Endoscopic and histologic healing of Crohn's (ileo-) colitis with azathioprine

Background: The correlation between disease activity and endoscopic finding s in Crohn's disease is poor. Corticosteroids induce symptom relief without consistent improvement of endoscopic lesions. Our aim was to examine the e ffect of azathioprine therapy on healing of inflammatory lesions in patient s with severe Crohn's disease. Methods: The study included 20 consecutive patients with Crohn's colitis or ileocolitis in clinical remission while taking azathioprine for at least 9 months and no corticosteroids for at least 3 months who had had an ileocol onoscopy less than 1 year before the start of azathioprine. All 20 patients underwent a new ileocolonoscopy with biopsies. Results: The duration of azathioprine therapy was 24.4 +/- 13.7 months. In the colon, we observed complete healing in 14 of 20 patients (70%), near-co mplete healing in 2 of 20 (10%), partial healing in 3 of 20 (15%), and no h ealing in 1 of 20 (5%). In the ileum complete healing was seen in 7 of 13 ( 54%) patients with ileitis, near-complete healing in 2 of 13 (15%), partial healing in 1 of 13(8%), and no healing in 2 of 13 (15%); the ileum was not reached in 1 patient. Histologic examination revealed disappearance of the inflammatory infiltrate, with a certain degree of architectural disturbanc e remaining. Conclusions: Successful azathioprine therapy is accompanied by mucosal heal ing and disappearance of the inflammatory infiltrate.