Procalcitonin is an early, sensitive, specific marker of bacterial infections. PCT is a polypeptide pro-hormone of calcitonin, a hormone synthesized by thyroid cells and involved in calcium homeostasis.
PCT circulates in very small quantities (< 0.1 µg/l) in the blood of healthy subjects. Its production can be stimulated by bacterial endotoxins. Elevated procalcitonin level correlates with severity of infection (up to 10,000 times)
The PCT assay measures the level of procalcitonin in your blood, it is indicated in suspected bacterial, parasitic or fungal infections (PCT is not increased during viral infections)
It is measured using a simple blood sample.
In general, there are no special preparations to make before testing, it is a blood test that can be done at any time and does not require fasting, except whether your blood sample will be used for further testing.
In healthy individuals, procalcitonin is rapidly transformed into calcitonin. Therefore, PCT values in uninfected individuals are very low < 0.1 µg/L. Levels greater than 0.25 ng/mL may indicate the presence of an infection.
Note: Values should be interpreted based on the clinical context.
Le médecin peut demander un test de procalcitonine pour :The doctor may order a procalcitonin test to
The PCT rises very early after the start of the infection (3 hours), its half-life is quite short (about 24 hours) and the rate decreases rapidly in the event of improvement, making it possible to shorten duration of antibiotic treatment
CRP is a good marker of the acute phase of inflammation, its use to distinguish infection bacterial from a viral infection is less obvious.
The concentration of procalcitonin increases in bacterial infections but remains low in viral infections and inflammatory diseases. The change is rapid and the molecule is stable, making it a potentially useful marker for distinguish between bacterial and viral infections.
The advantages of PCT over older markers include:
Serum procalcitonin levels decline rapidly with appropriate antibiotic treatment (48-72 hours after admission).