May 21, 2024
Fecal Calprotectin Test

Fecal Calprotectin Test: Advantages, Limitations, and Clinical Applications

What is Fecal Calprotectin?

Fecal calprotectin is a protein found in the neutrophils (a type of white blood cell) present in the intestine. When the intestines become inflamed due to conditions such as inflammatory bowel disease (IBD), the number of neutrophils in the intestines increases. This causes higher levels of calprotectin to be released into the feces. Measuring the level of calprotectin in a stool sample can help determine if there is intestinal inflammation present.

How is the Fecal Calprotectin Test Performed?

The fecal calprotectin test is a non-invasive laboratory test. To perform the test, the patient collects a small sample of their stool, usually about 250 mg or half a teaspoon. The stool sample is then tested for calprotectin levels using special test kits which contain antibodies that bind to the calprotectin in the stool. Based on how much the antibodies bind to calprotectin in the sample, the amount of calprotectin present is quantified. Test results are usually reported as micrograms of calprotectin per gram of stool sample.

What do the Test Results Mean?

Normal calprotectin levels are typically below 50 micrograms per gram of stool. Levels above this threshold may indicate intestinal inflammation. However, the exact significance of calprotectin levels can differ according to the clinical situation and other test results. Here is a guide to interpreting fecal calprotectin test results:

– Less than 50 mcg/g – This is considered a normal result. Intestinal inflammation is unlikely.

– 50-150 mcg/g – Slightly elevated levels may suggest mild intestinal inflammation. However, other conditions need to be ruled out first.

– 150-250 mcg/g – Moderate elevation suggests active intestinal inflammation is present.

– Over 250 mcg/g – Levels this high are strongly indicative of significant intestinal inflammation due to conditions like IBD.

Uses and Benefits of the Fecal Calprotectin Test

Diagnosing Inflammatory Bowel Disease

The Fecal Calprotectin Test is very useful for diagnosing inflammatory bowel diseases like Crohn’s disease and ulcerative colitis. Elevated calprotectin levels along with symptoms point strongly to the presence of IBD. The test can help distinguish IBD from irritable bowel syndrome which usually does not cause elevated calprotectin.

Monitoring Disease Activity and Treatment Response

In patients who have been diagnosed with IBD, serial fecal calprotectin testing helps monitor disease activity over time. Declining calprotectin levels after starting treatment indicate the treatment is effective in reducing intestinal inflammation. Persistently high levels may require adjusting medications or more aggressive treatment.

Distinguishing IBD from IBS

As mentioned above, the calprotectin test differentiates IBD from IBS by detecting underlying intestinal inflammation. Most patients with IBS will have normal calprotectin levels while those with IBD usually present with elevated levels.

Predicting Relapse Risk

Studies show persistently moderately-high calprotectin levels in patients with IBD in remission may predict an upcoming relapse. Early treatment based on rising calprotectin can help prevent clinical relapse of symptoms.

Advantages of the Fecal Calprotectin Test

Compared to other diagnostic methods for evaluating intestinal inflammation like colonoscopy and imaging tests, the fecal calprotectin test offers several advantages:

– It is non-invasive and uses a simple stool sample collection method.

– Test results are available quicker than other procedures like endoscopy.

– Serial testing is convenient for long-term monitoring of disease activity and response to treatment changes.

– Useful for detecting subclinical intestinal inflammation before symptoms appear.

Limitations and Interpreting Results

While a useful test, fecal calprotectin has some limitations to keep in mind:

– Transitory elevated levels may occur due to infections, medications, and other non-inflammatory causes.

– Test cannot pinpoint the specific location of inflammation within the intestine.

– Normal levels do not completely rule out IBD as calprotectin may be normal during remission phases.

– Results should be interpreted together with clinical symptoms and findings of other diagnostic tests.

1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it