A protein called procalcitonin is created by several cell types in the body, frequently in reaction to bacterial infections but also response to tissue damage. In sepsis and systemic bacterial infections, the amount of procalcitonin in the blood may considerably rise. Procalcitonin in the blood is measured by this test. 

What is the Procalcitonin (PCT) Test?

A protein called procalcitonin is created by several cell types in the body, frequently in reaction to bacterial infections but also response to tissue damage. In sepsis and systemic bacterial infections, the amount of procalcitonin in the blood may considerably rise. Procalcitonin in the blood is measured by this test. 

What is the Purpose of the Procalcitonin (PCT) Test? 

Sepsis is the body's severe, excessive, and occasionally lethal inflammatory reaction to a bacterial infection. Typically, infection is targeted by the immune system, which confines the bacterium and restricts its reaction to the afflicted region. On the other hand, certain infections may start in one area of the body before spreading to the blood (bacteremia) and perhaps to other locations. Sepsis is an inflammatory condition in which the body overreacts to an infection. This may result in a marked change in body temperature, an accelerated heartbeat and breathing rate, and a drop in blood pressure. Sepsis can worsen and become severe if not properly handled. Body temperature may significantly increase or decrease as a result, along with heart and breathing rates, and blood pressure may drop. Severe sepsis may develop if the condition is not effectively managed. 

Although procalcitonin levels can sometimes rise due to other diseases, they are typically only slightly to moderately increased. Examples of these ailments include tissue damage brought on by accidents, operations, pancreatitis, burns, cardiogenic shock (associated with a heart attack), acute organ transplant rejection, and renal involvement in paediatric UTI. The procalcitonin test is beneficial in helping to distinguish between a bacterial infection and other non-bacterial sources of signs and symptoms in a very unwell individual. It also helps detect sepsis and severe bacterial infections in the early stages. 

What Does a Procalcitonin (PCT) Test Diagnose? 

A doctor may ask for a series of procalcitonin tests regularly to monitor an antibiotic therapy and/or decide if it may be stopped safely. 

The procalcitonin test can assist with: 

• A bacterial infection in neutropenic individuals is identified 

• monitoring, risk classification, and diagnosis of septic shock 

• Systemic secondary infection after surgery, as well as in cases of severe trauma, burns, and multiorgan failure, diagnosis 

• bacterial versus viral meningitis differential diagnosis 

• Differential diagnosis of viral pneumonia vs community-acquired bacteria 

• Tracking the therapeutic impact of antibacterial treatment.  

The test may be used to assist determine whether or not antibiotics should be administered or stopped for patients with lower respiratory infections and whether or not medications may be withdrawn in patients with sepsis. 

Who Needs a Procalcitonin (PCT) Test? 

A very unwell patient may undergo the procalcitonin test in conjunction with other tests and exams to help identify or rule out sepsis. It has mostly been utilised in patients who visit emergency rooms or are hospitalised in intensive care units (ICUs) and have signs and symptoms that might indicate sepsis. When a very unwell individual exhibits symptoms and/or indications that might indicate sepsis, a severe bacterial infection, or both, a procalcitonin test may be prescribed. Sepsis may show the following signs and symptoms: 

• shivering, fever, and chills 

• clammy or perspiration of the skin 

• severe suffering or discomfort 

• breathing quickly 

• swift heartbeat 

• Uncertainty or disorientation 

• fewer urine emergencies 

When a person gets an illness, such as meningitis or pneumonia, and it is unknown whether a bacterial or non-bacterial aetiology is present, the test may be prescribed. When a kid has symptoms suggestive of a urinary tract infection, the test may occasionally be prescribed. When a doctor wishes to keep track of antibiotic therapy and/or determine if it may be stopped safely, they may request a series of procalcitonin tests at regular intervals. 

Preparation and Procedure of the Procalcitonin (PCT) Test 

When a sample from a subject who is taking a supplement containing a high amount of biotin is taken for this test, interference may be seen (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is advised to discuss biotin supplementation with all individuals who could be suggested for this test. Patients should be advised to abstain from biotin for at least 72 hours before sample collection. 

With a small needle, a medical consultant will take out the blood from a vein in your arm. Following the insertion of the needle, a tiny quantity of blood will be collected in a test tube or vial. You can feel a tiny sting as the needle enters or departs. This usually just takes a few minutes. 

Understanding of the Procalcitonin (PCT) Test  Results 

Plasma PCT concentrations are reported to be less than 0.1 g/L in healthy individuals. A PCT concentration exceeding 0.1 g/L may suggest a clinically significant bacterial infection that has to be treated with antibiotics, depending on the clinical context. After 6 to 12 hours following a bacterial infectious insult with systemic effects, PCT levels increase quickly. The degree of the bacterial infection coincides with the extent of the PCT concentration rise. A patient should be thought to be in danger of developing severe sepsis or septic shock if their PCT concentration is greater than 0.5 g/L. 5,6 On the other hand, the PCT concentration drops when the septic illness is treated and returns to normal with a half-life of 24 hours. 

Interpretation of risk criteria: 

• Procalcitonin levels that are low in a very unwell patient may suggest a low risk of sepsis development and progression to severe sepsis and/or septic shock, but they do not rule it out. 

• Low levels might mean that the patient's symptoms are brought on by anything other than a bacterial illness, such as a viral infection. A low level might also mean that an infection is confined, hasn't spread, hasn't gone systemic, or is just six hours old. 

• High levels signal a significant likelihood of sepsis as well as a higher risk of developing severe sepsis and septic shock. Elevated amounts may also be seen in those who have severe bacterial illnesses like meningitis. 

• Mild elevations should be carefully examined together with other results as they might indicate an early infection or a non-infectious disease. Kids with kidney infections may also exhibit them. 

• Procalcitonin levels that gradually decrease in a patient with sepsis or a bacterial infection suggest that their treatment is working. The necessity for ongoing treatment may be indicated by stable or rising procalcitonin levels.