The levels of interleukin-6, serum calprotectin, and hypersensitive C-reactive protein in patients with Crohn's disease-related mucosal damage

Background: To evaluate the ability of calprotectin, hypersensitive C-reactive protein, and interleukin-6 to detect digestive tract mucosal injury in patients with Crohn's disease (CD). Methods: Fifty-two patients diagnosed with CD were selected. Faecal samples from the patients were collected to detect calprotectin (ELISA), and serum samples were collected to detect hs-CRP (immunoturbidimetry) and IL-6 (chemiluminescence). All patients with CD underwent colonoscopy or capsule endoscopy, according to the modified endoscopic severity index of CD (SES-CD). Comparisons of the differences in calprotectin, hs-CRP and IL-6 levels were made between the two groups, and receiver operating characteristic (ROC) curves were drawn to analyse the diagnostic efficacy (AUC) of each index and combined detection for mucosal injury. Results: In the Mucosal injury group, the calprotectin and hs-CRP levels were significantly greater than those in the Mucosal healing group. According to the ROC analysis, calprotectin had the highest AUC (0.93, 95% CI: 0.88-0.98), sensitivity (88.5%) and specificity (89.2%) when the critical value was greater than 250 mg/g. The AUC of the three indicators' combined detection (logistic regression model) rose to 0.96, which was noticeably superior to that of a single indicator (P< 0.05). Conclusions: Interleukin-6, serum calprotectin, and hypersensitive C-reactive protein levels are significantly correlated with the degree of mucosal injury in patients with CD. Among them, calprotectin has the best diagnostic value. The combined detection of these three factors can significantly improve the recognition of mucosal injury in the active stage of CD.