The ultra-sensitive C-Reactive Protein (CRP) assay, a marker of the acute phase of inflammation, is commonly used for the diagnosis and monitoring of inflammatory processes. It can be high or low in some cases. For what ? Answers with Dr. Alexis Guérin, medical biologist.
What is ultra-sensitive CRP in a blood test?
Ultra-sensitive CRP (C-reactive protein) is a blood test that measures C-reactive protein levels in the blood at very low concentrations. “CRP is a protein produced by the liver in response to inflammation in the body, explains Dr. Alexis Guérin, medical biologist. It can be used as marker of general inflammation in the body and in the monitoring of diseases with a chronic inflammatory component with clinical signs (pain, fever, redness, swelling, etc.) such as rheumatoid arthritis, Crohn’s disease or with an acute inflammatory component such as certain bacterial infections for example“. “The ultra-sensitive CRP measurement makes it possible to detect variations in the value of this protein at very low levels between 0.1 and 5mg/L while the sensitivity of CRP makes it possible to effectively detect variations in the expression of this protein generally of the order of 2mg/L and 250mg/L“. Ultra-sensitive CRP is therefore often used to detect inflammation without clinical signs or asymptomaticand may be associated with an increased risk of developing certain chronic cardiovascular diseases or type 2 diabetes.”Attention, if the ultra-sensitive CRP makes it possible to identify an underlying inflammatory context, it is not specific to any pathology and must be interpreted in light of other examinations and outside of clinical contexts proven inflammatory (chronic inflammatory disease, bacterial infection, etc.). Additionally, ultra-sensitive CRP levels can be influenced by other factors, such as age, sex, smoking, obesity or pregnancy“. It is recommended to seek the advice of a doctor or medical biologist for all requests for dosage and/or interpretation of ultra-sensitive CRP results.
Ultra-sensitive CRP high rate: what causes?
Apart from any inflammatory pathology (cancer, infection, chronic inflammatory joint or digestive disease, etc.), a high level of ultra-sensitive CRP can be caused by various factors. “Obesity is a common cause of high levels of ultra-sensitive CRP, observes Dr. Guérin. excess body fat can trigger chronic inflammation in the body, leading to higher levels of ultrasensitive CRP. Likewise, in patients at cardiovascular riska high level of ultra-sensitive CRP is associated with a greater risk of developing cardiovascular complications such as myocardial infarction or stroke“. smoking is another common cause of high ultra-sensitive CRP. Cigarette smoke can trigger inflammation in the lungs and the rest of the body, leading to high levels of CRP. Chronic stress can also lead to inflammation in the body, which can lead to high CRP levels. Other causes include:
- age : Ultrasensitive CRP increases naturally with age
- The pregnancy : ultra-sensitive CRP may increase during pregnancy
- Some medications such as the pill or hormone replacement therapy can increase ultra-sensitive CRP
“Elevated levels of ultra-sensitive CRP are not specific to any particular disease or disorder. High levels may simply indicate general inflammation with no clinical expression and a higher risk of developing certain cardiovascular complications or even type 2 diabetes.“.
Low ultra-sensitive CRP: what causes?
An ultra-sensitive low CRP level is generally considered normal, but it can also be associated with various causes. “Some medications, such as corticosteroids (steroidal anti-inflammatory drugs) or statins (used to lower cholesterol), can reduce CRP levels in the bodyexplains our interlocutor. Severe malnutrition may also decrease CRP synthesis. As strenuous physical activity can temporarily reduce CRP levels in the body, as it can stimulate the production of anti-inflammatory cytokines”. In some cases, low levels of ultra-sensitive CRP can be completely normal and do not require treatment. “In other cases, low levels of ultra-sensitive CRP may indicate a underlying disease or nutritional deficiency and require further clinical evaluation“.
CRP ultra-sensible et cancer
“While high levels of “standard” CRP have been associated with certain types of cancer, the place of ultra-sensitive CRP is debatable in cancer screening or monitoring“recognizes the biologist.
Ultra-sensitive CRP and pregnancy
The ultra-sensitive CRP level may increase during pregnancy, especially during the third trimester. “It is because of the natural inflammation that occurs during pregnancy, especially in the uterus and placenta. The CRP level may also be increased due to an iinfection or pre-existing inflammation in the mother”.
Pricing and Reimbursement of Ultra-Sensitive CRP Analysis
“The price of the ultra-sensitive CRP analysis may vary depending on the laboratory and the region from a few euros to a few tens of euros“, concludes Dr Guérin. It is important to note that lab fees may also depend on other blood tests performed at the same time. “In France, for example, on medical prescription, the analysis of ultra-sensitive CRP is reimbursed at 70% of the convention rate by the compulsory health insurance“.
Thanks to Doctor Alexis Guérin, medical biologist, director of the Cerballiance laboratories in Manche and Vire Normandie.
