Biochemical markers for the early assessment of neonatal sepsis: the role of procalcitonin.

Procalcitonin (PCT) is the precursor of calcitonin, normally synthesized in the C-cells of the thyroid gland. Systemic inflammation and sepsis induce PCT production by various cell types, including hepatocytes, nephrons, monocytes. PCT begins to rise four hours after exposure to bacterial endotoxins, peaking at six to eight hours, and remaining raised for at least 24 hours with a half-life of 25-30 hours. Serum PCT levels significantly increase in systemic bacterial infection, necrotizing enterocolitis, and during both early and late onset neonatal sepsis. By using a cut-off limit of 0,5 microg/L, the PCT positive likelihoud ratio was found of 12.5. PCT has a theoretical advantage as a marker of systemic induction in sepsis and its half-life suitable for daily monitoring of disease progress. PCT may be useful in assessing the severity of infection, following the progress of treatment, and predicting outcomes.