Brussels, 07 Sep 2005
Two presentations during the ongoing BA Festival of Science in Dublin, Ireland, have focused on European research into asthma. British scientists from Imperial College London have suggested that dirt could educate the immune system and help treat asthma, while researchers at Trinity College, Dublin have managed to cure experimental asthma in the lab using a live worm.
80 million adults in Europe suffer from allergies, and it is widely predicted that by 2015, 40 per cent of the European population will fall into that category. Asthma alone is responsible for the annual loss of some nine billion workdays in the EU. The UK and Ireland are experiencing an asthma epidemic and have some of the highest rates of asthma in the world.
Many scientists believe that an increased susceptibility to allergies is the price we pay for living in a cleaner, more disease free society. Scientists have called this the 'hygiene' hypothesis, where a lack of exposure to dirt and common parasitic worms, and bacterial or viral infections among children results in their not being able to build up resistance, and thus become more susceptible to disease later in life. Speaking at the BA Festival of Science, Imperial College's Peter Openshaw explained that this could be the reason behind the rise in levels of asthma.
Professor Openshaw, a respiratory medicine researcher based at St Mary's Hospital, explained: 'Although we have seen a dramatic decline in many previously common childhood infections over the past 100 years, we have also seen a considerable rise in the prevalence of diseases such as asthma. The increase in asthma cannot be blamed purely on changes in genetic risk, so must be down to environmental factors.'
Studies have shown that most common colds can help protect against wheezing in later childhood, and other childhood infections such as chickenpox also provide a level of protection. According to Professor Openshaw, 'the challenge now is to find ways of reproducing the protective effects of early childhood infections, while reducing the burden of actually getting these infectious diseases. Knowing exactly which dirt provides the best education for the immune system, and how to mimic its affects in a cleaner environment, could be the key to reducing the rise in the prevalence of asthma and related diseases.'
Dr Padraic Fallon, from the Department of Biochemistry at Trinity College, Dublin, presented an unexpected key source in preventing asthma and reducing allergies: parasitic worms.
Studies have already shown that people in developing countries have fewer allergies. During a study in Gabon, it was found that schoolchildren infected with worms had lower allergic responses to house dust mites than children with no worms. When the children had their worms removed by drugs they then developed increased allergic responses. Allergies are caused when the immune system responds to allergens and this immune response can stimulate allergic diseases, including eczema, anaphylaxis and asthma. Infections with parasitic worms also induce these immune responses and it is argued that this type of immune response was not designed to cause allergies, but evolved to control worm infections. As in most modern societies there are no longer parasitic worms present, the immune system responds to other common allergens, such as dust mites or cats and induces allergies.
The particular worm in question, the schistosome, is the cause of Bilharzia. Dr Fallon described his group's research at the BA Festival of Science: looking at how schistosomes alter a person's immune response. The objective of the research is to use molecules from the schistosome worm to treat or prevent diseases such as asthma and inflammatory bowel disease. Previously, his group has shown that when transgenic mice, engineered to have a high susceptibility to anaphylaxis and asthma, were infected with the worm they developed resistance to anaphylaxis.
'We believe that this research will lead us to develop new ways of preventing and treating asthma and anaphylaxis, which can then be extended to treat inflammatory bowel disease and arthritis,' says Dr Fallon.
The European Commission has already invested 14.4 million euro to fund the GA2LEN (global allergy and asthma European network) Network of Excellence under the 'Food quality and safety' priority of the Sixth Framework Programme (FP6). GA2LEN, launched in February 2004, involves 25 partners and some 650 junior and senior researchers in 16 countries.
For further information on GA2LEN, please consult the following web address: http://www.ga2len.net