Variability of Faecal Calprotectin in Inflammatory Bowel Disease Patients: An Observational Case-control Study. (4th April 2019)

• Record Type: Journal Article
• Authors: Cremer, Anneline; Ku, Jade; Amininejad, Leila; Bouvry, Marie-Rose; Brohet, Fabian; Liefferinckx, Claire; Devière, Jacques; van Gossum, André; Smet, Julie; Stordeur, Patrick; Franchimont, Denis
• Is Part Of: Journal of Crohn's and colitis. Volume 13:Number 11(2019)
• Page Start: 1372
• Page End: 1379
• Publication Date: 2019-04-04
• Subjects: Faecal calprotectin -- variability -- inflammatory bowel disease; Inflammatory bowel diseases -- Periodicals; 616.344005
• DOI: 10.1093/ecco-jcc/jjz069
• Languages: English
• ISSNs: 1873-9946

Abstract

Abstract: Background and Aims: Several factors have been reported to affect faecal calprotectin [FC] values, and significant variation in FC concentrations has been observed in inflammatory bowel disease [IBD] patients. We aimed to evaluate FC variability in IBD patients, and to assess the robustness of a single stool punch. Methods: This is a single-centre observational case-control study. Disease activity was assessed using endoscopic and clinical activity scores, as well as C-reactive protein levels. Stool samples were collected twice within a 1 to 6 days interval, and FC was measured on punches and homogenates by fluorometric enzyme immunocapture assay. Results: In all, 260 stool samples were collected from 120 patients. Intrastool variability was low, with an intraclass correlation coefficient for single measures between three punches from a single stool sample of 0.91, and median coefficient of variation [CV] of 17%. CV of two stool samples a few days apart [intra-individual variability] were significantly higher [ p <0.01] with median CV of 36%. FC standard deviations correlated with mean FC levels either for intrastool or for intra-individual variability, with a Spearman's coefficient of rank correlation of 0.85 and 0.78, respectively [ p <0.01]. Disease type, location, activity, and FC levels did not influence variability. Conclusions: A single stool punch is reliable for FC measurement, considering that intrastool variability is low. Intra-individual variability a few days apart is significantly higher. Therefore, decision-making strategies based on single measurements should consider this variability, to determine the minimum optimal variation to be achieved, rather than a cut-off, especially in high FC levels.