A recent study revealed an association between outdoor urban air pollution and nonviral asthma exacerbations and with specific inflammatory pathways in the airways of children with asthma.
The prevalence and severity of asthma increased with the rise of urbanization, with studies showing that children living in low-income urban areas had the highest incidence of asthma. However, the mechanisms involved are not understood, especially compared to those driving the relationship between respiratory viruses and asthma exacerbations.
In this study, Matthew Altman, M.D., Ph.D., Division of Systems Immunology at the Benaroya Institute, and researchers focused on asthma exacerbations in the absence of respiratory viruses, while the team focused on local air pollutants. Concentration, respiratory disease, pulmonary function, and upper airway transcriptional signatures in children with asthma.
Specific Inflammatory Pathways and Air Pollutants
A retrospective analysis evaluated data from the 2017 MUPPITS1 cohort. This cohort enrolled 208 of her children aged 6–17 years from urban areas in 9 cities. The participating patient had asthma prone to exacerbations and between October 2015 and October 2016 she was recruited and monitored for respiratory status. The last survey visit she took place in January 2017.
Investigators then validated the findings in the ICATA cohort of 419 people aged 6 to 20 years with persistent allergic asthma living in urban areas of eight US cities. Registration was from She October 2006 to She March 2008, last visit He December 2009.
For this evaluation, investigators included patients who reported respiratory illness within the MUPPITS1 study period. Patient data from the ICATA cohort were included if they had respiratory disease or nasal samples collected at scheduled visits.
PM Air Quality Index Value and Air Pollutant Concentration2.5,afternoonTenO3number2so2, CO, and Pb across years from both cohorts from the US Environmental Protection Agency were used to match values and concentrations for each disease in each participant. The researchers then used a generalized additive model to identify associations between local air pollutant concentrations and exacerbations of respiratory disease and asthma, lung function, and upper airway transcriptional signatures. , case crossover analysis, and fusion of generalized linear mixed-effects models were utilized.
Effects of asthma without viral infection
Data showed rising air quality index values due to increased PM2.5O3 Concentrations were significantly associated with decreased lung function and the presence of asthma exacerbations without viral infection. The analysis consisted of 168 patients (98 male, 70 female) from MUPPITS1 and 189 patients (115 male, 74 female) from ICATA.
Evidence for altered gene expression in coordinated inflammatory pathways was highly relevant to individual contaminants. This observation related to PM2・5 Increased epithelial induction of tissue kallikrein, mucus hypersecretion, barrier function and O3 With type 2 inflammation on the rise, the team reported.
“Our findings demonstrate that air pollution is an important independent risk factor for asthma exacerbations in urban children, potentially associated with exacerbations through specific inflammatory pathways in the airways. “Further investigation of these potential mechanistic pathways may benefit approaches to asthma prevention and management.”
The study “Association of outdoor air pollutants with nonviral asthma exacerbations and airway inflammatory responses in urban children and adolescents in the United States: A retrospective secondary analysis” has been published. Lancet Planetary Health.