Grant: DRA : Canada Graduate Research Scholarship - Doctoral Program (CGRS D)

Allergic rhinitis (AR), or hay fever, affects up to 80% of people with asthma. Both conditions occur when the immune system overreacts to harmless substances called allergens, like pollen or dust mites. When these individuals breathe in allergens, cells in their nose and lungs release thymic stromal lymphopoietin (TSLP). TSLP acts like an alarm, activating the immune system and causing inflammation and symptoms such as sneezing, congestion, coughing, and wheezing. Tezepelumab is a medication approved in Canada to treat severe asthma by blocking TSLP. Many people with asthma also have AR and high levels of TSLP in their noses, yet tezepelumab is not approved to treat both conditions due to limited research on its effects on nasal symptoms. Studying tezepelumab in people with AR and asthma could improve their quality of life and reduce healthcare strain. We believe tezepelumab will treat both conditions by reducing symptoms and inflammation in the nose. In our study, 14 participants with AR and asthma will receive tezepelumab for 12 months. We will use a Nasal Allergen Challenge to trigger an allergic response by applying allergen directly into the nose. Before treatment, we will assess participants' symptoms, measure TSLP and other markers of inflammation. These assessments will be repeated at 6 and 12 months after starting treatment, and we will also monitor quality of life and lung function changes. Five participants without asthma or allergies will undergo the challenge for comparison. Our study focuses on people with both AR and asthma; a common yet overlooked group. Positive results could lead to larger clinical trials studying tezepelumab in these individuals. Even if results are not as expected, we will gain valuable insights into how blocking TSLP affects AR. This knowledge will guide future research and help develop better treatments to address both conditions simultaneously. This could improve health outcomes and ease the burden on healthcare services.