C-reactive protein (CRP) is a protein produced by the liver that is generally increased when there is inflammation or infection in the body.
This protein is widely used to assess the possibility of an infection or inflammation that is not visible, such as appendicitis or atherosclerosis, for example. However, CRP can also be used to assess a person’s risk of developing cardiovascular disease, as the higher it is, the greater the risk of heart problems.
The amount of C-reactive protein does not indicate exactly what inflammation or infection the person has. Therefore, the PCR value must always be analyzed by the doctor, who may order other tests and evaluate the person’s health history, to arrive at the most correct diagnosis. This test is also not the same test used to diagnose COVID-19, which is known as RT-PCR. Find out more about the PCR test for COVID-19.
Normal CRP value
The C-reactive protein (CRP) value is considered normal when it is below 10 mg/L or 1 mg/dL. However, this value may vary slightly, depending on the laboratory where the test was carried out.
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The risk of developing cardiovascular diseases is greater the higher the level of C-reactive protein (CRP) in the body. In general, the values that indicate the chance of developing heart disease are:
- Very high risk: above 10 mg/L or 1 mg/dL;
- High risk: 2,0 mg/L ou 0,2 mg/dL;
- Medium risk: between 1.0 and 2.0 mg/L or 0.1 and 0.2 mg/dL;
- Low risk: menor que 1,0 mg/L ou 0,1 mg/dL.
The interpretation of the result must be made by the doctor, as in order to reach a diagnostic conclusion, it is important that other tests are analyzed together, making it possible to better identify the cause of the increase or decrease in CRP.
What is the ultra-sensitive PCR test
The ultra-sensitive PCR test is ordered by doctors when they want to assess a person’s risk of cardiovascular problems, such as a heart attack or stroke. In this case, the test is requested when the person is healthy, without any apparent symptoms or infection. This test is more specific and can detect minimal amounts of PCR in the blood.
If a person is apparently healthy and has high ultra-sensitive CRP values, it means that they are at risk of developing peripheral arterial disease, or suffering a heart attack or stroke, and therefore they should eat correctly and exercise regularly. See 7 other tips to reduce the risk of cardiovascular disease.
What can be high CRP
High C-reactive protein normally indicates some inflammatory or infectious process in the body, and may be a sign of a bacterial infection, cardiovascular disease, rheumatism or even transplant rejection, for example.
C-reactive protein (CRP) values can indicate the severity of inflammation or infection:
- PCR between 1.0 and 10.0 mg/L: generally indicates mild inflammation or mild infections such as gingivitis, flu or cold;
- PCR entre 10,0 a 40,0 mg/L: may be a sign of more serious infections and moderate infections, such as chickenpox, COVID-19 or another respiratory infection;
- PCR superior a 40 mg/L: usually indicates bacterial infection;
- PCR superior a 200 mg/L: It may indicate septicemia, a serious situation that puts a person’s life at risk.
An increase in this protein can also indicate chronic diseases and therefore the doctor must order other tests to try to find out what led to its increase in the bloodstream, as PCR alone is not capable of determining the disease. Check out the main symptoms of inflammation.
Low C-reactive protein
Low C-reactive protein (CRP) values can also be observed in some situations, such as in people who have lost a lot of weight, practice physical exercise, consume alcoholic beverages and use some medications, and it is important for the doctor to identify the cause.
What to do when CRP is high
After confirming high PCR values, the doctor must evaluate the results of other requested tests, as well as evaluate the patient, taking into account the symptoms presented. Thus, once the cause is identified, treatment can be started in a more targeted and specific way.
When the patient only presents with discomfort without any other symptoms or specific risk factors, the doctor may request other tests, such as the measurement of tumor markers or computed tomography, for example, to check the chance of an increase in CRP. be related to cancer.
When PCR values are above 200 mg/L and the diagnosis of infection is confirmed, it is usually recommended that the person be hospitalized to receive antibiotics through a vein. CRP values begin to rise 6 hours after the start of the infection and tend to fall when antibiotics are started. If 2 days after using antibiotics the CRP values do not decrease, it is important that the doctor establishes another treatment strategy.
Bibliography
- NURSHAD, Ali. Elevated level of C‐reactive protein may be an early marker to predict risk for severity of COVID‐19. Journal of Medical Virology. 2020
