ALTERED TH1 TH2 CYTOKINE PROFILES IN THE INTESTINAL-MUCOSA OF PATIENTS WITH INFLAMMATORY BOWEL-DISEASE AS ASSESSED BY QUANTITATIVE REVERSEDTRANSCRIBED POLYMERASE CHAIN-REACTION (RT-PCR)/

Cytokines serve a central function as key factors in the regulation of the intestinal immune response and mediation of tissue damage in infl ammatory bowel disease (IBD). Abnormalities in the expression of immun oregulatory cytokines such as IL-2, IL-4, IL-10 and interferon-gamma ( IFN-gamma) may indicate a dysregulation of intestinal immunity probabl y associated with pathogenic events. Therefore, cytokine mRNA concentr ations were determined in the mucosa of patients with IBD at sites of active (n = 13) and inactive (n = 12) ulcerative colitis (UC), active (n = 11) and. inactive (n = 11) Crohn's disease (CD) and in control pa tients (n = 14) using quantitative RT-PCR. IL-10 mRNA concentrations w ere significantly increased in patients with both active UC (P < 0.001 ) and active CD (P < 0.005) compared with control patients. lFN-gamma mRNA concentrations were also significantly increased both in patients with active UC (P < 0.02) and active CD (P < 0.05) compared with cont rol patients, whereas IL-2 mRNA levels were significantly (P < 0.02) i ncreased only in active CD. IL-4 mRNA expression in the intestinal muc osa was frequently below the detection limit. Our results demonstrate that chronic intestinal inflammation in patients with CD is characteri zed by an increase of Th1-like cytokines. Furthermore, the increased I L-10 mRNA expression at sites of active IBD suggests that IL-10 is an important regulatory component involved in the control of the inflamma tory response in inflammatory bowel disease.