Testing for IBD

WHAT IS CALPROTECTIN TESTING?

Calprotectin is an antimicrobial protein that is a biomarker for inflammation.

This protein is expressed (secreted) by some immune cells (white blood cells), especially neutrophils.

During inflammation, neutrophils enter the gut lumen from the blood via a process called transepithelial migration.

When the neutrophils in the gut lumen secrete the Calprotectin protein, it ends up in the faeces.

When there is calprotectin protein in the faeces, this can be detected by testing a faeces sample.

A test that shows a positive result for calprotectin in the faeces indicates there is inflammation in the gut, which is suggestive of IBD.

Image courtesy of Springer: https://link.springer.com/article/10.1007/s00535-016-1182-4/figures/1