Correlation analyses among Capsule Endoscopy Scroring Index, simplified Crohn Disease Activity Index and C-reactive protein in small bowel Crohn disease

Abstract

Objective To investigate the correlation between any two of Capsule Endoscopy Scroring Index （Lewis score）, simplified Crohn Disease Activity Index （CDAI） and C-reactive protein （CRP） in small bowel Crohn disease （CD）. Methods A total of 58 consecutive patients with known small bowel CD were enrolled. We evaluated disease activity with Lewis score and simplified CDAI. Correlations among CRP, simplified CDAI and Lewis score were calculated with Spearman＇s rank order correlation coefficient. The optimal CRP cut-off value was calculated using the ROC curve. Results The Lewis score showed inac- tive, mild and moderate-severe patients were 13, 21 and 24, respectively. CRP of moderate-severe group was significantly higher than that in mild and inactive groups （P 〈 0.05）. The optimal CRP cut-off value that differentiated patients with moderate to severe disease from the others was 13.50 mg/L with sensitivity of 87. 5% and specificity of 82. 4%. The area under the ROC curve to analyze the cut-off was 0. 849. Lewis score was moderately correlated with CRP （ r = 0. 58, P 〈 0.01 ）, and weakly correlated with the simplified CDAI （ r = 0. 40, P 〈 0. 01 ）. Conclusion Serum CRP and the simplified CDAI cannot replace Lewis score for capsule endoscopy in the assessment of disease activity in small bowel CD. However, CRP may be considered as an inflammatory marker for evaluating the moderate to severe capsule endoscopic activity. Key words: C-reactive protein; Capsule endoscopy scoring index; The simplified Crohn disease activity index; Small bowel Crohn disease