new research on Crohn's disease

[Guest guest]

Considering that there had been much conversation recently about

ulcerative colitis I thought this article may be of interest to some

of you on the list.

blessings

ovasoul

 

 

Weak immune response may cause Crohn's disease

 

* 11:30 24 February 2006

* NewScientist.com news service

* Lisa Hitchen

 

 

 

Crohn's disease might be due to a weak immune response, contrary to

current thinking, suggests research by UK scientists. They also

suggest that Viagra might help treat the disease by increasing blood

flow and enhancing the body's immune response.

 

Crohn's disease is a long term, inflammatory condition that leads to

holes and ulcers in the small and large intestines and can severely

impact on sufferers' quality of life. Its cause has remained a mystery

but current thinking is that it is an autoimmune disorder; where the

body attacks its own tissues.

 

But a team from University College London, UK, wondered if the

disorder might be due to an under reaction of the immune system instead.

 

A lack of an acute inflammatory response might lead to the delay or

incomplete removal of bacteria and other bowel contents from the gut

characterised by Crohn's. This material then breaches the mucosal

barrier, and its continued presence might provoke a huge immune

reaction and secondary chronic inflammation, the researchers reasoned.

 

White blood cells

 

The team compared patients with Crohn's disease with matched healthy

controls. They took a sample from the rectums of nine controls and six

patients to see the gut's reaction to the scraping.

 

The mucosa (or membrane) was normal in all patients at the start, but

six hours after the biopsy, healthy controls had an acute inflammatory

response but the patients with Crohn's did not. They produced much

lower amounts of white blood cells and inflammatory mediators – with a

79% reduction in immune cells called neutrophils and a 63% reduction

in interleukin 8-positive cells, in comparison with controls. Research

on the small intestine gave a similar result.

 

To check whether the response was just confined to the gut, the team

did another experiment using sandpaper to breach the skin barrier.

Five hours after this trauma, 13 Crohn's patients still had much lower

numbers of neutrophils and interleukin 8 cells at the trauma site than

controls.

 

Dead E. coli

 

Further experiments injecting heat-killed Escherichia coli into the

skin on the forearm lead to a nine-fold increase in blood flow to the

trauma site in healthy controls 24 hours later, but not in the 12

Crohn's patients tested.

 

"In Crohn's patients this was grossly defective," Anthony Segal, who

led the study, told New Scientist. The researchers then tested Viagra

(sildenafil) to see its effect on blood flow.

 

"This resulted in marked increases in blood flow in all patients so it

might be helpful in treatment of Crohn's, particularly in the colon,"

says Segal. He says his team are the first to trial use of Viagra for

patients with Crohn's disease. The study was self-funded, he notes.

 

Journal reference: The Lancet (vol 367 p 668)