Elevated cell-associated levels of interleukin 1beta and interleukin 6 in inflamed mucosa of inflammatory bowel disease.
The aim of this study was to investigate the involvement of the monocyte-derived cytokines interleukin 1beta (IL-1beta), interleukin 6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) in idiopathic inflammatory bowel disease. Endoscopic biopsies of normal and inflamed intestinal mucosa were obtained from patients with ulcerative colitis (n = 11) and with Crohn's disease (n = 10). Intestinal mucosal cells were isolated by collagenase digestion. Cell viability, morphology and CD14 expression were determined. To measure cell-associated cytokine levels, cells were lysed and analysed for IL-1beta and TNF-alpha in specific radioimmunoassays and for IL-6 using a biological assay. Compared with mucosal cells from control patients without inflammatory bowel disease the inflamed intestine in ulcerative colitis and Crohn's disease displayed markedly enhanced levels of IL-1beta (median 245 pg 10(-6) cells, range 30-1275) and IL-6 (median 22 U 10(-6) cells, range 1-298). Non-inflamed mucosa in patients with ulcerative colitis and Crohn's disease did not show elevated levels of IL-1beta (median 50 pg 10(-6) cells, range 33-90) or IL-6 (mean below detection limit of assay, i.e. 1 U 10(-6) cells). In contrast, no clear cut difference between inflamed and non-inflamed mucosa could be detected for TNF-alpha. High tissue levels of IL-6 were associated with a high endoscopic grade of local inflammation. These results suggest that the monocyte-derived cytokines IL-1beta and IL-6 are mediators of inflammation in inflammatory bowel disease.
Virchow-Klinikum, Humboldt-Universitat Berlin, Germany.
E
E
Grottrup-Wolfers
J
J
Moeller
U
U
Karbach
S
S
Muller-Lissner
S
S
Endres
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000209:etiology / Q000378:metabolism*; D007375:Interleukin-1 / Q000032:analysis*; D015850:Interleukin-6 / Q000032:analysis*; D007413:Intestinal Mucosa / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha