A Mouse With A Sniffle Was The Beginning But Now Research Into The Common Cold And Asthma Takes Its Next Steps
Asthma attacks result in around 1,200 deaths a year and cost the NHS approximately £1 billion annually. The common cold is one of the main causes of asthma attacks with 90% of people with asthma saying that colds and flu trigger their symptoms, and around 80% of all asthma attacks being caused by such viruses. Despite this, the mechanisms of rhinovirus infection and its links with asthma symptoms and attacks are poorly understood, and clinical evidence supporting how rhinoviruses can cause these symptoms is weak.
Following his exciting work, published earlier this year, which used a mouse model to explore the role of the common cold in triggering allergic inflammation of the airways (like that seen in asthma), Professor Sebastian Johnston, at Imperial College London, has been further investigating how rhinovirus infection can cause a reaction within the human body that is typical of an asthma attack, and why this reaction occurs.
The research, funded jointly by the Medical Research Council, Asthma UK, the British Lung Foundation, the British Medical Association, the National Institute for Health Research, Imperial College London and the Wellcome Trust, investigated responses to rhinovirus infection in 10 people with asthma and 15 control volunteers without asthma. Subjects were given a standard dose of the virus and their reactions were monitored and recorded.
After administering the virus both groups had colds of similar severity, but it was found that the volunteers with asthma had a clear increase in asthma symptoms compared with the control volunteers who developed only minimal symptoms. People with asthma also experienced a reduction in lung function and increased airway sensitivity in response to the infection; however this was not seen in the control volunteers.
After further analysis, it became apparent that the reaction seen in people with asthma was related to a deficiency in anti-viral immune responses which normally restrict the replication of a virus within the lung, thereby limiting asthma symptoms. With an impaired response, the virus replicates to higher levels, meaning that airway inflammation, and therefore asthma symptoms, are increased.
Although the number of subjects in the study was small, the results mark a new stage in investigations into the causal relationship between rhinovirus infection and asthma symptoms. The model used by Professor Johnston and his colleagues will now form the basis for testing possible future treatments for the worsening of asthma symptoms and asthma attacks as a result of rhinovirus infection. Similarly, novel approaches based on inhibiting viral replication and encouraging protective immune responses may have important therapeutic potential in the treatment of virus-induced asthma attacks in the future.
Sebastian L Johnston, Professor of Respiratory Medicine, says 'This study has demonstrated clear differences between the responses of asthmatic and normal subjects to rhinovirus infection both in terms of clinical symptoms and airway function.
'These observations provide compelling evidence supporting an important role for rhinovirus induced lower airway inflammation in precipitating asthma exacerbations and they identify new avenues for development of novel approaches to therapy.
'The study also showed that the reaction seen in people with asthma was related to the severity of their allergic airway inflammation before they were infected. This important finding emphasises the importance of keeping allergic airway inflammation under control by taking asthma controller medications.'
Notes
This research was funded by:
1. Asthma UK is the charity dedicated to improving the health and well-being of the 5.2 million people in the UK whose lives are affected by asthma. For up-to-date news on asthma, information and publications, visit the Asthma UK website http://www.asthma.org.uk.
1. British Lung Foundation The British Lung Foundation is the only UK charity working for everyone affected by lung disease. The charity focuses its resources on providing support for people affected by lung disease today; and works in a variety of ways (including funding world-class research) to bring about positive change, to improve treatment, care and support for people affected by lung disease in the future. http://www.lunguk.org
2. Imperial College London - rated the world's fifth best university in the 2007 Times Higher Education Supplement University Rankings - is a science-based institution with a reputation for excellence in teaching and research that attracts 12,000 students and 6,000 staff of the highest international quality. Innovative research at the College explores the interface between science, medicine, engineering and business, delivering practical solutions that improve quality of life and the environment - underpinned by a dynamic enterprise culture.
Imperial College London
3. The Medical Research Council supports the best scientific research to improve human health. Its work ranges from molecular level science to public health medicine and has led to pioneering discoveries in our understanding of the human body and the diseases which affect us all.
The Medical Research Council
4. The Wellcome Trust is the largest charity in the UK. It funds innovative biomedical research, in the UK and internationally, spending over £600 million each year to support the brightest scientists with the best ideas. The Wellcome Trust supports public debate about biomedical research and its impact on health and wellbeing.
The Wellcome Trust
Un mouse Cu Un Sniffle a fost începutul Dar acum, cercetarea în comun, rece ºi Astm ia Paºii urmãtori - A Mouse With A Sniffle Was The Beginning But Now Research Into The Common Cold And Asthma Takes Its Next Steps - articole medicale engleza - startsanatate