CRP (C-reactive Protein) is an acute-phase, nonspecific marker of inflammation & infection and has been found to broadly correlate with disease severity and treatment response across a variety of infectious and non-infectious conditions1. Its rate of synthesis and secretion increases within hours of acute injury and may reach as high as 20 times the normal levels1.

Elevated serum concentration of CRP is an unequivocal indicator of active tissue damage and CRP measurements provide a simple screening test for inflammatory-related infections, as well as neonatal septicaemia and meningitis where standard microbiological investigations are difficult2.

In relation to COVID-19, recent studies have reported that CRP levels are elevated in patients with COVID-19 and may correlate with severity of disease and disease progression2. As such, CRP holds promise as a potential prognostic biomarker. The rate at which CRP level rises during the first seven days of hospitalization could also be used to identify the need for early ICU transfer, as it is suspected that the rate of increase in CRP is indicative of disease worsening and a measure of underlying systemic inflammatory responses3. In addition, CRP can also be measured to monitor effectiveness of treatment, due to the protein’s short half-life of 19 hours (CRP levels will decrease as the inflammatory stimulus ends, indicating recovery)3.

A 2020 study by Wang et al4, observed that in the early stage of COVID-19, C-reactive protein levels can reflect the extent of lung lesions and disease severity. Differences in the diameter and CRP levels were compared in the following groups of patients: mild group, moderate group, severe group, and critical group:

Fig 1. CRP levels measured in patients with early stage COVID-19 correlated with the size of their respective lung lesions and severity of symptoms (mild, moderate, severe & critical). Reference: Wang et al (2020)4.

CRP is also a useful biomarker for sepsis infection, a life- threatening organ dysfunction caused by a dysregulated host response to infection. Signs of multi-organ injury typical of sepsis occur in approximately 2-5% of those with COVID-19 after approximately 8-10 days5. Many patients affected by COVID-19 will die from sepsis and its complications. Sepsis needs to be diagnosed and treated with antibiotics urgently. Signs of sepsis include:

Slurred speech or confusion
Extreme pain in the muscles or joints
Passing no urine in a day
Severe breathlessness
It feels like I’m going to die”
Skin that’s mottled, discoloured or very pale

The NICE guidelines recommend venous blood testing for CRP amongst other markers in patients suspected with Sepsis6. CRP levels can be monitored throughout antibiotic treatment to monitor the progression of the infection and determine if the treatment is effective (or whether other antibiotics are required)6.

As part of our COVID-19 support, we are pleased to offer customers a discount on our CRP rapid tests to encourage regular monitoring of CRP levels in COVID-19 patients and those suspected of Sepsis infection.

Our CRP Latex Test Kit is a semi-quantitative latex agglutination slide test for the detection of CRP. The serum sample is mixed with the CRP latex reagent to react. If the CRP concentration is greater than 0.6mg/dl (considered ‘normal’ levels), a visible agglutination is observed, indicating a systemic inflammatory response seen in infection. If CRP concentration is less than 0.6mg/dl then no agglutination will occur.

Our CRP promotion is available whilst stocks last. Please contact us for pricing and availability at


  1. Clyne & Olshaker (1999). The C-reactive protein. J Emerg Med 17(6): 1019-25
  2. Chen et al (2020). Plasma CRP level is positively associated with the severity of COVID-19. Ann Clin Microbiol Antibmicrob 19 (1): 18
  3. Sharifpour et al (2020). C-reactive protein as a prognostic indicator in hospitilised patients with COVID-19. PLOS One 15(11): e0242400.
  4. Wang et al (2020). C-reactive protein levels in the early stage of COVID-19. Medecine et Maladies Infectieuses 50 (4): 332-334
  5. Global Sepsis Alliance