Faecal calprotectin: a new marker for Crohn's disease?

Background: Gastroenterologists are often hampered by the lack of a reliable, non-invasive index of bowel inflammation when establishing a differential diagnosis for patients presenting with chronic diarrhoea. Investigations aim to distinguish between inflammatory bowel disease (IBD) (e.g. Crohn's disease, ulcerative colitis) and irritable bowel syndrome (IBS). As an acute phase protein, faecal calprotectin measurement may be useful in this context.

Methods: A new ELISA-based assay for calprotectin was evaluated. The ability of calprotectin to distinguish between patients with IBS and Crohn's disease was studied.

Results: The assay showed adequate inter- and intra-batch imprecision and was suitable for routine use in the laboratory. Calprotectin concentration was significantly greater in patients with Crohn's disease compared with controls (n = 25, P <0.001) and patients with IBS (n = 25, P <0.001).

Conclusion: A single calprotectin measurement may aid gastroenterologists in the differential diagnosis of Crohn's disease and IBS. Its use could decrease the number of invasive or radiological investigations undertaken in the latter group of patients.