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.

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.

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