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‐1&bgr;(IL‐1&bgr;), interleukin‐6 (IL‐6), interleukin‐8 (IL‐8), and tumor necrosis factor alpha (TNF&agr;) 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‐1&bgr;,IL‐6, IL‐8, and TNF&agr;secretions 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.