Having performed some medical work in Mexico in the 1970's, (I'm that ancient), it has always occurred to me that chronic parasitosis was a problem that quietly devastated the potential of so many Mexican children. Harboring intestinal worms for the long term remains a public health problem throughout the Americas. It results from the consumption of drinking water that mixes with sewage.
People with these creepy crawlers on board can be fatigued for the long term, suffer abdominal difficulties, and sustain lifetime malabsorption which causes vitamin deficiency states.
What in tarnation does this have to do with Multiple Sclerosis? Have I been out in the sun too long, seeking higher Vitamin D levels to help thwart future disease?
Doctors tend to talk in riddles. So I shoot back to you: "Crohn's disease, Ulcerative Colitis, Multiple Sclerosis, Rheumatoid Arthritis, Insulin-dependent (Type 1) Diabetes and Asthma."
"That's it", you say, "Dr. Gross is so confused, he's ready for the funny farm. Send him to Tijuana where he can stumble around babbling about worms, Rheumatoid Arthritis and the price of tacos".
No. I have not lost it. Helminths (worms) living in the human gut blunt immune system overactivity and may be valuable therapy in defeating certain immune diseases including MS.
According to Maria Yazdanbakhsh, Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands chronic helminth infections are associated with immune lost of responsiveness to parasite antigens. Dr. Y (was she in Borat?) notes some level of spill over suppression to third party antigens has also been reported in helminth infected subjects. In several epidemiological studies, a negative association has been found between worm infections and immune/allergic disorders.
The immune disorder list I rattled off above from Crohn's to Asthma falls into the category to which Yazdanbaksh referred. And it's the "spill over suppression of third party antigens" that may specifically relate to studies in the tropics that suggest that people infected with certain worms experience fewer symptoms of MS than those who are not so afflicted.
Molecular mimicry may trigger autoimmune diseases such as MS. If antibodies are busy attacking something in the worm that resembles myelin rather than launching attacks against one's own myelin, that's a worthy distraction for the MS patient.
In this spirit, Ovamed has embarked on clinical trials involving the swallowing of helminth eggs that once hatched activate the patients' Th2 cells to destroy them, thus "keeping preoccupied" same cells busy destroying worms rather than one's own central nervous system myelin. Also such active Th2 cells modulate Th1 cells, which are also implicated in diseases like MS.
Dr. David Elliott, from the University of Iowa Department of Internal Medicine notes that autoimmune diseases "increase in prevalence and emerge as populations adopt meticulously hygienic lifestyles. Loss of natural helminth exposure, precluded by this lifestyle change, removes a previously universal Th2 and regulatory immune biasing imparted by these organisms." Translation? The worms may prevent autoimmune disease prevalence and as per clinical trials with Crohn's and Ulcerative Colitis, lessen disease activity when they reside in the gut.
A nod to Ockham's Razor should be given here if indeed groups with chronic parasitosis have less Multiple Sclerosis: "Plurality (of disease in this case) should not be posited without necessity".
I would be quite interested in learning of MS disease rates in those worm infected Mexican children I encountered thirty years ago. I suspect MS prevalence is quite low in such a parasitically challenged population. Ockham would agree they've got enough problems.
Published On: March 28, 2008