Development of Bile Acid Metabolism in Neonates during Perinatal Period | Part 2. Mass screening of congenital biliary atresia by radioimmunoassay using dried blood spot

Inour country, congenital biliary atresia (CBA) has occurred in approximately 1 of 10,000 live births, but its prognosis has been extremely poor. In the mass screening of this disease, glycocholic acid (GCA) or chenodeoxycholic acid (CDCA) level in dried blood spots on filter paper in5-day-old neonates was determined by radioimmunoassay (RIA).
To determine GCA in dried blood spots on filter paper, the procedures in this experiment were modified using commercial kit for serum.
The mean GCA level of controls (n=391) was 5.88±4.28 nM/ml and that of CBA (n=22) was 14.1 ±3.1 nM/ml. On the other hand the mean CDCA level of controls (n=86) was 5.86 ±3.07 pM/l disc that of CBA (n=22) was 30.0 ±35.9 pM/l disc. When the criterion is assumed to be more than 16 nM/ml of GCA level or 10 pM/l disc of CDCA level, false negative diagnoses of CBA are 31.8% and 18.2% respectively. On the other hand false positive diagnoses of CBA are 6.9% and 3.5% respectively. It was thought that false negative diagnosis on mass screening with GCA level would decrease using fresh dried blood spot within 2 weeks after taking blood.
In 22 CBA cases, the GCA levels in dried blood spots on filter paper were not always parallel with the CDCA levels.     

Perinatal bile acid metabolism: analysis of urinary unsaturated ketonic bile acids in preterm and full-term infants

AIM: To compare urinary concentrations of unsaturated ketonic bile acids in preterm and full-term infants. METHODS: Urinary unsaturated ketonic bile acids were determined using gas chromatography-mass spectrometry. RESULTS: Urinary concentrations of total bile acids in early preterm infants (of less than 29wk gestational age) exceeded concentrations in late preterm (between 30 and 37 wk) and full-term infants (between 38 and 41 wk; p < 0.01). The percentage of ketonic bile acids (7alpha, 12alpha-dihydroxy-3-oxo-4-cholenoic acid and 7alpha-hydroxy-3-oxo-4-cholenoic acid) among total urinary bile acids in full-term infants (20.2 +/- 14.1%) was higher than that in early preterm infants (8.94 +/- 8.1%; p < 0.05). The percentage of unsaturated bile acids (3beta-hydroxy-delta5-bile acids) among total bile acids in urine did not differ greatly between groups. CONCLUSION: The percentage of 3-oxo-delta4 bile acids among total bile acids in urine gradually increased from early to late preterm infants, while healthy full-term infants excreted large amounts of 3-oxo-delta4 bile acids in urine at delivery.