Sterol Profiling in Red Blood Cell Membranes and Plasma of Newborns Receiving Total Parenteral Nutrition

Background And Objectives: Total parenteral nutrition (TPN) is a lifesaving therapy in children with intestinal failure, frequently complicated by liver dysfunction. Plant sterols (phytosterols) of lipid emulsions have been supposed to contribute to cholestasis in TPN-treated children. The present study aimed to evaluate the plasma and red blood cell membrane (RBCM) phytosterol levels in newborns after a short period of TPN.

Patients And Methods: Phytosterols, cholesterol, and other sterol levels were quantified by gas chromatography-mass spectrometry in 15 healthy control infants, 22 patients after TPN, and 11 patients before TPN. Sterols of lipid emulsions were quantified.

Results: Plasma and RBCM phytosterol levels were, respectively, on average 56 micromol/L and 83 micromol/g per protein in patients after TPN, 13 micromol/L and 15 micromol/g per protein in patients before TPN, and 9 micromol/L and 13 micromoL/g per protein in control infants (P < 0.05 for differences). The days of TPN and the total amount of infused lipids correlated significantly with RBCM phytosterol (P < 0.05); correlations for plasma were positive but not significant. No correlation was observed with plasma bilirubin, gamma-glutamyltransferase, or alanine transaminase.

Conclusions: Plasma and RBCM phytosterols increase significantly in newborns after a short period of TPN. Higher phytosterol levels were observed in some patients that could have been due to their individual variability in phytosterol metabolism and/or clearance. A greater accumulation of phytosterols in membranes may induce TPN-related cholestasis.