Background: Capsule endoscopy (CE) represents the non-invasive method with the highest sensitivity in the evaluation of small-bowel mucosa in Crohn's disease (CD). Recent recommendations advocate the employment of validated CE scores for the assessment of small-bowel inflammatory activity in CD, allowing a standardized description of lesions and an objective assessment of severity and follow-up. Lewis Score (LS) and Capsule Endoscopy Crohn's Disease Activity Index (CECDAI) are the two validated scores currently available, but comparative studies are scarce. Moreover, evidence concerning the correlation of these endoscopic scores with biomarkers and clinical activity in small-bowel CD is lacking.
The primary aim of this study was to compare LS with CECDAI and to determine cutoff values for CECDAI similar to those of LS (135 and 790). The second aim was to correlate LS and CECDAI with biomarkers and symptoms.
Methods: All patients with CD who underwent CE between March 2010 and February 2016 were included. LS and CECDAI were determined after analysis of each CE. In patients with CD confined to the small-bowel, C-reactive protein (CRP) and Harvey-Bradshaw index (HBI) were evaluated. Statistical analysis: Spearman's correlation coefficient and linear regression analysis. Significance: p<0.05.
Results: Fifty-three patients were included, 60.4% (n=32) were women, with a mean age of 41.8 years. CD was restricted to the small-bowel in 64.2% (n=34) of patients and in the remaining 35.8% (n=19) the activity was ileocolonic. Mean values obtained for LS were 1147 (±1453), CECDAI 11.3 (±6.9), CRP 0.92 (±1.5) mg/dL and HBI 2.4 (±2.8). There was a very strong correlation between LS and CECDAI (rs=0.878; p<0.0001). In linear regression analysis, thresholds values of 135–790 in LS corresponded to 7.7–10.3 cutoff values in CECDAI, respectively, with an accuracy of 62.3%. Neither CRP correlated with LS (rs=0.068; p=0.72) or CECDAI (rs=−0.004; p=0.98), nor HBI with LS (rs=−0.15; p=0.40) or CECDAI (rs=−0.10; p=0.23).
Conclusions: Correlation between the two CE activity scores was very strong, with LS thresholds of 135 and 790 corresponding to CECDAI values of 7.7 and 10.3. HBI and CRP had no correlation with endoscopic activity scores in small-bowel CD.