The Molecular Basis of Procalcitonin Synthesis in Different Infectious and Non-Infectious Acute Conditions

Bacterial infections: By and large PCT levels are elevated in bacterial infections as reported by several studies, but the feature of the response can be different. For example higher peak PCT concentrations are expected in Gram negative as compared to Gram positive infections. Furthermore, differences may also be seen even within the family of Gram negative bacteria: as higher peak PCT concentrations can be detected in Enterobacteriaceae, as compared to non-fermentative Gram negatives or obligate Gram negative anaerobes. [5, 6] This is due to the polymorphism of the pathogen associated molecular patterns (PAMP) resulting in slightly different cytokine profiles hence different PCT values. In neutropenic patients, as the vast majority of the PCT synthesis is originated from the monocytes and macrophage cells, an attenuated response is expected with lower PCT levels [7-11].