Relationship of interleukin-1 receptor antagonist to mucosal inflammation in inflammatory bowel disease

J Pediatr Gastroenterol Nutr. 1995 Nov;21(4):419-25. doi: 10.1097/00005176-199511000-00008.


Previous work has suggested that the interleukin-1 (IL-1) receptor antagonist, IL-1ra, may regulate mucosal inflammation in inflammatory bowel disease. The present study assessed the relationship of mucosal IL-1ra levels to histologic severity of inflammation and the related proinflammatory cytokines IL-1 beta and IL-6 in children with inflammatory bowel disease. Colonic biopsy specimens from 29 patients with ulcerative colitis, 27 with Crohn's disease, and 24 noninflammatory control subjects were assayed for IL-1ra, IL-1 beta, and IL-6 by enzyme-linked immunosorbent assay. Histologic activity was graded as none, mild, moderate, or severe. Mucosal IL-1 beta levels, but not IL-1ra levels, were significantly elevated in moderate/severely inflamed biopsies from patients with either ulcerative colitis (p < 0.01) or Crohn's disease (p < 0.001) compared with those with none/mild inflammation. The mucosal molar ratio of IL-1ra/IL-1 beta was significantly lower for moderate/severe inflammation compared with none/mild inflammation for patients with ulcerative colitis (p < 0.05) and Crohn's disease (p < 0.01). The mucosal IL-1ra/IL-1 beta ratio was similar in controls to none/mild inflamed biopsies from subjects with either ulcerative colitis or Crohn's disease. Our observations suggest that increasing mucosal inflammation in inflammatory bowel disease in children is associated with a decrease in the "normal" effective IL-1ra/IL-1 beta ratio in which IL-1ra predominates. The importance of this abnormality to the pathogenesis of inflammatory bowel disease awaits further study.

MeSH terms

  • Adolescent
  • Adult
  • Biopsy
  • Child
  • Colitis, Ulcerative / metabolism
  • Colitis, Ulcerative / pathology*
  • Crohn Disease / metabolism
  • Crohn Disease / pathology*
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Interleukin 1 Receptor Antagonist Protein
  • Interleukin-1 / analysis
  • Interleukin-6 / analysis
  • Intestinal Mucosa / metabolism
  • Intestinal Mucosa / pathology*
  • Sialoglycoproteins / analysis
  • Sialoglycoproteins / physiology*


  • IL1RN protein, human
  • Interleukin 1 Receptor Antagonist Protein
  • Interleukin-1
  • Interleukin-6
  • Sialoglycoproteins