Calprotectin is a calcium- and zinc-binding protein which is produced by neutrophil granulocytes and monocytes and has bactericidal and fungicidal properties. In the case of an inflammatory intestinal disease, granulocytes move into the gut lumen where they release calprotectin, which is secreted with stool. The calprotectin concentration in stool shows the extent of an inflammation in the intestine.
The non-invasive determination of calprotectin levels in stool is useful for:
Differential diagnostic delimitation of an irritable colon (irritable bowel syndrome) from acute and chronic inflammations of the intestine (e.g. viral or bacterial infections, Crohn’s disease, ulcerative colitis). The calprotectin level in stool is increased in chronic inflammatory bowel diseases (CIBD) and malignant intestinal tumors with an inflammatory component, but not in intestinal polyps, benign intestinal tumors, and irritable colon.
Monitoring the disease course and therapy response in patients with CIBD. With successful treatment, the originally increased calprotectin level decreases significantly. In the case of a relapse, it increases again. The level correlates very well with the histological and endoscopical findings. Owing to the non-invasive calprotectin determination, patients can be spared biopsies and other complicated procedures.