Scientific Abstract

Proposal No. IBD-0005
Principal Investigator:  Robert W. Summers, M.D.
Applicant Organization:  University of Iowa (Iowa City, U.S.A.)
Project Title:  A controlled clinical trial of Trichuris suis in the therapy of active ulcerative colitis
Period of Award:  July 1, 2002 - December 31, 2003

The development of ulcerative colitis (UC) appears to involve both genetic and environmental factors.  Normal luminal flora may trigger the disorder inducing destructive intestinal inflammation in a genetically susceptible host.  Helminths reduce hyperreactive immune responses and potentially could serve a favorable immunomodulatory role in UC.

We will colonize patients who have active UC with a safe helminth to exploit this unique immunological interaction between these organisms and their host to see if they can inhibit the destructive immune activity.  This idea corresponds with the epidemiological observation that idiopathic inflammatory bowel disease (IBD) is common in industrialized countries where there are few helminths.  Conversely, IBD is rare in regions of the world where most people harbor worms.  This hypothesis is supported by observations in our laboratory where helminthic colonization reduced the inflammation in experimental murine IBD.  In an open trial with helminthic eggs, we also have had success in treating UC and CD patients and observed no adverse effects.

Because of these epidemiological, experimental and clinical observations, we now plan to initiate a double blind, placebo-controlled clinical trial to investigate this new therapeutic approach.  We will administer the eggs of Trichuris suis biweekly to patients with active UC to induce temporary colonizations.  We will compare the clinical outcomes of these subjects to those of placebo controls using accepted clinical measurements of disease activity.  We will include measures of inflammation in selected patients to collect data that may contribute to understanding of the mechanisms of actions of this proposed therapeutic agent.