Cytokine production in pouchitis is similar to that in ulcerative colitis

PURPOSE: Controversy exists as to whether pouchitis represents a reactivation of the immunologic mechanisms that lead to ulcerative colitis (UC). The aims of this study were to determine local levels of the cytokines: interleukin-1β(IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor alpha (TNFα) in the mucosa of patients with “asymptomatic” ileoanal pouch (n=25), pouchitis (n=9), active UC (n=20), normal ileum (n=15), proctitis (n=10), and normal colon (n=15). METHODS: Lamina propria mononuclear cells were isolated from mucosal biopsies by enzymatic dispersion and cultured for 48 hours. Proinflammatory cytokine levels were measured in the supernatants by enzyme-linked immunosorbent assay. RESULTS: IL-1β,IL-6, IL-8, and TNFαsecretions were significantly greater in pouchitis and active UC than in the noninflamed ileoanal pouch and normal controls (P<0.001). There was significant correlation (r=0.63,P< 0.05) between levels of cytokines expressed in pouchitis and active UC. CONCLUSIONS: Increased cytokine expression occurs in both active UC and pouchitis and to a lesser extent in the long-standing ileoanal pouch.