C Reactive Protein Test (CRP Test)

C - Reactive protein (CRP) test

A test that measures C-Reactive protein levels in your blood. c-Reactive Protein, an acute phase reactant, is a pentameric protein found in blood and whose circulating concentrations increase inflammatory reaction. 

CRP is a protein which is produced by liver whenever there is inflammation in the body. Whenever there is inflammation in the body its levels rise quickly and also its level falls quickly on removal of inflammatory stimulus.

Whenever there is chronic inflammation in the body in conditions such as chronic infectionsthe CRP levels is   persistently elevated. It is a very nonspecific test and its levels can beelevated in any inflammatorycondition. 

It binds to lysophosphatidylcholine expressed on the surface of dead or dying cells and some strains of bacteria. This binding then activates the complement system and promotes phagocytosis by macrophages to clear the dead cells/bacteria. 

Why is C-Reactive protein test (CRP Test) prescribed?

CRP plays a role in innate immunity as an early defence system against infections.

CRP level (hs-CRP or high sensitivity CRP) is an independent risk factor for atherosclerotic disease, hence used as a risk factor for cardiovascular disease (stroke, myocardial infarction and peripheral vascular disease).

Elevated levels are also seen in IBD, colon cancer, obstructive sleep apnoea, avian influenza etc. 

What are components of this test?

There are two types of CRP test-standard CRP test and high-sensitivity C-reactive protein test (hs-CRP). The hs-CRP test is highly sensitive and thusdetects even slight increase in CRP levels. This test is usually used to determine the risk of developing coronary artery disease.

Reference range

Biological Reference range- < 0.5mg/dl

The reference range varies from laboratoryto laboratory. 

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