Submitted to: American Journal of Gastroenterology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/17/2003
Publication Date: 9/15/2003
Citation: Summers, R.W., Elliott, D.E., Qadir, K., Urban Jr, J.F., Thompson, R., Weinstock, J.V. 2003. Trichuris suis appears safe and effective in the treatment of inflammatory bowel disease. American Journal of Gastroenterology. 11:420-426 (1999)
Interpretive Summary: Inflammatory bowel diseases (IBD) have been increasing in developed but not lesser-developed countries over the last 50 years. There is a counter-regulatory balance between immune and inflammatory responses to intracellular bacteria and viruses versus responses to extracellular worm parasites. The fact that individuals from developed countries have good hygiene and are generally worm-free while those from lesser-developed countries are not may account for demographic pattern of IBD worldwide. Based on this information, 6 patients with refractory IBD were given eggs from the whipworm parasite of swine. Swine whipworm can infect humans but does not develop to mature adult worms. This represented a naturally abbreviated infection for humans. The eggs were found to be free from any known zoonotic organisms that could harm the patients. The results of the study show a mild improvement to complete remission for the treated patients. This experience may also be relevant to certain diseases of livestock, especially animals kept parasite-free in confinement where the composition of infectious agents is altered from natural exposure conditions. It is envisioned that therapeutic control of intestinal pathologies in both humans and livestock can be developed as more information on the mechanism of regulation is obtained
Technical Abstract: Inflammatory bowel disease (IBD) probably results from failure to down-regulate chronic Th1 inflammatory process in the intestine. Induction of the Th2 immune response by helminths can diminish Th1 responsiveness. IBD is rare in underdeveloped countries where helminthic colonization is common, but it is common in industrialized countries where humans rarely harbor helminths. Six patients with refractory IBD were treated with 2,50 Trichuris suis eggs administered orally to reverse the pathology. All of the patients improved clinically. The number of stools per day decreased by 50%. Three of the 4 patients with Crohn's disease entered remission according to the CDAI and the fourth experienced a fall in the CDAI of 151. An accepted IBD quality of life index increased to 140% of baseline. The patients' perceived response to the therapy varied from mild improvement to complete remission. All patients eventually returned to their baseline disease values after 2 to 16 weeks of improvement following the single ora dose. The agent induced no clinical adverse events or laboratory abnormalities. The initial results of this trial are encouraging and support the concept that it is possible to down-regulate aberrantly strong Th1 response in humans through helminthic induction of a Th2 response.