[Nutritional and acute phase proteins in preterm newborns: reference standards and interrelations]

Area of Science:

• Neonatal Nutrition
• Biochemistry
• Clinical Chemistry

Background:

• Nutritional and acute phase proteins are crucial biomarkers in newborns.
• Understanding their serum concentrations in relation to feeding and gestational age is important for clinical assessment.

Purpose of the Study:

• To prospectively study serum concentrations of nutritional and acute phase proteins in term and preterm newborns under different feeding conditions.
• To determine if common reference values can be applied across these diverse newborn groups.

Main Methods:

• Nephelometric methods were used to measure serum concentrations of 5 nutritional and 5 acute phase proteins.
• Three groups of newborns were studied: healthy term (breastfed), healthy preterm (enterally fed), and preterm (parenteral nutrition).
• Infants with specific medical conditions were excluded.

Main Results:

• Most protein concentrations were similar across groups, with minor differences not consistently related to age or weight.
• Prealbumin, apolipoprotein A, B, and C4 levels differed significantly between term and preterm infants.
• Enterally fed preterm infants showed lower alpha 1 acid glycoprotein and higher albumin, transferrin, and apolipoprotein A compared to parenterally fed infants.

Conclusions:

• Observed differences in protein levels were generally small, supporting the use of common serum reference values for healthy growing newborns.
• Nutritional and acute phase proteins appear to be regulated by distinct metabolic systems, with some overlap observed.