Allergy researchers create halo of hope

[Guest guest]

Allergy researchers create halo of hope

Janelle Miles

03jun05

http://www.thecouriermail.news.com.au/common/story_page/0,5936,154869

29%255E953,00.html

AUSTRALIAN scientists have developed a new technique that might one

day help doctors better identify asthma and allergy triggers in

patients.

The novel diagnostic tool, known as the halogen immunoassay, may

eventually be used with worldwide standard skin-prick tests to

pinpoint the wide range of culprits exacerbating allergic symptoms

in different people.

It allows researchers to collect airborne particles in an

individual's environment and combine them with serum from the

patient's blood, causing a protein reaction that lights up the

offending allergens with a halo.

Euan Tovey, of Sydney's Woolcock Institute of Medical Research,

originally developed the tool to diagnose an individual's

susceptibility to dust mite allergens.

The technique, licensed to the University of Sydney, has since been

modified to pick up a patient's response to a range of airborne

particles including pollen, cat and dog hair, rat and cockroach

allergens.

More recently, PhD student Brett Green, of the Woolcock's allergen

unit, used the tool to highlight an individual's sensitivity to

fungal fragments. Mr Green used air-sampling pumps to collect fungi

from indoor residential environments for 2½ hours a day over 21

days.

" The new technique has provided a way to stain the offending fungi

with serum from a person allergic to the fungi, thus identifying

which ones they are allergic to, " Mr Green said.

" This is a very significant progress as it provides a new way to

link exactly what a person is exposed to, allergic to and their

symptoms. "

Mr Green's data, published recently in The Journal of Allergy and

Clinical Immunology, identified many more types of allergenic fungi

than previously thought.

" What we found completely amazed us because it was very different to

the traditional way of thinking to what fungi were important to

exacerbate allergic diseases, " he said.

" The diagnosis of fungal allergy is usually made on the basis of

responses to three or four species.

" Our findings suggest a much more diverse range of fungi, including

smaller fungal fragments, function as sources of allergen. "

Mr Green said traditional skin-prick testing screened for only a few

species of fungi that may or may not occur in a patient's individual

environment.

" Our technique tests what occurs naturally in someone's environment

so you're looking at the full spectrum of what someone's exposed

to, " he said.

Mr Green's research is considered a breakthrough, given that

epidemiologic studies have found fungal exposure is linked to

symptoms of seasonal rhinitis, asthma and even death in subjects

with fungal allergy.

Once people know what they are allergic to, they can take steps to

try to avoid it.

The Woolcock Institute hopes to commercialise the halogen test.