C-reactive protein or CRP is an acute-phase protein produced by the liver and released into the blood a few hours after the onset of an infection, inflammation or tissue injury.
CRP test results are used for the evaluation of infections and tissue injury and provide valuable information for diagnosis, therapy and monitoring.
Causes associated with increased CRP levels include bacterial, viral and fungal infections, sepsis, various forms of arthritis, myocardial infarction and several other infectious and inflammatory conditions.
Because of the non-specific nature of the acute-phase response which leads to increased CRP levels, CRP should be used as a diagnostic aid in the clinical assessment of a patient .
CRP values and antibiotic treatment
When a patient is admitted with signs and symptoms of an infection, the physician faces the clinical dilemma of
- Administering antibiotics in a timely manner.
Treatment with antibiotics is considered the most cost-effective treatment available in bacterial infections.
- Avoiding inappropriate usage of antibiotics.
Misuse of antibiotics when not required has contributed to the problem of multiresistant bacterial infections, which are very difficult to treat.
Interpreting the CRP value
- <5 mg/L (95th percentile) indicates a healthy patient on the AQT90 FLEX analyser for both whole blood and plasma
- ~10-50 mg/L indicates a viral infection > no antibiotics will be administered
- >100 mg/L indicates a bacterial infection > antibiotics will be administered [2-4]
CRP test on the AQT90 FLEX analyser: lab quality at the point of care
The AQT90 FLEX C-reactive protein (CRP) assay can be used both in the lab and at the point of care without any sample or assay preparations, providing a fast result without any exposure to blood.
Quick facts on the CRP assay
- Runs on the AQT90 FLEX immunoassay analyser
- Sample types: EDTA and lithium-heparin
- Specimen types: Venous whole blood and plasma
- Sample tubes: Fits most 13 × 75 mm standard tubes
- No blood exposure: Closed system
- No sample or assay preparation
- Short TAT: Less than 13 minutes
- Limit of detection: 1 mg/L
- Reportable range: 5-500 mg/L
- Total* CV% at conc. 7.4 mg/L (spiked plasma): 5.3 %
- Total** CV% at conc. 6.5 mg/L (spiked whole blood): 12.8 %
- No presence of hook effect, carry-over or known interferences
- Standardization: Calibration is traceable to ERM-DA472/IFCC
* Includes within-run, between-run and between-day contributions
** Includes within-run, between-run, between-batch and between-day (for plasma) contributions