Post by Roland of Gilead on Mar 17, 2009 16:46:17 GMT -5
This article is a couple of years old, but I've been hearing a lot of discussion on this subject lately.
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Scientists team up with an unlikely ally — hookworms
04 August 2006
PA130/06
They are barely 1cm long and can live inside the human gut for up to five years without causing any symptoms.
But the hookworm may be a lot more than an inconspicuous parasite — it could also hold the key to autoimmune diseases like Crohn’s Disease, University of Nottingham experts believe.
In the first clinical trial of its kind in the world, scientists at the University are seeking to establish whether the hookworm, Necator Americanus, could help to reduce symptoms of Crohn’s and aid the search for an effective long-term therapy.
Patients are being recruited to test the theory — by being deliberately infected with hookworms for a 12-week period.
Those taking part in the study will be infected with 10 larvae, administered by medical staff through the skin of the arm. Their progress will be monitored over 12 weeks to see if there is a reduction in Crohn’s symptoms.
At the end of the study, they take a short course of tablets which kill the hookworms and flush them from the body.
The University of Nottingham team believes the tiny worms could help to ’down-regulate’ the human immune system, to stop it reacting in a way that causes the symptoms of diseases like Crohn’s. Autoimmune diseases are caused by an over-active immune response, which causes the body to attack its own tissues.
It is thought that the parasites have evolved a way of surviving in the gut by ’turning down’ the immune response so the body doesn’t attack them.
The study is being conducted by Dr Paul Fortun and Professor Chris Hawkey of the University’s Wolfson Digestive Diseases Centre, and Professor David Pritchard, an immunoparasitologist in the School of Pharmacy.
Dr Fortun said: “If you look at a map of the world, the areas where hookworm is prevalent — such as sub-Saharan Africa and south-east Asia — tend to be where inflammatory bowel diseases (IBD) such as Crohn’s and ulcerative colitis are extremely rare.
“Conversely, in developed countries with low levels of hookworm infestation, IBD is prevalent. African-Americans living in the USA have the same rate of IBD as Caucasian Americans, which suggests it is related to environment rather than genes.”
He added: “In order for the parasite to survive, it induces a ’state of tolerance’ in the host. It has found a way to counteract the immune system. There is a lot of evidence that inducing this state of tolerance would reverse the problem that causes Crohn’s disease.”
Hookworms cannot be passed from person to person through normal day-to-day contact. Natural transmission only occurs when hookworm larvae enter the body through the skin when people walk barefoot on contaminated soil. For this reason, hookworm infestation is virtually unknown in the developed world due to modern standards of hygiene and sanitation.
In the study, just 10 larvae are placed on the skin and covered with a plaster, so they are not dislodged. Over a period of hours, the larvae enter the skin and then gradually make their way to the intestine, via the lung.
According to Professor Pritchard — who has deliberately infected himself in the past — provided the dosage is carefully regulated the only sensation is a mild itching when the larvae are on the skin. The tiny number of hookworms means that ill effects are unlikely.
The format is a ’double-blind, placebo-controlled’ study, which means half the patient volunteers will be given the larvae, and half will get a placebo in the form of histamine that replicates the itching sensation on the surface of the skin.
The study follows on from work by Professor Pritchard and Professor John Britton, which is exploring the use of hookworms in the treatment of hayfever and asthma.
Crohn’s Disease is a chronic ongoing condition that most commonly affects the small intestine and colon. It causes inflammation, deep ulcers and scarring to the wall of the intestine, with main symptoms including pain in the abdomen, diarrhoea, fatigue and weight loss. It affects up to 60,000 people in the UK, with 3–6,000 new cases being diagnosed each year.
Currently, there is no way of curing Crohn’s Disease. Normal treatment includes steroids, which cannot be taken long-term, and immune suppressant drugs.
But if the new study is successful, drug therapies developed in the future could help to mimic the effect of the hookworm and may even be able to stop the condition occurring at all, scientists hope.
The study is being funded with a grant from the Broad Foundation, based in Los Angeles. Volunteer patients will be recruited to centres in Nottingham, Mansfield, Derby and Rotherham.
Notes to editors: The University of Nottingham undertakes world-changing research and provides teaching of the highest quality. Ranked in the THES World Top 100 Universities, its academics have won two Nobel Prizes since 2003. An international institution, the University has campuses in the United Kingdom, Malaysia and China.
More information is available from Dr Paul Fortun, Nottingham University Medical School, on +44 (0)115 823 1038, paul.fortun@nottingham.ac.uk; or Media Relations Manager Tim Utton in the University’s Public Affairs Office on +44 (0)115 846 8092, tim.utton@nottingham.ac.uk
__________________
Scientists team up with an unlikely ally — hookworms
04 August 2006
PA130/06
They are barely 1cm long and can live inside the human gut for up to five years without causing any symptoms.
But the hookworm may be a lot more than an inconspicuous parasite — it could also hold the key to autoimmune diseases like Crohn’s Disease, University of Nottingham experts believe.
In the first clinical trial of its kind in the world, scientists at the University are seeking to establish whether the hookworm, Necator Americanus, could help to reduce symptoms of Crohn’s and aid the search for an effective long-term therapy.
Patients are being recruited to test the theory — by being deliberately infected with hookworms for a 12-week period.
Those taking part in the study will be infected with 10 larvae, administered by medical staff through the skin of the arm. Their progress will be monitored over 12 weeks to see if there is a reduction in Crohn’s symptoms.
At the end of the study, they take a short course of tablets which kill the hookworms and flush them from the body.
The University of Nottingham team believes the tiny worms could help to ’down-regulate’ the human immune system, to stop it reacting in a way that causes the symptoms of diseases like Crohn’s. Autoimmune diseases are caused by an over-active immune response, which causes the body to attack its own tissues.
It is thought that the parasites have evolved a way of surviving in the gut by ’turning down’ the immune response so the body doesn’t attack them.
The study is being conducted by Dr Paul Fortun and Professor Chris Hawkey of the University’s Wolfson Digestive Diseases Centre, and Professor David Pritchard, an immunoparasitologist in the School of Pharmacy.
Dr Fortun said: “If you look at a map of the world, the areas where hookworm is prevalent — such as sub-Saharan Africa and south-east Asia — tend to be where inflammatory bowel diseases (IBD) such as Crohn’s and ulcerative colitis are extremely rare.
“Conversely, in developed countries with low levels of hookworm infestation, IBD is prevalent. African-Americans living in the USA have the same rate of IBD as Caucasian Americans, which suggests it is related to environment rather than genes.”
He added: “In order for the parasite to survive, it induces a ’state of tolerance’ in the host. It has found a way to counteract the immune system. There is a lot of evidence that inducing this state of tolerance would reverse the problem that causes Crohn’s disease.”
Hookworms cannot be passed from person to person through normal day-to-day contact. Natural transmission only occurs when hookworm larvae enter the body through the skin when people walk barefoot on contaminated soil. For this reason, hookworm infestation is virtually unknown in the developed world due to modern standards of hygiene and sanitation.
In the study, just 10 larvae are placed on the skin and covered with a plaster, so they are not dislodged. Over a period of hours, the larvae enter the skin and then gradually make their way to the intestine, via the lung.
According to Professor Pritchard — who has deliberately infected himself in the past — provided the dosage is carefully regulated the only sensation is a mild itching when the larvae are on the skin. The tiny number of hookworms means that ill effects are unlikely.
The format is a ’double-blind, placebo-controlled’ study, which means half the patient volunteers will be given the larvae, and half will get a placebo in the form of histamine that replicates the itching sensation on the surface of the skin.
The study follows on from work by Professor Pritchard and Professor John Britton, which is exploring the use of hookworms in the treatment of hayfever and asthma.
Crohn’s Disease is a chronic ongoing condition that most commonly affects the small intestine and colon. It causes inflammation, deep ulcers and scarring to the wall of the intestine, with main symptoms including pain in the abdomen, diarrhoea, fatigue and weight loss. It affects up to 60,000 people in the UK, with 3–6,000 new cases being diagnosed each year.
Currently, there is no way of curing Crohn’s Disease. Normal treatment includes steroids, which cannot be taken long-term, and immune suppressant drugs.
But if the new study is successful, drug therapies developed in the future could help to mimic the effect of the hookworm and may even be able to stop the condition occurring at all, scientists hope.
The study is being funded with a grant from the Broad Foundation, based in Los Angeles. Volunteer patients will be recruited to centres in Nottingham, Mansfield, Derby and Rotherham.
Notes to editors: The University of Nottingham undertakes world-changing research and provides teaching of the highest quality. Ranked in the THES World Top 100 Universities, its academics have won two Nobel Prizes since 2003. An international institution, the University has campuses in the United Kingdom, Malaysia and China.
More information is available from Dr Paul Fortun, Nottingham University Medical School, on +44 (0)115 823 1038, paul.fortun@nottingham.ac.uk; or Media Relations Manager Tim Utton in the University’s Public Affairs Office on +44 (0)115 846 8092, tim.utton@nottingham.ac.uk