Among the hot topics raised at the recently held World Allergy Congress (WAC) in Orlando, Florida (USA) – ahead of World Allergy Week (22-28 April) – was scientists’ discovery of a method using immune cell transfer and genetic engineering, which can switch on or turn off people’s reaction to allergies.
Scientists from the University of Queensland (Australia) were able to manipulate the immune response which triggers allergy symptoms in mice. An allergic response is typically caused by immune cells, commonly referred to as T-cells, reacting to a protein in an allergen. The challenge lies in the fact that T-cells can become resistant to treatments over time.
Associate Professor Jonny Peter, Head of the Division of Allergy and Clinical Immunology at UCT and Allergy Advisor to Pharma Dynamics (one of the leading providers of allergy medication in the country) explains that the researchers and scientists essentially found a way to silence the allergic inflammation in mice with a form of immune transfer and gene therapy allowing the immune system to become tolerant of previous allergens, such as egg protein, as opposed to viewing it as a threat.
“Animal experiments such as these give us a glimpse of what may be possible for the human immune system. The ability to re-program the immune system of allergy sufferers to be tolerant is the holy grail. Currently, available immune therapies take at least three years of daily treatment and may not provide lifelong benefits. These therapies are currently only available for inhaled allergens like house dust mite and not for life-threatening food allergies. If translated to humans, this research would be a game-changer. However, mice are not human, and translation has a long way to go. Furthermore, this worked focused on allergic airway inflammation, while food allergy mechanisms may be different. Human trials are expected to start in about five to six years, and only time will tell whether it is a viable option,” he says.
To build on the evidence which supports gene-based approaches in tackling allergic disease, other conference experts presented research related to the mechanisms used to pinpoint the various genetic components that can cause allergies.
Prof Peter says up to now progress on this front has been slow and expensive, due to the lack of high throughput technologies to investigate genetic variation in a large enough sample of patients.
“Fortunately, costs are coming down, technologies are improving and global consortiums are developing to allow for bigger Genome-Wide Association Studies (GWAS), which makes it possible for researchers to investigate large numbers of common variants spanning the entire genome in allergic- and non-allergic patients. These studies, together with next generation sequencing to identify rare gene defects in severe allergy individuals, will likely continue to improve our understanding of the genes responsible for a range of allergic diseases, including those for allergic rhinitis, asthma and atopic dermatitis.
“In the future, we will likely see sequencing in the clinic. The next frontier will then be to understand the additional layers of complexity provided by epigenetics and the interaction between genetics and the environment, especially the microbiota.”
In South Africa alone, an estimated 30% of the population suffer from allergic rhinitis (inflammation in the nose, which occurs when the immune system overreacts to allergens in the air), while 40% suffers from asthma. The effect of climate change on pollen allergy and respiratory allergic diseases was also at the forefront of the conference discussions. Although scientists are sketchy on exactly how climate change will impact respiratory allergies, they say the extreme weather events of the past decade have resulted in massive changes in our climate to which biologic systems on all continents are reacting – something that doctors and allergy-sufferers should keep a close eye on. A conference data presentation indicated that in a survey of allergy rhinitis sufferers, 51% of patients blamed pollution for their worsening symptoms, while 80% incriminated climate change. Prof Peter says there is some evidence of significantly stronger allergenicity in pollen from trees growing at increased temperatures and that climate change may affect air pollutant levels, such as tropospheric ozone (O3), but a lot more research is needed, before firm conclusions can be made.
Another recent survey conducted among 1 184 doctors who belong to the American Academy of Allergy Asthma and Immunology (AAAAI) confirmed that most doctors are witnessing medical problems caused by climate change among their patients. Nearly two-thirds reported a need for increased care for allergic sensitization and symptoms following exposure to plants or mould.
Scientists say possible effects of climate change on respiratory allergy could be as follows:
- An increase in rain and heavy downpours, such as thunderstorms could lead to asthma epidemics, with sudden pollen surges and ruptures. Last year, tragedy struck Melbourne following the death of nine asthma sufferers after an unprecedented thunderstorm. The moisture in the air caused pollen to burst into hundreds of allergenic particles – akin to 150 bombs exploding at the same time, which triggered widespread asthma attacks.
- Global warming could increase the length and intensity of the pollen season causing prolonged respiratory allergy symptoms.
- On the flipside, a reduction in colder days could potentially lower a patient’s risk to upper respiratory infections.
- Changes in atmospheric circulation patterns may increase the occurrence of long distance transport of pollen and pollutants.
- Increased air pollution and risk of wildfire smoke (CO2) could lead to an aggravation of existing respiratory allergies.
Pharma Dynamics has partnered with the University of Cape Town’s Lung institute to offer weekly pollen and fungal atmospheric counts to help allergy and asthma sufferers manage their condition better. Given the uncertainty of the climate at present, the only accurate method to guide allergy care is weekly sampling. Weekly pollen and fungal spore counts for the Cape Town area are available at www.allergyexpert.co.za
“The rate at which allergic diseases and asthma are increasing worldwide, is alarming. The World Allergy Organisation (WAO) reports that worldwide sensitization to allergies in the environment is present in up to 40% of the population. These disorders significantly impair a patient’s quality of life. Apart from chronic sneezing, nasal stuffiness and a post-nasal drip making them more susceptible to colds and flu, sufferers also complain of fatigue, memory loss, weakened physical and social functional and depression, hence the intense focus on developing safe and effective therapies for the future.
“World Allergy Week not only allows us to raise local awareness of allergic diseases, but to also share new insights into preventing and managing allergic conditions. For now, there is no silver bullet that can treat each and every symptom, but antihistamines, decongestants and other treatments should offer relief, and immunotherapy should be considered. Thankfully international research shows a promising future for treating and possibly even preventing (certain) allergies all-together,” says Prof Peter.