Parasitic worms could offer a new treatment for people with Multiple Sclerosis (MS) say researchers from the University of Nottingham.
Scientists are recruiting patients who suffer from MS for a clinical trial which will see them infected with a low, harmless dose of the Necator americanus or hookworm. They hope to prove that the presence of the parasite in the body switches off the mechanism by which the immune system becomes overactive – the main cause of MS – and can reduce both the severity of symptoms and number of relapses suffered by patients.
“This study appears counter-intuitive – we are introducing a parasite which is by definition harmful, to act as a stimulus to moderate disease,” said Professor David Pritchard, Professor of Parasite Immunology. “As a safeguard the hookworms are being used in carefully controlled and monitored conditions, and if successful could herald a much needed therapy for MS patients.”
The team are recruiting patients with relapse remitting MS (RRMS) – the most common type of the disease in which patients suffer vision problems, dizziness and fatigue – and secondary progressive MS with superimposed relapses.
Half the patients will be given a low a low dose of the hookworms – 25 of the microscopic larvae – on a plaster applied to the arm, while the other half with receive a placebo plaster. Once the larvae come into contact with the skin, they will work their way into the blood stream and to the lungs where they are coughed up and swallowed. Once in the gut, they will latch onto the gut lining and feeding on the host’s blood.
At the beginning of the trial – which has received £400,000 from the MS Society – patients will undergo an MRI scan to record the scarring on the brain which is present in MS patients. Over the course of nine months, they will be scanned on a regular basis for new or worsening legions, which can be a sign of relapse. The patients will also be given regular blood tests to check they are not anaemic – a signal that the dose of hookworms could be too high for that individual.