The proportion of Th1 cells, which prevail in gut mucosa, is decreased in inflammatory bowel syndrome

T lymphocytes and their cytokines have an important role in the regulation of immune responses in the gut and in the pathogenesis of intestinal inflam mation such as in Crohn's disease. The aim of this study was to analyse the Th1/Th2 cytokine profile (IFN-gamma, IL-2, IL-4 and IL-10) in intraepithel ial lymphocytes (IEL) and lamina propria lymphocytes (LPL) in Crohn's disea se (CD) and ulcerative colitis (UC) in relation to healthy controls (C). Co lonic and ileal biopsy specimens were obtained from controls (n = 13) and p atients with CD (n = 32). Colonic biopsies were obtained from patients with UC (n = 11). Intracytoplasmic IFN-gamma, IL-2, IL-4 and IL-10 were determi ned by flow cytometry after PMA-ionomycin stimulation in IEL and LPL. In co lonic LPL, a significant proportional decrease of IFN-gamma and IL-2 produc ing CD3(+) cells was observed in patients with CD and UC compared to contro ls. In ileal LPL, a similar tendency was found although differences were no t significant. In IEL no differences in cytokine profiles could be observed . Flow cytometric analysis of intracytoplasmic cytokines at single cell lev el showed a proportional decrease of IFN-gamma and IL-2 producing T cells i n colonic lamina propria in patients with inflammatory bowel disease.