Increased presence of eosinophilic granulocytes expressing transforming growth factor-beta1 in collagenous colitis

Scand J Gastroenterol. 2000 Jul;35(7):742-6. doi: 10.1080/003655200750023426.


Background: Collagenous colitis is a disease characterized by chronic watery diarrhea, and on microscopic examination of colonic tissue, a typical thickening of the subepithelial collagen layer is seen. The etiology and pathophysiology behind this disease state are largely unknown.

Methods: We have used in situ hybridization and immunohistochemistry to study the expression of transforming growth factor (TGF) -beta1, a growth factor with the capacity to cause accumulation of collagen in tissues, in collagenous colitis. Colonic pinch biopsy specimens from a total of 34 patients were investigated: 17 patients with collagenous colitis and 17 controls.

Results: In patients with collagenous colitis there was increased expression of the TGF-beta1 gene compared with controls, as visualized by in situ hybridization. The vast majority of the TGF-beta1-expressing cells were eosinophils, both in collagenous colitis and controls, but there were also scattered fibroblastic and histiocytic stromal cells. Immunohistochemistry showed the presence of TGF-beta1, mainly in eosinophils, in the colonic mucosa. Morphometric quantification showed 603 +/- 192 eosinophils/mm2, (mean +/- standard error of the mean) in the colonic mucosa of patients with collagenous colitis compared with 30 +/- 7 eosinophils/mm2 in the controls.

Conclusions: The present results suggest that eosinophils expressing TGF-beta1 may be of pathophysiologic importance in the connective tissue remodeling seen in collagenous colitis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Colitis / metabolism*
  • Colitis / pathology
  • Collagen / metabolism
  • Colon / pathology
  • Eosinophils / metabolism*
  • Eosinophils / pathology
  • Female
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization
  • Intestinal Mucosa / pathology
  • Male
  • Middle Aged
  • Transforming Growth Factor beta / biosynthesis*
  • Transforming Growth Factor beta1


  • TGFB1 protein, human
  • Transforming Growth Factor beta
  • Transforming Growth Factor beta1
  • Collagen