Procalcitonin: A novel biomarker for bacterial infections and sepsis
PCT is the prohormone of calcitonin (CT). Whereas CT is secreted by the C-cells of the thyroid after hormonal stimulation, PCT can be produced by numerous cell types and organs after proinflammatory stimulation, especially when caused by bacterial challenge.1
In healthy people, plasma PCT concentrations are found to be below 0.05 ng/ml, but can increase up to 1,000 ng/ml in patients with severe sepsis or septic shock.
Elevated PCT levels indicate bacterial infection accompanies by a systemic inflammatory reaction.
Localized infections do not generally cause circulating PCT increases. Slightly elevated PCT concentrations are observed in bacterial infections with minor systemic inflammatory response.
Very high values have been observed during acute disease conditions with severe systemic reactions to infection, in cases of severe sepsis or septic shock.
1 Christ-Crain M, Müller B. Procalcitonin in bacterial infections – hype, hope or more or less? Swiss Med Wkly 2005; 135: 451-60. |
