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Also known as: PCT
Formal name: Procalcitonin

The Test Sample

What is being tested?

Procalcitonin is a precursor to the thyroid hormone calcitonin. It is normally produced by special cells in the thyroid gland called C-cells and is present in low levels in the blood. However, it may also be made by other cells in the body when stimulated by an intense stressor, in particular systemic bacterial infection (sepsis; as opposed to local bacterial infections). Other stressors include tissue damage due to events such as trauma, surgery, pancreatitis, burns, cardiogenic shock (related to a heart attack), acute organ transplant rejection, and kidney involvement in urinary tract infections in children.

This test measures the amount of procalcitonin in the blood. Levels of procalcitonin in the blood increase rapidly and significantly when a person has sepsis. They are typically only mildly to moderately elevated when a person has a viral infection, a localized infection, or other illnesses as noted above, which may present with some of the same symptoms as sepsis. This gives the procalcitonin test the potential to be used to help detect the presence of a severe bacterial infection in its early stages and to distinguish between a bacterial infection and other causes of symptoms in a seriously ill person.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.