Scientists at the University of Nottingham have published new research in JAMA Neurology looking at the effect of helminthic (worm) therapy in people with relapsing MS.
This research, which we funded, was led by Professor Cris Constantinescu. It aimed to discover whether helminthic therapy can impact the number and size of MS lesions, and the number of regulatory T cells (which keep the immune system under control).
Why are scientists studying hookworms?
We know that in MS, there's an imbalance between inflammatory factors (which cause damage) and immunoregulatory factors (which protect against damage). The damage that results from this imbalance that causes the symptoms of MS.
It might sound a bit gross, but in recent years helminthic therapies have been explored for their potential to treat inflammatory conditions. The ‘hygiene hypothesis’ theory suggests that as improved hygiene conditions have led to the eradication of gut parasites, inflammatory conditions (such as asthma and inflammatory bowel disease) have increased in frequency. And preliminary research has shown that hookworms can dampen down the inflammation that causes MS.
What effect did the hookworms have?
In this Phase 2 trial, researchers’ recruited 73 people with relapsing MS. Half of these participants were given a low dose of Necator americanus (N americanus) via a plaster on their arm. The rest of the participants were given a placebo plaster. N americanus is a type of hookworm that lives in the small intestine of humans and in most cases isn't harmful.
Researchers found that treatment with hookworms didn't have a significant effect on the number and size of MS lesions after 9 months, compared to the group who'd been given a placebo. However, they did report that participants who'd been infected with hookworms showed an increase in the number of regulatory T cells present in the bloodstream.
What does this mean for people with MS?
Dr Emma Gray, Our Assistant Director of Research, said: “There are over 130,000 people living with MS in the UK and – though we now have a dozen treatments for people with relapsing MS – we're always keen to fund novel and exciting research.
“These results indicate that, while helminthic therapy appears to be a safe and well-tolerated treatment, the benefits are modest in comparison to existing treatments for relapsing MS. But although it’s unlikely that worm therapy will replace other options, this study has given us a deeper insight into the effects of helminthic therapy on the immune system.”