Gene Variants Linked to Pollution-Exacerbated Asthma

Air-quality advisories often foreshadow symptom flares for people with asthma, yet individual responses to pollution vary widely. Predicting who will be most affected has remained difficult in both routine care and research, in part because the molecular basis for this variability is not well understood. New findings now demonstrate gene–environment interactions linked to oxidative stress that help explain these differences.

University of Pittsburgh School of Public Health, working with the Severe Asthma Research Program (SARP), analyzed nearly 1,000 adults with asthma to identify biological pathways that modulate susceptibility to air pollution. The work, published in eBioMedicine on June 23, 2026, is among the largest and most comprehensive studies of its kind. Investigators combined whole‑genome sequencing, air‑pollution exposure data, and gene‑expression profiling to probe why pollution exacerbates symptoms for some patients more than others.

Image: The large study could support new asthma drug targets, biomarkers, and public health interventions for people most vulnerable to pollution-exacerbated asthma (Image credit: iStock)

The analysis concentrated on approximately 450 genes that regulate oxidative stress, a process through which highly reactive molecules can damage cells and tissues. Researchers examined exposure to fine particulate matter (PM2.5), microscopic particles smaller than 2.5 microns that can penetrate deep into the lungs. A first-of-its-kind transcriptomic assessment using human airway samples was performed: bronchial brushings from a subset of about 200 participants enabled direct measurement of how DNA is transcribed into RNA in airway epithelial cells following pollution exposure.

A clear exposure–response relationship emerged across the cohort, linking higher PM2.5 levels to lower lung function in people already living with asthma. Gene activity data showed how pollution altered transcriptional programs in airway cells. 

Genetic analyses identified seven oxidative stress–related genes whose variants appear to influence vulnerability to pollution-exacerbated asthma. Less common variants in OXSR1 and PXDN were associated with disproportionately worse lung function because of weaker protective RNA responses to PM2.5. A specific variant in TPO was also linked to worse lung function, but through stronger RNA responses, highlighting distinct mechanistic pathways. Other variants appeared to either enhance protection or intensify damage.

According to the authors, the molecular pathways identified could inform future therapeutic targets, as well as potential biomarkers and public health strategies for those at greatest risk. Next steps include deeper investigation of these pathways and studies testing whether targeted interventions, from behavioral changes to antioxidant approaches, can blunt the effects of pollution in high-risk individuals.

"You could imagine a simple test for a panel of genes that could be used to flag someone as highly susceptible to the effects of pollution," said Sally Wenzel, M.D., chair of Pitt Public Health’s Department of Environmental and Occupational Health and director of Pitt’s Asthma and Environmental Lung Health Institute at UPMC.

“We’re already exploring some of these pathways. Ultimately, while reducing the amount of pollution remains the most effective approach, the findings from our study suggest we could develop interventions specific to at-risk people that would lessen the impact of pollution,” said Wenzel.

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