From the Guidelines
A calprotectin level of 125 μg/g is slightly elevated and indicates mild intestinal inflammation, suggesting the need for further evaluation to determine the underlying cause, as recommended by the American Gastroenterological Association (AGA) in their 2023 clinical practice guideline on the role of biomarkers for the management of ulcerative colitis 1. This level falls above the normal range (typically <50-100 μg/g, depending on the laboratory) and may suggest conditions like inflammatory bowel disease (IBD), including Crohn's disease or ulcerative colitis, or other causes of intestinal inflammation such as infections or medication effects. Some key points to consider include:
- The AGA suggests using fecal calprotectin <150 mg/g to rule out active inflammation and avoid routine endoscopic assessment of disease activity in patients with ulcerative colitis in symptomatic remission 1.
- In patients with ulcerative colitis in symptomatic remission but elevated stool or serum markers of inflammation (fecal calprotectin >150 mg/g), the AGA suggests endoscopic assessment of disease activity rather than empiric treatment adjustment 1.
- Repeat measurement of biomarkers (in 3–6 mo) may be a reasonable alternative to endoscopic assessment in patients with elevated biomarkers of inflammation 1. It is essential to consult with a gastroenterologist for proper evaluation, as this level may require additional tests such as colonoscopy with biopsies, other stool tests, or blood work to determine the cause. While waiting for your appointment, it is crucial to:
- Track your symptoms, including abdominal pain, diarrhea, blood in stool, or weight loss.
- Avoid NSAIDs like ibuprofen, as they can artificially elevate calprotectin levels. Calprotectin is a protein released by neutrophils during inflammation in the intestinal tract, making it a useful biomarker for distinguishing between inflammatory and non-inflammatory gastrointestinal conditions.
From the Research
Significance of Elevated Calprotectin Levels
- An elevated calprotectin level of 125 indicates intestinal inflammation or gastrointestinal disease 2, 3, 4, 5, 6
- Calprotectin is a protein complex produced by neutrophils in the inflamed gut, and its levels are related to the degree of mucosal inflammation 2, 4, 5
- High fecal calprotectin concentrations are found in diseases with an inflammatory component, such as inflammatory bowel disease (IBD), infectious enteritis, or colorectal cancer 2, 5, 6
Diagnostic and Monitoring Applications
- Fecal calprotectin is a useful surrogate marker to distinguish patients with IBD from those with irritable bowel syndrome (IBS) 2, 3, 4, 5, 6
- It allows for the monitoring of intestinal inflammation with a high negative predictive value, making it possible to exclude the diagnosis of IBD in symptomatic patients 2, 3, 6
- Calprotectin levels can be used to evaluate the degree of disease activity and monitor therapeutic response in patients with IBD 3, 4, 5, 6
Clinical Interpretation
- Interpretation of calprotectin levels must take into account the clinical history and symptoms specific to each patient 2
- Elevated calprotectin levels can indicate a relapse of IBD, and targeted treatment at an asymptomatic stage of the disease may be indicated 5
- Fecal calprotectin has been shown to consistently differentiate IBD from IBS and may be useful in determining whether clinical symptoms in patients with known IBD are caused by disease flares or noninflammatory complications 6