Background: Small-bowel capsule endoscopy (SBCE) is an invaluable imaging method for the small bowel. The Lewis score (LS) and the Capsule Endoscopy Crohn's Disease Activity Index (CECDAI) have been developed to standardize the reporting of small-bowel inflammation. Fecal calprotectin (FC) represents a highly reliable biomarker of intestinal inflammation.
Aim: To assess the performance of the two SBCE inflammation scoring systems by correlating them with FC. Furthermore, to define threshold levels for CECDAI.
Methods: Retrospective study; patients who underwent SBCE and had FC measurement shortly before or after SBCE. LS and CECDAI were calculated by a single reviewer and correlated [Spearman's (r ( s ))] with the FC results. Linear regression analysis was used to identify threshold levels for CECDAI.
Results: Forty-nine patients; three subgroups A, B and C (based on FC levels <100, 100-200, and ≥200 μg/g, respectively). LS appears to correlate with FC (r ( s ) = 0.448, p = 0.0014), unlike CECDAI, which does not demonstrate significant correlation (r ( s ) = 0.245, p = 0.089). Strongly positive correlation between FC and LS was observed in subgroup A (r ( s ) = 0.68, p = 0.0047), while in subgroups B and C, neither LS nor CECDAI showed correlation with FC. Significant correlation between LS and CECDAI was demonstrated (r ( s ) = 0. 6324, p < 0.0001). Linear regression analysis demonstrates that LS thresholds of 135 and 790 correspond with CECDAI levels of 3.8 and 5.8, respectively.
Conclusions: LS performs better than CECDAI in describing small-bowel inflammation, especially at FC levels of <100 μg/g. Furthermore, CECDAI levels of 3.8 and 5.8 seem to correspond to LS thresholds of 135 and 790, respectively.