12 weeks after birth in 47 infants with extrahepatic biliary atresia (BA), 10 infants with neonatal hepatitis (NH) and 130 age-matched control infants (CO) without cholestatic diseases. The mean of each test value for each week after birth was derived from the actual data examined in each infant. No differences were observed between BA and CO in the levels of aminotransferases within 2 weeks after birth. Total bilirubin and direct bilirubin levels were significantly different between BA and CO within 1 week after birth (16.1 ± 3.2 mg/dL vs 11.1 ± 4.5 mg/dL, 4.6 ± 2.6 mg/dL vs 0.7 ± 0.3 mg/dL, respectively) The direct bilirubin-total bilirubin ratio exceeded 25% within the first week in BA. The individual values of direct bilirubin (DB) exceeded 2 mg/dL within the first week in all infants with BA, while none of the individual values exceeded 1.6 mg/dL in CO. Gamma-glutamyl transpeptidase levels were significantly different between BA and CO at 4 weeks (432 ± 272 IU/L vs 79 ± 43 IU/L) and thereafter; and were significantly different between BA and NH at 6 weeks (314 ± 232 IU/l vs 69 ± 58 IU/L) and thereafter. These data suggest that the determination of direct bilirubin within 1 week after birth can detect extrahepatic biliary atresia patients from those with physiologic jaundice, and γ-glutamyl transpeptidase levels may discriminate BA from NH at no later than 6 weeks of age.