Ulcerative colitis and Crohn's disease tissue cytotoxins.

Bowel-wall tissue filtrates from patients with inflammatory bowel disease produce cytopathic effects in tissue culture. The cytopathic effects inducers have been reported to have the characteristics of a small RNA virus. Clostridium difficile toxin also produces cytopathic effects and has been found in the stools of patients with Crohn's disease and ulcerative colitis. The present study concerns the further characterization of the cytopathic inducers in tissues of inflammatory bowel disease patients. It was found that they are nonsedimentable at 148,000 g for 2 h and resistant to inactivation by UV light. They are proteins that are distinct from C. difficile toxin and are unique cytotoxins which are associated with the early cytopathic effects observed in Riff-free chick embryo and rabbit ileum cell cultures. These results suggest that the early cytopathic effects previously described are not produced by a virus. They do not explain the delayed cytopathic effects seen in rabbit ileum or WI-38 cells.