Reagent | C-Reactive Protein (CRP)
C-Reactive Protein (CRP): The Most Sensitive Acute Phase Reactant
Benefits of the Randox Assay
The Randox CRP assay has shown to have limited interference from conjugate and free bilirubin, haemoglobin, Intralipid® and triglycerides.
Wide measuring range
The Randox CRP assay has a measuring range of 2.88 – 220 mg/l for the comfortable detection of clinically important results.
The Randox CRP assay is available in a liquid ready-to-use format for convenience and ease-of-use.
Stable to expiry
The Randox CRP assay is stable to expiry when stored at +2oC to +8oC.
Dedicated calibrator and controls available
Dedicated CRP calibrator and controls available offering a complete testing package.
Applications available detailing instrument-specific settings for the convenient use of the Randox CRP assay on a variety of clinical chemistry analysers.
Instrument Specific Applications (ISA’s) are available for a wide range of biochemistry analysers. Contact us to enquire about your specific analyser.
C-reactive protein (CRP) is the dominant acute phase protein in mammals 1. Elevated levels of CRP are not disease specific but are synthesised, by hepatocytes, in response to pro-inflammatory cytokines during inflammatory and/or infectious processes 2, 3. The physiological function of CRP is the enhancement of cell-mediated immunity through the promotion of phagocytosis, accelerated chemotaxis and the activation of platelets 1.
Known as a biomarker of acute inflammation, many large-scale prospective studies demonstrate the association between CRP and chronic inflammation, including: cardiovascular disease (CVD), cerebrovascular accident (CVA) (ischaemic stroke), Alzheimer’s Disease, and age-related macular degeneration 2.
CRP is a major cardiovascular disease (CVD) risk factor. A CRP level of >10mg/l correlates with a >4% risk of developing a fatal CVD event in 10 years, including: myocardial infarction, peripheral arterial disease, stroke and sudden cardiac death. Inflammation is an integral part in the development and rapid progression of coronary heart disease (CHD) 4.
The coronary artery disease (CAD) process is characterised by increasing levels of inflammatory biomarkers. CRP is not only an excellent biomarker or mediator of atherosclerosis but is a strong independent marker in the prediction of adverse CV events, including: myocardial infarction, ischaemic stroke, and sudden cardiac death. CPR can be utilised as a clinical guide for the diagnosis, management and prognosis of CVD 5.
The development of a cerebrovascular accident (CVA) (stroke) is the result of longstanding vascular inflammation, thrombosis, plaque rupture and subsequent brain ischaemia or infarction. Elevated CRP levels is associated with the development of CVA 6.
High sensitivity CRP (hsCRP) plays an important role in the early diagnosis, prognosis, long and short death risk and prediction of etiological subtypes of stroke 7. Find out more about the Randox hsCRP assay.
Alzheimer’s disease (AD) is the most common form of dementia, accounting for 60-80% of dementia cases 7. CRP is believed to be involved in the pathophysiology of cerebral small vessel disease (CSVD) and neurodegeneration 8. CRP levels are associated with cognitive impairment 9. Inflammation should be considered as a target treatment, with the aim of delaying the progression of subclinical brain damage and cognitive decline 8. Midlife elevations in CRP are associated with an increased risk of developing AD. Patients with AD, CRP elevations continues to predict increased dementia severity suggestive of a possible pro-inflammatory endophenotype in AD 10.
In COVID-19 patients, CRP testing has proved to perform well in discriminating disease severity and predicting adverse outcomes 11. CRP levels positively correlates with lung lesions, reflecting disease severity, and should be considered a key indicator in disease monitoring (see fig. 1) 12.
CRP levels are associated with computed tomography (CT) scores and COVID-19 disease development, with CRP levels increasing in the initial stage of severe COVID-19, prior to the CT findings 13.
Elevated CRP levels have been identified in 86% of patients admitted to hospital. CRP measurements are useful in diagnosis, assessing prognosis and monitoring for clinical improvements or deterioration 14.
Fig. 1. Relation between CRP levels, clinical severity, and lung lesions 12
Specific Protein EQA
 Thanoon IAJ, Abdul-Jabber HAS, Taha DA. Oxidative Stress and C-Reactive Protein in Patients with Cerebrovascular Accident (Ischaemic Stroke) The role of Ginkgo biloba extract. Sultan Qaboos University Medical Journal 2012; 12(2): 197-205.
 Cozlea DL, Farcas DM, Nagy A, Keresztesi AA, Tifrea R, Cozlea L, Carasca E. The Impact of C Reactive Protein on Global Cardiovascular Risk on Patients with Coronary Artery Disease. Current Health Sciences Journal 2013; 39(4): 225-231.
 Avan A, Tavakoly Sany SB, Ghayour-Mobarhan M, Rahimi HR, Tajfard M, et al. Serum C‐reactive protein in the prediction of cardiovascular diseases: Overview of the latest clinical studies and public health practice. Journal of Cellular Physiology 2018; 223(11): 1-18.
 Yu H, Huang Y, Chen XY, Nie WB, Wang YJ, Jiao Y, et al. High-sensitivity C-reactive protein in stroke patients – The importance in consideration of influence of multiple factors in the predictability for disease severity and death. Journal of Clinical Neuroscience 2017; 36(2017): 12-19.
 Hilal S, Ikram MA, Verbeek MM, Franco OH, Stoops E, Vanderstichele H, et al. C-Reactive Protein, Plasma Amyloid-β Levels, and Their Interaction With Magnetic Resonance Imaging Markers. Stroke 2018; 49(11): 2692-2698.
 Watanabe Y, Kitamura K, Nakamura K, Sanpei K, Wakasugi M, Yokoseki A, et al. Elevated C-Reactive Protein Is Associated with Cognitive Decline in Outpatients of a General Hospital: The Project in Sado for Total Health (PROST). Dementia and Genetic Cognitive Disorders 2016; 6(): 10-19.
 O’Bryant SE, Waring SC, Hobson V, Hall JR, Moore CB, Bottiglieri T, et al. Decreased C-Reactive Protein Levels in Alzheimer Disease. Journal of Geriatric Psychiatry and Neurology 2011; 23(1): 49-53.
 Tan C, Huang Y, Shi F, Tan K, Ma Q, Chen Y, et al. C‐reactive protein correlates with computed tomographic findings and predicts severe COVID‐19 early. Journal of Medical Virology 2020; 92(7): 856-862.
 The Royal College of Pathologists. Guidance on the use and interpretation of clinical biochemistry tests in patients with COVID-19 infection. https://www.rcpath.org/uploads/assets/3f1048e5-22ea-4bda-953af20671771524/G217-RCPath-guidance-on-use-and-interpretation-of-clinical-biochemistry-tests-in-patients-with-COVID-19-infection.pdf (accessed 14 June 2020).