Faecal calprotectin—a useful screening test for detecting gastrointestinal inflammation in children

Aims

Faecal calprotectin is a neutrophil cytosolic protein which is validated as a reliable non-invasive marker of gastrointestinal inflammation in adults as well as children. The authors carried out an audit to assess the utility of faecal calprotectin in evaluation of children with chronic gastrointestinal symptoms.

Methods

Stool samples from 104 children aged 1–16 years who presented to a medium sized district general hospital with gastrointestinal symptoms were analysed using a commercially available kit. The normal range of faecal calprotectin is < 50 mcg/g.

Results

Faecal calprotectin was outside the normal range in 37 out of 104 patients (36%). There were a total of 20 children with inflammatory bowel disease (14—newly diagnosed, 6—relapse) and all of them except one had elevated faecal calprotectin of greater than 200.The likelihood of organic bowel pathology was high when faecal calprotectin was greater than 200. Faecal calprotectin as a stool marker for inflammatory bowel disease (IBD) had an overall sensitivity of 95% and specificity of 79%. The specificity of the test in predicting IBD increased to 98.8% when calprotectin measured greater than 200. The positive predictive value was 95% and negative predictive value was 98% when faecal calprotectin value was > 200. High faecal calprotectin did not co-relate well with other inflammatory markers in children diagnosed with inflammatory bowel disease.

Conclusion

Raised faecal calprotectin of greater than 200 should prompt urgent further assessment in children as IBD can be a likely diagnosis however these levels can be found in non-IBD organic GI disease. Faecal calprotectin can be used as a screening test reliably in evaluation of a child with chronic gastrointestinal symptoms and faecal calprotectin value outside the normal range of 50 mcg/g should involve prompt review to decide whether further investigations are needed.