C reactive protein or CRP is a protein secreted by the liver in response to inflammation or infection in the body. It is measured in order to give an idea of ​​the inflammatory state of a person at a given moment.

C-reactive protein (CRP) is a protein produced by hepatocytes, i.e. liver cells, which is then secreted into the blood. It was discovered in the 30s in the plasma of patients with pneumococcal pneumonia. The concentration of C reactive protein increases with inflammation or infection.

It is an early marker of the inflammatory response. This is because its production by the liver and its release into the bloodstream increase within 4 to 6 hours of the trigger, reaching its highest concentration after 36 to 50 hours. Its production usually precedes pain, fever and other clinical manifestations of inflammation.

In some diseases, the rise in C reactive protein can be very large. This is the case, for example:

• bacterial or fungal infections;
• inflammatory diseases: rheumatic such as rheumatoid arthritis or spondyloarthritis, digestive such as Crohn’s disease, dermatological such as psoriasis;
• cancers such as lymphoma or carcinoma;
• myocardial infarction;
• trauma.

It can increase but to a lesser extent in viral infections, lupus, ulcerative colitis, leukemia or in inflammatory conditions concomitant with liver failure.

The CRP assay can reliably confirm the presence of inflammation. However, it is not very specific, that is to say it does not provide information on the nature of what causes the inflammation.

The C reactive protein being a marker of inflammation, its assay makes it possible to evaluate the inflammatory state of a patient. A dosage may be requested in different cases:

• it makes it possible to confirm or rule out the presence of inflammation and / or infection;
• it makes it possible to monitor the effectiveness of a treatment;
• the C-reactive protein assay may also be requested in a person who has just undergone surgery and in whom complications are suspected;
• it can also be used to diagnose and monitor the condition of a chronic inflammatory disease, as well as to monitor its treatment.

The dosage is done by means of a blood test. It is not necessary to be on an empty stomach. Be careful, however, taking certain drugs such as non-steroidal anti-inflammatory drugs or estrogens (contraceptive pill, contraceptive implant, IUD, replacement hormones for menopause, etc.) can falsify the result. It is important to inform the doctor and the laboratory of analyzes, the taking of any medication (prescribed or over-the-counter) or natural health product (food supplement, herbal medicine, essential oil, etc.).

Another test to assess inflammation can be done in conjunction with the CRP test. This is the rate of sedimentation of red blood cells. This also provides interesting information about the inflammatory state of the person. However, the concentration of C reactive protein is more correlated over time with inflammation. Indeed, its concentration increases rapidly after the trigger and decreases rapidly when the treatment is effective. The sedimentation rate can remain disturbed for a longer time.

In case of high result

A high result means the presence of inflammation in the body. This inflammation can be caused by infection (bacterial or fungal), inflammatory disease, cancer, etc. Overweight people and pregnant women also tend to have higher than normal C-reactive protein levels.

In general, we find:

• concentrations of 10-40 mg / L, in case of moderate inflammation or viral infections;
• concentrations of 50-200 mg / L, in severe inflammation or bacterial infections;
• small increases, between 3 and 10 mg / L, can also be found in cases of obesity, smoking, diabetes, high blood pressure, sedentary lifestyle, hormone therapy, sleep disorders, chronic fatigue and depression.

If the result is high, the doctor will need to do further tests and examinations to find the cause of this inflammation. Its increase is a warning sign for doctors. These will have to adapt the monitoring and treatment of the patient accordingly.

In case of low result

A low result is desired.

Treatment for inflammation will depend on the cause of it (chronic disease, infection, cancer, etc.). If treatment for the inflammation is successful, the level of C reactive protein will quickly return to normal.