The allergen exposure paradox; early exposure, tolerance development and long-term effects

The overall purpose of this research proposal is to address the paradox that allergen exposure (pollen, pets) can be both a risk and a protective factor for development and long-term outcomes of asthma and allergic disease in children and adolescents. We will study how genetic propensity, respiratory tract infections and urban living contribute to the associations.

We will also study the molecular genetic architecture for dog ownership.

We use information on diagnoses and medication from the national health care linked to pollen counts, pet ownership and area of residence as well as genetic susceptibility (genome-wide association, GWAS and polygenic risk scores) from clinical twin cohorts.

The direction of associations between exposure to pollen and pets and 1) development of asthma and allergy or 2) long-term outcomes for those with established disease will be estimated exploring the role of genetic propensity, respiratory tract infections and urban living. A GWAS will be performed to 3) identify variants associated with dog ownership.

The project organisation and infrastructure is already in place, and we will collect additional data during the first few years.

The studies will provide powerful insights on the role of genetic liability, respiratory infections and urban living for the association between allergen exposure and asthma or allergic disease.

The results will contribute to improved diagnostic methods and therapies for individually adapted prevention and treatment.