CRP begins to rise within 4-6 hours after stimulus from an inflammation/infection. The level doubles every eight hours and peaks at 36-50 hours.
CRP is a sensitive marker of inflammation and tissue damage. However, it has a low specificity. Conditions other than sepsis that can cause a rise in CRP levels include:
- Rheumatic diseases
- Systemic lupus erythematosus
- Systemic sclerosis
- Sjogren syndrome
- Inflammatory bowel disease
- Transfusion associated graft-vs-host disease
Once the determination has been made that sepsis is present and therapy has been initiated, CRP is useful for monitoring response to antibiotics and predicting prognosis.