Collagenous colitis: A disease of pericryptal fibroblast sheath?

Abstract

Mucosal biopsies from four women with collagenous colitis and ten controls were studied. By light microscopy the cells of the pericryptal fibroblast sheath appeared diminished in number but increased in size in collagenous colitis. Electron optically in the controls the pericryptal fibroblasts were in intimate contact with the epithelial basal lamina in the crypts. On the free surface the fibroblasts maintained contact with the epithelial cells by attenuated cell processes. In collagenous colitis, in the middle and upper thirds of the crypts the fibroblasts sheath was separated from the epithelium and the fibroblasts assumed the characteristics of myofibroblasts. The separation was accentuated towards the mouths of the crypts. Beneath the surface epithelium the attenuated fibroblast cell processes seen in normal colon were grossly deficient. The basal lamina was also deficient focally and the surface epithelial cells were resting directly on a thickened collagen table. In collagenous colitis the excess collagen appeared to be secreted by the activated myofibroblasts of the pericryptal sheath.

Collagenous, microscopic and lymphocytic colitis. An evolving concept

“…Collagenous colitis combined with coeliac disease and some degree of villous atrophy has been described in about ten patients [9,12,24,25,47,50]. However, the small number of patients with this combination is in marked contrast with over 200 reported cases of patients with collagenous colitis but without malabsorption and with biopsy-proven normal small gut.…”

“…In 1986, the first three cases of collagenous colitis, coexisting with small intestinal villous atrophy [24,25] and the first autopsy case [49] were reported.…”

Are Collagenous Colitis and Lymphocytic Colitis Distinct Syndromes?

“…Ultrastructural studies have demonstrated exten sive changes of the pericryptal fibroblasts in collagenous colitis. The fibroblasts have been noted to take the features of myofibroblasts, the proliferative cells often seen in granula tion tissue [32]. However, this theory does not account for the lamina propria inflammation or the fact that the type of collagen deposited is the type found in any reparative process.…”

Evolution of ideas on microscopic colitis

“…Еще в 80-х годах XX века высказано предположение, что КК связан с альтерацией синтеза коллагена. При проведении иммуно-гистохимического анализа установлено, что субэпителиальные слои состоят из коллагена I и III типов [49,50]. Тем не менее в по-следующем исследовании, проведенном T. Aigner и соавт.…”