Association of clinical and inflammatory markers with small bowel capsule endoscopy findings in Crohn’s disease

Abstract

Mucosal healing is an established treatment endpoint in Crohn's disease (CD). Still, clinical indices and inflammatory markers are used widely in CD surveillance. The aim of this study was to investigate the diagnostic performance as well as the relationship of C-reactive protein (CRP) and Crohn's Disease Activity Index (CDAI) with small bowel capsule endoscopy's (SBCE) inflammation scoring index, the Lewis Score (LS). CDAI, CRP, and SBCE findings of 30 CD patients with isolated small bowel disease were retrieved from our academic institution patient records and were analyzed statistically. SBCE showed significant mucosal inflammation [mean (SD) LS: 1599 (1380)], in nine (60.0%) of 15 patients who were in both clinical and biochemical remission. CDAI and CRP showed a weak and moderate correlation with LS (r=0.317, P=0.088 and r=0.516, P=0.004, respectively). The diagnostic performance of CDAI and CRP in predicting mucosal inflammation was as follows: sensitivity 23.8 and 52.4%; specificity 100 and 66.7%; positive predictive value 100 and 78.6%; and negative predictive value 36.0 and 37.5%. The area under the curve toward endoscopic activity prediction was 0.70 and 0.69, respectively. Both CDAI and CRP underestimated endoscopic activity as expressed by the LS in a significant proportion of patients with quiescent disease.