Effects of budesonide on responses to diesel exhaust and allergen exposures in allergic rhinitis

About one in every four Canadians suffers from a disease called allergic rhinitis. This causes symptoms like sneezing, itching, watery eyes, and difficulty breathing, especially when people inhale allergens from sources like trees and grasses. A type of medicine called nasal corticosteroids can usually help reduce these symptoms.
However, we do not know how exposure to air pollution, such as diesel exhaust, which is common in cities and industrial areas, might make this disease worse. We also do not know if nasal corticosteroids can help reduce the effects of exposure to diesel exhaust.

 

To investigate this, we conducted a study where we exposed people with allergic rhinitis to allergens and diesel exhaust separately, both with and without the use of nasal corticosteroids. This study was conducted at the Air Pollution Exposure Laboratory (APEL), a leading research facility that uses advanced controlled exposure methods to study how air pollution affects human health.

 

I will be looking at changes in how the nose functions as well as the levels of cells and small proteins in the nose that can underly symptoms, to see if nasal corticosteroids can effectively treat the effects of exposure to allergens and diesel exhaust.

 

The Master’s Studentship 2023 Award, supported by the Canadian Consortium of Clinical Trial Training Platform (CANTRAIN) Clinical Trials Training Program and Michael Smith Health Research BC, will thus help us evaluate a low-cost, accessible treatment for this growing health concern. This work will be supported by the Legacy for Airway Health (LAH), which supports knowledge translation and allows us to consult directly with patients. Since this work is being done in British Columbia, it also helps build local expertise in respiratory clinical trials and research.

End of Award Update – December 2024

 

Results

Allergens and air pollution can trigger inflammation in the nose, leading to irritation and discomfort for many people. We discovered that budesonide, a medicine often used to treat nasal allergies, can reduce levels of an important inflammation-causing protein (IL-5) in the nose. Budesonide works well even after exposure to diesel exhaust (DE), a major component of traffic related air pollution (TRAP). We also found that exposure to allergen and DE can lead to temporary changes to the DNA of nasal cells, which may affect how they function. These changes are what we call epigenetic changes, as they do not change the DNA sequence, just what is stuck on it. Interestingly, we found that budesonide may reverse these changes caused by allergens. These results are exciting because they show that budesonide can likely help people with nasal allergies breathe more easily, even if they are exposed to allergens or traffic pollution, which are very common.  

 

Impact

We have presented our findings at major national and international venues, such as the American Thoracic Society (ATS) 2024 International Conference, and are working on submitting them to a leading health research journal for publication. This will help doctors and other healthcare professionals learn about how this common medicine has new beneficial effects so that they can better treat patients during allergy season or periods of higher air pollution.  

 

Potential Influence

Our findings will allow us to get a better understanding of how medicines like budesonide interact with things we breathe in, like allergens and traffic pollution, on multiple levels. Other scientists can use our results to help them in making new medicines, as well as to research new health benefits for existing medicines. Scientists and doctors can also use our results to help improve guidelines so that patients can make better use of medicines like budesonide to reduce the impact of their nasal allergies. In addition to helping patients live better lives, this will reduce missed work due to symptoms, reducing costs to the Canadian and international economy. Leading this study has also allowed me to gain valuable skills for performing independent clinical research as part of a diverse, interdisciplinary team. This will allow me to continue to contribute to future clinical trials and health research in Canada so that we can tackle current and emerging health challenges, like the COVID-19 pandemic. 

 

Next Steps

We are in the process of finalizing and submitting a manuscript containing our research findings to a leading health research journal so other scientists and healthcare professionals can learn about this work. We are also collaborating with our highly capable knowledge mobilization unit, the Legacy for Airway Health (https://www.legacyairwayhealth.ca/), to get the word out throughout the wider community, based on dialogue with patient partners and additional outreach efforts. 

 

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