Discover

(Redirected from C-Reactive protein)

'C-reactive protein' ('CRP') is a plasma protein, an acute phase protein produced by the liver. It is a member of the pentraxin family of proteins. It should not be confused with C-peptide or Protein C.

Contents

History and nomenclature

Genetics and biochemistry

Function

Diagnostic use

Cardiology diagnostic test

Role in cardiovascular disease

Role in colon cancer

See also

Additional images

References

External links

History and nomenclature

C-reactive protein was originally discovered by Tillett and Francis in 1930 as a substance in the serum of patients with acute inflammation that reacted with the ''C'' polysaccharide of ''pneumococcus'' ^[1].

Genetics and biochemistry

The ''CRP'' gene is located on the first chromosome (1q21-q23). CRP is a 224 residue protein ^[2] with a monomer molar mass of 25106 Da, and native cyclic pentamer mass of 125530.

Function

CRP is a member of the class of acute phase reactants as its levels rise dramatically during inflammatory processes occurring in the body. This increment is due to a rise in the plasma concentration of IL-6, which is produced in macrophages, endothelial cells and T-cells. CRP binds to phosphorylcholine on microbes. It is thought to assist in complement binding to foreign and damaged cells and enhances phagocytosis by macrophages, which express a receptor for CRP. It is also believed to play an important role in innate immunity, as an early defense system against infections.

Diagnostic use

CRP is used mainly as a marker of inflammation. Measuring and charting C-reactive protein values can prove useful in determining disease progress or the effectiveness of treatments. Blood, usually collected in a serum-separating tube, is analysed in a medical laboratory or at the point of testing.
Various analytical methods are available for CRP determination, such as ELISA, immunoturbidimetry, rapid immunodiffusion and visual agglutination.
Viral infections tend to give a lower CRP level than bacterial infection.

Cardiology diagnostic test

C-reactive protein blood test^[3]
: Low risk: <1mg/L
: High risk: >3mg/L
: How to lower: Exercise, stop smoking, flaxseed, aspirin, niacin, statins, alcohol, clean teeth

Role in cardiovascular disease

Recent research suggests that patients with elevated basal levels of CRP are at an increased risk for diabetes^[4], hypertension and cardiovascular disease. A study of over 700 nurses showed that those in the highest quartile of trans fat consumption had blood levels of C-reactive protein (CRP, a pro-inflammatory cytokine which is a cardiovascular disease risk factor) that were 73% higher than those in the lowest quartile^[5] Although one group of researchers indicated that CRP may only be a moderate risk factor for cardiovascular disease ^[6], this study (known as the Reykjavik Study) was found to have some problems for this type of analysis related to the characteristics of the population studied, and there was an extremely long follow-up time which may have attenuated the association between CRP and future outcomes ^[7]. Others have shown that CRP can exacerbate ischemic necrosis in a complement-dependent fashion and that CRP inhibition can be a safe and effective therapy for myocardial and cerebral infarcts^[8].
To measure the CRP level, a "high-sensitivity" CRP or hs-CRP test needs to be performed and analyzed by a laboratory. This is an automated blood test designed for greater accuracy in measuring low levels of CRP, which allows the physician to assess cardiovascular risk. If a result in the low-risk range is found ( < 1 mg/L), it does not need repeating. Higher levels need repeating, and clinical evaluation as necessary.

Role in colon cancer

The role of inflammation in cancer is not well known. Some organs of the body show greater risk of cancer when they are chronically inflamed.
Blood samples of persons with colon cancer have an average CRP concentration of 2.69 milligrams per liter. Persons without colon cancer average 1.97 milligrams per liter. The difference was statistically significant ^[9]. These findings concur with previous studies that indicate that anti-inflammatory drugs could lower colon cancer risk ^[10].

See also

★ acute phase

★ erythrocyte sedimentation rate

★ immunology

★ Cardiology diagnostic tests and procedures

Additional images

References

1. Serological reactions in pneumonia with a nonprotein somatic fraction of pneumococcus, Tillett WS, Francis Jr T, , , J Exp Med, 1930
2. NCBI Entrez Protein #CAA39671 [1]
3. Torelli, Julius (2005), ''Beyond Cholesterol'', p.45. ISBN 0-312-34863-0
4. C-reactive protein, interleukin 6, and risk of developing type 2 diabetes mellitus, Pradhan AD, , , JAMA, 2001
5. Consumption of Trans Fatty Acids Is Related to Plasma Biomarkers of Inflammation and Endothelial Dysfunction, Esther Lopez-Garcia, , , The Journal of Nutrition, 2005
6. C-Reactive Protein and Other Circulating Markers of Inflammation in the Prediction of Coronary Heart Disease, John Danesh, , , New England Journal of Medicine, 2004
7. Koenig, Wolfgang (2006). ''C-Reactive Protein – A Critical Cardiovascular Risk Marker'' [2]
8. Targeting C-reactive protein for the treatment of cardiovascular disease., Pepys MB, Hirschfield GM, Tennent GA, Gallimore JR, Kahan MC, Bellotti V, Hawkins PN, Myers RM, Smith MD, Polara A, Cobb AJ, Ley SV, Aquilina JA, Robinson CV, Sharif I, Gray GA, Sabin CA, Jenvey MC, Kolstoe SE, Thompson D, Wood SP, , , Nature, 2006
9. C-reactive protein and the risk of incident colorectal cancer, Erlinger TP, Platz EA, Rifai N, Helzlsouer KJ, , , Journal of the American Medical Association, 2004
10. A randomized trial of aspirin to prevent colorectal adenomas, Baron JA, Cole BF, Sandler RS, Haile RW, Ahnen D, Bresalier R, McKeown-Eyssen G, Summers RW, Rothstein R, Burke CA, Snover DC, Church TR, Allen JI, Beach M, Beck GJ, Bond JH, Byers T, Greenberg ER, Mandel JS, Marcon N, Mott LA, Pearson L, Saibil F, van Stolk RU, , , New England Journal of Medicine, 2003

External links

★

★ Inflammation, Heart Disease and Stroke: The Role of C-Reactive Protein (American Heart Association)

★