Selective effect of infliximab on the inflammatory component of a colonic stricture in Crohn's disease.

Although infliximab has been shown to improve the clinical course of Crohn's disease, its effect on intestinal strictures is controversial. We describe the case of a woman with steroid-resistant colonic Crohn's disease presenting with intermittent obstruction because of a tight stricture in the splenic flexure. Compared with uninvolved areas, biopsies showed intense edema and inflammatory cell infiltration and immunohistochemistry revealed an excess of TNF-alpha. Her symptoms responded promptly (CDAI went from 444 to 168) to an infliximab infusion (10 mg kg(-1) BW), which also had a dramatic effect on the stricture, now presenting radiologically as a moderate residual, apparently fibrotic, narrowing of the lumen. Endoscopy and histology confirmed the resolution of inflammation and TNF-alpha virtually disappeared. The patient refused additional infusions and after a few months the disease recurred with features identical to the pre-treatment phase. She then opted for surgery. Histology of the resected strictured colon revealed edema, inflammation, and fibrosis, with TNF-alpha back to pre-treatment levels. This case indicates that, in the colon, infliximab specifically relieves the TNF-alpha-mediated inflammatory component of the stricture while having no effect on fibrosis and suggests that the response to infliximab treatment may depend on the nature of the, stricture itself.