Apr 11, 2008
Society Funds Novel Clinical Trial of Harmless Worms, Based on “Hygiene Hypothesis”
Investigators at the University of Wisconsin, Madison, are planning a small, novel study using the eggs of a harmless parasitic worm – called a helminth – to treat people with MS. The concept is based on the as yet unproven “hygiene hypothesis,” which states that MS is less common in underdeveloped regions because early exposure to common infectious agents may stimulate the immune response in a positive way and help offset the attack on the brain and spinal cord in MS. John Fleming, MD, and colleagues are funded by a research grant from the National MS Society to conduct a small clinical trial to determine whether the treatment can reduce relapses. The team expects to begin recruiting participants for this study within weeks, which will involve up to 20 people.
Scientists have noted that autoimmune diseases and allergies are less common in underdeveloped regions. Some researchers have noted that early exposure to common infectious agents, such as occurs to people in regions with poor sanitation, may stimulate immune regulation in a positive way and aid healthy immune responses. Because MS is more prevalent in regions with high standards of hygiene, researchers have been testing the hygiene hypothesis – the idea that lack of exposure to common innocuous agents at an early age may cause the immune system to over-react and cause MS.
Studies in MS-like disease in lab rodents and preliminary clinical trials in Crohn’s disease, an autoimmune disease of the bowel, suggest that drinking a concoction containing eggs from the helminth might alter immune attacks and improve these conditions.
Based on these and other studies, Dr. Fleming’s team is conducting a small clinical trial to test the potential of oral helminth eggs for improving relapsing-remitting MS.* In the first phase, five participants who have declined to take medications approved to treat MS (and who meet other study criteria) will be given a solution containing the tiny eggs of the helminth. The eggs will hatch and mature inside the body, reaching about the size of an eyelash. When they reach the large intestine, the larvae interact with the immune system and are then killed. The ingestion of the eggs is not expected to cause intestinal problems.
Participants will be followed for seven months with MRI and clinical measures to evaluate safety and effectiveness. The primary outcome being measured is how treatment affects the number of new, active lesions (areas of myelin damage) as observed on MRI. If the first phase demonstrates safety and effectiveness, the team will enroll 15 people for a year-long study. If treatment shows effectiveness, a longer-term goal is to determine the exact mechanism of action so that patients could reap the potential benefits using a pill.
This cutting-edge research should provide important information as to whether this unique therapy has the potential to benefit those with MS.
*Relapsing-Remitting MS is a course of MS characterized by clearly defined flare-ups followed by partial or complete recovery periods (remissions) free of disease progression.