hs-CRP

Also known as: High-sensitivity CRP; Ultra-sensitive CRP

Formal name: High-sensitivity C-reactive protein

Related tests: Lipid profile, Cardiac risk assessment, CRP, Lp-PLA2

The Test Sample

What is being tested?

C-reactive protein (CRP) is made by the liver and secreted into the bloodstream. It can be measured with two different tests: the CRP test and the high-sensitivity CRP (hs-CRP) test, each measuring different ranges of CRP levels in the blood. The hs-CRP test can more accurately detect lower concentrations of the protein (it is more sensitive) than the standard CRP test. CRP increases with inflammation and infection as well as following a myocardial infarction (MI, heart attack), surgery, and trauma. As a result, CRP is one of several proteins that are often referred to as acute phase reactants and is used to monitor changes in inflammation associated with many infectious and autoimmune diseases.

It is now believed that inflammation plays a major role in atheroslcerosis (the narrowing of blood vessels due to build-up of cholesterol and other lipids), which is often associated with cardiovascular disease (CVD). Studies have shown that measuring CRP with the improved methodology of the highly sensitive assay can identify the risk level for CVD in apparently healthy people. For these high-risk individuals, this more sensitive test allows for measurement of lower concentrations of CRP that may be within the normal range but consistently at the higher end of the range. These normal but relatively high levels of CRP in otherwise healthy individuals have been found to be predictive of the future risk of a heart attack, stroke, sudden cardiac death, and peripheral arterial disease, even when cholesterol levels are within an acceptable range.

How is the sample collected for testing?

A blood sample is drawn by needle from a vein in the arm.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed; however, you may be asked to fast for 9-12 hours before the blood sample is taken if a lipid profile (including triglycerides) is to be done. In addition, you should be healthy at the time of the sample collection, without any recent illnesses, infections, inflammation, or other tissue injuries.