Selecting children with suspected inflammatory bowel disease for endoscopy with the calgranulin C or calprotectin stool test: protocol of the CACATU study

Abstract

Introduction: The introduction of the faecal calprotectin (FC) test to screen children with chronic gastrointestinal complaints has helped the clinician to decide whether or not to subject the patient to endoscopy. In spite of this, a considerable number of patients without inflammatory bowel disease (IBD) is still scoped. Faecal calgranulin C (S100A12) is a marker of intestinal inflammation that is potentially more specific for IBD than FC, as it is exclusively released by activated granulocytes.

Objective: To determine whether the specificity of S100A12 is superior to the specificity of FC without sacrificing sensitivity in patients with suspected IBD.

Methods: An international prospective cohort of children with suspected IBD will be screened with the existing FC stool test and the new S100A12 stool test. The reference standard (endoscopy with biopsies) will be applied to patients at high risk of IBD, while a secondary reference (clinical follow-up) will be applied to those at low risk of IBD. The differences in specificity and sensitivity between the two markers will be calculated.

Ethics and dissemination: This study is submitted to and approved by the Medical Ethics Review Committee of the University Medical Center Groningen (the Netherlands) and the Antwerp University Hospital (Belgium). The results will be disseminated through a peer-reviewed publication, conference presentation and incorporation in the upcoming National Guideline on Diagnosis and Therapy of IBD in Children.

Trial registration: ClinicalTrials.gov identifier: NCT02197780 .

Keywords: S100A12 protein; S100 proteins; inflammatory bowel disease; screening.

Conflict of interest statement

Competing interests: This trial is supported by CisBio Bioassays, producer of the Inflamark ELISA kit. PvR and AH received financial support from BÜHLMANN Laboratories AG (Schönenbuch, Switzerland) for other ongoing trials.

© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Figures

Figure 1

CACATU study flow. IBD, inflammatory bowel disease.

Figure 2

CACATU study flow from first hospital visit to choice of reference test. Step 1: The clinician registers the patient on the study website (www.cacatustudie.eu). Step 2: The patient (or parent) collects the stool specimen and sends it to the hospital laboratory. Step 3: The lab divides the specimen into three portions: calprotectin and PCR are immediately performed; one tube is stored at −80°C for calgranulin C testing. Step 4: The lab sends the results of calprotectin and PCR to the researcher. Step 5: The researcher enters the test results on the website. Step 6: The clinician receives a notification with the results and an automated advice on the next best move. Step 7: Paediatrician decides the next best move: in case of high probability of inflammatory bowel disease (IBD): endoscopy; in case of low probability of IBD: clinical follow-up. The ultimate decision to scope is in the hands of the endoscopist. FC, faecal calprotectin; UMCG, University Medical Center Groningen.