Calprotectin (feces)

Patients with symptoms of lower gastrointestinal tract injury often require additional tests to distinguish a functional condition (e.g., irritable bowel syndrome) from an organic disease (Crohn's disease, ulcerative colitis, etc.). Theoretically, indicators of the acute phase of inflammation (CRP, ESR) should be able to distinguish between these two conditions. However, studies have shown that indicators such as C-reactive protein (CRP) are not sufficient to differentiate between organic and functional states. For this purpose, new tests were seen to confirm the inflammatory process in the intestine. Such indicators are the examination of calprotectin and lactoferrin in a fecal sample.

Calprotectin is an important component of the cytoplasm of polymorphonuclear granulocytes. It is so called because of its binding to calcium, which protects the cell from the destructive action of its own enzymes. It also exhibits antibacterial properties by inactivation of bacterial enzymes due to its binding to zinc.

Thus, calprotectin has a regulatory function in the inflammatory process, as well as has antimicrobial and antiproliferative properties.

When should we take a test for calprotectin?

Fecal calprotectin can be used as a screening test to distinguish inflammatory bowel disease (organic damage) from irritable bowel syndrome (functional disorder).

Research is recommended in the following cases:

• Differential diagnostics (separation) of inflammatory bowel disease and irritable bowel syndrome;
• Triage of patients with abdominal symptoms for invasive examinations;
• Assess the severity of inflammatory bowel disease in patients, the degree of mucosal healing after treatment, and the risk of recurrence.
• Monitoring the effectiveness of treatment. This test, as a non-invasive method, is especially useful in children because invasive research procedures are difficult to perform and require general anesthesia.

How to prepare for the test?

The analysis requires approximately 2 grams of fecal mass (feces) spontaneously obtained at any time of the day, which is collected in a single fecal container with a tightly closed lid.

Avoid taking nonsteroidal anti-inflammatory drugs for 2 days before the test.

Possible interpretation of the results

It is important to note that fecal calprotectin is a specific marker of inflammation and not disease diagnostics.

Negative result (<50 μg / g) indicates the absence of inflammation in the gastrointestinal tract.

In patients who meet the criteria for irritable bowel syndrome, a negative result, with a very high probability (> 99%), precludes organic damage.

False negative results May be detected in patients with granulocytopenia, with impaired bone marrow function.

Increased calprotectin levels in adults and children older than 4 years:

• 50-150 mcg / g - The result shows a slight inflammation of the intestinal tract. Inflammation can be caused by an infection, food allergy, or by taking nonsteroidal anti-inflammatory drugs (NSAIDs).
• > 150 μg / g - The result shows significant inflammation of the intestinal tract, which may be caused by inflammatory bowel disease, infection, nonsteroidal anti-inflammatory drugs, adenomas, polyps or colorectal cancer. Additional studies are needed to determine the cause of the inflammation.
• > 250 μg / g - Except for the above comment: In patients with inflammatory bowel disease, this result indicates disease activity with severe inflammation of the mucosa. In patients with remission, this result indicates a higher risk of exacerbation in the following year.