P198 Faecal calprotectin level correlates well with balloon-assisted endoscopy and computed tomography enterography findings in small bowel Crohn’s disease
T. Arai1, K. Takeuchi*1, A. Yamada1, M. Miyamura1, R. Ishikawa2, Y. Suzuki1
1Toho University, Sakura Medical Centre, Division of Gastroenterology, Department of Internal Medicine, Sakura, Japan, 2Toho University, Sakura Medical Centre, Department of Radiology, Sakura, Japan
There are multiple reports claiming that faecal calprotectin (FC) level shows poor correlation with small bowel Crohn’s disease (CD) findings. However, endoscopic evaluation in those reports was mainly undertaken by ileocolonoscopy, which might cover up to the terminal ileum. Therefore, a detailed observation in the distal segment of the small intestine might be inadequate to provide clinically relevant data. The aim of this study was to see the reliability of FC level for assessing small bowel CD by factoring disease activity and the extension of both balloon-assisted enteroscopy and computed tomography (CT) enterography (CTE).
In 151 Crohn’s disease patients (45 ileitis, 87 ileo-colitis, and 15 colitis), we investigated the relationship between FC level and the simple endoscopic index for CD (SES-CD), except for stricture factor at balloon enteroscopy. We factored a novel CTE score based on the following items: bowel wall thickness, mural hyper-enhancement, stratification, and engorged versa recta.
FC level was well correlated with the modified SES-CD (r = 0.6362, p < 0.0001), even in the CD patients with only active small intestinal lesions (r = 0.6594, p = 0.0005). Sixteen patients had strictures, and therefore, the enteroscope could not pass through, but the CTE could detect all the lesions beyond the strictures, as well as areas in the distal side of the stricture. Likewise, FC level was well correlated with the CTE score (n = 63, r = 0.4018, p = 0.0011). In receiver operating characteristic (ROC) analyses, the cut-off value of FC for mucosal healing was 215 μg/g with a sensitivity of 82.8%, specificity of 71.4%, positive predictive value of 74.3%, negative predictive value of 80.6%, odds ratio 12.000, and the area under the ROC curve, 0.8091.
In the present investigation involving patients with Crohn’s disease with active small bowel lesions, the FC level appeared to show a close correlation with the findings on small intestinal inflammatory or otherwise pathologic lesions as determined by balloon-assisted enteroscopy and CTE. Accordingly, a combination of FC and CTE could be a relevant strategy for monitoring CD activity in patients with small intestinal lesions, including strictures where conventional endoscopy cannot reach.