From the Guidelines
Diverticulitis can cause significantly elevated C-reactive protein (CRP) levels, with a CRP cutoff value of 149.5 mg/l significantly discriminating acute uncomplicated diverticulitis from complicated diverticulitis. CRP is an inflammatory marker produced by the liver that increases in response to inflammation in the body. During a diverticulitis flare, the inflammation in the colon's diverticular pouches triggers the body's immune response, leading to increased CRP production. CRP levels typically rise within 4-6 hours of the inflammatory process beginning and can reach peak levels within 24-48 hours.
Key Findings
- In uncomplicated diverticulitis, CRP levels may range from slightly elevated to moderately high (often 10-100 mg/L) 1.
- Severe or complicated diverticulitis with abscess formation or perforation can cause significantly higher CRP levels (sometimes exceeding 100-200 mg/L) 1.
- A CRP value over 150 mg/l and old age were independent risk factors for acute complicated diverticulitis 1.
- The optimal cutoff value calculated by receiver operating characteristic curve analysis was found to be 173 mg/l (sensitivity 90.9%, specificity 90.9%, p < 0.001) 1.
Clinical Implications
- Physicians often use CRP measurements, along with other clinical findings and imaging studies, to diagnose diverticulitis, assess its severity, and monitor response to treatment 1.
- As the inflammation resolves with appropriate treatment (antibiotics, bowel rest, etc.), CRP levels should gradually decrease, making it a useful marker for tracking recovery 1.
- Antibiotic treatment is advised in patients with uncomplicated diverticulitis who have comorbidities or are frail, who present with refractory symptoms or vomiting, or who have a CRP >140 mg/L or baseline white blood cell count > 15 × 10^9 cells per liter 1.
From the Research
Diverticulitis and Elevated CRP
- Diverticulitis can cause elevated C-reactive protein (CRP) levels, as shown in several studies 2, 3, 4, 5, 6.
- Elevated CRP levels are associated with the severity of diverticulitis, with higher levels indicating more severe disease 2, 3, 4, 6.
- A CRP cutoff value of 170 mg/L can significantly discriminate between severe and mild diverticulitis, with a sensitivity of 87.5% and specificity of 91.1% 2.
- Other studies have reported similar CRP cutoff values, such as 149.5 mg/L 4 and 175 mg/L 6, to distinguish between complicated and uncomplicated diverticulitis.
- The use of CRP as a biomarker for diverticulitis severity is supported by multiple studies, which suggest that it can be a useful tool in predicting the need for surgical intervention or other complications 2, 3, 4, 5, 6.
Factors Affecting CRP Levels
- The use of anti-inflammatory medications, such as aspirin and corticosteroids, can affect CRP levels and may limit their usefulness as a biomarker for diverticulitis severity 3.
- Age and other patient characteristics, such as co-morbidities, can also influence CRP levels and diverticulitis severity 5.
- Imaging studies, such as CT scans, remain an important tool in diagnosing and staging diverticulitis, particularly in patients with elevated CRP levels or other risk factors for severe disease 4, 5.