22 August 2011
The prevalence of allergic disease in this country is among the highest in the world, with 1 in 5 New Zealanders affected by food allergy, asthma, eczema or hay fever.
For parents of young children, asthma and allergy are of major concern, said Director of Research Prof Graham Le Gros. Food allergies are especially relevant because of their impact on a childs quality of life.
Parents of allergic children have a lot to consider when it comes to sending their child to preschool and school, birthday parties or playdates, because of the potential risks of exposing their child to allergy-inducing foods, says Prof Le Gros.
Food-induced allergic reactions can range from mild discomfort to serious and life threatening events, with anaphylaxis (the rapid onset of breathing difficulties, skin reactions, vomiting) the most severe form of food allergy.
Until we know why some children react to particular foods in this way, we cannot begin to address how best to treat them, says Prof Le Gros. Despite extensive research into the potential epidemiological, genetic or clinical associations of allergic disease, little progress has been made in this area.
Food allergies occur when the immune system, which normally serves to protect us against parasites, viruses and bacteria, mounts an attack on harmless food components such as proteins. The particular proteins that trigger this immune response are called allergens.
Prof Le Gros and colleagues believe that the answer to treating food allergy lies in understanding how these foods set off the allergic immune response, and why it only happens in some individuals.
There are few treatment options for individuals with allergic disease, says Prof Le Gros. Patients are advised to avoid the allergen (especially in the case of foods) and are offered the drugs corticosteroids, which act by suppressing all immune responses regardless of whether they are beneficial or harmful.
Desensitisation therapy, where a patient is gradually exposed to an allergen in a controlled manner to get their immune system used to seeing it, is currently the only curative option available, however, it is not always effective and the mechanism by which it acts is not well understood. Prof Le Gros says that further research on better treatments and on the immune mechanisms involved in controlling allergic disease is needed.
Working alongside Dr Elizabeth Forbes-Blom, a Research Fellow at the Malaghan Institute who specialises in food allergy, Prof Le Gros will use the HRC funding to develop new food allergy disease models.
We will use these models to reveal for the first time the earliest cellular and molecular events involved in sensitising the immune cells in the gut to food allergens, says Prof Le Gros. These models will also support further research into the identification of improved strategies for treating food allergy.
One such therapeutic strategy that has shown promising results in asthma disease models is the targeted killing of the immune cells that are responsible for setting off the allergic immune response. In an earlier HRC funded research project, Prof Franca Ronchese and colleagues showed that by exploiting the killing activity of specialised immune cells called cytotoxic T lymphocytes, they can reduce allergic airway inflammation and alleviate the symptoms of asthma.
With the support of the HRC, Prof Ronchese will now extend these studies further to determine if this therapy is equally effective in reducing inflammation in other tissues affected by allergic disease such as the gut (food allergy) or skin (eczema).
With the HRC funding the Malaghan Institute is now uniquely placed to better address New Zealands growing food allergy problem, says Prof Le Gros. The new knowledge generated from the two funded research programmes will improve our ability to treat allergic diseases more effectively and with fewer side effects, which will lead to significantly improved outcomes for allergy sufferers.