Published online: January 14, 2020
Asthma and rhinitis often co-exist in the same patient and are caused by a combination of genetic and environmental factors. Having pets at home may protect against the development of allergies.
DNA may be modified by environmental factors, which can affect gene function. This is called epigenetics. Epigenetic variation, such as DNA methylation, might mediate genetic and environmental effects on the development of asthma and rhinitis. This could be visible in nasal cells, which are the first place where environmental air comes into contact with the body; therefore, DNA methylation signatures in nasal cells might help understand the origins of asthma and rhinitis.
In an article recently published in The Journal of Allergy and Clinical Immunology (JACI), Qi and colleagues used big data analysis by integrating genome-wide DNA methylation and gene expression to understand the origins of asthma and rhinitis. They investigated nasal cells from 455 16-year-old children from a Dutch birth cohort. The authors performed epigenome-wide association studies on asthma, rhinitis and their combination, and replicated the top findings in two US cohorts. They also interpreted their top findings by correlating significant DNA methylation signals to genes nearby and to environmental exposures, such as exposure to smoking, or having pets.
The authors identified nasal DNA methylation sites that were associated with asthma and rhinitis. Based on these sites, they provided a model that can be used across different populations to diagnose asthma and rhinitis in children. The epigenetic signals were correlated to the expression of nearby genes, which mostly had an immune function. They also found that having pets was related to a higher methylation level at a methylation site which was associated with lower risk of asthma and rhinitis.
This study identified nasal epigenetic markers which are significantly correlated with asthma and rhinitis. One of the markers was also associated with childhood pet exposure, suggesting an epigenetic link between having pets and less risk of asthma and/or rhinitis. These findings also suggested that nasal DNA methylation profiles may help to diagnose of asthma and rhinitis.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.