Objectives: In this study, our purpose was to determine whether locally generated interleukin-8 (IL-8) is involved in neutrophil migration and binding to extracellular matrix, using the colonic mucosal specimens obtained from patients with inflammatory bowel disease (IBD).
Methods: Levels of IL-8 secreted in the organ cultures were measured by enzyme-linked immunosorbent assay. Chemotactic activity and binding capacity of neutrophils were induced by the organ culture supernatants.
Results: Significantly higher levels of IL-8 were secreted in patients with IBD, and its elevation was more prominent in patients with active ulcerative colitis. The organ culture supernatants induced higher chemotactic activity and binding capacity of neutrophils in patients with IBD, especially in those with active ulcerative colitis, compared with controls. These effects were inhibited significantly when the supernatants were submitted to preincubation with neutralizing anti-IL-8 antibody.
Conclusions: Increased mucosal generation of IL-8 may attract neutrophils from the circulation into the inflammatory site and induce binding of neutrophils in the interstitial tissue, contributing to accumulation and activation of neutrophils in the affected mucosa with IBD.