The Childhood Asthma Management Program (CAMP): Contributions to the Understanding of Therapy and the Natural History of Childhood Asthma

Circulating miRNAs associate with historical childhood asthma hospitalization in different serum vitamin D groups

BACKGROUND

Vitamin D may help to alleviate asthma exacerbation because of its anti-inflammation effect, but the evidence is inconsistent in childhood asthma. MiRNAs are important mediators in asthma pathogenesis and also excellent non-invasive biomarkers. We hypothesized that circulating miRNAs are associated with asthma exacerbation and modified by vitamin D levels.

METHODS

We sequenced baseline serum miRNAs from 461 participants in the Childhood Asthma Management Program (CAMP). Logistic regression was used to associate miRNA expression with asthma exacerbation through interaction analysis first and then stratified by vitamin D insufficient and sufficient groups. Microarray from lymphoblastoid B-cells (LCLs) treated by vitamin D or sham of 43 subjects in CAMP were used for validation in vitro. The function of miRNAs was associated with gene modules by weighted gene co-expression network analysis (WGCNA).

RESULTS

We identified eleven miRNAs associated with asthma exacerbation with vitamin D effect modification. Of which, five were significant in vitamin D insufficient group and nine were significant in vitamin D sufficient group. Six miRNAs, including hsa-miR-143-3p, hsa-miR-192-5p, hsa-miR-151a-5p, hsa-miR-24-3p, hsa-miR-22-3p and hsa-miR-451a were significantly associated with gene modules of immune-related functions, implying miRNAs may mediate vitamin D effect on asthma exacerbation through immune pathways. In addition, hsa-miR-143-3p and hsa-miR-451a are potential predictors of childhood asthma exacerbation at different vitamin D levels.

CONCLUSIONS

miRNAs are potential mediators of asthma exacerbation and their effects are directly impacted by vitamin D levels.

A novel piwi-interacting RNA associates with type 2-high asthma phenotypes

BACKGROUND

Piwi-interacting RNAs (piRNAs), comprising the largest noncoding RNA group, regulate transcriptional processes. Whether piRNAs are associated with type 2 (T2)-high asthma is unknown.

OBJECTIVE

We sought to investigate the association between piRNAs and T2-high asthma in childhood asthma.

METHODS

We sequenced plasma samples from 462 subjects in the Childhood Asthma Management Program (CAMP) as the discovery cohort and 1165 subjects in the Genetics of Asthma in Costa Rica Study (GACRS) as a replication cohort. Sequencing reads were filtered first, and piRNA reads were annotated and normalized. Linear regression was used for the association analysis of piRNAs and peripheral blood eosinophil count, total serum IgE level, and long-term asthma exacerbation in children with asthma. Mediation analysis was performed to investigate the effect direction. We then ascertained if the circulating piRNAs were present in asthmatic airway epithelial cells in a Gene Expression Omnibus (GEO; www.ncbi.nlm.nih.gov/geo) public data set.

RESULTS

Fifteen piRNAs were significantly associated with eosinophil count in CAMP (P ≤ .05), and 3 were successfully replicated in GACRS. Eleven piRNAs were associated with total IgE in CAMP, and one of these was replicated in GACRS. All 22 significant piRNAs were identified in epithelial cells in vitro, and 6 of these were differentially expressed between subjects with asthma and healthy controls. Fourteen piRNAs were associated with long-term asthma exacerbation, and effect of piRNAs on long-term asthma exacerbation are mediated through eosinophil count and serum IgE level.

CONCLUSION

piRNAs are associated with peripheral blood eosinophils and total serum IgE in childhood asthma and may play important roles in T2-high asthma.

Mild asthma: Conundrums, complexities and the need to customize care

Mild and moderate asthma cover a wide range of asthma presentations, phenotypes and symptom burden, and account for the majority of people with asthma worldwide. Mild asthma has been difficult to define because of its heterogeneity and wide spectrum of impact and outcomes, including being associated with severe exacerbations. Assessment of mild-moderate asthma is best made by combining asthma symptom control and exacerbation risk as the principle means by which to determine treatment needs. Incontrovertible evidence and guidelines support treatment initiation with anti-inflammatory medication, completely avoiding reliever-only treatment of mild asthma. Shared decision making with patients and a treatable traits approach will ensure that a holistic approach is taken to maximize patient outcomes. Most importantly, mild asthma should be regarded as a reversible, potentially curable condition, remaining in long-term remission through minimizing triggers and optimizing care.

ACDC: a general approach for detecting phenotype or exposure associated co-expression

Background

Existing module-based differential co-expression methods identify differences in gene-gene relationships across phenotype or exposure structures by testing for consistent changes in transcription abundance. Current methods only allow for assessment of co-expression variation across a singular, binary or categorical exposure or phenotype, limiting the information that can be obtained from these analyses.

Methods

Here, we propose a novel approach for detection of differential co-expression that simultaneously accommodates multiple phenotypes or exposures with binary, ordinal, or continuous data types.

Results

We report an application to two cohorts of asthmatic patients with varying levels of asthma control to identify associations between gene co-expression and asthma control test scores. Results suggest that both expression levels and covariances of ADORA3, ALOX15, and IDO1 are associated with asthma control.

Conclusion

ACDC is a flexible extension to existing methodology that can detect differential co-expression across varying external variables.

Springer: An R package for bi-level variable selection of high-dimensional longitudinal data

In high-dimensional data analysis, the bi-level (or the sparse group) variable selection can simultaneously conduct penalization on the group level and within groups, which has been developed for continuous, binary, and survival responses in the literature. Zhou et al. (2022) (PMID: 35766061) has further extended it under the longitudinal response by proposing a quadratic inference function-based penalization method in gene–environment interaction studies. This study introduces “springer,” an R package implementing the bi-level variable selection within the QIF framework developed in Zhou et al. (2022). In addition, R package “springer” has also implemented the generalized estimating equation-based sparse group penalization method. Alternative methods focusing only on the group level or individual level have also been provided by the package. In this study, we have systematically introduced the longitudinal penalization methods implemented in the “springer” package. We demonstrate the usage of the core and supporting functions, which is followed by the numerical examples and discussions. R package “springer” is available at https://cran.r-project.org/package=springer.

Zinc finger protein 33B demonstrates sex interaction with atopy-related markers in childhood asthma

BACKGROUND

Sex differences related to immune responses can influence atopic manifestations in childhood asthma. While genome-wide association studies have investigated a sex-specific genetic architecture of the immune response, gene-by-sex interactions have not been extensively analysed for atopy-related markers including allergy skin tests, IgE and eosinophils in asthmatic children.

METHODS

We performed a genome-wide gene-by-sex interaction analysis for atopy-related markers using whole-genome sequencing data based on 889 trios from the Genetic Epidemiology of Asthma in Costa Rica Study (GACRS) and 284 trios from the Childhood Asthma Management Program (CAMP). We also tested the findings in UK Biobank participants with self-reported childhood asthma. Furthermore, downstream analyses in GACRS integrated gene expression to disentangle observed associations.

RESULTS

Single nucleotide polymorphism (SNP) rs1255383 at 10q11.21 demonstrated a genome-wide significant gene-by-sex interaction (pinteraction=9.08×10-10) for atopy (positive skin test) with opposite direction of effects between females and males. In the UK Biobank participants with a history of childhood asthma, the signal was consistently observed with the same sex-specific effect directions for high eosinophil count (pinteraction=0.0058). Gene expression of ZNF33B (zinc finger protein 33B), located at 10q11.21, was moderately associated with atopy in girls, but not in boys.

CONCLUSIONS

We report SNPs in/near a zinc finger gene as novel sex-differential loci for atopy-related markers with opposite effect directions in females and males. A potential role for ZNF33B should be studied further as an important driver of sex-divergent features of atopy in childhood asthma.

Predicting Young Adult Tobacco, Drug and Alcohol Use Among Participants in the CAMP Trial

The development of substance abuse in youth with asthma have seldom been examined with longitudinal research. The prospective and well-characterized CAMP cohort provides outcome data on youth with asthma over 13 years. This manuscript seeks to determine the contributions of asthma features and child behavioral/emotional functioning to subsequent tobacco, alcohol, and drug use in early adulthood. Childhood smoking exposures as well as parent report and youth report of substance use were prospectively assessed concurrently with assessments of asthma symptoms, study medication, and lung development. Logistic regression models evaluated predictors of adolescent and young adult tobacco, alcohol, and drug use. Use of tobacco products was reported by 33% of youth with mild/moderate asthma. Tobacco use was significantly associated with self-reported externalizing behaviors. Early life passive smoke exposure, especially in utero exposure, makes a significant contribution to tobacco use (OR1.58). Greater risk for tobacco use is conveyed by self-reported externalizing behaviors, which are consistently robust predictors of any future use of tobacco products, alcohol and drugs. These findings provide evidence for health care providers to use routine behavioral screening in youth with asthma.

DDX58 Is Associated With Susceptibility to Severe Influenza Virus Infection in Children and Adolescents

BACKGROUND

Seasonal influenza virus infection causes a range of disease severity, including lower respiratory tract infection with respiratory failure. We evaluated the association of common variants in interferon (IFN) regulatory genes with susceptibility to critical influenza infection in children.

METHODS

We performed targeted sequencing of 69 influenza-associated candidate genes in 348 children from 24 US centers admitted to the intensive care unit with influenza infection and lacking risk factors for severe influenza infection (PICFlu cohort, 59.4% male). As controls, whole genome sequencing from 675 children with asthma (CAMP cohort, 62.5% male) was compared. We assessed functional relevance using PICFlu whole blood gene expression levels for the gene and calculated IFN gene signature score.

RESULTS

Common variants in DDX58, encoding the retinoic acid-inducible gene I (RIG-I) receptor, demonstrated association above or around the Bonferroni-corrected threshold (synonymous variant rs3205166; intronic variant rs4487862). The intronic single-nucleotide polymorphism rs4487862 minor allele was associated with decreased DDX58 expression and IFN signature (P < .05 and P = .0009, respectively) which provided evidence supporting the genetic variants' impact on RIG-I and IFN immunity.

CONCLUSIONS

We provide evidence associating common gene variants in DDX58 with susceptibility to severe influenza infection in children. RIG-I may be essential for preventing life-threatening influenza-associated disease.

Sparse group variable selection for gene-environment interactions in the longitudinal study

Penalized variable selection for high-dimensional longitudinal data has received much attention as it can account for the correlation among repeated measurements while providing additional and essential information for improved identification and prediction performance. Despite the success, in longitudinal studies, the potential of penalization methods is far from fully understood for accommodating structured sparsity. In this article, we develop a sparse group penalization method to conduct the bi-level gene-environment (G  × $\times $  E) interaction study under the repeatedly measured phenotype. Within the quadratic inference function framework, the proposed method can achieve simultaneous identification of main and interaction effects on both the group and individual levels. Simulation studies have shown that the proposed method outperforms major competitors. In the case study of asthma data from the Childhood Asthma Management Program, we conduct G  × $\times $  E study by using high-dimensional single nucleotide polymorphism data as genetic factors and the longitudinal trait, forced expiratory volume in 1 s, as the phenotype. Our method leads to improved prediction and identification of main and interaction effects with important implications.

A pilot school-based health center intervention to improve asthma chronic care in high-poverty schools

OBJECTIVE

To test the feasibility and effectiveness of a multifaceted intervention administered through school-based health centers (SBHCs) to improve asthma control for children in high-poverty schools with not well controlled asthma.

METHODS

Students 4-14 years old with persistent asthma were enrolled from three SBHCs. The centers' advanced practice providers received training on evidence-based asthma guidelines. Students randomized to the intervention received directly observed therapy of their asthma controller medication, medication adjustments as needed by the centers' providers, and daily self-management support. Students randomized to usual care were referred back to their primary care provider (PCP) for routine asthma care.

RESULTS

We enrolled 29 students. Students in the intervention group received their controller medication 92% of days they were in school. Ninety-four percent of follow-up assessments were completed. During the study, 11 of 12 intervention students had a step-up in medication; 2 of 15 usual care students were stepped up by their PCP. Asthma Control Test scores did not differ between groups, although there were significant improvements from baseline to the 7 month follow-up within each group (both p < .01). Both FEV₁% predicted and FEV₁/FVC ratio significantly worsened in the usual care group (both p = .001), but did not change in the intervention group (p = .76 and .28 respectively).

CONCLUSIONS

Our pilot data suggest that a multifaceted intervention can be feasibly administered through SBHCs in communities with health disparities. Despite the small sample size, spirometry detected advantages in the intervention group. Further study is needed to optimize the intervention and evaluate outcomes.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT03032744.

Novel recessive locus for body mass index in childhood asthma

Most genome-wide association studies of obesity and body mass index (BMI) have so far assumed an additive mode of inheritance in their analysis, although association testing supports a recessive effect for some of the established loci, for example, rs1421085 in FTO In two whole-genome sequencing (WGS) studies of children with asthma and their parents (892 Costa Rican trios and 286 North American trios), we discovered an association between a locus (rs9292139) in LOC102724122 and BMI that reaches genome-wide significance under a recessive model in the combined analysis. As the association does not achieve significance under an additive model, our finding illustrates the benefits of the recessive model in WGS analyses.

Machine learning-driven identification of early-life air toxic combinations associated with childhood asthma outcomes

Air pollution is a well-known contributor to asthma. Air toxics are hazardous air pollutants that cause or may cause serious health effects. Although individual air toxics have been associated with asthma, only a limited number of studies have specifically examined combinations of air toxics associated with the disease. We geocoded air toxic levels from the US National Air Toxics Assessment (NATA) to residential locations for participants of our AiRway in Asthma (ARIA) study. We then applied Data-driven ExposurE Profile extraction (DEEP), a machine learning-based method, to discover combinations of early-life air toxics associated with current use of daily asthma controller medication, lifetime emergency department visit for asthma, and lifetime overnight hospitalization for asthma. We discovered 20 multi-air toxic combinations and 18 single air toxics associated with at least 1 outcome. The multi-air toxic combinations included those containing acrylic acid, ethylidene dichloride, and hydroquinone, and they were significantly associated with asthma outcomes. Several air toxic members of the combinations would not have been identified by single air toxic analyses, supporting the use of machine learning-based methods designed to detect combinatorial effects. Our findings provide knowledge about air toxic combinations associated with childhood asthma.

Seven Pillars of Small Airways Disease in Asthma and COPD: Supporting Opportunities for Novel Therapies

Identification of pathologic changes in early and mild obstructive lung disease has shown the importance of the small airways and their contribution to symptoms. Indeed, significant small airways dysfunction has been found prior to any overt airway obstruction being detectable by conventional spirometry techniques. However, most therapies for the treatment of obstructive lung disease target the physiological changes and associated symptoms that result from chronic lung disease, rather than directly targeting the specific underlying causes of airflow disruption or the drivers of disease progression. In addition, although spirometry is the current standard for diagnosis and monitoring of response to therapy, the most widely used measure, FEV1 , does not align with the pathologic changes in early or mild disease and may not align with symptoms or exacerbation frequency in the individual patient. Newer functional and imaging techniques allow more effective assessment of small airways dysfunction; however, significant gaps in our understanding remain. Improving our knowledge of the role of small airways dysfunction in early disease in the airways, along with the identification of novel end points to measure subclinical changes in this region (ie, those not captured as symptoms or identified through standard FEV1), may lead to the development of novel therapies that directly combat early airways disease processes with a view to slowing disease progression and reversing damage. This expert opinion paper discusses small airways disease in the context of asthma and COPD and highlights gaps in current knowledge that impede earlier identification of obstructive lung disease and the development and standardization of novel small airways-specific end points for use in clinical trials.

Persistent airflow obstruction in inner-city children with asthma

Background: Airway remodeling has been shown to be persistent in patients with asthma despite treatment with controller medications. Patients with early airflow obstruction may continue to experience poor lung function despite treatment. Objectives: To determine whether early airflow obstruction in inner-city children with asthma persists despite guideline-based asthma care. Methods: In a retrospective study that used a cohort of inner-city children with asthma treated by using an asthma-specific disease management system, the patients were stratified into "low" or "high" lung function groups at the time of the initial visit (high, forced expiratory volume in the first second of expiration [FEV₁] % predicted and FEV₁/forced vital capacity [FVC] ≥ 80%; and low, FEV₁% predicted and FEV₁/FVC < 80%). These patients then received National Heart, Lung, and Blood Institute guideline-based asthma treatment at regular follow-up intervals with spirometry performed at these visits as part of regular care. FEV₁% predicted and FEV₁/FVC were followed up for up to 10 years for both the high and low cohorts. Results: Over 10 years, the patients initially in the "high" group maintained FEV₁% predicted and FEV₁/FVC at values similar to the initial visit (94 to 96% and 87 to 89%, respectively), whereas those in the low group had only slight increases of FEV₁% predicted and FEV₁/FVC over the same time (77 to 82% and 78 to 82%, respectively). Low FEV₁% predicted and FEV₁/FVC at the time of the first visit was significantly associated with an increased risk of low values of these lung functions over the next 3-5 years despite treatment. African American ethnicity and male gender were also associated with lower lung function over time. Conclusion: Early airflow obstruction in inner city children asthma is associated with poor lung function in later life despite guideline-based asthma care. Current asthma therapy may not affect pathways and leads to airway remodeling in children with asthma.

A novel locus for exertional dyspnoea in childhood asthma

Most children diagnosed with asthma have respiratory symptoms such as cough, dyspnoea and wheezing, which are also important markers of overall respiratory function. A decade of genome-wide association studies (GWAS) have investigated genetic susceptibility to asthma itself, but few have focused on important respiratory symptoms that characterise childhood asthma.Using whole-genome sequencing (WGS) data for 894 asthmatic trios from a Costa Rican cohort, we performed family-based association tests (FBATs) to assess the association between genetic variants and multiple asthma-relevant respiratory phenotypes: cough, phlegm, wheezing, exertional dyspnoea and exertional chest tightness. We tested whether genome-wide significant associations were replicated in two additional studies: 1) 286 asthmatic trios from the Childhood Asthma Management Program (CAMP), and 2) 2691 African American current or former smokers from the COPDGene study.In the 894 Costa Rican trios, we identified a genome-wide significant association (p=2.16×10-9) between exertional dyspnoea and the single nucleotide polymorphism (SNP) rs10165869, located on chromosome 2q37.3, that was replicated in the CAMP cohort (p=0.023) with the same direction of association (combined p=3.28×10-10). This association was not found in the African American participants from COPDGene. We also found suggestive evidence for an association between SNP rs10165869 and the atypical chemokine receptor 3 (ACKR3).Our finding encourages the secondary association analysis of a wider range of phenotypes that characterise respiratory symptoms in other airway diseases/studies.

Complications and Health Care Resource Utilization Associated with Systemic Corticosteroids in Children and Adolescents with Persistent Asthma

BACKGROUND:

Limited comparative data are available on the impact of systemic corticosteroid (SCS) use in children and adolescents.

OBJECTIVE:

To determine if asthmatic children and adolescents treated with SCS have a higher likelihood of developing complications versus those not receiving SCS and to examine health care resource utilization (HCRU) in this population.

METHODS:

A retrospective study of data from children and adolescents with persistent asthma retrieved from the MarketScan database, a large US health claims data set, for the period 2000 to 2017 was performed. Propensity score matching was used to pair patients in the SCS and control cohorts. For complications, SCS subgroups (≥4 or 1-3 annual prescriptions) were compared with asthmatic controls without SCS using logistic regression, and for HCRU, cohorts were compared using negative binomial regression.

RESULTS:

A total of 67,081 patients were included (SCS: 23,898; control: 43,183). The odds of having a complication were 2.9 (95% confidence interval [CI], 2.5-3.2; P < .001) and 1.6 (95% CI, 1.6-1.7; P < .001) times higher in the ≥4 and 1 to 3 SCS groups, respectively, in the first year of follow-up versus controls. For asthma-related hospitalizations, the incidence rate ratio (IRR) was 6.9 (95% CI, 5.6-8.6) and 3.1 (95% CI, 2.8-3.4) times greater in the ≥4 SCS and 1 to 3 SCS groups, respectively, versus controls; for asthma-related emergency department visits, IRR was 5.0 (95% CI, 4.4-5.6) and 2.9 (95% CI, 2.7-3.0) times greater, respectively, versus controls (all P < .01).

CONCLUSION:

Children and adolescents receiving SCS for persistent asthma have an increased risk of developing complications and have greater HCRU in the first year of follow-up versus those without SCS exposure.

Circulating MicroRNAs and Treatment Response in Childhood Asthma

Rationale: Inhaled corticosteroids (ICS) are key treatments for controlling asthma and preventing asthma attacks. However, the responsiveness to ICS varies among individuals. MicroRNAs (miRNAs) have been lauded for their prognostic utility.Objectives: We hypothesized that circulating miRNAs obtained at baseline/prerandomization in the Childhood Asthma Management Program (CAMP) could serve as biomarkers and biologic mediators of ICS clinical response over the 4-year clinical trial period.Methods: We selected baseline serum samples from 462 CAMP subjects subsequently randomized to either ICS (budesonide) or placebo. Samples underwent small RNA sequencing, and read counts were normalized and filtered by depth and coverage. Linear regression was used to associate miRNAs with change in FEV1% (prebronchodilator FEV1 as a percent predicted) over the 4-year treatment period in both main effects and interaction models. We validated the function of the top associated miRNAs by luciferase reporter assays of glucocorticoid-mediated transrepression and predicted response to ICS through logistic regression models.Measurements and Main Results: We identified 7 miRNAs significantly associated with FEV1% change (P ≤ 0.05) and 15 miRNAs with significant interaction (P ≤ 0.05) to ICS versus placebo treatments. We selected three miRNAs for functional validation, of which hsa-miR-155-5p and hsa-miR-532-5p were significantly associated with changes in dexamethasone-induced transrepression of NF-κB. Combined, these two miRNAs were predictive of ICS response over the course of the clinical trial, with an area under the receiver operating characteristic curve of 0.86.Conclusions: We identified two functional circulating miRNAs predictive of asthma ICS treatment response over time.

Sensitization to inhaled allergens in asthmatic children in southern Jordan: a cross-sectional study

BACKGROUND

Sensitization to inhaled allergens in children with bronchial asthma significantly affects asthma pathogenesis, severity and persistence into late childhood and adulthood. The present study determined the prevalence of sensitization to inhaled allergens in children with bronchial asthma and wheezing episodes in order to investigate the effect of positive sensitization on the severity and control of asthma symptoms and to screen for other associated allergic conditions.

METHODS

A cross-sectional study was conducted, including children between 6 months and 14 years of age attending the chest clinic of Al-Karak, south of Jordan, between November 2013 and February 2016. Skin prick tests (SPTs) using 11 standardized allergen extracts were conducted in 277 children. The severity of asthma was determined based on the Global Initiative for Asthma (GINA) assessment and the Childhood Asthma Control Test (C-ACT) in addition to the history of use of systemic steroids and hospital admissions within the past 12 months.

RESULTS

Sixty-seven percent of children with bronchial asthma reported sensitization to one or more of the inhaled allergens. The most common allergens were olive pollens (18%), cat fur (13.5%), and Dermatophagoides pteronyssinus (11.9%). There was a significant increase in allergen sensitization with age (p < 0.001). The most common concomitant allergic condition among children was allergic rhinitis (71.5%); however, allergic conjunctivitis was the only allergic condition that correlated with the skin test reactivity (p = 0.01). A family history of bronchial asthma was confirmed in 40.4% of children. Children with positive SPTs had lower ACT scores and reported more frequent use of systemic steroids and admissions to hospital within the past 12 months; however, this effect was not statistically significant (p > 0.05).

CONCLUSIONS

Sensitization to inhaled allergens is highly prevalent in children with asthma and wheezing episodes in southern Jordan and may be correlated with the severity of the disease. Therefore, appropriate measures to recognize and avoid these allergens are highly recommended. Most children in our study suffered from concomitant allergic rhinitis, indicating that an appropriate diagnosis and treatment of allergic rhinitis could significantly improve asthma control and thus the quality of life of these children.

TRIAL REGISTRATION

This study is not a clinical trial.

The Swiss Paediatric Airway Cohort (SPAC)

Chronic respiratory symptoms, such as cough, wheeze and dyspnoea, are common in children; however, most research has, with the exception of a few large-scale clinical cohort studies, been performed in the general population or in small, highly-selected samples.

The Swiss Paediatric Airway Cohort (SPAC) is a national, prospective clinical cohort of children and adolescents who visit physicians for recurrent conditions, such as wheeze and cough, and exercise-related respiratory problems. The SPAC is an observational study and baseline assessment includes standardised questionnaires for families and data extracted from hospital records, including results of clinically indicated investigations, diagnoses and treatments. Outcomes are assessed through annual questionnaires, monthly symptom reporting via mobile phone and follow-up visits.

The SPAC will address important questions about clinical phenotypes, diagnosis, treatment, and the short- and long-term prognosis of common respiratory problems in children. The cohort currently consists of 347 patients from four major hospitals (Bern, Zurich, Basel and Lucerne), with 70–80 additional patients joining each month. More centres will join and the target sample size is a minimum of 3000 patients.

The SPAC will provide real-life data on children visiting the Swiss healthcare system for common respiratory problems and will provide a research platform for health services research and nested clinical and translational studies.

The Swiss Paediatric Airway Cohort (SPAC) is a unique research platform for common respiratory problems in childrenhttp://ow.ly/Y1v030lDnji

A Nasal Brush-based Classifier of Asthma Identified by Machine Learning Analysis of Nasal RNA Sequence Data

Asthma is a common, under-diagnosed disease affecting all ages. We sought to identify a nasal brush-based classifier of mild/moderate asthma. 190 subjects with mild/moderate asthma and controls underwent nasal brushing and RNA sequencing of nasal samples. A machine learning-based pipeline identified an asthma classifier consisting of 90 genes interpreted via an L2-regularized logistic regression classification model. This classifier performed with strong predictive value and sensitivity across eight test sets, including (1) a test set of independent asthmatic and control subjects profiled by RNA sequencing (positive and negative predictive values of 1.00 and 0.96, respectively; AUC of 0.994), (2) two independent case-control cohorts of asthma profiled by microarray, and (3) five cohorts with other respiratory conditions (allergic rhinitis, upper respiratory infection, cystic fibrosis, smoking), where the classifier had a low to zero misclassification rate. Following validation in large, prospective cohorts, this classifier could be developed into a nasal biomarker of asthma.

Benefits and Risks of Long-Term Asthma Management in Children: Where Are We Heading?

International guidelines provide recommendations for a stepwise approach to the management of asthma in children 0-4 years old, 5-11 years old, and adolescents who are treated as adults. Therapy is aimed at two domains of control: current impairment and future risk. The long-term controller medications, inhaled corticosteroids (ICSs), ICSs in combination with long-acting β₂ agonists, leukotriene receptor antagonists, and immunomodulators, exhibit different efficacies for these domains. The risk:benefit ratios of the available medications need to be carefully assessed. This review briefly presents the benefits and the potential risks of available asthma medications in children to assist the practitioner in the optimal use of asthma medications. Specifically, the systemic activity of the ICSs and how to minimize their effects on growth and adrenal activity are reviewed as well as other potential adverse effects. Dosing strategies such as intermittent therapy are also assessed.

Longitudinal Evaluation of Chronic Rhinosinusitis Symptoms in a Population-Based Sample

BACKGROUND

Chronic rhinosinusitis (CRS) is a prevalent and disabling condition of the nose and sinuses. The natural history of CRS symptoms in a general population sample has not been previously studied.

OBJECTIVE

In a general population-based sample from Pennsylvania, we used 2 questionnaires mailed 6 months apart to estimate the prevalence of, and identify predictors for, stability or change in symptoms over time.

METHODS

We mailed the baseline and 6-month follow-up questionnaires to 23,700 primary care patients and 7,801 baseline responders, respectively. We categorized nasal and sinus symptoms using European Position Paper on Rhinosinusitis (EPOS) epidemiologic criteria. We defined 6 symptom groups over time on the basis of the presence of CRS symptoms at baseline and follow-up. We performed multivariable survey logistic regression controlling for confounding variables comparing persistent versus nonpersistent, recurrent versus stable past, and incident versus never.

RESULTS

There were 4,966 responders at follow-up: 558 had persistent symptoms, 190 recurrent symptoms, and 83 new symptoms meeting EPOS criteria for CRS. The prevalence of persistent symptoms was 4.8% (95% CI, 3.8-5.8), whereas the annual cumulative incidence of new symptoms was 1.9% and of recurrent symptoms was 3.2%. More severe symptoms at baseline were associated with persistence, whereas minor symptoms, allergies, and multiple treatments were associated with the development of new symptoms.

CONCLUSIONS

Less than half with nasal and sinus symptoms meeting CRS EPOS criteria in our general, regional population had symptom persistence over time, with symptom profiles at baseline and age of onset being strongly associated with stability of symptoms.

Gene expression profiling of asthma phenotypes demonstrates molecular signatures of atopy and asthma control

BACKGROUND

Recent studies have used cluster analysis to identify phenotypic clusters of asthma with differences in clinical traits, as well as differences in response to therapy with anti-inflammatory medications. However, the correspondence between different phenotypic clusters and differences in the underlying molecular mechanisms of asthma pathogenesis remains unclear.

OBJECTIVE

We sought to determine whether clinical differences among children with asthma in different phenotypic clusters corresponded to differences in levels of gene expression.

METHODS

We explored differences in gene expression profiles of CD4(+) lymphocytes isolated from the peripheral blood of 299 young adult participants in the Childhood Asthma Management Program study. We obtained gene expression profiles from study subjects between 9 and 14 years of age after they participated in a randomized, controlled longitudinal study examining the effects of inhaled anti-inflammatory medications over a 48-month study period, and we evaluated the correspondence between our earlier phenotypic cluster analysis and subsequent follow-up clinical and molecular profiles.

RESULTS

We found that differences in clinical characteristics observed between subjects assigned to different phenotypic clusters persisted into young adulthood and that these clinical differences were associated with differences in gene expression patterns between subjects in different clusters. We identified a subset of genes associated with atopic status, validated the presence of an atopic signature among these genes in an independent cohort of asthmatic subjects, and identified the presence of common transcription factor binding sites corresponding to glucocorticoid receptor binding.

CONCLUSION

These findings suggest that phenotypic clusters are associated with differences in the underlying pathobiology of asthma. Further experiments are necessary to confirm these findings.

Evidence of hypothalamic-pituitary-adrenal axis suppression during moderate-to-high-dose inhaled corticosteroid use

The possible risk of adverse effects due to regular use of inhaled corticosteroids (ICS) is a real concern. Our aim was to describe the factors that have an impact on hypothalamic-pituitary-adrenal axis suppression (HPA-AS) in children and adolescents taking ICS regularly. The HPA axis status of patients who were on moderate-to-high-dose ICS [>176 and >264 μg/day fluticasone propionate-hydrofluoroalkane (FP-HFA) for patients 0-11 and ≥12 years, respectively] was investigated. Various types of ICS were converted to FP-HFA equivalent according to National Asthma Education and Prevention Program (NAEPP) guidelines. Participants with a baseline (8 a.m.) serum cortisol <15 μg/dL underwent a low-dose ACTH stimulation test (LDAT) to diagnose HPA-AS. Among 91 patients, 60 (75.9 %) participants underwent LDAT, and seven (7.7, 95 % CI 3.5-15.3 %) were diagnosed with HPA-AS. Ciclesonide was more frequently used by the participants with HPA-AS compared to patients with a normal HPA axis (42.9 vs. 4.8 %, p = 0.009). Use of ICS at moderate-to-high doses for at least 7 months distinguished participants with HPA-AS from those with a normal HPA axis. Among the duration, type, and dose of ICS, solely the use of ICS with a body mass index (BMI)-adjusted daily dose of ≥22 μg FP was found to increase the risk for HPA-AS (odds ratio (OR) 7.22, 95 % confidence interval (CI) 1.23-42.26, p = 0.028). The receiver operating characteristics (ROC) curve analysis revealed a cutoff value of 291 μg/day FP (area under the curve (AUC) = 0.840, p = 0.003) for predicting HPA-AS Conclusion: The prevalence of HPA-AS was found to be 7.7 % in children taking not only high-dose ICS but also moderate-dose ICS. Dose alone was found to be an actual risk factor for HPA-AS.

Steroid Pathway Genes and Neonatal Respiratory Distress After Betamethasone Use in Anticipated Preterm Birth

OBJECTIVE

To test several key glucocorticoid genes that are enhanced in lung development for associations with respiratory distress syndrome (RDS) after antenatal corticosteroid use.

METHODS

A prospective cohort of women received betamethasone to accelerate fetal lung maturity for threatened preterm delivery. DNA was obtained from mothers and newborns. Neonatal RDS was the primary outcome. Genotyping for single-nucleotide polymorphisms (SNPs) in 68 glucocorticoid genes found to be differentially expressed during lung development was performed. Multivariable analysis tested for associations of SNPs in the candidate genes with RDS.

RESULTS

Genotypic results for 867 SNPs in 96 mothers and 73 babies were included. Thirty-nine (53.4%) babies developed RDS. Maternal SNPs in the centromeric protein E (CENPE), GLRX, CD9, and AURKA genes provided evidence of association with RDS (P < .01). In newborns, SNPs in COL4A3, BHLHE40, and SRGN provided evidence of association with RDS (P < .01).

CONCLUSION

Single-nucleotide polymorphisms in several glucocorticoid responsive genes suggest association with neonatal RDS after antenatal corticosteroid use.