What is Calprotectin?
Calprotectin is a protein found in large amounts in human intestines, specifically within a type of white blood cell (a type of leukocyte – neutrophils), particularly when an inflammatory process is present in the intestines. It is produced as part of the body’s immune response to inflammation in the gastrointestinal tract.
Why is Calprotectin Measured in Stool?
The role of calprotectin is to help detect and monitor inflammatory conditions in the gastrointestinal tract. When inflammation occurs in the intestines, the level of calprotectin in stool significantly increases. This makes calprotectin a very useful biomarker for diagnosing and monitoring inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis.Diagnosis (and monitoring of these conditions) is crucial, as inflammatory processes in the gastrointestinal tract can be complex and may require prolonged treatment. Traditionally, colonoscopy was used, which is often uncomfortable and stressful for the patient. With the advancement of laboratory medicine, a quick, simple, and highly specific test has been developed that is painless for the patient.
Fecal calprotectin measurement is a non-invasive test that helps differentiate functional bowel disorders (e.g., irritable bowel syndrome, IBS) from organic inflammatory bowel diseases (IBD) in patients who wish to avoid invasive (uncomfortable) endoscopic examinations. In individuals with confirmed inflammatory bowel disease, it is used to predict treatment response, detect relapses, and generally monitor therapy.
Symptoms of Inflammatory Processes in the Gastrointestinal Tract
- Altered bowel movements
- Persistent diarrhea
- Abdominal pain
- Fatigue
- Decreased appetite
- Weight loss
- Possible fever
- Presence of blood in stool (often with ulcerative colitis)
Monitoring Therapy Effectiveness
In addition to diagnosis, calprotectin is also used to monitor the effectiveness of therapy. After starting treatment, a decrease in calprotectin levels is expected in patients with inflammatory bowel disease. If the calprotectin level remains high, it may indicate poor inflammation control or insufficiently effective therapy.
Calprotectin Measurement and Expected Values
The test is routinely performed daily, using a spontaneous stool sample without prior patient preparation. It is commonly conducted with the ELISA technique, and results are expressed in micrograms per gram of stool (μg/g). The calprotectin concentration in healthy individuals ranges from 0 to 50 μg/g. Elevated results (>50 μg/g) indicate the presence of an inflammatory process in the intestines.
There are also semi-quantitative tests (immunochromatographic) on the market to confirm the presence or absence of calprotectin in stool. However, the ELISA test is more sensitive and valuable, as it determines the exact amount of calprotectin in the stool.
Neparno 10