Procalcitonin (PCT)
Procalcitonin (PCT) is a peptide precursor of the hormone calcitonin, normally present in the blood at very low concentrations. In severe bacterial infections and sepsis, procalcitonin levels sharply increase due to synthesis in various tissues of the body, making it an important marker for diagnosis and monitoring of severe inflammatory processes.
Significance of the test:
- Detection of bacterial infections and sepsis.
- Differentiation between bacterial and viral infections (procalcitonin levels generally do not increase in viral infections).
- Assessment of patient’s condition severity and risk of septic shock.
- Monitoring the effectiveness of antibacterial therapy: successful treatment leads to a 30–50% decrease in procalcitonin levels per day.
- Diagnosis of complications after surgery, trauma, and burns.
Indications for testing:
- Suspected sepsis and severe bacterial infections.
- Monitoring patients after surgical interventions.
- Differential diagnosis of fever of unknown origin.
- Assessment of therapy effectiveness and disease prognosis.
Interpretation of results:
- Up to 0.5 ng/mL — normal, no bacterial infection.
- 0.5–2 ng/mL — possible localized or systemic bacterial infection.
- Above 2 ng/mL — high probability of severe bacterial infection or sepsis.
Test features:
- Procalcitonin responds rapidly to bacterial infection and helps doctors make timely decisions regarding initiation or adjustment of treatment.
- If elevated levels persist for more than 4 days, therapy review is required.
- The test is performed on venous blood using highly sensitive immunological methods that ensure accuracy and reliability of results.
Thus, the procalcitonin test is an important diagnostic tool for early detection and monitoring of severe bacterial infections and sepsis.