Effects of anti-TNF-α in experimental diversion colitis

Purpose: To evaluate the effects of infliximab on the inflammation of the colonic mucosa devoid from fecal stream. Methods: Twenty-four rats were submitted to a Hartmann's procedure. They remained for 12 weeks with the fecal derivation to development of diversion colitis on excluded colorectal stump. After this period, they were divided into 3 groups: one group received intervention with saline (2.0 mL/week), other group infliximab at doses of 5 mg/kg/week and the other 10 mg/kg/week for five consecutively weeks. Concluded the intervention period, the animals were euthanized to remove colon segments with and without fecal stream. Colitis was diagnosed by histological analysis and the degree of inflammation by validated score. The neutrophilic infiltrate was evaluated by tissue expression of myeloperoxidase identified by immunohistochemical. The tissue content of myeloperoxidase was measured by computer-assisted image analysis. Results: The inflammatory score was high in colonic segments without fecal stream. The intervention with infliximab reduced the inflammatory score in excluded colonic segments. The content of myeloperoxidase was reduced in colonic segments of animals treated with infliximab mainly in high concentrations. Conclusion: Intervention with infliximab reduced the inflammation and the neutrophil infiltrate in colonic segments devoid of the fecal stream.