Gene-based association study of rare variants in children of diverse ancestries implicates TNFRSF21 in the development of allergic asthma

BACKGROUND

Most genetic studies of asthma and allergy have focused on common variation in individuals primarily of European ancestry. Studying the role of rare variation in quantitative phenotypes and in asthma phenotypes in populations of diverse ancestries can provide additional, important insights into the development of these traits.

OBJECTIVE

We sought to examine the contribution of rare variants to different asthma- or allergy-associated quantitative traits in children with diverse ancestries and explore their role in asthma phenotypes.

METHODS

We examined whole-genome sequencing data from children participants in longitudinal studies of asthma (n = 1035; parent-identified as 67% Black and 25% Hispanic) to identify rare variants (minor allele frequency < 0.01). We assigned variants to genes and tested for associations using an omnibus variant-set test between each of 24,902 genes and 8 asthma-associated quantitative traits. On combining our results with external data on predicted gene expression in humans and mouse knockout studies, we identified 3 candidate genes. A burden of rare variants in each gene and in a combined 3-gene score was tested for its associations with clinical phenotypes of asthma. Finally, published single-cell gene expression data in lower airway mucosal cells after allergen challenge were used to assess transcriptional responses to allergen.

RESULTS

Rare variants in USF1 were significantly associated with blood neutrophil count (P = 2.18 × 10-7); rare variants in TNFRSF21 with total IgE (P = 6.47 × 10-6) and PIK3R6 with eosinophil count (P = 4.10 × 10-5) reached suggestive significance. These 3 findings were supported by independent data from human and mouse studies. A burden of rare variants in TNFRSF21 and in a 3-gene score was associated with allergy-related phenotypes in cohorts of children with mild and severe asthma. Furthermore, TNFRSF21 was significantly upregulated in bronchial basal epithelial cells from adults with allergic asthma but not in adults with allergies (but not asthma) after allergen challenge.

CONCLUSIONS

We report novel associations between rare variants in genes and allergic and inflammatory phenotypes in children with diverse ancestries, highlighting TNFRSF21 as contributing to the development of allergic asthma.

Cannabis use and the prevalence of current asthma among adolescents and adults in the United States

OBJECTIVES

Cannabis use has increased among adolescents and adults in the United States (US) in recent years. Few data are available on the prevalence of asthma by frequency of cannabis use. This study aimed to estimate the prevalence of asthma by frequency of past 30-day cannabis use among US individuals.

METHODS

Data were drawn from the 2020 National Survey on Drug Use and Health (NSDUH), a nationally representative, annual cross-sectional survey of US individuals aged 12 and older in the United States (N = 32,893). Logistic regression models were used to examine the relationship between frequency of any cannabis and/or blunt (i.e., cannabis smoked in a hollowed-out cigar) use in the past 30 days and current asthma, adjusting for demographics and current cigarette smoking.

RESULTS

Current asthma was more common among US individuals who reported cannabis use in the past 30-days, relative to those who did not (9.8% vs. 7.4%, p < 0.0001). The odds of asthma was significantly greater among individuals reporting cannabis use 20-30 days/month (Adjusted Odds Ratio [AOR] = 1.67, 95% CI:1.21, 2.31), blunt use 6-15 and 20-30 days/month (AOR = 1.9, 95% CI:1.1, 3.2; AOR = 2.2, 95% CI:1.4, 3.6), respectively, than among those without. A positive linear relationship was observed between frequency of a) cannabis use (p < 0.0001) and b) blunt use (p < 0.0001) and current asthma prevalence.

CONCLUSIONS

Findings suggest a dose-response relationship between frequency of current cannabis use and the prevalence of current asthma in the US individuals.

Immune profile of adipose tissue from youth with obesity and asthma

BACKGROUND

Obesity is a risk factor for paediatric asthma. Obesity-mediated systemic inflammation correlates with metabolic dysregulation; both are associated with asthma burden. However, adipose tissue inflammation is not defined in obesity-related asthma.

OBJECTIVE

Define adipose tissue inflammation and its association with metabolic measures in paediatric obesity-related asthma.

METHODS

Cellular profile of stromal vascular fraction from visceral adipose tissue (VAT) from youth with obesity-related asthma (n = 14) and obesity without asthma (n = 23) was analyzed using flow cytometry and correlated with metabolic measures.

RESULTS

Compared to youth without asthma, VAT from youth with obesity-related asthma was enriched for leukocytes and macrophages, including M1 and dual M1M2 cells, but did not differ for CD4+ lymphocytes, and endothelial cells, their progenitors, and preadipocytes. M1 macrophage counts positively correlated with glucose, while M1M2 cells, CD4+ lymphocytes, and their subsets negatively correlated with high-density lipoprotein, in youth with obesity without asthma, but not among those with obesity-related asthma.

CONCLUSIONS

Enrichment of macrophage-mediated inflammation in VAT from youth with obesity-related asthma supports its role in systemic inflammation linked with asthma morbidity. Lack of correlation of VAT cells with metabolic dysregulation in youth with obesity-related asthma identifies a need to define distinguishing factors associated with VAT inflammation in obesity-related asthma.

Impact of family socioeconomic position on childhood asthma outcomes, severity, and specialist referral - a Danish nationwide study

BACKGROUND

Asthma is the most common chronic illness in children, carrying a major burden. Socioeconomic position (SEP) affects adult asthma outcomes, but its impact on childhood asthma, particularly in primary versus specialist care, has not been studied thoroughly.

METHODS

In a Danish cohort consisting of all children aged 2-17 years redeeming inhaled corticosteroids in 2015, parental SEP impact on asthma outcomes was investigated. Workforce attachment, income, education, and metropolitan residence were chosen as covariates in logistic regression. Outcomes were uncontrolled (excessive use of short-acting beta2-agonists), exacerbating (oral corticosteroid use or hospitalization), and severe asthma (according to GINA 2020).

RESULTS

The cohort comprised 29,851 children (median age 8.0, 59% boys). 16% had uncontrolled asthma, 8% had ≥1 exacerbation. Lower income and metropolitan residence correlated with higher odds of poor control, exacerbations, and severe asthma. Lower education correlated with worse asthma outcomes. Education and income were protective factors in primary care, but not in specialist care. Metropolitan residence was the sole factor linked to specialist care referral for severe asthma.

CONCLUSION

Low parental SEP and metropolitan residence associated with poor asthma outcomes. However, specialist care often mitigated these effects, though such care was less likely for at-risk children in non-metropolitan areas.

Attention-Deficit Hyperactivity Disorder Symptoms, Underperception of Respiratory Compromise, and Illness Representations in Black and Latino Children With Asthma

OBJECTIVE

This study examined the associations between attention-deficit/hyperactivity disorder (ADHD) symptoms, underperception of respiratory compromise, and illness representations in Black and Latino children with asthma. We hypothesized that increased child-reported ADHD symptoms, as well as parent reports for their child, would be associated with underperception of respiratory compromise, and maladaptive asthma beliefs.

METHODS

Two hundred ninety-six parent-child dyads were recruited from pediatric asthma and primary care clinics in the Bronx. Participants completed demographic questionnaires, the Conners-3 ADHD Index to measure ADHD symptoms, and the Asthma Illness Representation Scale to assess asthma beliefs. Perception of respiratory compromise was assessed by programmable electronic peak flow monitors that measured the child's subjective estimates of peak expiratory flow (PEF) and actual PEF, with underperception as the primary measure.

RESULTS

Child-reported ADHD symptoms were associated with greater underperception (β = .117, p = .049) of respiratory compromise. Parent-reported ADHD symptoms were associated with greater underperception (β = .129, p = .028) of respiratory compromise. Child-reported ADHD symptoms (β = -.188, p < .001) were associated with more maladaptive asthma beliefs, F(1, 341) = 13.135. Parent-reported ADHD symptoms (β = -.203, p ≤ .001) were associated with more maladaptive asthma beliefs, F(1, 341) = 15.644.

CONCLUSIONS

ADHD symptoms were associated with a greater underperception of respiratory compromise and more maladaptive asthma beliefs. Deficits of attentional processes and/or hyperactivity levels might be contributing factors. We emphasize the need for psychoeducation and interventions that improve perception and health beliefs in children with comorbid ADHD and asthma.

The Relationship Between Pediatric Attention-Deficit/Hyperactivity Disorder Symptoms and Asthma Management

PURPOSE

Children with comorbid Attention-Deficit/Hyperactivity Disorder (ADHD) and asthma are at an increased risk for adverse health outcomes and reduced quality of life. The objective of these analyses was to examine if self-reported ADHD symptoms in children with asthma are associated with asthma control, asthma controller medication adherence, quick relief medication use, pulmonary function, and acute healthcare utilization.

METHODS

We analyzed data from a larger study testing a behavioral intervention for Black and Latinx children with asthma aged 10-17 years and their caregivers. Participants completed the Conners-3AI self-report assessment for ADHD symptoms. Asthma medication usage data were collected for 3 weeks following baseline via electronic devices fitted to participants' asthma medications. Other outcome measures included the Asthma Control Test, self-reported healthcare utilization, and pulmonary function measured by spirometry testing.

RESULTS

The study sample consisted of 302 pediatric participants with an average age of 12.8 years. Increased ADHD symptoms were directly associated with reduced adherence to controller medications, but no evidence of mediation was observed. Direct effects of ADHD symptoms on quick-relief medication use, health care utilization, asthma control, or pulmonary function were not observed. However, the effect of ADHD symptoms on emergency room visits was mediated by controller medication adherence.

DISCUSSION

ADHD symptoms were associated with significantly reduced asthma controller medication adherence and indirectly with emergency room visits. There are significant potential clinical implications to these findings, including the need for the development of interventions for pediatric asthma patients with ADHD.

Childhood Asthma and Parental Antidepressant Use in a Nationwide Danish Cohort

Background

Paediatric asthma is associated with caregiver depression, which in turn is associated with poor asthma control. Although sociodemographic risk factors are associated with parental depression among children with asthma, the contribution of these factors to caregiver depression in free-to-access universal healthcare settings is unknown.

Methods

The association between childhood asthma and parental antidepressant use was investigated in a Danish nationwide cohort of children aged 2-17 years that redeemed inhaled corticosteroids in 2015. The odds of antidepressant use were estimated in comparison to control families that were matched 1:1 on the number of siblings, residence, income, and education.

Results

Among the families of 28,595 children with actively treated asthma, 12% of mothers and 6.2% of fathers were on antidepressant therapy, compared to 9.3% and 5.3% in controls (p<0.001). Paediatric asthma was associated with increased odds of parental antidepressant use (OR 1.29 (1.23-1.35)), even after adjusting for parental asthma. Poor asthma control, but not higher asthma severity, was associated with higher odds of antidepressant use (1.43 (1.31-1.56)). Compared with the controls, families with two or more children with asthma had higher OR (1.42 (1.29-1.56)) than those with a single child (OR 1.27 (1.21-1.34)). Low socioeconomic status was associated with parental antidepressant use.

Conclusion

Caregiver depression in a Danish cohort is more prevalent among mothers than among fathers and is associated with poor asthma control in children. Antidepressant use among caregivers was associated with total family asthma burden and was independent of socioeconomic status.

Complications associated with incorrect use of nasal CPAP

Nasal continuous positive airway pressure (nCPAP) is a safe, effective, non-invasive respiratory modality to deliver positive end expiratory pressure in neonates. Many studies have established its associated improved respiratory outcomes without increase in major morbidities associated with preterm neonates. In contrast, there is paucity in literature addressing complications such as nasal injury, abdominal distention, air leak syndromes (especially pneumothorax), hearing loss, heat and chemical burns, swallowing and aspiration of small components of the nasal interface and delay in escalation of respiratory support associated with the use of nCPAP, most frequently due to its incorrect use. This is a comprehensive review that seeks to address the different complications that are associated with the incorrect use of nCPAP highlighting that these are operator-related and not device-related.

Carnitine supplementation increases serum concentrations of free carnitine and total acylcarnitine in preterm neonates: A retrospective cohort study

OBJECTIVE

Our goal was to determine the efficacy of the American Society for Parenteral and Enteral Nutrition's recommended carnitine dosage of 5 mg/kg/day in maintaining normal serum free carnitine and total acylcarnitine levels in preterm neonates receiving parenteral nutrition (PN).

STUDY DESIGN

A retrospective cohort study was conducted on neonates born <30 weeks gestation and weighing <1250 g, comparing those who received carnitine supplementation to those without supplementation. Free carnitine and total acylcarnitine data were collected from routine newborn screens in the first days of life and on full enetral feeds. Univariate analysis was performed, and those factors that were significantly different between the two groups were adjusted for using mixed effects analysis.

RESULTS

There were 108 supplemented and 45 unsupplemented neonates in the study. At baseline, free carnitine (19.8 ± 3.3 vs 18.9 ± 3.7 µmol/L, P = 0.53) and total acylcarnitine (26.6 ± 5.1 vs 22.5 ± 7.1 µmol/L, P = 0.11) were similar between the two groups. At full enteral feeds, compared with unsupplemented group, supplemented infants had significantly higher free carnitine (27.1 ± 16.4 vs 17.1 ± 8.5 µmol/L, P < 0.001) and total acylcarnitine (30.3 ± 11.5 vs 20.2 ± 10.1 µmol/L, P < 0.001). None of the supplemented neonates developed biochemical carnitine deficiency as compared with 18% in the unsupplemented group (P < 0.001). No difference was observed in time to reach full lipid provision, and there were no differences in the change in the triglyceride levels from baseline to the time on full PN lipid provision (P = 0.39).

CONCLUSION

Preterm neonates routinely supplemented with parenteral carnitine at 5 mg/kg/day demonstrated higher free carnitine and total acylcarnitine levels at full feeds, with none developing biochemical carnitine deficiency.

Obesity-related pediatric asthma: relationships between pulmonary function and clinical outcomes

OBJECTIVE

We hypothesized that children with obesity-related asthma would have worse self-reported asthma control, report an increased number of asthma symptoms and have lower FEV1/FVC associated with worse clinical asthma outcomes compared to children with asthma only.

METHODS

Cross sectional analyses examined two hundred and eighteen (obesity-related asthma = 109, asthma only = 109) children, ages 7-15 that were recruited from clinics and hospitals within the Bronx, NY. Pulmonary function was assessed by forced expiratory volume in the first second (percent predicted FEV1) and the ratio of FEV1 to the forced vital capacity of the lungs (FEV1/FVC). Structural equation modeling examined if pulmonary function was associated with asthma control and clinical outcomes between groups.

RESULTS

Lower percent predicted FEV1 was associated with increased hospitalizations (p = 0.03) and oral steroid bursts in the past 12 months (p = 0.03) in the obesity-related asthma group but not in the asthma only group. FEV1/FVC was also associated with increased hospitalizations (p = 0.02) and oral steroid bursts (p = 0.008) in the obesity-related asthma group but not the asthma only group. Lower FEV1/FVC was associated with the number of asthma symptoms endorsed in the asthma only group but not in the obesity-related asthma group. Percent predicted FEV1 and FEV1/FVC was not associated with asthma control in either group.

CONCLUSIONS

Pulmonary function was associated with oral steroid bursts and hospitalizations but not self-reported asthma control, suggesting the importance of incorporating measures of pulmonary function into the treatment of pediatric obesity-related asthma.

Burden and unmet need for specialist care in poorly controlled and severe childhood asthma in a Danish nationwide cohort

BACKGROUND

Asthma is a common disease in childhood and adolescence with lifelong consequences particularly among those at risk of severe disease, poor control and/or frequent exacerbations. Specialist care is recommended for at-risk children and adolescents, yet access to specialist management in free-to-access healthcare settings remains poorly understood.

METHODS

A Danish nationwide cohort of children and adolescents aged 2-17 years with persistent asthma, defined as repeated redemption of inhaled corticosteroids (ICS) during 2015, were followed for two years, to identify at-risk children and adolescents comprising those with severe asthma (classified according to GINA 2020 guidelines), poor control (defined as use of 400/600 (ages 2-11/12 +) annual doses of short-acting bronchodilators), or frequent exacerbations (defined as use of oral steroids or hospitalization), and access to specialist care. The population is chosen due to detailed medical records in the setting of universal health care.

RESULTS

The cohort comprised of 29,851 children and adolescents (59% boys), with a median age of 9 years. While 17% of children were on high dose ICS, 22% were on daily ICS below GINA low dose cut-off. Prevalence of severe asthma (3.0-6.5%) was lower than poor asthma control (6.4-25%); both declined from childhood to adolescence. Exacerbations occurred in 7.1-9.0% of children, with median number of exacerbations being 1 (IQR 1-1). Despite being classified as having mild-to-moderate asthma, 15% had poor asthma control and 3.8% experienced exacerbation(s), respectively. While 61% of children with severe asthma and 58% with exacerbation-prone disease were in specialist care, only 24% with uncontrolled disease were receiving specialist care. Of children and adolescents using high-dose ICS, 71% were managed in primary care, while the use of additional controllers was more common in specialist care.

CONCLUSIONS

Throughout childhood and adolescence, there was a high prevalence of severe asthma and poor control, although their prevalence declined with age. We demonstrate a large unmet need for specialist care among children with at-risk asthma, particularly among those with poorly controlled asthma, even in a system with free-to-access, tax-funded healthcare.

Mechanistic Links Between Obesity and Airway Pathobiology Inform Therapies for Obesity-Related Asthma

Obesity-related asthma is associated with a high disease burden and a poor response to existent asthma therapies, suggesting that it is a distinct asthma phenotype. The proposed mechanisms that contribute to obesity-related asthma include the effects of the mechanical load of obesity, adipokine perturbations, and immune dysregulation. Each of these influences airway smooth muscle function. Mechanical fat load alters airway smooth muscle stretch affecting airway wall geometry, airway smooth muscle contractility, and agonist delivery; weight loss strategies, including medically induced weight loss, counter these effects. Among the metabolic disturbances, insulin resistance and free fatty acid receptor activation influence distinct signaling pathways in the airway smooth muscle downstream of both the M2 muscarinic receptor and the β2 adrenergic receptor, such as phospholipase C and the extracellular signal-regulated kinase signaling cascade. Medications that decrease insulin resistance and dyslipidemia are associated with a lower asthma disease burden. Leptin resistance is best understood to modulate muscarinic receptors via the neural pathways but there are no specific therapies for leptin resistance. From the immune perspective, monocytes and T helper cells are involved in systemic pro-inflammatory profiles driven by obesity, notably associated with elevated levels of interleukin-6. Clinical trials on tocilizumab, an anti-interleukin antibody, are ongoing for obesity-related asthma. This armamentarium of therapies is distinct from standard asthma medications, and once investigated for its efficacy and safety among children, will serve as a novel therapeutic intervention for pediatric obesity-related asthma. Irrespective of the directionality of the association between asthma and obesity, airway-specific mechanistic studies are needed to identify additional novel therapeutic targets for obesity-related asthma.

Risk Factors for Pneumothorax and Its Association with Ventilation in Neonates

OBJECTIVE

 The mode of ventilation that is implicated in pneumothorax is the one at the time of its diagnosis. Although there is evidence that air leak starts many hours before it is clinically evident, there are no prior studies that have investigated the association of pneumothorax with the mode of ventilation few hours before rather than at the time of its diagnosis.

STUDY DESIGN

 A retrospective case-control study was conducted in the neonatal intensive care unit (NICU) between 2006 and 2016 where cases of neonates with pneumothorax were compared with gestational age-matched control neonates without pneumothorax. Respiratory support associated with pneumothorax was classified as the mode of ventilation 6 hours before the clinical diagnosis of pneumothorax. We investigated the factors that were different between cases and controls, and between cases of pneumothorax on bubble continuous positive airway pressure (bCPAP) and invasive mechanical ventilation (IMV).

RESULT

 Of the 8,029 neonates admitted in the NICU during the study period, 223 (2.8%) developed pneumothorax. Among these, 127 occurred among 2,980 (4.3%) neonates on bCPAP, 38 among 809 (4.7%) neonates on IMV, and the remaining 58 among 4,240 (1.3%) neonates on room air. Those with pneumothorax were more likely to be male, have higher body weight, require respiratory support and surfactant administration, and have bronchopulmonary dysplasia (BPD). Among those who developed pneumothorax, there were differences in the gestational age, gender, and use of antenatal steroids between those who were on bCPAP as compared to those on IMV. IMV was associated with increased odds of pneumothorax as compared to those on bCPAP in a multivariable regression analysis. Cases on IMV had higher incidence of intraventricular hemorrhage, retinopathy of prematurity, BPD, and necrotizing enterocolitis, as well as longer length of stay as compared to those on bCPAP.

CONCLUSION

 Neonates who require any respiratory support have higher incidence of pneumothorax. Among those on respiratory support, those on IMV had higher odds of pneumothorax and worse clinical outcomes as compared to those on bCPAP.

KEY POINTS

· The process of air leak leading to pneumothorax in majority of neonates starts much before it is clinically diagnosed.. · It is possible to detect the air leak early in the process by subtle changes in the signs, symptoms and changes in lung function.. · True association of the ventilation associated with pneumothorax is not at the time of diagnosis of pneumothorax but few hours before it is diagnosed.. · There is higher incidence of pneumothorax in neonates on any respiratory support.. · There is significantly higher incidence of pneumothorax among neonates on invasive ventilations as compared to noninvasive ventilation after correction for all other clinical factors..

Association of fractional exhaled nitric oxide with asthma morbidity in urban minority children

OBJECTIVE

Fractional exhaled nitric oxide (FeNO) is a well-established measure of allergic airway inflammation and possible useful adjunct disease management tool. We investigated the association of baseline and follow-up FeNO measurements with disease burden in minority children with persistent asthma.

METHODS

A retrospective chart review was conducted on 352 African American and Hispanic children seen at an urban Asthma Center in Bronx, NY. Demographic, clinical characteristics, and pulmonary function tests (PFTs) were compared between children with low, intermediate, and high baseline FeNO levels. Among 95 children with subsequent follow up visits, associations of change in FeNO with demographics, clinical characteristics, and PFTs were examined using mixed effects linear regression models.

RESULTS

A higher proportion of children with intermediate (54%) and high FeNO (58%) levels had lower airways obstruction compared to those with low FeNO levels (33%). Children with intermediate FeNO levels had more annual hospitalizations (2.8 ± 6.2) compared to those with low and high FeNO levels (1.3 ± 2.8 and 1.3 ± 2.5). These associations did not differ between ethnicities. An increase in FeNO over time was associated with higher BMI z-scores (β = 6.2, 95% CI: 1.0 to 11.4) and two or more hospitalizations in the past year (β = 16.1, 95% CI: 1.5 to 30.8).

CONCLUSIONS

Intermediate and high FeNO levels are associated with lower airways obstruction and hospitalizations. Initial and serial FeNO measurements can be a useful adjunctive tool in identifying asthma-related morbidity in urban African American and Hispanic children.

Crosstalk between CD4+ T Cells and Airway Smooth Muscle in Pediatric Obesity-related Asthma

Rationale: Pediatric obesity-related asthma is a nonatopic asthma phenotype with high disease burden and few effective therapies. RhoGTPase upregulation in peripheral blood T helper (Th) cells is associated with the phenotype, but the mechanisms that underlie this association are not known. Objectives: To investigate the mechanisms by which upregulation of CDC42 (Cell Division Cycle 42), a RhoGTPase, in Th cells is associated with airway smooth muscle (ASM) biology. Methods: Chemotaxis of obese asthma and healthy-weight asthma Th cells, and their adhesion to obese and healthy-weight nonasthmatic ASM, was investigated. Transcriptomics and proteomics were used to determine the differential effect of obese and healthy-weight asthma Th cell adhesion to obese or healthy-weight ASM biology. Measurements and Main Results: Chemotaxis of obese asthma Th cells with CDC42 upregulation was resistant to CDC42 inhibition. Obese asthma Th cells were more adherent to obese ASM compared with healthy-weight asthma Th cells to healthy-weight ASM. Compared with coculture with healthy-weight ASM, obese asthma Th cell coculture with obese ASM was positively enriched for genes and proteins involved in actin cytoskeleton organization, transmembrane receptor protein kinase signaling, and cell mitosis, and negatively enriched for extracellular matrix organization. Targeted gene evaluation revealed upregulation of IFNG, TNF (tumor necrosis factor), and Cluster of Differentiation 247 (CD247) among Th cell genes, and of Ak strain transforming (AKT), Ras homolog family member A (RHOA), and CD38, with downregulation of PRKCA (Protein kinase C-alpha), among smooth muscle genes. Conclusions: Obese asthma Th cells have uninhibited chemotaxis and are more adherent to obese ASM, which is associated with upregulation of genes and proteins associated with smooth muscle proliferation and reciprocal nonatopic Th cell activation.

Metabolic Contributions to Pathobiology of Asthma

Asthma is a heterogenous disorder driven by inflammatory mechanisms that result in multiple phenotypes. Given the complex nature of this condition, metabolomics is being used to delineate the pathobiology of asthma. Metabolomics is the study of metabolites in biology, which includes biofluids, cells, and tissues. These metabolites have a vital role in a disease as they contribute to the pathogenesis of said condition. This review describes how macrometabolic and micrometabolic studies pertaining to these metabolites have contributed to our current understanding of asthma, as well as its many phenotypes. One of the main phenotypes this review will discuss in further detail is obesity as well as diabetes. Distinct roles of metabolites in endotyping asthma and their translation to potential therapy development for asthma is also discussed in this review.

Asthma as a comorbidity in COVID-19 pediatric ICU admissions in a large metropolitan children's hospital

RATIONALE

Children contribute to 5% of coronavirus disease of 2019 (COVID-19)-related hospitalizations in the United States. There is mounting evidence suggesting childhood asthma is a risk factor for severe disease. We hypothesized that asthma is associated with longer length of stay (LOS) and need for respiratory support among children admitted to pediatric intensive care unit (PICU) with COVID-19.

METHODS

We reviewed 150 charts of children and young adults with a positive severe acute respiratory syndrome coronavirus 2polymerase chain reaction test admitted to the PICU at Children's National Hospital, Washington, DC between 2020 and 2021. We recorded demographics, anthropometrics, past medical history, clinical course, laboratory findings, imaging, medication usage, respiratory support, and outcomes. Functional Status Scale (FSS), which measures an Intensive Care Unitpatient's physical function, was used to characterize children with multiple comorbidities; FSS and obesity were included as covariates in multivariate analysis. Statistical analysis was performed using SPSS v25.0.

RESULTS

Sixty-Eight patients ages 0-21 years met inclusion criteria. Median age was 14.9 years, 55.9% were female, median Body Mass Index percentile was 62, and 42.6% were African American. Compared with those without asthma, patients with asthma averaged longer LOS (20.7 vs. 10.2 days, p = 0.02), with longer PICU stay (15.9 vs. 7.6 days, p = 0.033) and prolonged maximum respiratory support (8.3 vs. 3.3 days, p = 0.016). Adjusted for obesity and poor physical function (FSS > 6), asthma remained a significant predictor of hospital LOS, PICU LOS, and days on maximum respiratory support.

CONCLUSION

Asthma can cause severe disease with prolonged need for maximum respiratory support among children with COVID-19.

Multi-omic association study identifies DNA methylation-mediated genotype and smoking exposure effects on lung function in children living in urban settings

Impaired lung function in early life is associated with the subsequent development of chronic respiratory disease. Most genetic associations with lung function have been identified in adults of European descent and therefore may not represent those most relevant to pediatric populations and populations of different ancestries. In this study, we performed genome-wide association analyses of lung function in a multiethnic cohort of children (n = 1,035) living in low-income urban neighborhoods. We identified one novel locus at the TDRD9 gene in chromosome 14q32.33 associated with percent predicted forced expiratory volume in one second (FEV1) (p = 2.4x10-9; βz = -0.31, 95% CI = -0.41- -0.21). Mendelian randomization and mediation analyses revealed that this genetic effect on FEV1 was partially mediated by DNA methylation levels at this locus in airway epithelial cells, which were also associated with environmental tobacco smoke exposure (p = 0.015). Promoter-enhancer interactions in airway epithelial cells revealed chromatin interaction loops between FEV1-associated variants in TDRD9 and the promoter region of the PPP1R13B gene, a stimulator of p53-mediated apoptosis. Expression of PPP1R13B in airway epithelial cells was significantly associated the FEV1 risk alleles (p = 1.3x10-5; β = 0.12, 95% CI = 0.06-0.17). These combined results highlight a potential novel mechanism for reduced lung function in urban youth resulting from both genetics and smoking exposure.

Impact of caregiver depression on child asthma outcomes in Mexicans and Puerto Ricans

OBJECTIVE

Examine whether caregiver depressive symptoms at baseline predict longitudinal child asthma outcomes in the two populations with the largest asthma disparities: Mexicans and Puerto Ricans.

METHODS

Two hundred and sixty-seven Hispanic caregiver-child dyads (Mexican = 188, Puerto Rican = 79; children 5-12 years) were recruited from clinics and hospitals in Phoenix, AZ and the Bronx, NY. The Center for Epidemiological Studies Depression Scale assessed caregiver depressive symptoms; higher scores indicate greater depressive symptomology. Medical records verified child asthma diagnosis. Assessments for outcome variables occurred at baseline, 3, 6, 9, and 12-month follow-ups. Pulmonary function was measured by spirometry, asthma control was measured by the Asthma Control Test, steroid bursts and acute healthcare utilization were assessed by caregiver report and medical records, and adherence was measured by doser devices on controller medications. Structural equation modeling analyzed baseline caregiver depressive symptoms as a predictor of longitudinal child asthma outcomes, and differences between subgroups.

RESULTS

Higher caregiver depressive symptoms predicted better pulmonary function (β = .02, p = .001) in Mexican children, and fewer steroid bursts (β = -.41, p = .01) and better medication adherence (β = .02, p = .07) in Puerto Rican children. Caregiver depressive symptoms did not predict pediatric asthma control or acute healthcare utilization in either subgroup.

CONCLUSIONS

Caregiver depressive symptomology had unexpected effects on child asthma outcomes. Results may be explained by the Hispanic paradox, caregiver resilience, acculturation, and the study's longitudinal nature. Further research is needed on social determinants of health that may influence differences in child asthma outcomes in heterogeneous Hispanic communities.

Endotyping pediatric obesity-related asthma: Contribution of anthropometrics, metabolism, nutrients, and CD4+ lymphocytes to pulmonary function

BACKGROUND

Obesity-related complications including visceral fat, metabolic abnormalities, nutrient deficiencies, and immune perturbations are interdependent but have been individually associated with childhood asthma.

OBJECTIVE

We sought to endotype childhood obesity-related asthma by quantifying contributions of obesity-related complications to symptoms and pulmonary function.

METHODS

Multiomics analysis using Similarity Network Fusion followed by mediation analysis were performed to quantify prediction of obese asthma phenotype by different combinations of anthropometric, metabolic, nutrient, and TH-cell transcriptome and DNA methylome data sets.

RESULTS

Two clusters (n = 28 and 26) distinct in their anthropometric (neck and midarm circumference, waist to hip ratio [WHR], and body mass index [BMI] z score), metabolic, nutrient, and TH-cell transcriptome and DNA methylome footprint predicted 5 or more pulmonary function indices across 7 different data set combinations. Metabolic measures attenuated the association of neck, WHR, and BMI z score with FEV1/forced vital capacity (FVC) ratio and expiratory reserve volume (ERV), of neck, midarm, and BMI z score with functional residual capacity, but only of WHR with inspiratory capacity. Nutrient levels attenuated the association of neck, midarm circumference, and BMI z score with functional residual capacity, and of WHR with FEV1/FVC ratio, ERV, and inspiratory capacity. TH-cell transcriptome attenuated the association of all 4 anthropometric measures with FEV1/FVC ratio, but only of WHR with ERV and inspiratory capacity. The DNA methylome attenuated the association of all 4 anthropometric measures with FEV1/FVC ratio and ERV, but only of WHR with inspiratory capacity.

CONCLUSIONS

Anthropometric, metabolic, nutrient, and immune perturbations have individual but interdependent contributions to obese asthma phenotype, with the most consistent effect of WHR, highlighting the role of truncal adiposity in endotyping childhood obesity-related asthma.

Obesity-related asthma in children and adolescents

There is substantial epidemiological and experimental evidence of an obesity-related asthma phenotype. Compared to children of healthy weight, children with obesity are at higher risk of asthma. Children with obesity who have asthma have greater severity and poorer control of their asthma symptoms, more frequent asthma exacerbations, and overall lower asthma-related quality of life than children with asthma who have a healthy weight. In this Review, we examine some of the latest evidence on the characteristics of this phenotype and its main underlying mechanisms, including genetics and genomics, changes in airway mechanics and lung function, sex hormone differences, alterations in immune responses, systemic and airway inflammation, metabolic dysregulation, and modifications in the microbiome. We also review current recommendations for the treatment of these children, including in the management of their asthma, and current evidence for weight loss interventions. We then discuss initial evidence for potential novel therapeutic approaches, such as dietary modifications and supplements, antidiabetic medications, and statins. Finally, we identify knowledge gaps and future directions to improve our understanding of asthma in children with obesity, and to improve outcomes in these susceptible children. We highlight important needs, such as designing paediatric-specific studies, implementing large multicentric trials with standardised interventions and outcomes, and including racial and ethnic groups along with other under-represented populations that are particularly affected by obesity and asthma.

Associations between sleep, obesity, and asthma in urban minority children

STUDY OBJECTIVES

Although obesity, asthma, and sleep-disordered breathing are interrelated, there is limited understanding of the independent contributions of body-mass index and pulmonary function on polysomnography in children with asthma.

METHODS

We conducted a retrospective chart review on 448 7- to 18-year-old children with asthma who had undergone polysomnography testing between 1/2007-12/2011 to elucidate the association between spirometry variables, body-mass index, and polysomnography parameters, adjusting for asthma and antiallergic medications.

RESULTS

Obese children had poorer sleep architecture and more severe gas exchange abnormalities compared to healthy weight children. Multivariate analysis revealed an independent association of body-mass index with sleep efficiency, with more light and less deep sleep in both obese and healthy-weight children, and with baseline oxygen saturation and oxygen nadir in obese children. In obese children, forced vital capacity was independently associated with less deep sleep (time in N3 sleep) as well as with oxygen nadir, while among healthy-weight children, forced expiratory volume directly correlated but forced vital capacity inversely correlated with deep sleep. In obese children, inhaled corticosteroid was associated with baseline oxygen saturation, and montelukast was associated with lower end-tidal carbon dioxide. In healthy-weight children, inhaled corticosteroid was associated with arousal awakening index, and montelukast was associated with light sleep. Antiallergic medications were not independently associated with polysomnography parameters.

CONCLUSIONS

Pulmonary function, body-mass index, and asthma medications have independent and differing influences on sleep architecture and gas exchange polysomnography parameters in obese and healthy-weight children with asthma. Asthma medications are associated with improved gas exchange in obese children and improved sleep architecture in healthy-weight children with asthma.

CITATION

Conrad LA, Nandalike K, Rani S, Rastogi D. Associations between sleep, obesity, and asthma in urban minority children. J Clin Sleep Med. 2022;18(10):2377-2385.

African-specific alleles modify risk for asthma at the 17q12-q21 locus in African Americans

BACKGROUND

Asthma is the most common chronic disease in children, occurring at higher frequencies and with more severe disease in children with African ancestry.

METHODS

We tested for association with haplotypes at the most replicated and significant childhood-onset asthma locus at 17q12-q21 and asthma in European American and African American children. Following this, we used whole-genome sequencing data from 1060 African American and 100 European American individuals to identify novel variants on a high-risk African American-specific haplotype. We characterized these variants in silico using gene expression and ATAC-seq data from airway epithelial cells, functional annotations from ENCODE, and promoter capture (pc)Hi-C maps in airway epithelial cells. Candidate causal variants were then assessed for correlation with asthma-associated phenotypes in African American children and adults.

RESULTS

Our studies revealed nine novel African-specific common variants, enriched on a high-risk asthma haplotype, which regulated the expression of GSDMA in airway epithelial cells and were associated with features of severe asthma. Using ENCODE annotations, ATAC-seq, and pcHi-C, we narrowed the associations to two candidate causal variants that are associated with features of T2 low severe asthma.

CONCLUSIONS

Previously unknown genetic variation at the 17q12-21 childhood-onset asthma locus contributes to asthma severity in individuals with African ancestries. We suggest that many other population-specific variants that have not been discovered in GWAS contribute to the genetic risk for asthma and other common diseases.

Effect of the coronavirus disease 2019 pandemic on morbidity among children hospitalized for an asthma exacerbation

BACKGROUND

Pediatric asthma exacerbations account for substantial morbidity, including emergency department (ED) visits and hospitalizations. Although the coronavirus disease 2019 (COVID-19) pandemic was associated with a decrease in pediatric asthma ED visits and hospitalizations, there is limited information on the clinical characteristics of children hospitalized with an asthma exacerbation during the pandemic.

OBJECTIVE

To investigate the clinical characteristics of children hospitalized with an asthma exacerbation during the pandemic as compared with those hospitalized during the same months in the year prior.

METHODS

A retrospective case-control study was conducted at the Children's National Hospital, Washington, DC, comparing demographic and clinical characteristics of all children, 2 to 18 years old, hospitalized for an asthma exacerbation between April to September 2020 (cases) and April to September 2019 (controls).

RESULTS

We identified 50 cases and 243 controls. Cases were significantly older than controls (9.8 ± 4.3 years vs 6.7 ± 3.8 years; P < .001), had significantly less eczema (16% vs 32.1%; P = .02) and food allergies (6% vs 18.5%; P = .03), and were more noncompliant with controller medications (46% vs 24.7%; P = .002) than controls. Magnesium sulfate was more frequently administered in the ED to the cases than to the controls (84% vs 63%; P = .004). Its use was associated with older age, African American race, and Hispanic ethnicity, but was independent of comorbid conditions.

CONCLUSION

Patients hospitalized for asthma during the COVID-19 pandemic were older and have less atopy than those hospitalized prepandemic. A larger proportion received magnesium sulfate in the ED, suggesting patients had with more severe asthma presentation during the pandemic.

The Epidemiology and Mechanisms of Lifetime Cardiopulmonary Morbidities Associated With Pre-Pregnancy Obesity and Excessive Gestational Weight Gain

Obesity has reached pandemic proportions in the last few decades. The global increase in obesity has contributed to an increase in the number of pregnant women with pre-pregnancy obesity or with excessive gestational weight gain. Obesity during pregnancy is associated with higher incidence of maternal co-morbidities such as gestational diabetes and hypertension. Both obesity during pregnancy and its associated complications are not only associated with immediate adverse outcomes for the mother and their newborns during the perinatal period but, more importantly, are linked with long-term morbidities in the offsprings. Neonates born to women with obesity are at higher risk for cardiac complications including cardiac malformations, and non-structural cardiac issues such as changes in the microvasculature, e.g., elevated systolic blood pressure, and overt systemic hypertension. Pulmonary diseases associated with maternal obesity include respiratory distress syndrome, asthma during childhood and adolescence, and adulthood diseases, such as chronic obstructive pulmonary disease. Sequelae of short-term complications compound long-term outcomes such as long-term obesity, hypertension later in life, and metabolic complications including insulin resistance and dyslipidemia. Multiple mechanisms have been proposed to explain these adverse outcomes and are related to the emerging knowledge of pathophysiology of obesity in adults. The best investigated ones include the role of obesity-mediated metabolic alterations and systemic inflammation. There is emerging evidence linking metabolic and immune derangements to altered biome, and alteration in epigenetics as one of the intermediary mechanisms underlying the adverse outcomes. These are initiated as part of fetal adaptation to obesity during pregnancy which are compounded by rapid weight gain during infancy and early childhood, a known complication of obesity during pregnancy. This newer evidence points toward the role of specific nutrients and changes in biome that may potentially modify the adverse outcomes observed in the offsprings of women with obesity.

Outcomes among preterm infants with patent ductus arteriosus: Relationship with treatment, gestational age, hemodynamic status and timing of treatment

BACKGROUND

There remains controversy regarding the outcomes resulting from treatment versus conservative management of patent ductus arteriosus (PDA) among preterm infants. The effects of extreme prematurity, hemodynamic status of the PDA, and age at treatment remain poorly defined.

STUDY DESIGN

This retrospective case-control study including infants <  1250 gm who were categorized into 3 groups: Group 1: without PDA, Group 2: with untreated PDA, and Group 3: treated PDA. Diagnosis and treatment of PDA extracted from the medical records. Demographics, clinical characteristics, and outcomes compared using chi-square and analysis of variance. Logistic regression used to estimate adjusted odds ratios.

RESULTS

The study included 734 infants, with 141(19%) in Group 1, 329 (45%) in 2, and 264 (36%) in 3. Group 3 had higher incidence of bronchopulmonary dysplasia (BPD) (aOR, 2.9; 95%CI 1.7-4.8). Infant treated for hemodynamically significant PDA (HSPDA) had higher incidence of BPD (aOR, 1.9; 95%CI 1.0-3.8) and retinopathy of prematurity (ROP) (aOR, 3.4; 95%CI 1.6-6.9). There were no differences in outcome associated with treatment among≤26 weeks gestation and the age when treated.

CONCLUSION

Infants with PDA who were treated had higher incidence of BPD. Among those who were treated, those with HSPDA had a higher incidence of BPD and ROP.

The airway epithelium during infancy and childhood: A complex multicellular immune barrier. Basic review for clinicians

The airway epithelium is a complex multicellular layer that extends from the nasopharynx to the small airways. It functions as an immune respiratory barrier during early life that develops, matures, and regenerates to adapt to the changes in the environment. While airway epithelial abnormalities have been identified in several clinical disorders, there is increasing interest in understanding its basic regulation and structure in humans. Indeed, recent advances in technology (e.g. single-cell analysis and new human airway epithelial cell models) have allowed us to identify additional cellular subtypes and functions that overall have greatly improved our understanding of the airway epithelium during health and disease. In this review we summarize key features of the airway epithelium including: 1) multilayer structure and cell heterogeneity; 2) adaptability to different environmental and developmental stimuli; 3) innate recognition; and 4) orchestration of immune responses. We discuss these features with a translational and clinical prospective focusing on the development of human respiratory immunity, particularly during early life.

Contribution of systemic and airway immune responses to pediatric obesity-related asthma

Childhood obesity contributes to many diseases, including asthma. Although the precise mechanism by which obesity causes asthma is not known, there is literature to suggest that innate and adaptive systemic and airway immune responses in obese children with asthma differ from those in normal-weight children with asthma. Both non-allergic or non-T2 phenotype with systemic T helper (Th)1 polarization and allergic Th cell responses have been reported in childhood obesity-related asthma. There is preliminary evidence to suggest that genetic and epigenetic mechanisms contribute to these immune responses. Initial investigations into the biology of non-T2 immune responses have identified upregulation of genes in the CDC42 pathway. CDC42 is a RhoGTPase that plays a key role in Th cell physiology, including preferential naïve Th cell differentiation to Th1 cells, as well as cytokine production and exocytosis. These novel pathways are promising findings to direct targeted therapy development for obesity-related asthma to address the disease burden.

Atopy and pulmonary function among healthy-weight and overweight/obese children with asthma

INTRODUCTION

Epidemiologic studies have found low/absence of atopy in obese asthmatic children, but the association or lack thereof of atopy with disease morbidity, including pulmonary function, in obese asthma is not well understood. We sought to define the association of atopy with pulmonary function in overweight/obese minority children with asthma.

METHODS

In a retrospective chart review of 200 predominantly minority children evaluated at an academic Pediatric Asthma Center over 5 years, we compared the prevalence of atopy, defined as ≥ 1 positive skin prick test or serum-specific immunoglobulin E quantification to environmental allergens, and its association with pulmonary function in overweight/obese (body mass index [BMI] > 85th percentile) (n = 99) to healthy-weight children (BMI, 5th-85th percentile for age) (n = 101).

RESULTS

In a cohort comprised of 47.5% Hispanics and 39.5% African Americans, 81% of overweight/obese and 74% of healthy-weight children were atopic. While atopic healthy-weight children had lower percent-predicted forced expiratory volume in the first second (FEV₁ ) (93 ± 13.6 vs 107% ± 33.2%, P = .03) and lower percent-predicted forced vital capacity (FVC) (93% ± 12.2% vs 104% ± 16.1%, P = .01) as compared to nonatopic children, atopy was not associated with FEV₁ (P = .7) or FVC (P = .17) in overweight/obese children. Adjusting for demographic and clinical variables, atopy was found to be an independent predictor of FEV₁ and FVC in healthy-weight (β = -2.4, P = .07 and β = -1.7, P = .04, respectively) but not in overweight/obese children (β = .6, P = .5 and β = .8, P = .3).

CONCLUSIONS

Atopy is associated with lower lung function in healthy-weight asthmatics but not in overweight/obese asthmatics, supporting the role of nonallergic mechanisms in disease burden in pediatric obesity-related asthma.

Functional Genomics of the Pediatric Obese Asthma Phenotype Reveal Enrichment of Rho-GTPase Pathways

Rationale: Obesity-related asthma disproportionately affects minority children and is associated with nonatopic T-helper type 1 (Th1) cell polarized inflammation that correlates with pulmonary function deficits. Its underlying mechanisms are poorly understood.Objectives: To use functional genomics to identify cellular mechanisms associated with nonatopic inflammation in obese minority children with asthma.Methods: CD4⁺ (cluster of differentiation 4-positive) Th cells from 59 obese Hispanic and African American children with asthma and 61 normal-weight Hispanic and African American children with asthma underwent quantification of the transcriptome and DNA methylome and genotyping. Expression and methylation quantitative trait loci revealed the contribution of genetic variation to transcription and DNA methylation. Adjusting for Th-cell subtype proportions discriminated loci where transcription or methylation differences were driven by differences in subtype proportions from loci that were independently associated with obesity-related asthma.Measurements and Main Results: Obese children with asthma had more memory and fewer naive Th cells than normal-weight children with asthma. Differentially expressed and methylated genes and methylation quantitative trait loci in obese children with asthma, independent of Th-cell subtype proportions, were enriched in Rho-GTPase pathways. Inhibition of CDC42 (cell division cycle 42), one of the Rho-GTPases associated with Th-cell differentiation, was associated with downregulation of the IFNγ, but not the IL-4, gene. Differential expression of the RPS27L (40S ribosomal protein S27-like) gene, part of the p53/mammalian target of rapamycin pathway, was due to nonrandom distribution of expression quantitative trait loci variants between groups. Differentially expressed and/or methylated genes, including RPS27L, were associated with pulmonary function deficits in obese children with asthma.Conclusions: We found enrichment of Rho-GTPase pathways in obese asthmatic Th cells, identifying them as a novel therapeutic target for obesity-related asthma, a disease that is suboptimally responsive to current therapies.

Pulmonary disease burden in Hispanic and non-Hispanic children with sickle cell disease

RATIONALE

Pulmonary complications are the leading cause of morbidity and mortality in sickle cell disease (SCD) patients. Research in SCD has predominantly been conducted on African-Americans, and the disease burden of SCD in other races and ethnicities, including Hispanic patients, is not well characterized.

OBJECTIVE

To compare pulmonary disease burden between Hispanic and non-Hispanic ethnic groups among children with SCD.

METHODS

In a retrospective chart review on 566 SCD patients followed at the Children's Hospital at Montefiore, NY, we compared the pulmonary disease burden and disease management in Hispanic patients to their non-Hispanic counterparts. We also compared the contribution of demographic and clinical variables to acute chest syndrome (ACS), vaso-occlusive crisis (VOC), and hospitalizations for SCD related complications between the two ethnic groups.

RESULTS

Hispanic patients had a greater proportion of ACS, and had lower forced expiratory volume (FEV1), forced vital capacity, and vital capacity, compared to non-Hispanics. Hispanic patients were more likely to be evaluated in pulmonary clinic and to be on inhaled corticosteroids, short-acting β agonizts, and leukotriene receptor antagonists. In addition, Hispanic children were more likely to be on hydroxyurea, and receive exchange transfusions. However, the association of asthma with the proportion of ACS did not differ between Hispanics and non-Hispanics.

CONCLUSION

Hispanic children with SCD had differences in their pulmonary function profile and received more pulmonary evaluations than non-Hispanic children.

Association between asthma and dental caries in US (United States) adult population

Objective: To investigate the associations of asthma with dental-caries-experience (DFT: decayed and filled teeth) and untreated-dental-caries (DT: decayed teeth) in the US adult population.Methods: Data from the National Health and Nutritional Examination Survey, 2009-2014 were analyzed. Study-participants were classified into current, former and never asthmatics based on their asthma-status. Former-asthmatics were excluded. Both the outcomes, dental-caries-experience and untreated-dental-caries were dichotomized as being either present or absent, and were also categorized into tertiles based on their distributions in our study-sample. Logistic regression analyses were performed to determine the associations of asthma with dichotomized outcomes. The generalized logit model was applied for multilevel categorical outcomes. Multivariable models were developed to control for common demographic, clinical, and lifestyle factors.Results: Total study-participants were 13,135, representing 175.26 million US adults. In the adjusted models, current-asthmatics, when compared to the reference group of never-asthmatics, were more likely to have dental-caries-experience (odds ratio [OR], 1.37; 95% confidence interval [CI], 1.13-1.66) and untreated-dental-caries (OR, 1.38; 95% CI, 1.10-1.73) in ≥1 tooth. Asthma was associated with all three categories of dental-caries-experience in our study-sample. We observed a positive gradient in the OR with an increasing extent of untreated-dental-caries. Relative to never-asthmatics, asthma doubled the odds of having untreated dental caries in the subgroup of current-smokers.Conclusion: Current-asthmatic adults had higher odds of dental-caries-experience and untreated-dental-caries as compared to never-asthmatic adults in the US. Based on the observations from this study, interprofessional collaboration should be recommended to institute caries control and health promotion in current-asthmatic adult population.

Extracorporeal and advanced therapies for progressive refractory near-fatal acute severe asthma in children

Asthma is the most common chronic illness and is one of the most common medical emergencies in children. Progressive refractory near-fatal asthma requiring intubation and mechanical ventilation can lead to death. Extracorporeal membrane oxygenation (ECMO) can provide adequate gas exchange during acute respiratory failure although data on outcomes in children requiring ECMO support for status asthmaticus is sparse with one study reporting survival rates of nearly 85% with asthma being one of the best outcome subsets for patients with refractory respiratory failure requiring ECMO support. We describe the current literature on the use of ECMO and other advanced extracorporeal therapies available for children with acute severe asthma. We also review other advanced invasive and noninvasive therapies in acute severe asthma both before and while on ECMO support.

Readmission and Ambulatory Health Care Use After Asthma Hospitalization Among Urban Minority Children

OBJECTIVES

The role of ambulatory follow-up after pediatric asthma hospitalization in preventing long-term readmissions is not well studied among hospitalized minority children. We sought to examine the association of ambulatory visit attendance with long-term readmission as well as identify predictors of attendance at these visits among urban, minority children with asthma.

METHODS

This 2-year retrospective cohort study analyzed data for urban, minority children 2 to 18 years old who were hospitalized for asthma at a tertiary-care center. Using bivariate and multivariable analyses, we examined the independent associations of attending a postdischarge visit (within 14 days), a routine visit (within 3 months of discharge or postdischarge visit), and both visits with likelihood of asthma readmission within 365 days. We also identified predictors of attending each of these visits.

RESULTS

The study included 613 children with a median age of 5 years. Of the children, 57.4% were boys, 51.2% were Hispanic, and 36.9% were non-Hispanic African American. One-quarter of the children were readmitted within 365 days of the index hospitalization. Children who attended the postdischarge visit had lower odds of long-term readmission (odds ratio = 0.65; 95% confidence interval = 0.43-0.97). However, attending a routine or both a postdischarge and a routine visit was not significantly associated with long-term readmission. Children with previous sick visits, complicating comorbidities, or more severe exacerbation were more likely to attend visits.

CONCLUSIONS

Attending a postdischarge visit within 14 days of hospitalization is associated with a lower likelihood of long-term readmission. Those with a previous sick visit, more severe disease, or exacerbation are more likely to attend ambulatory visits after hospital discharge. This knowledge is important in fostering quality care transitions for children with asthma.

Pediatric obesity-related asthma: A prototype of pediatric severe non-T2 asthma

Childhood obesity contributes to many diseases, including asthma. There is literature to suggest that asthma developing as a consequence of obesity has a nonallergic or non-T2 phenotype. In this review, obesity-related asthma is utilized as a prototype of non-T2 asthma in children to discuss several nonallergic mechanisms that underlie childhood asthma. Obesity-related asthma is associated with systemic T helper (Th)1 polarization occurring with monocyte activation. These immune responses are mediated by insulin resistance and dyslipidemia, metabolic abnormalities associated with obesity, that are themselves associated with pulmonary function deficits in obese asthmatics. As in other multifactorial diseases, there is both a genetic and an environmental contribution to pediatric obesity-related asthma. In addition to genetic susceptibility, differential DNA methylation is associated with non-T2 immune responses in pediatric obesity-related asthma. Initial investigations into the biology of non-T2 immune responses have identified the upregulation of genes in the CDC42 pathway. CDC42 is a RhoGTPase that plays a key role in Th cell physiology, including preferential naïve Th cell differentiation to Th1 cells, and cytokine production and exocytosis. Although these novel pathways are promising findings to direct targeted therapy development for obesity-related asthma to address the disease burden, there is evidence to suggest that dietary interventions, including diet modification, rather than caloric restriction alone, decrease disease burden. Adoption of a diet rich in micronutrients, including carotenoids and 25-OH cholecalciferol, a vitamin D metabolite, may be beneficial since these are positively correlated with pulmonary function indices, while being protective against metabolic abnormalities associated with the obese asthma phenotype.

The Adaptive Effect of Illness-Specific Panic-Fear on Asthma Outcomes in Mexican and Puerto Rican Children

OBJECTIVE

To examine baseline measures of illness-specific panic-fear (ie, the level of anxiety experienced specifically during asthma exacerbations) as a protective factor in pediatric asthma outcomes over a 1-year period.

STUDY DESIGN

The sample comprised 267 children (Mexican, n = 188; Puerto Rican, n = 79; age 5-12 years) from a longitudinal observational study conducted in Phoenix, AZ and Bronx, NY. Assessments were done at baseline and 3, 6, 9, and 12 months. The Childhood Asthma Symptom Checklist was administered at baseline to children and caregivers to assess children's illness-specific panic-fear. Asthma outcome variables quantified longitudinally included pulmonary function, the Asthma Control Test, acute healthcare utilization, and medication adherence, measured by devices attached to inhaled corticosteroids.

RESULTS

Child report of illness-specific panic-fear at baseline predicted higher forced expiratory volume in 1 second (FEV₁) % across 1-year follow-up in Mexican children (β = 0.17, P = .02), better asthma control in Puerto Rican children (β = 0.45, P = .007), and less acute healthcare utilization for asthma in both groups (Mexicans: β = -0.39, P = .03; Puerto Ricans: β = -0.47, P = .02). Caregiver report of child panic-fear predicted higher FEV₁% in Mexican (β = 0.30; P = .02) and Puerto Rican (β = 0.19; P = .05) children. Panic-fear was not related to medication adherence.

CONCLUSIONS

Illness-specific panic-fear had beneficial effects on asthma outcomes in both groups of Latino children. The heightened vigilance associated with illness-specific panic-fear may lead children to be more aware of their asthma symptoms and lead to better strategies for asthma management.

Airway Inflammation and Lung Function in Sickle Cell Disease

Rationale: Asthma is a common comorbid condition in sickle cell disease (SCD). However, obstructive lung disease is prevalent in SCD, independent of a diagnosis of asthma. It is speculated that the heightened state of inflammation in SCD, involving pathways distinct from allergic asthma, may underlie the SCD-specific obstructive disease. Objective: The objective of the study was to compare airway and systemic inflammatory markers between SCD patients with pulmonary manifestations and patients with allergic asthma, and correlate the discriminating inflammatory markers with clinical measures of pulmonary disease. Materials and Methods: In a pilot translational study conducted at the Children's Hospital at Montefiore, 15 patients with SCD, and history of asthma, airway obstruction, or airway hyper-reactivity, and 15 control patients with allergic asthma 6-21 years of age were recruited. Inflammatory markers, including peripheral blood T helper cell subsets, serum and exhaled breath condensate (EBC) cytokines and chemokines of the Th-1/Th-17, Th-2, and monocytic pathways, and serum cysteinyl leukotrienes B4 (LTB4), were quantified, compared between the study groups, and correlated with atopic sensitization, pulmonary function tests, and markers of hemolysis. Results: White blood cells (P < 0.05) and monocytes (P < 0.001) were elevated in the SCD group, while atopic characteristics were higher in the control asthma group. Tumor necrosis factor-alpha (P < 0.01), interferon gamma inducible protein (IP)-10 (P < 0.05), and interleukin-4 (P < 0.01) in serum and monocyte chemotactic protein (MCP)-1 in EBC were higher in the SCD group (P ≤ 0.05). Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) in patients with SCD inversely correlated with serum IP-10 and LTB4 levels. Conclusions: Compared with atopic asthmatic patients, inflammatory markers involving Th-1, Th-2, and monocytic pathways were higher in the SCD group, among which Th-1 measures correlated with pulmonary function deficits.

Association of pediatric obesity and asthma, pulmonary physiology, metabolic dysregulation, and atopy; and the role of weight management

Introduction: Obesity affects about 40% of US adults and 18% of children. Its impact on the pulmonary system is best described for asthma. Areas covered: We reviewed the literature on PubMed and Google Scholar databases and summarize the effect of obesity, its associated metabolic dysregulation and altered systemic immune responses, and that of weight gain and loss on pulmonary mechanics, asthma inception, and disease burden. We include a distinct approach for diagnosing and managing the disease, including pulmonary function deficits inherent to obesity-related asthma, in light of its poor response to current asthma medications. Expert opinion: Given the projected increase in obesity, obesity-related asthma needs to be addressed now. Research on the contribution of metabolic abnormalities and systemic immune responses, intricately linked with truncal adiposity, and that of lack of atopy, to asthma disease burden, and pulmonary function deficits among obese children is fairly consistent. Since current asthma medications are more effective for atopic asthma, investigation for atopy will guide management by distinguishing asthma responsive to current medications from the non-responsive disease. Future research is needed to elucidate mechanisms by which obesity-mediated metabolic abnormalities and immune responses cause medication non-responsive asthma, which will inform repurposing of medications and drug discovery.

A physicians survey assessing management of pulmonary airway involvement in sickle cell disease

BACKGROUND

Airway involvement in patients with sickle cell disease (SCD) involves recurrent episodes of acute chest syndrome (ACS), co-existent asthma, lower airway obstruction (LAO), or airway hyper-responsiveness/ bronchodilator response (AHR/BDR). With increased recognition that sickle cell (SC) airway inflammation may be distinct from asthma, our aim was to study regional and individual practices among pediatric pulmonologists and elucidate the patient characteristics that determine the diagnosis of asthma or SC airway inflammation.

METHODS

A cross-sectional web-based survey including 6 case scenarios on diagnosis and management of pulmonary manifestations of pediatric SC airway disease was conducted. The case scenarios, combined different risk factors for airway inflammation: history of recurrent ACS, atopy, family history of asthma, LAO, or AHR/BDR, with possible responses including - diagnosis of asthma, SC airway inflammation, both or neither.

RESULTS

Of the 130 responses, 83 were complete. "Asthma" was diagnosed when LAO (OR, 7.96 [4.28, 14.79]; p < 0.001), family history of asthma (OR 18.88 [5.87, 60.7]; p < 0.001), and atopy (OR 3.19 [1.74, 5.8]; p < 0.001) were present. "SC airway inflammation" was diagnosed when ACS (OR 3.95 [2.08, 7.51]; p < 0.001), and restrictive pattern on PFT (OR 3.75 [2.3, 6.09]; p < 0.001) were present in the scenarios. Regardless of the diagnosis, there was a high likelihood of initiating or stepping up inhaled corticosteroid as compared to prescribing montelukast.

CONCLUSION

There is variability in the diagnosis and management of SC airway inflammation among pediatric pulmonologists. This study highlights the need for consensus guidelines to improve management of SC airway inflammation.

Longitudinal Patterns of Mexican and Puerto Rican Children's Asthma Controller Medication Adherence and Acute Healthcare Use

Rationale: Researchers tend to study Latinos as a single group, but recent asthma research confirmed differences among Latino subgroups. Variations in controller medication adherence may be a factor in the observed health disparities between Mexican and Puerto Rican children. Adherence is not a stable phenomenon; however, there is a paucity of data on patterns of adherence, sociodemographic predictors of patterns, and variations in asthma-related acute healthcare use by adherence pattern among Latino subgroups. Objectives: To identify patterns of inhaled corticosteroid medication adherence over 12 months among Mexican and Puerto Rican children with persistent asthma, to examine sociodemographic predictors of adherence patterns by ethnicity, and to investigate asthma-related acute healthcare use based on these patterns. Methods: We analyzed controller medication Doser data from Mexican and Puerto Rican children (n = 123; ages 5-12 yr) with persistent asthma who participated with their caregivers in a longitudinal nonintervention study (Phoenix, AZ, and Bronx, NY). Interview and medical record data were collected at enrollment and at 3, 6, 9, and 12 months after enrollment. Results: Forty-seven to fifty-three percent of children had poor adherence (<50%) over each of the follow-up periods (cross-sectional). Children with lowest adherence were Puerto Rican, from nonpoor families, or female. Longitudinal latent class analysis yielded four adherence classes: poor, moderate, decreasing adherence, and increasing adherence. Puerto Rican children had significantly higher odds of "decreasing" (odds ratio [OR], 2.86; 95% confidence interval [CI], 0.40 to 20.50) and "poor" (OR, 5.62; 95% CI, 1.44 to 21.90) adherence than Mexican children. Females had significantly greater odds of "decreasing" (OR, 4.80; 95% CI, 0.73 to 31.74) and "poor" (OR, 5.20; 95% CI, 1.77 to 15.30) adherence group membership than males. The "decreasing" adherence group was comprised of only poor children. Children in the "poor" adherence class had the highest mean number of acute visits and emergency department visits/hospitalizations across all assessment periods. Conclusions: This study demonstrated that unique ethnicity within Latino populations may be associated with different risk levels for suboptimal controller medication adherence, which may be a factor in the observed asthma health disparities between Mexican and Puerto Rican children. Increased understanding of and attention to children's controller medication adherence patterns will provide evidence needed to identify children at highest risk for acute healthcare use and offer more-intensive intervention using less-intensive approaches for those at low risk. Clinical trial registered with www.clinicaltrials.gov (NCT01099800).

Comparison of severity of asthma hospitalization between African American and Hispanic children in the Bronx

Objective: There are racial and ethnic disparities in childhood asthma burden and outcomes. Although there have been comparisons between whites and minorities, there are few between minority groups. This study aimed to compare characteristics of asthma hospitalizations in African American and Hispanic children.Methods: A retrospective chart review was conducted to compare asthma characteristics between African American and Hispanic children aged 2-18 years hospitalized at an urban, tertiary care hospital for an acute asthma exacerbation. Length of stay (LOS), need for intensive care unit (ICU), and need for additional medications or respiratory support were compared between the groups.Results: Of the 925 children that met the inclusion criteria, 64% were Hispanic and 36% were African American. The groups were similar in age, gender, insurance status, and weight classification. African American children were more likely to have severe persistent asthma (12% vs. 7%, p = .02). They were also more likely to require magnesium sulfate (45% vs. 32%, p < .001) and admission to the ICU from the emergency department (ED) (14% vs. 8%, p = .01), which were independent of asthma severity. There was no significant difference in LOS or other characteristics of hospitalization.Conclusions: African American children hospitalized for asthma have more severe exacerbations compared to Hispanic children, which is independent of their asthma severity. However, this was not associated with longer LOS, which may indicate greater responsiveness to inpatient asthma management. Further investigation is needed to understand the mechanisms underlying asthma and exacerbation severity among minority groups.

Carotenoids, fatty acids and disease burden in obese minority adolescents with asthma

BACKGROUND

Paediatric obesity-related asthma causes high disease burden, is associated with metabolic abnormalities, has few therapeutic options, and disproportionately affects urban minority children. Although poor diet quality is linked to asthma, the association of nutritional status with disease burden among children with obesity-related asthma is not well understood.

OBJECTIVE

To quantify nutritional status, defined as concentrations of serum carotenoids and n-3 fatty acids, and its association with pulmonary function and metabolic markers among obese asthmatic children.

METHODS

We quantified serum carotenoids and fatty acids in a study cohort of 158 urban minority adolescents including 39 obese asthmatics, 39 healthy weight asthmatics, 38 obese controls and 42 healthy weight controls and compared between the groups. We correlated carotenoid and fatty acid levels with pulmonary function indices and with insulin resistance and dyslipidemia.

RESULTS

Mean total carotenoids were lowest in obese asthmatic children (0.41 μg/mL), lower than healthy weight asthmatics (0.52 μg/mL, P < 0.05) and healthy weight controls (0.60 μg/mL, P < 0.001). n-6/n-3 polyunsaturated fatty acid (PUFA) ratio also differed between the groups (P < 0.05). Total carotenoids positively correlated with per cent-predicted FEV₁ and inversely correlated with insulin resistance among obese asthmatics only. n-6/n-3 PUFA ratio inversely correlated with per cent-predicted FEV₁ in obese asthmatics.

CONCLUSIONS & CLINICAL RELEVANCE

Our findings suggest that carotenoids, which are lowest in obese asthmatic children, may have protective effects on metabolic health and pulmonary function among obese asthmatic children. Similarly, n-3 PUFA appear to be protective for pulmonary function.

Insights from deconvolution of cell subtype proportions enhance the interpretation of functional genomic data

Cell subtype proportion variability between samples contributes significantly to the variation of functional genomic properties such as gene expression or DNA methylation. Although the impact of the variation of cell subtype composition on measured genomic quantities is recognized, and some innovative tools have been developed for the analysis of heterogeneous samples, most functional genomics studies using samples with mixed cell types still ignore the influence of cell subtype proportion variation, or just deal with it as a nuisance variable to be eliminated. Here we demonstrate how harvesting information about cell subtype proportions from functional genomics data can provide insights into cellular changes associated with phenotypes. We focused on two types of mixed cell populations, human blood and mouse kidney. Cell type prediction is well developed in the former, but not currently in the latter. Estimating the cellular repertoire is easier when a reference dataset from purified samples of all cell types in the tissue is available, as is the case for blood. However, reference datasets are not available for most other tissues, such as the kidney. In this study, we showed that the proportion of alterations attributable to changes in the cellular composition varies strikingly in the two disorders (asthma and systemic lupus erythematosus), suggesting that the contribution of cell subtype proportion changes to functional genomic properties can be disease-specific. We also showed that a reference dataset from a single-cell RNA-seq study successfully estimated the cell subtype proportions in mouse kidney and allowed us to distinguish altered cell subtype differences between two different knock-out mouse models, both of which had reported a reduced number of glomeruli compared to their wild-type counterparts. These findings demonstrate that testing for changes in cell subtype proportions between conditions can yield important insights in functional genomics studies.

Trends in epidemiology and outcomes of respiratory distress syndrome in the United States

BACKGROUND

The management practices of Respiratory Distress Syndrome (RDS) in the newborn have changed over time. We examine the trends in the epidemiology, resource utilization, and outcomes (mortality and bronchopulmonary dysplasia [BPD]) of RDS in preterm neonates ≤34 weeks gestational age (GA) in the United States.

METHODS

In this retrospective serial cross-sectional study, we used ICD-9 codes to classify preterm infants GA ≤34 weeks between 2003 and 2014 from the National Inpatient Sample as having RDS or not. Trends in the prevalence of infants defined as RDS by ICD-9 code (ICD9-RDS), length of stay, BPD, and mortality were analyzed using Cochran-Armitage and Jonckheere-Terpstra tests and multivariable logistic regression.

RESULTS

Of 1 526 186 preterm live births with GA ≤34 weeks, 554 409 had ICD9-RDS (260 cases per 1000 live births) with the prevalence increasing from 170 to 361 (P_trend  < 0.001) and associated decrease in all-cause mortality (7.6% to 6.1%; P_trend  < 0.001) from 2003 to 2014. Increased utilization of non-invasive mechanical ventilation (NIMV) (69.5% to 74.3%; P_trend  < 0.001) was associated with decreased invasive mechanical ventilation (IMV) use >96 h (60.4 to 56.6%; P_trend  < 0.001). Exclusive NIMV use increased from 16.8% to 29.1% (P_trend  < 0.0001). BPD incidence decreased from 14% to 12.5% (P_trend  < 0.001). LOS increased from 32 days to 38 days (P_trend  < 0.001) and cost increased from $49,521 to $55,394 (P_trend  < 0.001).

CONCLUSION

From 2003 to 2014, the assigned ICD9-RDS diagnosis, and utilization of NIMV increased and mortality among infants assigned the ICD9-RDS diagnosis decreased. With higher survival, hospital cost increased incrementally, indicating the importance of ongoing analysis of appropriate reimbursement for the care provided at tertiary centers for preterm infants.

Impact of Obesity on Asthma Morbidity During a Hospitalization

BACKGROUND

Asthma and obesity are 2 common pediatric problems. Obesity is a known risk factor for asthma, and obese children with asthma have higher disease burden. However, little is known on how obesity in urban minority children, mainly Hispanic and African American children, impacts morbidity during pediatric asthma hospitalizations.

METHODS

A retrospective chart review was conducted on children and adolescents age 2 to 18 years hospitalized at the Children's Hospital at Montefiore for an acute asthma exacerbation. We elucidated the association of overweight or obese status with severity of the exacerbation, quantified by length of stay (LOS) and need for intensive care management. Multivariate analysis was conducted to identify independent predictors of LOS.

RESULTS

A total of 975 children met the inclusion criteria, of whom 55% were normal weight and 45% were overweight or obese. Sixty percent were Hispanic, and 37% were African American. The overall average LOS was 2.57 days (range: 0.67-12.92). Overweight or obese status was associated with a higher asthma severity at baseline (P = .021). Overweight or obese children had a longer average LOS compared with normal weight children (2.75 vs 2.39 days; P < .01) with more PICU stays (P = .006), even after adjustment for higher baseline asthma severity. The severity of the exacerbation did not differ by ethnicity.

CONCLUSIONS

Obesity in children hospitalized for asthma is associated with more severe asthma exacerbations, longer LOS, and increased use of PICU level care, independent of their higher baseline disease severity and ethnicity.

Obesity increases airway smooth muscle responses to contractile agonists

The asthma-obesity syndrome represents a major public health concern that disproportionately contributes to asthma severity and induces insensitivity to therapy. To date, no study has shown an intrinsic difference between human airway smooth muscle (HASM) cells derived from nonobese subjects and those derived from obese subjects. The objective of this study was to address whether there is a greater response to agonist-induced calcium mobilization, phosphorylation of myosin light chain (MLC), and greater shortening in HASM cells derived from obese subjects. HASM cells derived from nonobese and obese subjects were age and sex matched. Phosphorylation of MLC was measured after having been stimulated by carbachol. Carbachol- or histamine-induced mobilization of calcium and cell shortening were assessed in HASM cells derived from nonobese and obese donors. Agonist-induced MLC phosphorylation, mobilization of calcium, and cell shortening were greater in obese compared with non-obese-derived HASM cells. The MLC response was comparable in HASM cells derived from obese nonasthma and nonobese fatal asthma subjects. HASM cells derived from obese female subjects were more responsive to carbachol than HASM cells derived from obese male subjects. Insulin pretreatment had little effect on these responses. Our results show an increase in agonist-induced calcium mobilization associated with an increase in MLC phosphorylation and an increase in ASM cell shortening in favor of agonist-induced hyperresponsiveness in HASM cells derived from obese subjects. Our studies suggest that obesity induces a retained phenotype of hyperresponsiveness in cultured human airway smooth muscle cells.