Background: It is well known that mucosal concentrations of many pro and anti-inflammatory cytokines are elevated in diseased segments of colon in Crohn's colitis. The present study, showing preliminary results, aims to determine whether the IL-1beta, IL-6 and IL-8 levels are increased throughout the entire colon in patients with Crohn's colitis.
Methods: Five patients with active Crohn's colitis and five controls were studied by mucosal biopsies. In the diseased patients IL-1beta, IL-6 and IL-8 levels have been measured in both pathologic and normal appearing colonic mucosa. The concentration of these cytokines was assessed using ELISA and compared. Histological sections were also performed to confirm diseased segment of colon.
Results: The concentrations IL-1beta and IL-8 were much more higher in patients with Crohn's colitis when compared to controls. Moreover IL-1beta and IL-8 were more elevated in uninvolved colonic segments than on diseased segments.
Conclusions: Our results confirm the finding of other authors that, although Crohn's colitis is a segmental disease, the concentration of IL-1beta and IL-8 in mucosal biopsies is increased throughout the entire colon. In particular our study shows that the concentrations of IL-1b and IL-8 is higher in uninvolved than involved colonic segments. These appearances favour the physio-pathologic hypothesis that Crohn's colitis involves the entire colon even when is not clinically or histologically apparent, and they suggest that uninvolved parts of colon may not be free of disease. Further studies are required to better understand the higher levels of cytokines found in macroscopically normal when compared to pathological mucosal in patients with Crohn's colitis.