PCT, or Procalcitonin test, is a blood test that measures the amount of procalcitonin in the blood. PCT is used for clinical diagnosis of bacterial infections and is a biological indicator in this sense. PCT can give results earlier than high fever, white blood cell count and blood culture tests, which can indicate the presence of bacterial infections and can be used to detect bacterial infections. Procalcitonin is a polypeptide that occurs before the calcitonin hormone is secreted. It is largely produced in the thyroid gland. However, 2 to 4 hours after a serious bacterial infection, immune cells also begin to produce procalcitonin. This means that the PCT level in the blood is high in the PCT test. PCT level is increased only in internal and bacterial infections. An increase in PCT level is not expected in infections from other pathogens such as viruses. The level of PCT in the blood is also very high due to thyroid cancer.Therefore:A high level of PCT in the blood can be a sign of a serious bacterial infection. High PCT increases the likelihood of sepsis. High PCT can increase the expectation of septic shock
What Does Low PCT Mean?
A low level of PCT in the blood may be a sign of a minor bacterial infection. This can be interpreted as the infection being local and not yet spreading to other parts of the body. From a low PCT level, it can be concluded that a systemic infection is less than six hours old. Low PCT, patient’s symptoms, Refusal of the body to accept the transplanted organ, Infections caused by viruses, Post-operative or other It can also be a sign that it is caused by a problem other than sepsis and bacterial infections and inflammations, such as traumas caused by various reasons. A low PCT level, again, may be an indication that the patient is less likely to have sepsis.
PCT and Sepsis Diagnosis
The PCT test is a relatively new test. For this reason, this test is generally used in intensive care units and emergency services. For diagnosis, PCT test can be applied on the first day that the patient sees the doctor. On other days, the PCT test can be useful in understanding how the patient responds to the treatment.
In Which Clinical Symptoms Can PCT Be Requested?
The clinical signs for which Procalcitonin blood test can be requested are listed below.
- Heart palpitations
- Low blood pressure
- Fast or deep breathing
- Mental health disorders
- Reduction in urine output
To detect the course of a known bacterial infection. More more serious symptoms that can be caused by sepsis in particular: Inflammation throughout the body, many small clots forming in veins and capillaries, failure of one or more organs (multiple organ failure), dangerous blood pressure In cases such as a fall, your doctor may consider a PCT test necessary. The PCT level obtained as a result of laboratory tests is not sufficient data to make a diagnosis on its own. After considering all the data and findings, your doctor will explain to you what your test results mean. Some other tests that may be ordered along with the PCT blood test are CRP (C-reactive protein), blood culture, blood count, CSF (brain and spinal fluid analysis); It will help diagnose or rule out such as sepsis, bacterial meningitis, or bacterial pneumonia in adults and children with an unexplained high fever.
What are the Requirements for the PCT Test?
The PCT Test can be performed with a blood sample taken from the arm veins with the help of a needle. No pre-test preparation is required for the test.
What are PCT Reference Values?
While it is 2.0 ng/mL or less at birth in children younger than 72 hours, it increases to 20 ng/mL or less between 18 and 30 hours after birth. It is 0.15 ng/mL or less in adults and children older than 72 hours.
Possible Side Effects of PCT
This test has no visible side effects and no unexpected effects have been observed if administered correctly. Due to the limitations of today’s medicine, it is not possible to know these features. This is because there is no reference test (gold standard) for diagnosing the infection. Pathogens were isolated in less than 10 percent of patients with a clinical diagnosis of pneumonia. This rate is less than 30 percent in patients diagnosed with sepsis. The precision of the PCT test cannot be fully calculated without a reference standard necessary for correct definition. Therefore, the vast majority of patients are treated empirically for suspected infections. These treatments are not fully justified, nor can they be completely ignored. Procalcitonin level will not be able to solve this problem. However, thanks to the PCT test, doctors can obtain additional data and make more accurate diagnoses. PCT could theoretically help physicians decide whether to start or discontinue antibiotic treatments.
There are no clinically validated and reproducible PCT values available to definitively detect or definitively rule out infections. Experts disagree on how procalcitonin testing should be optimally or appropriately applied in clinical trials. These deposits are stored in the body as amyloid. Diseases caused by amyloid deposition are called amyloidosis. Some of the drugs you are currently using may also affect your PCT blood test result. For this reason, it is important to tell your doctor about all the medicines you are using, including herbal supplements and medicines. This information will enable your doctor to interpret your PCT test results more accurately and will prevent your doctor from making a wrong diagnosis. The psychological significance of precalcitonin and how precalcitonin production will be regulated have not been clarified yet. Many hypotheses argue that precalcitonin is involved in calcium metabolism, cytokine network, and modulation of nitric oxide (NO) synthesis. No enzyme in plasma can break down precalcitonin. Therefore, precalcitonin enters the bloodstream, remaining unchanged. Its half-life is up to 30 hours. In a study, mortality rates of critical septicemia patients were investigated by PCT in critical care units. Accordingly, the mortality rate of critical septicemia patients with PCT levels between 1 and 5 ng/mL was 11 percent, while the mortality rate within 90 days of patients with critical septicemia between 51 and 100 ng/mL was 43 percent.
- PCT blood test,
- Differentiating between acute gout and cellulitis infection,
- Acute cellulitis infection and deep vein thrombosis (DVT) It can be used to differentiate,
- to distinguish severe asthma caused by viruses and severe asthma caused by bacteria,
- to determine whether chronic obstructive pulmonary disease (COPD) is caused by virus or bacteria