collection procedure and analysis interpretation

C-reactive protein (CRP) is produced by the liver and released into the blood, if the body is threatened by bacteria or other pathogens. This inflammatory response, with a role in the organization of the body’s safety, can also be manifested in the case of chronic conditions or autoimmune diseases.

The concentration level of this protein in the bloodstream is measured in the analysis laboratory, after taking and evaluating a blood sample. Testing is essential in the diagnosis stage of chronic inflammatory diseases, such as chronic rheumatoid arthritis or lupus, but also of some cardiac diseases (coronary diseases or myocardial infarction).

Also, the specialist can recommend testing the CRP level in the patient’s blood, to verify the effectiveness of the prescribed anti-inflammatory treatment. In this article, you will find out the basic information regarding the collection procedure for evaluating the CRP value and the interpretation of the results of this blood analysis.

How does the collection procedure for CRP work?

Collecting a blood sample, in order to determine the C-reactive protein concentration, does not involve special preparations. The specialist doctor can provide you with the information you need regarding this routine procedure. After the sampling, the concentration of C-reactive protein (CRP) is measured in the serum obtained from the blood sample.

CRP testing can be recommended by the specialist in the case of certain manifestations of the body, possibly associated with an inflammatory response. It is also essential for monitoring certain chronic conditions or health problems:

• 
  bacterial infections;
• 
  viral infections;
• 
  febrile episodes;
• 
  minor inflammations;
• 
  autoimmune diseases.

How are CRP test results interpreted?

Reference values* for C-reactive protein: < 0.5 mg/dL.

If an inflammatory response occurs in the body, the C-reactive protein values ​​can increase even 100 times above the reference values. The maximum concentration of CRP reaches a maximum threshold at approximately 24-72 hours at the onset, then begins to decrease slowly and reaches normal values ​​again after 2-3 weeks.

In patients with cardiovascular problems, CRP testing allows establishing the degree of cardiovascular risk, according to the following reference values:

• 
  < 0.1mg/dL – the patient has a low cardiovascular risk;
• 
  0.1 – 0.3 mg/dL – the patient presents a moderate cardiovascular risk;
• 
  0.3 – 1 mg/dL – the patient presents an increased cardiovascular risk;
• 
  > 1 mg/dL – the patient presents a very high cardiovascular risk.

If a patient with cardiovascular problems or risk of myocardial infarction faces at the time of the test an inflammation in the body, or a visible trauma, the collection and examination of the sample will be postponed, because the CRP values ​​are already increased, independent of the cardiovascular risk. If the C-reactive protein value is higher than 1 mg/dL in one of the two tests, the specialist doctor will look for another non-cardiovascular cause for the inflammatory response produced in the body.

*The reference values ​​may vary from one analysis laboratory to another, depending on the test technology, the reagents used or the working method applied.

What could indicate the values ​​above the limits of the CRP concentration?

Increased values ​​of CRP concentration

They can also indicate the presence of:

• 
  traumas;
• 
  inflammatory conditions;
• 
  tissue damage or necrosis;
• 
  infections in the case of certain types of cancer;
• 
  acute bacterial infections;
• 
  inflammations occurring in the first and last trimester of pregnancy;

Reduced values ​​of CRP concentration

The low values ​​of the C-reactive protein level are not clinically relevant.

C-reactive protein (CRP): possible interferences

C-reactive protein (CRP) is among the most sensitive reactants of the acute phase. For this reason, various inflammatory processes, infections or neoplastic diseases can cause the increase in blood concentration values.

Gammapathies (in particular, those of the IgM type) could cause high or falsely low values ​​of the CRP concentration in the blood. But these cases are very rare. Also, some drug treatments could cause falsely low C-reactive protein concentration values ​​to be obtained.

Disclaimer: This article does not replace medical advice. If you have symptoms that worry you, schedule a visit to the specialist doctor!

Source:

“C-reactive protein | MedLife”, www.medlife.ro, https://www.medlife.ro/glosar-medical/analize-medicale/crp-cantitativ. Accessed on 16.04.2024

PHOTO: shutterstock.com

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