Procalcitonin Test

What is a Procalcitonin Test?

A procalcitonin test is a laboratory test used to diagnose bacterial infections, especially those of the lower respiratory tract. It measures procalcitonin, a protein released by the body during inflammation or the presence of a bacterial infection. The test can be used to rule out bacterial infections, differentiate between viral and bacterial infection, or to monitor the effectiveness of treatment.

Why is the Procalcitonin Test Done?

The procalcitonin test is done to help diagnose infections and determine the most effective course of treatment. It is especially helpful in differentiating between viral and bacterial infections because procalcitonin is only produced when bacteria are present. The test is most commonly used to diagnose or rule out an infection of the lower respiratory tract, such as pneumonia or bronchitis.

How is the Procalcitonin Test Performed?

The procalcitonin test is performed with a blood sample. A healthcare professional will draw a sample of blood from a vein in the arm. The sample is then sent to a laboratory for analysis.

Types of Procalcitonin Tests

There are two types of procalcitonin tests commonly performed: enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assay (IFA). ELISA is more sensitive than IFA, meaning it can detect smaller concentrations of procalcitonin in the blood. However, both tests are able to reliably detect even small amounts of procalcitonin and differentiate between bacterial and viral infections.

Risks of the Procalcitonin Test

The procalcitonin test is a safe and simple procedure with very few risks. Those who are allergic to certain substances may be advised to avoid the test. In rare cases, the blood sample may not be sufficient or an infection may not be correctly identified.

When is the Procalcitonin Test Done?

The procalcitonin test is usually done when a person is suspected of having a bacterial infection, such as a lower respiratory infection. It may also be done when a person is suspected of having an infection that is not responding to treatment or an infection that is worsening despite treatment. The test may also be done to monitor the effectiveness of a course of antibiotics.