Serum bile acid fractions in neonates on total parenteral nutrition is lithocholic acid responsible for the occurrence of cholestasis?

In order to determine whether lithocholic acid (LCA) contributes to the occurrence of total parenteral nutrition (TPN) associated intrahepatic cholestasis (IHC) in neonates, we investigated the serum bile acid fractions of neonates on TPN. Twenty-five surgical neonates, receiving TPN for more than 2 weeks were studied. TPN associated IHC was defined as serum defect bilirubin greater than 2.0 mg/dL. Serum bile acid fractions were examined by HPLC using 3α -hydroxy steroid dehydrogenase. Eight patients (32%; IHC group) developed TPN associated IHC. Serum direct bilirubin concentrations in the non IHC and IHC groups were 0.99 and 3.31 mg/dL respectively. Serum total bile acid levels in both groups were 14.4 and 71.6 nmol/ml respectively. Glycine and taurine conjugated cholic and chenodeoxycholic acids could be detected, and unconjugated and secondary (deoxycholic and lithocholic) bile acid were detected in trace levels in both the IHC and non-IHC groups. In conclusion, LCA is unlikely to be a causative factor in TPN associated IHC in neonates.