Values of PCT in neonates

Background: Procalciton (PCT) is a precursor polypeptide of the hormone calcitonin, produced in C cells of the thyroid. It has been demonstrated that microbial toxins and proinflammatory mediators can cause the release of PCT from tissues and cells in the body. PCT thus has become an important marker in the diagnosis of infection. Methods: In this retrospective study we analyzed blood samples performed for clinical purposes from the newborns present in our hospital in the year 2019. We developed a database of 1356 PCT values obtained from 224 infants at risk for neonatal infection; we selected those PCT values obtained within 24 hours from a blood sampling for blood culture. Results: Babies with positive blood culture had PCT values more elevated than those with negative blood culture (17.061 ng/mL [C.I. 10.8-23.2] vs. 4.6 ng/mL [C.I. 2.6-6.6]). No statistically significant difference was found between babies with negative blood culture born before or after 37 weeks of gestation. Conclusions: This paper gives useful data of PCT values in non-infective babies. It is worth to show that the normality values should not be confused with those of older children or adults. Moreover, it shows the reliability of PCT as an infection index.