Site-specific changes in transforming growth factor-alpha and -beta l expression in colonic mucosa of adolescents with inflammatory bowel disease

Background: Transforming growth factors (TGF-alpha and -beta 1) play import ant roles in intestinal growth and repair. To further understand their role s in the pathophysiology of inflammatory bowel disease (IBD), this study ex amined changes in their expression in colonic mucose of adolescents with IB D. Methods: TGF-alpha and -beta 1 expression was examined by immunohistoche mistry and in situ hybridization. Results: TGF-alpha immunostaining and mRN A labelling appeared unchanged in the epithelium of specimens with active I BD. Similarly, expression of epithelial TGF-beta 1 remained unaltered in IB D. However, the numbers of TGF-beta 1-positive cells, including T cells, ne utrophils, and monocytes/macrophages, in the lamina propria increased durin g disease activity. Conclusions: Adolescent IBD is characterized by a norma l expression of TGF-alpha and -beta 1 peptide and mRNA in the colonic epith elium but by an increased density of TGF-beta 1-positive immune cells in th e lamina propria during disease activity, suggesting a role in inflammatory modulation in IBD.