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Background: The relationship between ambient air pollution (AAP) exposure and asthma exacerbations is well-established. However, mitigation efforts have yielded mixed results, potentially due to genetic variability in the response to AAP. We hypothesize that common single nucleotide polymorphisms (SNPs) are linked to AAP sensitivity and test this through a Genome Wide Association Study (GWAS). Methods: We selected a cohort of pediatric asthma patients frequently exposed to AAP. Patients experiencing exacerbations immediately following AAP spikes were deemed sensitive. A GWAS compared sensitive versus non-sensitive patients. Findings were validated using data from the All of Us program. Results: Our study included 6,023 pediatric asthma patients. Due to the association between AAP exposure and race, GWAS analysis was feasible only in the African ancestry cohort. Seven risk loci reached genome-wide significance, including four non-intergenic variants. Two variants were validated: rs111970601 associated with sensitivity to CO (odds ratio [OR], 6.58; PL=L1.63L×L10-8; 95% CI, 3.42-12.66) and rs9836522 to PM2.5 sensitivity (OR 0.75; PL=L3,87 ×L10-9; 95% CI, 0.62-0.91). Interpretation: While genetic variants have been previously linked to asthma incidence and AAP exposure, this study is the first to link specific SNPs with AAP-related asthma exacerbations. The identified variants implicate genes with a known role in asthma and established links to AAP. Future research should explore how clinical interventions interact with genetic risk to mitigate the effects of AAP, particularly to enhance health equity for vulnerable populations. What is already known on this topic: The relationship between ambient air pollution (AAP) exposure and asthma exacerbations is well-established. However, efforts to mitigate the impact of AAP on children with asthma have yielded mixed results, potentially due to genetic variability in response to AAP. What this study adds: Using publicly available AAP data, we identify which children with asthma experience exacerbations immediately following spikes in AAP. We then conduct a Genome Wide Association Study (GWAS) comparing these patients with those who have no temporal association between AAP spikes and asthma exacerbations, identifying several Single Nucleotide Polymorphisms (SNPs) significantly associated with AAP sensitivity. How this study might affect research practice or policy: While genetic variants have previously been linked to asthma incidence and AAP exposure, this study is the first to link specific SNPs with AAP-related asthma exacerbations. This creates a framework for identifying children especially at risk when exposed to AAP. These children should be targeted with policy interventions to reduce exposure and may require specific treatments to mitigate the effects of ongoing AAP exposure in the interim.
RESUMO
RATIONALE: In the outpatient setting, inhaled corticosteroids (ICS) are frequently given to children with bronchopulmonary dysplasia (BPD) for treatment of respiratory and asthma-associated symptoms. In this study we sought to determine if correlations existed between ICS use and ICS initiation and patient characteristics and outpatient respiratory outcomes. METHODS: This study included children with the diagnosis of BPD (n = 661) who were seen in outpatient pulmonary clinics at the Children's Hospital of Philadelphia between 2016 and 2021. Chart review was used to determine patient demographics, use and timing of ICS initiation, asthma diagnosis, and acute care usage following initial hospital discharge. RESULTS: At the first pulmonary visit, 9.2% of children had been prescribed an ICS at NICU discharge, 13.9% had been prescribed an ICS after NICU discharge but before their first pulmonary appointment, and 6.9% were prescribed an ICS at the completion of initial pulmonary visit. Children started on an ICS as outpatients had a higher likelihood of ER visits (adjusted odds ratio: 2.68 ± 0.7), hospitalizations (4.81 ± 1.16), and a diagnosis of asthma (3.58 ± 0.84), compared to children never on an ICS. Of those diagnosed with asthma, children prescribed an ICS in the outpatient setting received the diagnosis at an earlier age. No associations between NICU BPD severity scores and ICS use were found. CONCLUSIONS: This study identifies an outpatient BPD phenotype associated with ICS use and ICS initiation independent of NICU severity score. Additionally, outpatient ICS initiation correlates with a subsequent diagnosis of asthma and acute care usage in children with BPD.