What does the PCT (Procalcitonin) in the blood indicate?

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Blood PCT is a specific parameter of severe bacterial inflammation, fungal infections, evidence of infection-associated inflammation and multi-organ failure. Blood tests for PCT are a specific marker for sepsis and sepsis.

1. What does the PCT index in the blood say clinically?

PCT is a parameter used to diagnose and monitor inflammatory diseases caused by infections such as:
Differential diagnosis of infectious and non-infectious inflammation Monitor patients at risk of infection (the patients after surgery, after organ transplantation, immunosuppressive processes, multiple trauma), patients in intensive care, to detect infections affecting the system or detect complications of infection. bacteria. Assess the prognosis and course of severe inflammatory diseases such as peritonitis, sepsis, systemic inflammatory response syndrome (SIRS) and multi-organ dysfunction syndrome. Indications for the use of antibiotics in the treatment of respiratory infections or pneumonia. Recommended values ​​for PCT concentrations include:
Normal values ​​are PCT readings < 0.05 ng/ml. PCT values ​​< 0.10 ng/ml do not indicate antibiotic use. PCT value < 0.25 ng/ml: Antibiotics are not recommended, if therapy drops to this level, continue to use it effectively. PCT value > 0.25ng/ml: Recommendations and considerations for antibiotic use. PCT value > 0.50 ng/ml: Prescribing antibiotics is mandatory. PCT value 0.50 - 2.0 (ng/ml): Infection due to relative systemic inflammatory response, the cause can be trauma, post-traumatic surgery, cardiogenic shock... PCT value 2 .0 - 10 (ng/ml): Severe systemic inflammatory response (SIRS), caused by systemic infection and sepsis, without multiple organ failure. PCT value > 10 ng/ml: Deep systemic inflammatory response due to severe sepsis or septic shock.

2. Procalcitonin test principle according to the principle of pairing with a total test time of 18 minutes

First incubation: Sample antigen (30 μL), biotinylated PCT-specific monoclonal antibody, and ruthenium complex-labeled anti-PCT-specific monoclonal antigen react to form a capture complex bag. Second incubation: After the addition of streptavidin-coated microparticles, the above immune complex becomes bound to the solid phase through the interaction between biotin and streptavidin. The reaction mixture is transferred to the measuring chamber, where the antimagnetic microparticles are captured on the surface of the electrode. Unbound components are expelled from the measuring chamber by the ProCell/ProCell M solution. Applying voltage to the electrode produces chemiluminescence as measured by a photonic amplifier. Results are determined via an on-board calibration curve generated by the 2-point test and master calibration information via the bar code on the reagent cartridge.

3. When to do a blood PCT test?

Procalcitonin testing is usually done in critically ill patients with symptoms suggestive of severe or systemic infection. It is usually done in the early days of admission. Complications of sepsis include: Fever, chills, nausea, rapid breathing, rapid pulse, lethargy, little urine. More severe symptoms: Systemic inflammation and the formation of many small blood clots in the microvasculature. One or more organs affected (Multiple Organ Failure, MOF) and hypotension Procalcitonin is also used to monitor antibacterial therapy in patients with suspected sepsis. It is also done when there is tissue damage from trauma, surgery, or viral pneumonia with suspected bacterial superinfection.

4. Factors affecting and limiting the PCT blood test

Tests are not affected by jaundice (bilirubin < 428 μmol/L or < 25 mg/dL), hemolysis (Hb < 0.559 mmol/L or < 0.900 g/dL), blood lipids (Intralipid < 1500 mg/dL). ) and biotin (<123 nmol/L or <30 ng/mL). Criterion: Recovery within ±15% of initial value. In patients receiving high doses of biotin (ie, >5 mg/day), samples should not be collected until at least 8 hours after the last dose of biotin. Test results are not confounded by rheumatoid factors with concentrations up to 1500 IU/mL. The high sample concentration effect has no effect on test results with PCT concentrations up to 1000 ng/mL. In vitro tests were carried out on 18 commonly used drugs and 10 specialty drugs. There is no interference to the test. In rare cases, interference may occur due to excessively high concentrations of anti-analyte-specific antibodies, anti-streptavidin or ruthenium in the analyte. The assay has been appropriately designed to minimize these effects.

5. PCT may increase in certain cases not due to infection

Prolonged or severe cardiogenic shock. Severe, persistent organ perfusion abnormalities. Small cell lung cancer or medullary C-cell carcinoma of the thyroid gland. Immediately after severe trauma, major surgical intervention, severe burns. The treatment induces the release of proinflammatory cytokines. Neonates (<48 hours after birth). For diagnostic purposes, laboratory results should be evaluated with history, physical examination, and other findings.
PCT with such outstanding values ​​has proven to be a reliable tool for diagnosing infections, especially systemic infections and distinguishing grades, and using the kinetics of combined PCT. With clinical data, it is an effective means of monitoring the course of infectious diseases and reliable antibiotic therapy, thereby reducing the duration of antibiotic use, the phenomenon of drug-resistant bacteria and, importantly, reducing the risk of antibiotic resistance. treatment costs.
Vinmec International General Hospital is one of the hospitals that not only ensures professional quality with a team of leading medical doctors, modern equipment and technology, but also stands out for its examination and consultation services. comprehensive and professional medical consultation and treatment; civilized, polite, safe and sterile medical examination and treatment space. Customers when choosing to perform tests here can be completely assured of the accuracy of test results.

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