Pathogenesis of pseudomembranous colitis

This work is concerned with new morphologic data pointing to an immune component in the pathogenesis of pseudomembranous colitis. The focal distribution of the pseudomembranes suggests selective damage induced by Clostridium difficile toxins. The sites of attachment to the mucosa correspond anatomically to the intestinal structures specialized for immune information and response. Furthermore, viable IgA production supports the view that toxins are carried to lymphoid aggregates where plasma cell proliferation takes place. A sharp increase in the mast cell population of the colon is also reported. Mast cells, whose role in the pathogenesis of intestinal diseases is still obscure, are diffusely distributed, irrespective of the focal lesions of pseudomembranous colitis.