An inflammatory biomarker detects inflammation in the body. Inflammation is not just the immediate, short-term response of the body to an injury or infection. Inflammation within the body can be a long-term, chronic condition resulting in a number of health implications. In diagnostics, measurement of an inflammatory biomarker can not only detect acute inflammation but provide a marker of treatment response.

C-reactive protein (CRP) is an acute phase protein produced by the liver in response to inflammation, infection and tissue injury. CRP is a particularly beneficial inflammatory biomarker as it is detected much faster than other markers in the blood. Levels of CRP increase when inflammation occurs and therefore it can be a significant biomarker in a range of diseases, including the following.

Cardiovascular Disease

An increasing amount of research exists to suggest CRP is not only a useful, non-specific inflammatory biomarker, but it may have a direct influence on coronary heart disease and cardiac events¹. Inflammation can occur when LDL cholesterol builds up in the artery walls causing atherosclerosis. Modifiable risk factors of atherosclerosis include smoking, diabetes, poor diet, high blood pressure and physical inactivity, all factors which subsequently increase the risk of heart attacks, ischemic stroke, peripheral artery disease and even vascular dementia^2,3.

Studies have also shown that persistent low levels of CRP can contribute to a person developing CVD. Therefore using high sensitivity CRP as an inflammatory biomarker can detect low levels, helping to predict the likelihood of a patient developing CVD in the future.

Diabetes

Research suggests that inflammation in the body can influence the development of type 2 diabetes. With the ability to be managed through diet and exercise, type 2 diabetes is commonly associated with obesity. Research has shown that excess body fat can cause continuous chronic low-grade inflammation as a result of inflammatory cytokines and increased plasma levels of CRP. As a result, this chronic inflammation has the ability to cause insulin resistance leading to the development of type 2 diabetes⁴.

Rheumatoid Arthritis

A three year study which analysed the bone and joint health of 10,000 patient samples in India has found that inflammatory biomarkers, in particular CRP and ESR (Erythrocyte Sedimentation Rate) were raised in most of the samples compared to any other markers⁵. Although CRP is a non-specific inflammatory biomarker, it can be used alongside other tests, such as Rheumatoid Factor, to diagnose inflammatory joint diseases such as Rheumatoid Arthritis. Not only will CRP levels be higher due to chronic inflammation, but CRP levels can be monitored to assess levels of inflammation over time, allowing clinicians offer effective treatment.

Chronic Obstructive Pulmonary Disease (COPD)

COPD is a condition associated with inflammation of the lungs and airways. Studies have shown that measuring CRP levels is beneficial to detect exacerbations, when symptoms of COPD get suddenly worse and can last for several days. This is because CRP levels spike when exacerbations happen, causing lung function to deteriorate⁶.

Neonatal Bacterial Infections

CRP is one of the preferred and frequently used tests in neonatal units when diagnosing suspected bacterial infections, such as neonatal sepsis, in newborns who show signs on infection. Due to delayed synthesis during the inflammatory response, the sensitivity of CRP is lowest during early stages of infection. It is therefore critical that extremely low levels of CRP can be detected during diagnosis to distinguish whether symptoms are related to an infectious or non-infectious condition. This early detection then allows for rapid and appropriate neonatal treatment⁷.

Inflammatory Bowel Disease

Research suggests that using CRP as an inflammatory biomarker can help distinguish between Inflammatory Bowel Disorder (IBD) and Irritable Bowel Syndrome (IBS)⁸. Although IBD and IBS have some similarities in symptoms, IBD causes chronic inflammation, whereas IBS is a non-inflammatory condition. Therefore using CRP as a biomarker can allow clinicians to deliver a confident and accurate diagnosis.

For health professionals

Randox Laboratories manufacture a wide range routine and niche biochemistry reagents for use in both a research and clinical setting. With a wide measuring range, the Randox CRP assay will perform excellently to detect levels outside of the healthy range. Also available is a Full Range CRP assay particularly beneficial for use in a neonatal setting, and a High Sensitivity CRP assay, depending on your diagnostic requirements. For more information, please contact: reagents@randox.com

References:

1. Shrivastava, A. K., Singh, H.V., Raizada, A. and Singh, S.K. C-reactive protein, inflammation and coronary heart disease. The Egyptian Heart Journal. 67, 89-97. (2015)
2. American Heart Association. Inflammation and Heart Disease. Available from: https://goo.gl/d82Ynr  (2016)
3. Harvard Health Publications. What you eat can fuel or cool inflammation. Harvard Health Publications. Available from: https://goo.gl/e8m3El (2007)
4. Zeyda, M. and Stulnig, T. M.  Obesity, Inflammation, and Insulin Resistance – A Mini-Review. Gerontology 2009; 55:379-386 (2009)
5. Mukherjeel, R.  Bone and joint health are crucial aspect, usually ignored by Indians. The Times of India. Available from: https://goo.gl/qluzhI (2016)
6. Anderson, G. P.  COPD, asthma and C-reactive protein. European Respiratory Journal 2006; 27: 874-876. (2006)
7. Hofer, N., Zacharias, E., Müller, W. and Resch, B.  An update on the Use of C-Reactive Protein in Early-Onset Neonatal Sepsis: Current Insights and New Tasks. Neonatology 2012; 102: 25-36 (2012)
8. Silva, P.  Two Specific Proteins Allow the Exclusion of IBD in Patients with Irritable Bowel Syndrome. IBD News Today. Available from: https://goo.gl/pxMP53 (2015)