RNA Sequencing Analysis of Monocytes Exposed to Airway Fluid From Children With Pediatric Acute Respiratory Distress Syndrome.

OBJECTIVES: Monocytes are plastic cells that assume different polarization states that can either promote inflammation or tissue repair and inflammation resolution. Polarized monocytes are partially defined by their transcriptional profiles that are influenced by environmental stimuli. The airway monocyte response in pediatric acute respiratory distress syndrome (PARDS) is undefined. To identify differentially expressed genes and networks using a novel transcriptomic reporter assay with donor monocytes exposed to the airway fluid of intubated children with and at-risk for PARDS. To determine differences in gene expression at two time points using the donor monocyte assay exposed to airway fluid from intubated children with PARDS obtained 48-96 hours following initial tracheal aspirate sampling. DESIGN: In vitro pilot study carried out using airway fluid supernatant. SETTING: Academic 40-bed PICU. PARTICIPANTS: Fifty-seven children: 44 children with PARDS and 13 children at-risk for PARDS. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We performed bulk RNA sequencing using a transcriptomic reporter assay of monocytes exposed to airway fluid from intubated children to discover gene networks differentiating PARDS from at-risk for PARDS and those differentiating mild/moderate from severe PARDS. We also report differences in gene expression in children with PARDS 48-96 hours following initial tracheal aspirate sampling. We found that interleukin (IL)-10, IL-4, and IL-13, cytokine/chemokine signaling, and the senescence-associated secretory phenotype are upregulated in monocytes exposed to airway fluid from intubated children with PARDS compared with those at-risk for PARDS. Signaling by NOTCH, histone deacetylation/acetylation, DNA methylation, chromatin modifications (B-WICH complex), and RNA polymerase I transcription and its associated regulatory apparatus were upregulated in children with PARDS 48-96 hours following initial tracheal aspirate sampling. CONCLUSIONS: We identified gene networks important to the PARDS airway immune response using bulk RNA sequencing from a monocyte reporter assay that exposed monocytes to airway fluid from intubated children with and at-risk for PARDS. Mechanistic investigations are needed to validate our findings.

Asthma Control and Associated Factors Among Children with Current Asthma - Findings from the 2019 Child Behavioral Risk Factor Surveillance System - Asthma Call-Back Survey.

Purpose: This study aimed to determine the prevalence and correlates of uncontrolled asthma among children with current asthma in four US states. We also determined the rates and correlates of asthma-related hospitalization, urgent care center (UCC), or emergency department (ED) visits. Participants and Methods: We analyzed the 2019 Behavioral Risk Factor Surveillance Survey (BRFSS) Asthma Call-back Survey (ACBS) datasets. Asthma control status was classified as well-controlled or uncontrolled asthma based on day- and night-time asthma symptoms, activity limitation or use of rescue medications. Multivariable logistic regression models were used to identify the correlates of uncontrolled asthma and asthma-related hospitalization or UCC/ED visits. Results: Among 249 children with current asthma, 55.1% had uncontrolled asthma while 40% reported asthma-related hospitalization or UCC/ED visits in the past year. Non-Hispanic ethnicity, ages of 0-9 and 15-17 years, household income <$25,000, and not having a flu vaccination had higher odds of uncontrolled asthma. Conversely, asthma self-management education and households with two children compared to one were positively associated with uncontrolled asthma. For healthcare utilization, male and non-Hispanic children, along with those from households earning <$25,000 exhibited higher odds of asthma-related hospitalization and UCC/ED visits. Conclusion: Uncontrolled asthma and asthma-related visits to UCC/ED and hospitalization are common among children with current asthma. These outcomes are influenced by low household income and male sex, among other factors which call for multi-faceted interventions by healthcare providers and policymakers. Targeted strategies to effectively manage asthma and reduce the need for emergency healthcare services are recommended.

Plasma metabolomics identifies differing endotypes of recurrent wheezing in preschool children differentiated by symptoms and social disadvantage.

Preschool children with recurrent wheezing are a heterogeneous population with many underlying biological pathways that contribute to clinical presentations. Although the morbidity of recurrent wheezing in preschool children is significant, biological studies in this population remain quite limited. To address this gap, this study performed untargeted plasma metabolomic analyses in 68 preschool children with recurrent wheezing to identify metabolomic endotypes of wheezing. K-means cluster analysis was performed on metabolomic dataset including a total of 1382 named and unnamed metabolites. We identified three metabolomic clusters which differed in symptom severity, exacerbation occurrence, and variables associated with social disadvantage. Metabolites that distinguished the clusters included those involved in fatty acid metabolism, fatty acids (long chain monounsaturated fatty acids, long chain polyunsaturated fatty acids, and long chain saturated fatty acids), lysophospholipids, phosphatidylcholines, and phosphatidylethanolamines. Pathway analyses identified pathways of interest in each cluster, including steroid metabolism, histidine metabolism, sphingomyelins, and sphingosines, among others. This study highlights the biologic complexity of recurrent wheezing in preschool children and offers novel metabolites and pathways that may be amenable to future study and intervention.

Clinical and inflammatory features of traffic-related diesel exposure in children with asthma.

BACKGROUND: Epidemiologic studies have revealed associations between traffic-related pollutants such as diesel particulate matter (PM) and asthma outcomes in children, but the inflammatory features associated with diesel PM exposure in children with asthma are not understood. OBJECTIVE: To evaluate symptoms, exacerbations, and lung function measures in children with uncontrolled asthma and their associations with residential proximity to major roadways and to determine associations between diesel PM exposure and systemic inflammatory cytokines, circulating markers of T-cell activation and exhaustion, and metabolomic features using biomarker studies. METHODS: Children 5 to 17 years of age with physician-diagnosed, uncontrolled asthma despite treatment with an asthma controller medication completed a research visit involving questionnaires, lung function testing, and venipuncture for biomarker studies. Geocoding was performed to quantify residential proximity to major roadways and pollutant exposure. RESULTS: A total of 447 children with uncontrolled asthma were enrolled. Children living closer to highly trafficked roadways were more disadvantaged and had more exposure to diesel PM, more exacerbations prompting an emergency department visit, and lower lung function measures. Children with the highest diesel PM exposure, compared with children with the lowest diesel PM exposure, also had blunted cytokine secretion and evidence of T-cell exhaustion, including disturbances in several metabolites associated with glutathione formation and oxidative stress. CONCLUSION: Traffic-related diesel PM exposure in children with poorly controlled asthma is associated with poorer clinical outcomes and unique patterns of inflammation and oxidative stress. These findings argue for continued mitigation efforts to improve traffic-related air quality and health equity in children with asthma.

HIGH THROUGHPUT QUANTITATION OF HUMAN NEUTROPHIL RECRUITMENT AND FUNCTIONAL RESPONSES IN AN AIR-BLOOD BARRIER ARRAY.

Dysregulated neutrophil recruitment drives many pulmonary diseases, but most preclinical screening methods are unsuited to evaluate pulmonary neutrophilia, limiting progress towards therapeutics. Namely, high throughput therapeutic screening systems typically exclude critical neutrophilic pathophysiology, including blood-to-lung recruitment, dysfunctional activation, and resulting impacts on the air-blood barrier. To meet the conflicting demands of physiological complexity and high throughput, we developed an assay of 96-well Leukocyte recruitment in an Air-Blood Barrier Array (L-ABBA-96) that enables in vivo -like neutrophil recruitment compatible with downstream phenotyping by automated flow cytometry. We modeled acute respiratory distress syndrome (ARDS) with neutrophil recruitment to 20 ng/mL epithelial-side interleukin 8 (IL-8) and found a dose dependent reduction in recruitment with physiologic doses of baricitinib, a JAK1/2 inhibitor recently FDA-approved for severe COVID-19 ARDS. Additionally, neutrophil recruitment to patient-derived cystic fibrosis sputum supernatant induced disease-mimetic recruitment and activation of healthy donor neutrophils and upregulated endothelial e-selectin. Compared to 24-well assays, the L-ABBA-96 reduces required patient sample volumes by 25 times per well and quadruples throughput per plate. Compared to microfluidic assays, the L-ABBA-96 recruits two orders of magnitude more neutrophils per well, enabling downstream flow cytometry and other standard biochemical assays. This novel pairing of high-throughput in vitro modeling of organ-level lung function with parallel high-throughput leukocyte phenotyping substantially advances opportunities for pathophysiological studies, personalized medicine, and drug testing applications.

Symptoms and quality of life in adults with cystic fibrosis: A cross-sectional analysis of the InSPIRe:CF trial.

BACKGROUND: People living with cystic fibrosis (CF) experience a high symptom burden. Due to the changing landscape of CF in the era of modulator therapy, we sought to examine the epidemiology of symptoms and their association with quality of life, to help CF clinicians improve symptom screening in clinic. METHODS: Using baseline data from a trial of specialist palliative care in adults with CF, we examined symptom prevalence, distress, and association with quality of life (measured with the Functional Assessment of Chronic Illness Therapy Total Score). RESULTS: Among 262 participants, median age was 33, and 78% were on modulator therapy. The most common symptoms were lack of energy (n = 194, 74%) and cough (190, 73%), whereas the most distressing were difficulty sleeping (range 0-4, mean 2.19, SD 1.15) and pain (mean 2.04, SD 1.1). The symptoms that impaired quality of life the most were extrapulmonary: lack of energy (average quality of life score -29.8, 95% CI -36.8 to -22.8), feeling sad (-29.8, 95% CI -35.6 to -23.9) and worrying (-28.7, 95% CI -34.9 to -22.5). CONCLUSIONS: The symptoms that were associated with the lowest quality of life were extrapulmonary. CF clinicians may consider screening for common symptoms that affect quality of life the most (lack of energy, worrying, difficulty sleeping, feeling irritable, pain, and shortness of breath). These symptoms may identify people living with CF who are most at risk for a decreased quality of life and may benefit from additional support.

Pediatric emergency department-based asthma education tools and parent/child asthma knowledge.

Asthma exacerbations are a leading cause of pediatric hospitalizations despite multiple efforts to educate patients and families on disease course and medication management. Asthma education in the pediatric emergency department (ED) is challenging, and although the use of written action plans has been associated with reduction in hospitalizations and ED visits, written tools may not be useful for individuals with low health literacy. Moreover, asthmatic children should participate in their asthma education. In this prospective randomized study of 53 families presenting to a pediatric ED with a child experiencing an asthma exacerbation, education on asthma was presented via an interactive mobile-based video-game versus a standard-of-care asthma education video (SAV). Median age was 10 years; 64% were males. Many patients had moderate-to-severe asthma, with 57% experiencing ≥ 2 asthma-related ED visits in the last year, 58% requiring hospitalization and 32% reporting a critical care admission. In this cohort, the mobile-based video-game was found to be a feasible, acceptable educational tool; 86% of parents and 96% of children liked the game, while 96% of parents and 76% of children preferred playing the game over watching a SAV. Despite a history of persistent asthma, only 34% of children used an inhaled corticosteroid while 70% required rescue inhaler use in the prior week. Basic asthma knowledge was sub-optimal with only 60% of parents and 43% of children correctly recognizing symptoms that should prompt immediate medical care. This reflects a major gap in asthma knowledge that coexists with parental misconceptions regarding optimal asthma management.

Dysfunctional neutrophil type 1 interferon responses in preschool children with recurrent wheezing and IL-4-mediated aeroallergen sensitization.

Background: The innate mechanisms associated with viral exacerbations in preschool children with recurrent wheezing are not understood. Objective: We sought to assess differential gene expression in blood neutrophils from preschool children with recurrent wheezing, stratified by aeroallergen sensitization, at baseline and after exposure to polyinosinic:polycytidylic acid (poly(I:C)) and also to examine whether poly(I:C)-stimulated blood neutrophils influenced airway epithelial gene expression. Methods: Blood neutrophils were purified and cultured overnight with poly(I:C) and underwent next-generation sequencing with Reactome pathway analysis. Primary human small airway epithelial cells were treated with poly(I:C)-treated neutrophil culture supernatants and were analyzed for type 1 interferon gene expression with a targeted array. Symptoms and exacerbations were assessed in participants over 12 months. Results: A total of 436 genes were differently expressed in neutrophils from children with versus without aeroallergen sensitization at baseline, with significant downregulation of type 1 interferons. These type 1 interferons were significantly upregulated in sensitized children after poly(I:C) stimulation. Confirmatory experiments demonstrated similar upregulation of type 1 interferons in IL-4-treated neutrophils stimulated with poly(I:C). Poly(I:C)-treated neutrophil supernatants from children with aeroallergen sensitization also induced a type 1 interferon response in epithelial cells. Children with aeroallergen sensitization also had higher symptom scores during exacerbations, and these symptom differences persisted for 3 days after prednisolone treatment. Conclusions: Type 1 interferon responses are dysregulated in preschool children with aeroallergen sensitization, which is in turn associated with exacerbation severity. Given the importance of type 1 interferon signaling in viral resolution, additional studies of neutrophil type 1 interferon responses are needed in this population.

Clustering by chemicals: A novel examination of chemical pollutants and social vulnerability in children and adolescents.

BACKGROUND: Inhaled air pollutants are environmental determinants of health with negative impacts on human health. Air pollution has been linked to the incidence and progression of disease, with its effects unequally distributed across the population. Children compared to adults are a highly vulnerable group and suffer disproportionately from systemic environmental inequities exacerbated by social determinants. OBJECTIVE: To explore air pollution cluster patterns among 6- to 19-year-olds from the 2015-2016 National Health and Nutrition Examination Survey (NHANES) and examine chemical cluster associations with social vulnerability. METHODS: NHANES data was extracted for 697 children and adolescents. Social vulnerability characteristics from questionnaires were assembled to construct a modified social vulnerability index (SVI). Thirty-four air pollutant exposure chemicals were measured in urine and available from the laboratory sub-sample A data. K-means clustering classified the sample into three groups: low, medium, and high chemical exposure groups. Logistic regression was used to examine associations between high chemical group membership and SVI after adjusting for age, biological sex, and BMI. Complex survey analysis was conducted using SAS v9.4 to reflect population effects. RESULTS: Air pollution clusters revealed significant differences in mean concentrations between groups for 31 analytes with minimal distinction in mixture profiles. SVI scores differed significantly between the three groups (P = .002), and with each point increase in their SVI, the odds of a child being assigned to the highest-chemical exposure group increased by 11.55% (95% CI: 1.02-1.31), after adjustment. CONCLUSION: Unsupervised clustering of environmental sub-sample specimens from NHANES provides an innovative, multi-pollutant model that can be used to explore exposure patterns in this population. Utilizing the modified SVI allows for the identification of children that may be highly susceptible to air pollution. It is imperative to interpret the research findings in light of historical structural and discriminatory inequalities to develop beneficial and sustainable solutions.

Environmental Injustice Is Associated With Poorer Asthma Outcomes in School-Age Children With Asthma in Metropolitan Atlanta, Georgia.

BACKGROUND: Environmental justice mandates that no person suffers disproportionately from environmental exposures. The Environmental Justice Index (EJI) provides an estimate of the environmental burden for each census tract but has not yet been used in asthma populations. OBJECTIVE: We hypothesized that children from census tracts with high environmental injustice determined by the EJI would have a greater burden of asthma exacerbations, poorer asthma control, and poorer lung function over 12 months. METHODS: Children aged 6 to 18 years with asthma (N = 575) from metropolitan Atlanta, Georgia, completed a baseline research visit. Participant addresses were geocoded to obtain the EJI Social-Environmental Ranking for each participant's census tract, which was divided into tertiles. Medical records were reviewed for 12 months for asthma exacerbations. A subset of participants completed a second research visit involving spirometry and questionnaires. RESULTS: Census tracts with the greatest environmental injustice had more racial and ethnic minorities, lower socioeconomic status, more hazardous exposures (particularly to airborne pollutants), and greater proximity to railroads and heavily trafficked roadways. Children with asthma residing in high injustice census tracts had a longer duration of asthma, greater historical asthma-related health care utilization, poorer asthma symptom control and quality of life, and more impaired lung function. By 12 months, children from high injustice census tracts also had more asthma exacerbations with a shorter time to exacerbation and persistently more symptoms, poorer asthma control, and reduced lung function. CONCLUSIONS: Disparities in environmental justice are present in metropolitan Atlanta that may contribute to asthma outcomes in children. These findings require an additional study and action to improve health equity.