What is procalcitonin?
Procalcitonin (PCT) is a protein that stimulates the release of cells after bacterial infection. The level in normal human body is extremely low, almost undetectable. PCT is not elevated in autoimmunity, allergy, and viral infections.
Elevation of procalcitonin occurs when the body is severely infected by bacteria, fungi, or parasites. A high level of PCT indicates a very severe systemic inflammatory response and a high risk of death. Antibiotics and other targeted treatments should be applied as soon as possible in combination with clinical practice.
Why test for procalcitonin?
· Helps determine if there is a serious bacterial fungal infection
· Monitor patients at risk of serious infection, such as organ transplants, sepsis, patients with extensive trauma, to determine the extent of infection
· Predict the development of severe intra-abdominal organ inflammation
· To monitor the postoperative condition of patients after major surgery
What is the normal range for procalcitonin?
1. The serum PCT concentration of healthy people is less than 0.05μg/L.
2. The serum PCT concentration of the elderly, patients with chronic diseases and less than 10% of healthy people is higher than 0.05μg/L, up to 0.1μg/L, but generally not more than 0.3μg/L.
Procalcitonin value is high/positive, what does it mean?
· Non-disease causes
Only the procalcitonin index value is higher than the standard range, which usually does not indicate a non-disease cause, and the doctor needs to make a judgment based on other symptoms or test results.
· Cause of disease
Infections: The most common are bacterial infections, followed by fungal or parasitic infections. For example, peritonitis, pancreatitis, hepatitis B, AIDS, medullary thyroid cancer, infection after major surgery
Non-infectious diseases: such as kidney transplantation, heart transplantation, liver transplantation, renal insufficiency, etc.
The role of PCT in assisting the diagnosis of bacterial infectious diseases?
1. If unexplained infection and sepsis are clinically suspected, it is recommended to perform PCT detection in time to help clarify the diagnosis of bacterial infectious diseases.
2. For patients with suspected lower respiratory tract infection, PCT ≥ 0.25 μg/L, indicating a high possibility of bacterial infection, and empiric antimicrobial therapy is recommended.
3. In patients with suspected sepsis, empiric antimicrobial therapy should be initiated immediately. PCT ≥ 0.5 μg/L is helpful for the diagnosis of sepsis, and high levels of PCT (especially > 10 μg/L) indicate a higher possibility of gram-negative bacterial infection.
4. For patients at risk of nosocomial infection (receiving long-term mechanical ventilation, surgical treatment, indwelling arterial or venous catheters, etc.), dynamic monitoring of PCT changes is recommended. If a significant increase in PCT indicates the possibility of bacterial infection, antibiotic treatment should be given in a timely manner in combination with clinical practice.