Aims Calprotectin is a neutrophil intracellular calcium and zinc binding protein that has been shown to be associated with intraluminal intestinal inflammation when detected in stool. Its use as a non-invasive marker of inflammatory bowel disease (IBD) is well validated in children and adults. Levels of faecal calprotectin (FC) >60 μg/g is considered abnormal, however a FC >100 μg/g has a sensitivity of 98% and specificity of 91% in detecting children with IBD.
The authors carried out a study to evaluate the current use of FC as screening tool for IBD, in a tertiary paediatric gastroenterology unit.
Methods All FC requests sent over a 3 year period between January 2008 and February 2011 in children aged 1 to 16 years of age (n=68) were reviewed. Additionally clinical notes were analysed for indication for testing, clinical impression on first consultation and subsequent change in management following FC result.
Results Of the 68 FC requests, 47 were in children suspected to have inflammatory bowel disease, 7 were used to monitor known inflammatory bowel disease and 14 were for other indications.
FC was >100 μg/g in 23 of 68 children (30%).
Of the 47 children with suspected IBD at referral, 35 (74%) had normal FC and did not subsequently undergo an endoscopy. 4 children with FC<100 μg/g underwent endoscopy – all of which were normal. There were no known false negative outcomes at the time of abstract submission.
5 children with suspected IBD with a FC>100 μg/g had abnormal endoscopy. 1 child with a FC>100 μg/g, had no endoscopy as campylobacter was isolated through stool culture, and responded well to treatment. There were however 2 children with elevated FC, but with normal histology following endoscopy.
Conclusion Review of our practice over the last 3 years has demonstrated that when FC was measured ie when IBD was possible but children seemed clinically well, IBD was only diagnosed in those with a raised FC. During the study period no child with symptoms consistent with IBD, with a normal FC was subsequently diagnosed with IBD. In well children a normal FC could reduce the need for diagnostic endoscopy. FC is a useful additional screening tool.