Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (775 page)

   Calprotectin is a major calcium-binding protein found predominantly in neutrophils with antimicrobial and antiproliferative activities. When inflammatory processes occur, calprotectin is released due to the degranulation of neutrophil granulocytes. In bowel inflammation, calprotectin may be detected in the stool. An increased calprotectin concentration in stool is the direct consequence of neutrophil degranulation due to mucosal damage. Calprotectin levels are higher in feces than in plasma and significantly elevated in IBD patients (ulcerative colitis and Crohn disease) and in indeterminate colitis. Similar sensitivity and specificity as of fecal lactoferrin assay.

   
Normal range:
negative.

   Use

   Diagnose inflammatory bowel disease (IBD), including Crohn disease and ulcerative colitis

   Differentiate IBD from irritable bowel syndrome (IBS)

   Monitor IBD activity and predict relapse

   Interpretation

Increased In

   Screening for inflammation in patients presenting with abdominal pain and diarrhea

   Distinguish patients with active IBD from noninflammatory IBS

   Monitor IBD activity

Decreased In

   NA

   Limitations

   Presence of GI infections and colorectal cancer may falsely elevate levels.