Related Subjects:
|Ferritin
|CEA
|ESR
|CRP
|ALP
|LDH
|HbA1c
|Alpha Fetoprotein
|Anti-Hu ab
|Biochemical Lab values
For poorly understood reasons the CRP is of no use as a useful guide of disease activity in Systemic lupus Erythematosus, Scleroderma, Ulcerative colitis and leukaemia
Overview of C-Reactive Protein (CRP)
C-reactive protein (CRP) is a substance produced by the liver in response to inflammation. It is part of the acute phase response, which is the body's early defense system against infections and injuries. CRP levels in the blood increase rapidly in response to inflammation and decrease when the inflammation subsides, making it a useful biomarker for assessing inflammatory conditions and monitoring treatment responses.
Structure of C-Reactive Protein
- Composition:
- CRP is a pentameric protein composed of five identical subunits, each containing 206 amino acids.
- These subunits form a cyclic, disc-shaped structure.
- Binding Properties:
- CRP binds to phosphocholine expressed on the surface of dead or dying cells and some types of bacteria.
- This binding activates the complement system, promoting phagocytosis by macrophages and neutrophils.
Functions of C-Reactive Protein
- Acute Phase Response:
- CRP is one of the first acute-phase proteins to increase in response to inflammatory stimuli.
- Its levels can rise dramatically within 6-8 hours of the onset of inflammation, reaching a peak at around 48 hours.
- Opsonization:
- CRP binds to the surface of pathogens and damaged cells, tagging them for destruction by the immune system.
- It enhances phagocytosis by acting as an opsonin.
- Activation of Complement System:
- CRP activates the classical complement pathway, which contributes to the clearance of pathogens and dead cells.
- Immune Modulation:
- CRP modulates the immune response by interacting with various immune cells, including macrophages and dendritic cells, influencing their activity and cytokine production.
Regulation of CRP Levels
- Inflammatory Stimuli:
- CRP production is primarily regulated by pro-inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1 (IL-1), and tumour necrosis factor-alpha (TNF-α).
- Acute Infections and Injuries:
- CRP levels increase significantly in response to acute bacterial infections, trauma, and tissue necrosis.
- Chronic Inflammatory Conditions:
- Elevated CRP levels can be observed in chronic inflammatory diseases, such as rheumatoid arthritis, inflammatory bowel disease, and systemic lupus erythematosus.
Clinical Significance
- Diagnosis and Monitoring:
- CRP levels are measured to diagnose and monitor acute and chronic inflammatory conditions.
- High-sensitivity CRP (hs-CRP) assays can detect low levels of CRP, which are useful for assessing cardiovascular risk.
- Cardiovascular Disease:
- Elevated CRP levels are associated with an increased risk of cardiovascular events, such as myocardial infarction and stroke.
- hs-CRP is used as a marker to evaluate cardiovascular risk in asymptomatic individuals.
- Infections:
- CRP levels can help differentiate between bacterial and viral infections, as bacterial infections typically cause a more significant increase in CRP levels.
- Inflammatory and Autoimmune Diseases:
- CRP is used to monitor disease activity and response to treatment in conditions like rheumatoid arthritis and lupus.
- Surgical and Postoperative Monitoring:
- CRP levels can indicate postoperative complications, such as infections or anastomotic leaks.
Summary
C-reactive protein (CRP) is a key marker of inflammation produced by the liver in response to various inflammatory stimuli. It plays a crucial role in the acute phase response, opsonization, complement activation, and immune modulation. CRP levels are widely used in clinical practice to diagnose and monitor inflammatory conditions, assess cardiovascular risk, and evaluate infections and autoimmune diseases. Understanding the function and regulation of CRP is essential for its effective use in medical diagnostics and treatment monitoring.