Various inflammatory processes are sometimes impossible to determine without laboratory research. For this, doctors prescribe clinical, biochemical analyzes of biological materials. Why is a PCT blood test necessary?
What is a PCT?
In our body, according to the state, the content of certain substances, the presence of any disease can be determined or disproved. Especially informative is a blood test in this regard. Another substance that helps make the correct diagnosis is procalcitonin (PCT), which precedes the formation of calcitonin. In turn, calcitonin is an indicator of the exchange of calcium in the body and a substance for the diagnosis of thyroid cancer.
Procalcitonin is produced by thyroid C cells. Due to chemical reactions, PCT is converted to calcitonin. In healthy people, this process occurs almost without residues, that is, PCT does not have time to enter the bloodstream. That is why only traces of this substance are determined in the blood, which show the necessary information about the state of human health.
Unlike the subsequent hormone calcitonin, PCT is necessary for the diagnosis of certain types of infectious diseases or inflammatory processes.
What material is used for analysis?
PCT testing is considered a general clinical and biochemical blood test. For this, it is necessary to take not capillary, but venous blood. Then, in the blood plasma, the laboratory assistant studies the traces of procalcitonin. To ensure that the results are not distorted, it is necessary to comply with all conditions for the analysis.
For what reason does this indicator increase in the blood?
An analysis of procalcitonin or PCT is a biochemical study that is important in determining the severity of sepsis and systemic inflammatory response syndrome (SIR).
Procalcitonin is normally synthesized in C cells of the thyroid gland. To determine the level of this marker in the body, a blood test is performed. Deciphering PCT is not an easy task for a doctor, since it increases with many life-threatening pathologies. Let's consider at what difficulties with health it is above the norm.
- Procalcitonin in the blood is increased in infections that do not have a viral etiology. This phenomenon is evident with bacterial sepsis.
- Serious injuries, burns, surgical interventions give impetus to increase PCT in two to three days.
- Individuals taking immunosuppressants, as well as other drugs that release anti-inflammatory cytoclines, often have high levels of procalcitonin.
- In newborns, PCT rises in the first two days after birth. A blood test, a transcript, the norm in other babies does not have features.
- Continuous and severe cardiogenic shock shows elevated numbers when tested for this test.
- Microcirculatory disorders that last for a long time also lead to an increase in procalcitonin.
When is a PCT blood test prescribed?
Experts resort to a similar study in the following conditions of the body:
- A PCT blood test is often prescribed , the interpretation of which is available only to specialists, for the diagnosis of septic conditions and their severity. It is also indicative of suspicions of severe ongoing infections, fever of unknown etiology.
- Monitoring the results of the treatment of sepsis, shock conditions, the prognosis of these pathologies require the appointment of a study on PCT.
- To diagnose complications of an infectious nature in patients after surgical interventions, organ transplants, during intensive care, and when they are on mechanical ventilation machines, a procalcitonin test is often used. For people with diagnoses of "neuropenia" and "immunosuppression", with undetermined diagnoses, the test is of great importance - for their clarification and evaluation of the therapy.
- In the differential diagnosis of infectious and non-infectious diseases, research is sometimes crucial.
- Complications of fungal and bacterial infections will also help identify this blood test. Deciphering PCT will help determine what is the possible causative agent of a particular complication.
- Diseases such as pneumonia, bacterial meningitis, peritonitis may also require the appointment of a study on procalcitonin.
Terms of analysis for this indicator
All patients, upon admission and when contacting a medical institution, are prescribed a general blood test. Deciphering PCT, the norm of which depends on the age and state of the patient’s health, is not often prescribed. But the study is becoming more and more popular every day, doctors understand its full significance for clarifying the diagnosis and predicting the patient's further condition.
All biochemical studies are performed on an empty stomach. And procalcitonin is no exception. Analysis should be submitted before 10 am. On the eve you need to refrain from fatty, fried, salty foods and alcohol. If possible, exclude medication. If they cannot be undone, the names of the drugs in the laboratory must be said.
On the day of the test, you can drink a glass of water, but no more, since we are talking about a "capricious" substance, the level of which must be carefully monitored. It is also important to take into account the day of the menstrual cycle in women, since women have certain days when it is most favorable to take blood to study the level of hormones. This information can be obtained from the doctor who ordered the test.
Decryption of the general PCT blood test
In each study, an important part is the interpretation of the results. Many often try to make a diagnosis for themselves according to the obtained indicators, but do not rush to put an end to yourself. A blood test, decoding of PCT are of great importance in the diagnosis of severity and prognosis of septic and other pathological conditions:
- If the indicator is below 0.5 ng / ml, this suggests that there is practically no risk for developing severe sepsis.
- 0.5-2 ng / ml - the so-called gray zone, coincides with the systemic inflammatory response syndrome. But it is impossible to say with confidence that the patient may develop a severe septic condition. It is recommended that the analysis be repeated after six to twenty-four hours.
- If the indicator of procalcitonin exceeds two ng / ml, then it is possible to suspect SSVR or severe sepsis.
- Above 10 ng / ml or more - this is a pronounced SSVR, resulting from severe sepsis or shock. May lead to multiple organ failure syndrome. The risk of patient death is very high.
Norms for adults and children
Normally, the concentration of PCT is very low. It is in the range of 0.01 - 0.045 ng / ml. Many clinical and biochemical parameters differ, depending on age and many other factors and circumstances. But this cannot be said for PCT.
A blood test, the decoding in children of which has practically no features, is carried out regardless of age. Unless in newborns, the studied indicator rises by several days, but then returns to normal again.
What does the reduced rate indicate?
It is known that in children who received perinatal dexamethasone when a PCT blood test is performed, the decoding is “lowered”. In adults, it is not possible to determine a reduced indicator of procalcitonin, since its normal values ​​are too low.
What should I do if a PCT blood test is performed, the decryption is “increased”?
Many people at the sight of the discrepancy between the
reference values and the actual ones in the analysis results begin to panic. But first, you should find out what such values ​​mean. In the diagnosis of many severe pathological processes, a blood test (decoding PCT) is of great importance. Elevated levels of procalcitonin may indicate such a terrible pathology as sepsis, and be a prognosis of death for the patient.
After the results of the tests become known, it is easier for the doctor to choose the necessary therapy that can save a person’s life. If we are talking about a malignant process, then this study allows us to identify it in the early stages, which makes it possible to quickly clarify the diagnosis with the help of other studies and undergo the necessary course of treatment in a timely manner. This increases the chances of recovery.
If the patient is admitted to a hospital with acute pancreatitis, but the blood and urine amylases are extremely high, a procalcitonin test will confirm or exclude pancreatic necrosis.
After organ transplants and other serious surgical interventions that give a high fever, patients can be tested for PCT to see if a fungal or bacterial infection has joined.
If in patients with a confirmed diagnosis of sepsis, the indicators are reduced, this indicates the effectiveness of the treatment. Patients in whom procalcitonin in the blood does not increase, but does not decrease, have a dubious prognosis. If the indicators, despite intensive therapy, not only do not decrease, but also grow, then the patient has practically no chance to survive.
What should a specialist consider when decoding this indicator?
The reference boundaries in healthy and sick patients may not have significant differences, therefore, when a patient submits a PCT blood test, deciphering this study requires special care from the specialist. It all depends on the individual characteristics of the body. Therefore, when interpreting such indicators, you need to be very vigilant, take into account the patient’s history and clinical data, as well as other indicators, such as a clinical blood test, urinalysis, C-reactive protein, tumor markers.