Procalcitonin

Why this test? 

For diagnosis of sepsis, septicemia, septic shock; 

For diagnosis of systemic inflammatory reaction syndrome; 

For the diagnosis of multiple organ failure syndrome;

For the diagnosis of severe bacterial infection of various localization; 

For the diagnosis of infectious complications in patients of surgical departments and intensive care units; For prescribing and monitoring the effectiveness of antibacterial therapy in patients with infectious and purulent-septic diseases.

In what cases is it prescribed?

In case of suspicion of sepsis, septic shock, development of systemic inflammatory reaction syndrome, multiple organ failure syndrome; 

With symptoms of severe infectious, purulent-inflammatory processes of various localization;

If the development of a generalized bacterial infection is suspected in adults, children and newborns; 

If the development of infectious complications is suspected in patients in the conditions of surgical and intensive care units; 

When secondary bacterial infection is suspected in patients with viral infections, allergic, autoimmune diseases; 

After significant surgical interventions, operations in conditions of artificial blood circulation, multiple injuries, with severe burns, acute transplant rejection, subarachnoid hemorrhage, with chronic heart failure; 

When prescribing and monitoring specific antibacterial therapy.

Testing preparation 

Exclude alcohol from the diet for 24 hours before the testing. 

Children under the age of 1 should not eat for 30-40 minutes before the testing. 

Children aged 1 to 5 years should not eat for 2-3 hours before the testing. 

Do not eat for 8 hours before the testing, you can drink clean still water. 

Exclude physical and emotional overstrain within 30 minutes before the testing.

Do not smoke for 30 minutes before the testing.

Test information 

Procalcitonin is a prohormone, a precursor of the hormone calcitonin, which is involved in the metabolism of calcium and maintains its constant level in the blood. 

Polypeptide procalcitonin consists of 116 amino acids and is synthesized by C cells of the thyroid gland. Normally, its amount is extremely small and is found in the blood in small amounts. In the presence of bacterial infection, exposure to toxins, the extrathyroidal synthesis of procalcitonin by neuroendocrine cells of the liver, kidneys, lungs, muscle tissue, and adipocytes increases, which leads to a significant increase in its level. With a systemic inflammatory response, under the influence of pro-inflammatory molecules - endotoxin, interleukins-1 and 6, tumor necrosis factor alpha - the synthesis of procalcitonin in macrophages and monocyte cells increases. 

The production of this biomarker can increase during the first 2-4 hours, reaching a maximum after 12 hours, the half-life is 22-26 hours. It should be noted that with a viral infection, the synthesis of procalcitonin is absent or inhibited. 

The advantage of determining procalcitonin is that its synthesis during the systemic inflammatory response reaches high levels earlier than other acute phase proteins. 

The syndrome of a systemic inflammatory response or reaction is characterized by a change in body temperature above 38 ° C or below 36 ° C, an increase in the heart rate more than 90 beats per minute, an increase in the respiratory rate more than 20 per minute, a change in the number of leukocytes in the blood (less than 4 × 109 or more 12 × 109 cells per liter of blood) or shifting the leukocyte formula to the left. In addition to bacterial agents, severe infections caused by fungal infections and protozoa can lead to an increase in its content. In patients who are in intensive care units, the determination of this marker is important for severe infectious processes of various localization.

 In particular, with severe bronchitis, pneumonia, pancreatitis, appendicitis, peritonitis. Local inflammatory process - tonsillitis, pharyngitis, sinusitis, gastritis and others - do not lead to a diagnostically significant increase in the level of procalcitonin. 

An increase in the concentration of procalcitonin in multiorgan failure syndrome, sepsis, shock, especially in newborns and children, is of important diagnostic value. The highest values are noted in sepsis, septic shock, septicemia, and meningitis. 

Also, the levels of this biomarker increase after extensive surgical interventions, operations with artificial blood circulation, multiple injuries, severe burns, acute transplant rejection, subarachnoid hemorrhage, and chronic heart failure. In seriously ill patients, procalcitonin levels correlate with the severity of the pathological process and mortality after the disease. 

Along with the assessment of the clinical course of the disease, the data of laboratory and instrumental research methods for detecting the level of procalcitonin can be used to determine the effectiveness of the antibacterial therapy, as well as to determine the moment to stop this treatment. In patients with viral infections, allergic, autoimmune diseases, the concentration of procalcitonin increases only in case of secondary bacterial infection.