Fecal calprotectin helpful in workup of kids with suspected IBD

Last Updated: 2017-08-14

By Megan Brooks

NEW YORK (Reuters Health) - Fecal calprotectin adds value to the diagnostic workup of children with suspected inflammatory bowel disease (IBD), suggest results of a meta-analysis of individual patient data.

It is a "diagnostic challenge" to distinguish between IBD and functional GI disorders, such as irritable bowel syndrome, in children, the researchers note in their August 14 JAMA Pediatrics online report.

"To make a definitive diagnosis of IBD, endoscopy is needed. This is an invasive, unpleasant and potentially harmful procedure. In children in whom a pediatrician is in doubt whether to perform endoscopy or not, fecal calprotectin, added to a careful history and physical exam, reduces this uncertainty," Dr. Marjolein Berger from University of Groningen, the Netherlands, told Reuters Health by email.

The study included individual patient data from eight relevant studies involving a total of 1,120 referred children or adolescents with symptoms suggestive of IBD, 560 of whom had IBD.

When added to symptom assessment alone, all laboratory blood markers (erythrocyte sedimentation rate, C-reactive protein, platelets, hemoglobin, albumin, and fecal calprotectin) as a single test - and fecal calprotectin individually - improved discrimination between patients with versus those without IBD, the researchers report.

The addition of fecal calprotectin to symptoms improved the area under the curve (AUC) of symptoms by 0.26 (95% CI, 0.21-0.31) - more than any of the individual blood markers. The second-best marker was erythrocyte sedimentation rate, which improved the AUC of symptoms by 0.16 (95% CI, 0.11-0.21).

Adding fecal calprotectin to the model had the following effects: the percentage of patients without IBD correctly classified as low risk of IBD increased from 33% to 91%; the percentage of patients with IBD incorrectly classified as low risk decreased from 16% to 9%; and the proportion of all patients who were then classified as intermediate risk dropped from 55% to 6%.

In the triage of pediatric patients for endoscopy, fecal calprotectin "showed the highest discriminative performance and should be recommended for this purpose, especially since a normal fecal calprotectin value (<50 mcg/g) makes the diagnosis of IBD unlikely," the researchers advise in their paper.

"The results of this study," they add, "are applicable to clinicians who evaluate referred pediatric patients for symptoms suggestive of IBD. One disadvantage to the routine use of fecal calprotectin in clinical practice might be the difficulty in obtaining stool from adolescents. None of the studies was performed in non-referred pediatric patients in primary care."

Despite these limitations, Dr. Berger said by email, "This study gives firm evidence for the diagnostic value of fecal calprotectin in the diagnostic workup for IBD. Before implementing a diagnostic pathway in which fecal calprotectin will be used to prevent endoscopy in children suspected of IBD, a clinical impact study is needed."

SOURCE: http://bit.ly/2w3VKrE

JAMA Pedatr 2017.