Increased expression of interleukin 17 in inflammatory bowel disease
- Department of Internal Medicine, Shiga University of Medical Science, Seta-Tukinowa, Otsu 520-2192, Japan
- Correspondence to:
Dr A Andoh, Department of Internal Medicine, Shiga University of Medical Science, Seta-Tukinowa, Otsu 520-2192, Japan;
- Accepted 5 July 2002
Background and aim: Interleukin (IL) 17 is a cytokine which exerts strong proinflammatory activities. In this study we evaluated changes in IL-17 expression in the inflamed mucosa and in the serum of patients with inflammatory bowel disease (IBD).
Methods: Tissue samples were obtained endoscopically or surgically from patients with ulcerative colitis (UC) (n=20), Crohn’s disease (CD) (n=20), infectious colitis (n=5), ischaemic colitis (n=8), and normal colorectal tissues (n=15). IL-17 expression was evaluated by a standard immunohistochemical procedure. Serum IL-17 levels were determined by ELISA. IL-17 mRNA expression was analysed by reverse transcriptase-polymerase chain reaction.
Results: IL-17 expression was not detected in samples from normal colonic mucosa, infectious colitis, or ischaemic colitis. In the inflamed mucosa of active UC and CD patients, IL-17 expression was clearly detectable in CD3+ T cells or CD68+ monocytes/macrophages. The average number of IL-17+ cells was significantly increased in active UC and CD patients compared with inactive patients. IL-17 mRNA expression was not detected in normal mucosa but was detectable in the mucosa from active UC and CD patients. IL-17 was not detected in the sera from normal individuals, infectious colitis, or ischaemic colitis patients but IL-17 levels were significantly elevated in IBD patients.
Conclusions: IL-17 expression in the mucosa and serum was increased in IBD patients. It is likely that IL-17 expression in IBD may be associated with altered immune and inflammatory responses in the intestinal mucosa.
- IBD, inflammatory bowel disease
- UC, ulcerative colitis
- CD Crohn’s disease
- IL, interleukin
- TNF, tumour necrosis factor
- FITC, fluorescein isothiocyanate
- ELISA, enzyme linked immunosorbent assay
- RT-PCR, reverse transcription-polymerase chain reaction
- AGPC, acid guanidium thiocyanate-phenol-chloroform
- PBS, phosphate buffered saline