Parasitic worms offer hope of cure for multiple sclerosis

Parasitic worms offer hope of cure for multiple sclerosis - Hookworm thought to relieve symptoms - MS sufferers recruited for trial to test theory

Researchers believe that a low dose of the Necator americanus - commonly known as the hookworm - may help relieve symptoms of MS

Parasitic worms could offer hope to millions suffering from multiple sclerosis, say scientists.

Currently there is no cure for the neurological condition, but now researchers believe that a low dose of the Necator americanus - commonly known as the hookworm - may help relieve symptoms.

MS sufferers often experience blurred vision, muscle weakness and problems with mobility as the disease attacks the central nervous system.

To test the theory, doctors have started recruiting patients for a trial that will see them infected with a harmless dose of the hookworm.

It is thought the presence of the parasite in the body can stop the immune system from becoming overactive - the main cause of MS - reducing both the severity of symptoms and the number of relapses.

Lead researcher professor David Pritchard, from Nottingham University, first noted the health benefits of parasitic worms while in Papua New Guinea during the late 1980s.

He observed that patients infected with the hookworm were rarely subject to a range of autoimmune-related illnesses, including hay fever and asthma.

Commenting on the latest study, he said: 'This study appears counter-intuitive - we are introducing a parasite which is by definition harmful, to act as a stimulus to moderate disease.

'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.

'Currently, there are many MS patients for whom conventional medicines are ineffective or are associated with unwanted side effects.

'Hookworms have an innate ability to moderate the immune system to allow them to survive in the body for years. This moderation may have a bystander effect on the progression of MS.'

During the trial patients will receive a low dose of the hookworms on a plaster applied to the arm

Prof Pritchard is in the process of recruiting more than 70 patients from the Nottingham and Derby areas who suffer from relapsing remitting MS (RRMS) - the most common type in which vision problems, dizziness and fatigue appear and disappear - and secondary progressive MS.

Half of the patients on the trial will receive a low dose of the hookworms - 25 of the microscopic larvae - on a plaster applied to the arm while the others will receive a placebo.

Once the larvae come into contact with the skin they work their way through into the blood stream until they reach the lungs where they are coughed up and swallowed to get to their final destination, the gut, where they survive by latching on to the gut lining and feeding on the host’s blood.

They can grow up to one centimeter in length as they burrow into blood vessels.

The worms do not multiply in the host but reproduce by producing fertile eggs, which are expelled in human faeces. These hatch into infective larvae outside the body, which go on to infect other patients.

At the end of the trial, the results of the two patient groups will be compared to establish whether the hookworms have been successful in damping down the immune system of the patients, keeping their symptoms in check and preventing relapses.

Multiple sclerosis is the most common neurological condition in young adults in the UK, affecting around 100,000 people.

It can occur at any age, but symptoms are mostly first seen between the ages of 20 and 40. ( dailymail.co.uk )