Colonic expression and synthesis of interleukin 13 and interleukin 15 in inflammatory bowel disease

Cytokine. 2000 Oct;12(10):1531-6. doi: 10.1006/cyto.2000.0744.

Abstract

A dysregulated local immune reaction with unbalanced cytokine expression seems essential in inflammatory bowel disease (IBD), i.e. ulcerative colitis (UC) and Crohn's disease (CD). Since the roles of interleukin (IL-)13 and IL-15 remain unclear, this study aimed at studying intestinal expression of IL-13 and IL-15 in IBD.

Methods: In colonic biopsies from 24 UC, 18 CD, and 12 controls IL-13 and IL-15 were measured using ELISA, and their gene expressions were assessed by RT-PCR. Leukocytes were visualised histochemically.

Results: Concentrations of IL-13 were decreased in UC (median 56 pg/mg tissue; interquartile range 30-99 pg/mg) compared to CD (82 pg/mg tissue; 41-122;P=0.004) and controls (83 pg/mg tissue; 18-134;P>0.05), and lower in active UC (53 pg/mg tissue; 33-96) than in inactive UC (80 pg/mg tissue; 65-99;P=0.02). IL-15 concentrations were higher in CD patients (34 pg/mg tissue; 24-53) as compared to controls (20 pg/mg tissue; 15-21;P=0.001) whilst being 22 pg/mg tissue (15-32) in UC. IL-13 mRNA and IL-15 mRNA were detected in 20% and 15%, respectively. Infiltration of leukocytes correlated inversely with IL-13 levels (P=0.02).

Conclusion: Active UC is associated with decreased colonic IL-13 suggesting that IL-13 levels are diminished as a part of UC exacerbations, or that exacerbations follow active downregulation of IL-13.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biopsy
  • Case-Control Studies
  • Colitis, Ulcerative / diagnosis
  • Colitis, Ulcerative / metabolism
  • Colon / metabolism*
  • Crohn Disease / diagnosis
  • Crohn Disease / metabolism
  • Down-Regulation
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Granulocytes / metabolism
  • Humans
  • Immunohistochemistry
  • Inflammatory Bowel Diseases / diagnosis
  • Inflammatory Bowel Diseases / metabolism*
  • Interleukin-13 / biosynthesis*
  • Interleukin-15 / biosynthesis*
  • Leukocytes / metabolism
  • Macrophages / metabolism
  • Male
  • Middle Aged
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Interleukin-13
  • Interleukin-15