Diversion of intestinal flow decreases the numbers of interleukin 4 secreting and interferon gamma secreting T lymphocytes in small bowel mucosa

Background/Aims-The intestinal immune system faces large amounts of antigen s, and its regulation is tightly balanced by cytokines. In this study, the effect of intestinal flow diversion on spontaneous secretion of interleukin (IL)-4 and interferon (IFN)- gamma was analysed. Methods-Eight patients (two with Crohn's disease, four with ulcerative coli tis, and two with previous colon cancer) carrying a double lumen small bowe l stoma after a total colectomy procedure were included in the study. For e ach patient, eight biopsy samples were taken endoscopically from both the d iverted and non-diverted part of the small bowel. Intraepithelial lymphocyt es (IELs) and lamina propria lymphocytes (LPLs) were isolated separately an d assayed for numbers of cells spontaneously secreting IL-4 and/or IFN-gamm a by an ELISPOT technique. Results-Compared with the non-diverted mucosa, a significant decrease in th e number of spontaneously IFN-gamma secreting CD3 lymphocytes was observed in the diverted small bowel mucosa among both IELs (p = 0.008) and LPLs (p = 0.007), The same results, although less significant, were obtained for IL -4, especially in LPLs (p = 0.01). Conclusion-The intestinal content influences the spontaneous secretion of I FN-gamma and IL-4 by intestinal lymphocytes. These results could help to el ucidate the antiinflammatory role of split ileostomy in patients suffering from inflammatory bowel diseases.