C-reactive protein (CRP)

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C-reactive protein (CRP)

C-reactive protein (CRP) is produced by the liver and released into the bloodstream in response to conditions such as tissue damage, infection, or inflammatory disease.

Standard CRP and high-sensitivity CRP (hs-CRP) tests assess the same protein, but at different concentrations. The standard test measures high CRP levels, whereas the hs-CRP test measures much lower levels. Therefore, the tests are used to assess different conditions.

Standard CRP test

Elevated CRP levels simply confirm the presence of inflammation. This test does not indicate the cause of the inflammation or where it is in the body. It can also be used to monitor the inflammatory state of an infection or autoimmune disease (e.g., arthritis, ulcerative colitis, Crohn's disease).

hs-CRP test

The hs-CRP test may be ordered to better assess a person's risk of cardiovascular diseases.

What is the purpose of this test?	Standard CRP test To assess an individual's inflammation levels (e.g., after surgery, due to an infection or disease). To evaluate how a patient is responding to treatment for an inflammatory disease. hs-CRP test Used only to assess the risk of cardiovascular diseases.
How to prepare?	Standard CRP test No preparation needed. hs-CRP test More than one test may be required. One of them may need to be done on an empty stomach. Follow the instructions you receive carefully.
Reference values*	Standard CRP test ≤ 10 mg/L hs-CRP test < 2="">
Associated tests	The standard CRP test may be done alongside an erythrocyte sedimentation rate (ESR) or rheumatoid factor test, among others. The hs-CRP test may be done alongside a full lipid panel that measures total cholesterol, HDL, LDL, triglycerides, and apolipoproteins B and A1.
How is it done?	A blood sample is drawn, usually from a vein in the arm
How long before I get the results?	Results are usually ready in a day. It may take longer to receive your results.

* These values are presented for information purposes only. As different laboratories may have different target values, the lab report usually specifies the values used for the test. It should also be noted that test results must be interpreted based on factors such as age, sex, and health condition. Values outside of this range may be considered normal for some individuals.

What does an abnormal test result mean?

High standard CRP test values:

High CRP levels indicate the presence of inflammation in the body. Possible causes of inflammation include:

Trauma
Autoimmune disease
Infection

High hs-CRP test values:

Increased risk of heart disease.

Low CRP test values:

Low test values are considered good.
With the standard CRP test, a low value could mean that the inflammatory disease is under control.
With the hs-CRP test, it could mean that the risk of heart disease is low.

Factors that can interfere with test accuracy

High CRP blood levels can also be caused by the following:

Obesity
Pregnancy
Diabetes
Smoking

What you should know before going for this test

When you go in for a blood test or any other medical exam, it's always a good idea to bring a complete list of any prescriptions, over-the-counter medications, or natural health products you're taking. Unless otherwise advised, it's best to take your medications as usual on blood test days. If in doubt, don't hesitate to talk to your healthcare professional.

© Copyright Vigilance Santé

The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.