Does clinical response correlate with mucosal healing in patients with Crohn's disease of the small bowel? A prospective, case-series study using wireless capsule endoscopy.

BACKGROUND: There are no studies assessing mucosal healing of the small bowel in patients with Crohn's disease (CD). Our aim was to assess the correlation between clinical response and mucosal healing of the small bowel using wireless capsule endoscopy (WCE).

METHODS: This was a prospective, multicenter, case-series study. Forty patients with known or suspected CD were included, recruited in 4 tertiary referral centers of Athens. They all had an acute flare-up of their disease (CD Activity Index [CDAI] >150), involvement of the small bowel, and the nonstricturing, nonpenetrating type of the disease. All patients underwent WCE prior to the initiation of any treatment. Treatment varied according to the treating physician. For the evaluation of mucosal healing, 3 endoscopic variables were collected: number of apthous ulcers, number of large ulcers, and period of time that any endoscopic lesion was visible (erythema, edema, ulcers). When patients achieved clinical response (after at least a month of treatment) they underwent a second WCE, with evaluation of the same parameters.

RESULTS: The number of large ulcers was the only endoscopic variable that showed a significant improvement. The numbers of large ulcers before and after treatment were 8.3 +/- 1.4 and 5 +/- 0.8, respectively (mean +/- SEM) (mean difference 3.3 +/- 1.2, 95% confidence interval [CI] 0.8-5.9, P = 0.01). The other 2 variables did not improve significantly.

CONCLUSIONS: Since only 1 out of 3 endoscopic variables improved significantly with treatment, we can conclude that clinical response does not seem to correlate with mucosal healing in patients with CD of the small bowel.