Long-term outcomes of early-onset wheeze and asthma

Deep multiomic profiling reveals molecular signatures that underpin preschool wheeze and asthma

BACKGROUND

Wheezing in childhood is prevalent, with over one-half of all children experiencing at least 1 episode by age 6. The pathophysiology of wheeze, especially why some children develop asthma while others do not, remains unclear.

OBJECTIVES

This study addresses the knowledge gap by investigating the transition from preschool wheeze to asthma using multiomic profiling.

METHODS

Unsupervised, group-agnostic integrative multiomic factor analysis was performed using host/bacterial (meta)transcriptomic and bacterial shotgun metagenomic datasets from bronchial brush samples paired with metabolomic/lipidomic data from bronchoalveolar lavage samples acquired from children 1-17 years old.

RESULTS

Two multiomic factors were identified: one characterizing preschool-aged recurrent wheeze and another capturing an inferred trajectory from health to wheeze and school-aged asthma. Recurrent wheeze was driven by type 1-immune signatures, coupled with upregulation of immune-related and neutrophil-associated lipids and metabolites. Comparatively, progression toward asthma from ages 1 to 18 was dominated by changes related to airway epithelial cell gene expression, type 2-immune responses, and constituents of the airway microbiome, such as increased Haemophilus influenzae.

CONCLUSIONS

These factors highlighted distinctions between an inflammation-related phenotype in preschool wheeze, and the predominance of airway epithelial-related changes linked with the inferred trajectory toward asthma. These findings provide insights into the differential mechanisms driving the progression from wheeze to asthma and may inform targeted therapeutic strategies.

Outdoor Alternaria and Cladosporium spores and acute asthma

BACKGROUND

Outdoor Alternaria and Cladosporium spores are ubiquitous. Few studies have assessed their impact on asthma hospitalizations providing conflicting results, mainly focused on vulnerable paediatric populations. We aimed to study the impact of outdoor Alternaria and Cladosporium concentrations on acute hospitalizations in the Capital Region of Denmark.

METHODS

This is a bi-directional case-crossover study with 26 years of national registry data at individual level on acute asthma hospitalizations and daily average data on Alternaria and Cladosporium, pollen (Artemisia, Poaceae), maximal temperature, and air pollution. Conditional logistic regression models were applied to assess the associations. Concentration quartiles at lag 0 were used for categorizing the exposure.

RESULTS

For lags 0-2, the odds of hospitalization were significantly higher for both Alternaria and Cladosporium at concentration quartile 2-4 compared with quartile 1. When stratified for age and sex, odds of hospitalization at Alternaria quartiles 2-4 were significantly higher in males below 40 years at lag 0-2, and at lag 0 in females (18-30 years), while quartiles 2-4 of Cladosporium concentrations were associated with significantly higher odds in boys (0-17 years) at lag 1-3, males (18-39 years) at lag 0-1, females (18-39 years) at lag 1-2, males (40-64 years) at lag 0-2, females (40-64 years) at lag 0 and 2, in seniors (65+ years) male at lag 1-2 and female at lag 0-1. The effect of Alternaria varied significantly depending on the level of Cladosporium (p < .0001).

CONCLUSION

Ambient Alternaria and Cladosporium spores can induce asthma hospitalizations. Males are more susceptible to both genera. Males and females under age 40 years are more susceptible to Alternaria.

Inflammatory related plasma proteins involved in acute preschool wheeze

BACKGROUND

Preschool wheeze is a risk factor for asthma development. However, the molecular mechanism behind a wheezing episode is not well understood.

OBJECTIVE

Our aims were to assess the association of plasma proteins with acute preschool wheeze and to study the proteins with differential expression at the acute phase at revisit after 3 months. Additionally, to investigate the relationship between protein expression and clinical parameters.

METHOD

We measured 92 inflammatory proteins in plasma and clinical parameters from 145 children during an episode of preschool wheeze (PW) and at the revisit after 3 months (PW-R, n = 113/145) and 101 healthy controls (HC) aged 6-48 months in the GEWAC cohort using the antibody-mediated proximity extension-based assay (Olink Proteomics, Uppsala).

RESULTS

Of the 74 analysed proteins, 52 were differentially expressed between PW and HC. The expression profiles of the top 10 proteins, Oncostatin M (OSM), IL-10, IL-6, Fibroblast growth factor 21 (FGF21), AXIN1, CXCL10, SIRT2, TNFSF11, Tumour necrosis factor β (TNF-β) and CASP8, could almost entirely separate PW from HC. Five out of 10 proteins were associated with intake of oral corticosteroids (OCS) 24 h preceding blood sampling (OSM, CASP8, IL-10, TNF-β and CXCL10). No differences in protein expression were seen between PWs with or without OCS in comparison to HC. At the revisit after 3 months, differential protein expressions were still seen between PW-R and HC for three (IL-10, SIRT2 and FGF21) of the 10 proteins.

CONCLUSION

Our results contribute to unravelling potential immunopathological pathways shared between preschool wheeze and asthma.

The Acceptability of Using Augmented Reality as a Mechanism to Engage Children in Asthma Inhaler Technique Training: Qualitative Interview Study With Deductive Thematic Analysis

BACKGROUND

Inhaled medications or inhalers provide first-line pharmacotherapeutic treatment for patients with asthma for both acute symptomatic relief and long-term management to keep symptoms under control. A good technique requires only basic instruction and training; however, a recent study identified that 92% of children do not follow all correct steps when using inhalers. There is a growing interest in technology-enhanced asthma education, with evidence demonstrating improvements in knowledge and treatment adherence. Subsequently, there are calls to explore the role of technology-based solutions in improving asthma management and disease outcomes from public health experts, health professionals, and patients with asthma. Augmented reality (AR) technology is an information delivery mechanism with proven efficacy in educational settings. AR displays digital content in a real-world environment using the camera on a smartphone or tablet device to create an immersive learning experience.

OBJECTIVE

The study aimed to evaluate the acceptability of AR as a mechanism for delivering asthma inhaler technique education from the perspective of children with asthma and their parents and health professionals, examined through the theoretical framework of acceptability (TFA).

METHODS

An asthma education resource enhanced with AR technology was created to provide inhaler technique education to children. An iterative co-design process was undertaken with target end users for a qualitative evaluation. The participants were 8 to 12 years old with asthma, their caregivers, and health professionals who had experience in managing asthma. Qualitative data were obtained through semistructured one-on-one interviews. Deductive thematic analysis using TFA was undertaken using NVivo software 2020 to assess the acceptability of AR as a delivery modality for asthma inhaler technique education.

RESULTS

Overall, 6 health care professionals, 5 asthmatic children, and 5 caregivers of children with asthma totaled a sample of 16. The use of AR in the asthma inhaler resource was found to be acceptable when responses were examined in accordance with TFA. Each of the 7 component constructs of TFA was coded throughout the 16 interviews, with perceived effectiveness (157 times) and affective attitude (63 times) coded most frequently. Positive responses included the intervention being accessible, easy to use, interesting, and fitting within the users' value systems. Negative responses included the need to maintain an interest in children and concerns about the loss of face-to-face interaction with health professionals.

CONCLUSIONS

AR appears to be an acceptable modality for delivering asthma education to children when explored using TFA constructs. Although some challenges were identified with the use of AR, the results were predominantly positive. Future designs of asthma education interventions involving AR should consider the results of this study, and further research should focus on the feasibility, usability, and barriers and facilitators of behavior change to ensure the successful implementation and uptake of AR into clinical settings.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1177/16094069211042229.

Diagnosis and management of asthma in infants and preschoolers

Asthma is one of the most common chronic disease affecting children, and it often starts in infancy and preschool years. In previous birth cohorts, frequent wheezing in early life was associated with the development of asthma in later childhood and reduced lung function persisting into adulthood. Preschool wheezing is considered an umbrella term for distinctive diseases with different clinical features (phenotypes), each of which may be related to different underlying pathophysiologic mechanisms (endotypes). The classification of phenotypes of early wheezing is needed to identify children at high risk for developing asthma later who might benefit from early intervention. However, diagnosis of asthma in infants and preschoolers is particularly difficult because objective lung function tests cannot be performed and definitive biomarkers are lacking. Moreover, management of early asthma is challenging because of its different phenotypic presentations. Many prediction models and asthma guidelines have been developed to provide useful information for physicians to assess young children with recurrent wheezing and manage them appropriately. Many recent studies have investigated the application of personalized medicine for early asthma by identifying specific phenotypes and biomarkers. Further researches, including genetic and molecular studies, are needed to establish a clear definition of asthma and develop more targeted therapeutic approaches in this age group.

Early-life residential exposure to moisture damage is associated with persistent wheezing in a Finnish birth cohort

BACKGROUND AND AIMS

Moisture damage increases the risk for respiratory disorders in childhood. Our aim was to determine whether early age residential exposure to inspector-observed moisture damage or mold is associated with different wheezing phenotypes later in childhood.

METHODS

Building inspections were performed by civil engineers, in a standardized manner, in the children's homes-mostly single family and row houses (N = 344)-in the first year of life. The children were followed up with repeated questionnaires until the age of 6 years and wheezing phenotypes-never/infrequent, transient, intermediate, late onset, and persistent-were defined using latent class analyses. The multinomial logistic regression model was used for statistical analysis.

RESULTS

A total of 63% (n = 218) had infrequent or no wheeze, 23% (n = 80) had transient and 9.6% (n = 21) had a persistent wheeze. Due to the low prevalence, results for intermediate (3.8%, n = 13) and late-onset wheeze (3.5%, n = 12) were not further evaluated. Most consistent associations were observed with the persistent wheeze phenotype with an adjusted odds ratio (95% confidence intervals) 2.04 (0.67-6.18) for minor moisture damage with or without mold spots (present in 23.8% of homes) and 3.68 (1.04-13.05) for major damage or any moisture damage with visible mold in a child's main living areas (present in 13.4% of homes). Early-age moisture damage or mold in the kitchen was associated with transient wheezing.

CONCLUSION

At an early age, residential exposure to moisture damage or mold, can be dose-dependently associated especially with persistent wheezing phenotype later in childhood.

Association Between Asthma Control Trajectories in Preschoolers and Long-Term Asthma Control

BACKGROUND

The potential influence of asthma control in early life on long-term outcomes in childhood remains largely unknown.

OBJECTIVE

To examine whether asthma control trajectories in the 2 years after diagnosis in preschoolers are associated with long-term unsatisfactory asthma control.

METHODS

We conducted a multicenter population-based retrospective cohort study, including four Canadian provincial birth cohorts derived from administrative databases. We included preschoolers (aged <5 years) with a diagnosis of asthma, defined as having one hospitalization or two physician visits for asthma within 2 years. Asthma control trajectories, ascertained over four 6-month periods after diagnosis using a validated index, were classified as controlled throughout, improving control, fluctuating control, worsening control, and out of control throughout. Long-term unsatisfactory control was defined as four or more short-acting β₂-agonist average doses per week or an exacerbation, measured within 6 months before index ages 6, 8, 10, 12, 14, and 16 years. Average risk ratios for long-term unsatisfactory control across all index ages were estimated using a robust Poisson model by province and meta-analyzed with a random effects model.

RESULTS

In 50,188 preschoolers with asthma, the pooled average risk of having unsatisfactory control at any index age was 42% (95% confidence interval, 34.6-49.4). Compared with children who were controlled throughout, incrementally higher average risk ratios (95% confidence interval) of long-term unsatisfactory control were observed in each trajectory: improving control, 1.38 (1.28-1.49); fluctuating control, 1.54 (1.40-1.68); worsening control, 1.70 (1.55-1.86) and out of control throughout, 2.00 (1.80-2.21).

CONCLUSIONS

Suboptimal asthma control trajectories shortly after a preschool diagnosis were associated with long-term unsatisfactory asthma control. Early control trajectories appear to be promising for predicting the risk for long-term adverse outcomes.

Wheezing trajectories from childhood to adulthood in a population-based cohort

BACKGROUND

Wheezing may lead to asthma and reduced pulmonary function in later life. The study aims to identify wheezing trajectories and investigate their relation with pulmonary function and asthma-related outcomes at 22 years of age.

METHODS

Individuals from a population-based cohort in Brazil (1993 Pelotas Birth Cohort) with post-bronchodilator pulmonary function data at 22 years (3350) were included in the study. From parentally reported (4 and 11 years) and self-reported (15, 18 and 22 years) history of wheezing in the last 12 months, we used a group-based trajectory modelling approach to derive wheezing trajectories.

RESULTS

Four trajectories were identified: never/infrequent, transient-early, late-onset and persistent wheeze. After adjustments, wheezing trajectories remained associated with lower post-bronchodilator values of pulmonary function. Individuals in the persistent wheeze trajectory had a markedly poorer pulmonary function and also showed greater odds of asthma-related outcomes compared to other trajectories groups. Those following this trajectory had on average -109 ml (95% CI: -188; -35), -1.80 percentage points (95% CI: -2.73; -0.87) and -316 ml/s (95% CI: -482; -150) lower FEV₁, FEV₁/FVC ratio and FEF_25-75% respectively; higher odds of self-reported medical diagnosis of allergy (OR 6.18; 95% CI: 3.59; 10.61) and asthma (OR 12.88; 95% CI: 8.91; 18.61) and asthma medication use (OR 9.42; 95% CI: 5.27; 16.87) compared to the never/infrequent group.

CONCLUSIONS

Wheezing trajectories, especially the persistent wheeze trajectory, were related to lower pulmonary function values and increased risk of asthma and allergy diagnosis in early adulthood.

Clinical Outcomes for Young Children Diagnosed With Asthma Versus Reactive Airway Disease

OBJECTIVE

Clinical diagnoses of asthma and reactive airway disease (RAD) in young children are subjective. We examined how often children were diagnosed with asthma versus RAD, and whether preventive care and 2-year clinical outcomes differed based on initial diagnosis.

METHODS

We conducted a retrospective cohort analysis of children (2-7 years) from a university-based general pediatrics practice who had been diagnosed with RAD or asthma. We performed adjusted comparisons between groups for time until subsequent asthma-related care. We also compared delivery of asthma-related healthcare services, corticosteroid and controller prescriptions, and action plans within 2 years of index diagnosis, using bivariate and regression analyses.

RESULTS

Four hundred three children were included (64% male, 67% Black, 25% Hispanic). RAD was diagnosed in 62% of index visits, and was more likely than asthma to be diagnosed in emergency settings. In the full sample, the time between index visit and subsequent asthma care did not differ between groups, after adjustment for index location. For subjects with complete 24-month follow-up (N = 300), no between-group differences were found in adjusted analyses. Most children with RAD received action plans and controller medications only after a subsequent asthma diagnosis, on average, 9 months after their index visit.

CONCLUSIONS

RAD diagnoses were linked to delayed delivery of preventive care measures, but within 2 years of initial diagnosis, clinical outcomes for those diagnosed with RAD and asthma did not differ. To facilitate clear communication and timely treatment, a prompt diagnosis of asthma, rather than RAD, should be considered for children with asthma symptoms.

TSLP bronchoalveolar lavage levels at baseline are linked to clinical disease severity and reduced lung function in children with asthma

RATIONALE

Thymic stromal lymphopoietin (TSLP) is increasingly recognized as a key molecule in asthma pathogenesis and as a promising therapeutic target in adults. In contrast, in asthmatic children the clinical relevance of TSLP secretion in the lower airways has been remarkably understudied. We tested the hypothesis that pulmonary TSLP levels in asthmatic children correlate with clinical severity, airway inflammation and lower airway obstruction.

METHODS

Bronchoalveolar lavage (BAL) samples and relevant clinical data were collected from asthmatic children undergoing clinically indicated bronchoscopy at Children's National Hospital in Washington D.C. Protein levels of TSLP, IL-5, IL-1β, and IL-33 were quantified in BAL at baseline and correlated with individual severity and clinical features including spirometry, serum IgE and eosinophils, BAL neutrophil and eosinophil counts.

RESULTS

We enrolled a total of 35 asthmatic children (median age: 9 years). Pediatric subjects with severe asthma had greater TSLP BAL levels at baseline relative to mild or moderate asthmatic subjects (p = 0.016). Asthmatic children with the highest TSLP levels (>75th percentile) had higher IL-5 and IL-1β BAL levels and greater lower airway obstruction (lower FEV1/FVC ratios).

CONCLUSION

Our study demonstrates for the first time that higher pulmonary TSLP levels obtained at baseline are linked to asthma disease severity in a subset of children. These data indicate that TSLP may play a key role in the pathogenesis of pediatric asthma and thus provide initial support to investigate the potential use of anti-TSLP biologics to treat severe uncontrolled asthmatic children.

Bronchopulmonary dysplasia as a determinant of respiratory outcomes in adult life

Respiratory disease is unfortunately common in preterm infants with the archetype being bronchopulmonary dysplasia (BPD). BPD affects approximately 50,000 preterm infants in the U.S. annually with substantial morbidity and mortality related to its pathology (alveolar, airway, and pulmonary vasculature maldevelopment). Predicting the likelihood and severity of chronic respiratory disease in these children as they age is difficult and compounded by the lack of consistent phenotyping. Barriers to understanding the actual scope of this problem include few longitudinal studies, information limited by small retrospective studies and the ever-changing landscape of therapies in the NICU that affect long-term respiratory outcomes. Thus, the true burden of adult respiratory disease caused by premature birth is currently unknown. Nevertheless, limited data suggest that a substantial percentage of children with a history of BPD have long-term respiratory symptoms and persistent airflow obstruction associated with altered lung function trajectories into adult life. Small airway disease with variable bronchodilator responsiveness, is the most common manifestation of lung dysfunction in adults with a history of BPD. The etiology of this is unclear however, developmental dysanapsis may underlie the airflow obstruction in some adults with a history of BPD. This type of flow limitation resembles that of aging adults with chronic obstructive lung disease with no history of smoking. It is also unclear whether lung function abnormalities in people with a history of BPD are static or if these individuals with BPD have a more accelerated decline in lung function as they age compared to controls. While some of the more significant mediators of lung function, such as tobacco smoke and respiratory infections have been identified, more work is necessary to identify the best means of preserving lung function for individuals born prematurely throughout their lifespan.

Infant Nasopharyngeal Microbiota Subphenotypes and Early Childhood Lung Function: Evidence from a Rural Ghanaian Pregnancy Cohort

Early life respiratory microbiota may increase risk for future pulmonary disease. Associations between respiratory microbiota and lung health in children from low- and middle-income countries are not well-described. Leveraging the Ghana Randomized Air Pollution and Health Study (GRAPHS) prospective pregnancy cohort in Kintampo, Ghana, we collected nasopharyngeal swabs in 112 asymptomatic children aged median 4.3 months (interquartile range (IQR) 2.9, 7.1) and analyzed 22 common bacterial and viral pathogens with MassTag polymerase chain reaction (PCR). We prospectively followed the cohort and measured lung function at age four years by impulse oscillometry. First, we employed latent class analysis (LCA) to identify nasopharyngeal microbiota (NPM) subphenotypes. Then, we used linear regression to analyze associations between subphenotype assignment and lung function. LCA suggest that a two-class model best described the infant NPM. We identified a higher diversity subphenotype (N = 38, 34%) with more pathogens (median 4; IQR 3.25, 4.75) and a lower diversity subphenotype (N = 74, 66%) with fewer pathogens (median 1; IQR 1, 2). In multivariable linear regression models, the less diverse NPM subphenotype had higher small airway resistance (R5-R20 β = 17.9%, 95% CI 35.6, 0.23; p = 0.047) compared with the more diverse subphenotype. Further studies are required to understand the role of the microbiota in future lung health.

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.

Association between asthma control trajectories in preschoolers and disease remission

INTRODUCTION

Early disease morbidity has been associated with asthma persistence in wheezing preschoolers; however, whether asthma control trajectories shortly after diagnosis could influence remission is unknown. We examined the association between asthma control trajectories 2 years post-diagnosis in preschoolers and subsequent disease remission.

METHODS

We conducted a multicentre population-based retrospective cohort study consisting of 48 687 children with asthma diagnosed before 5 years old and born between 1990 and 2013 in four Canadian provinces who had prolonged disease activity post-diagnosis. Prolonged disease activity was defined as one or more medical visits or medications for asthma every 6-month period for at least four of the six periods post-diagnosis. Follow-up began at 3 years post-diagnosis (at cohort entry). Remission was defined as 2 consecutive years without drug claims or medical visits for asthma or asthma-like conditions following cohort entry. Asthma control trajectories, ascertained over four 6-month periods following diagnosis using a validated index, were classified as: "controlled throughout", "improving control", "worsening control", "out of control throughout" and "fluctuating control". Adjusted Cox models estimated associations between asthma control trajectories and time to remission. A random effects meta-analysis summarised province-specific hazard ratios (HRs).

RESULTS

The pooled remission rate was 8.91 (95% CI 8.80-9.02) per 100 person-years. Compared with children controlled throughout, poorer asthma control was associated with incrementally lower hazard ratios of remission in four other trajectories: improving control (HR 0.89, 95% CI 0.82-0.96), fluctuating control (HR 0.78, 95% CI 0.71-0.85), worsening control (HR 0.68, 95% CI 0.62-0.75) and out of control throughout (HR 0.52, 95% CI 0.45-0.59).

CONCLUSIONS

Asthma control trajectories 2 years following a diagnosis in preschoolers were associated with remission, highlighting the clinical relevance of documenting control trajectories in early life.

Factors and mechanisms contributing to the development of preschool wheezing disorders

INTRODUCTION

Half of all children will experience an episode of wheezing by their sixth birthday and acute episodes of wheezing in preschool children account for the majority of all childhood hospital admissions for wheeze. Recurrent preschool wheezing associates with early loss of lung function and a life-long impact on lung health.

AREAS COVERED

We reviewed the literature on PubMed from August 2010-2020 focussing on factors associated with wheeze inception and persistence, paying specific attention to mechanistic studies that have investigated the impact of early life exposures in shaping immune responses in children with underlying susceptibility to wheezing. In particular, the role of early allergen sensitization, respiratory infections, and the impact of the environment on shaping the airway microbiome and resulting immune responses are discussed.

EXPERT OPINION

There is an abundance of associative data showing the role of in utero and postnatal factors influencing wheeze onset and persistence. However, mechanistic and stratified, biomarker-based interventional studies that confirm these associations are now needed if we are to impact the significant healthcare burden resulting from preschool wheezing disorders.

Lung Function of Children Following an Intensive Care Unit Admission for Asthma

Background: To determine the lung function of children admitted to the intensive care unit (ICU) for a severe asthma exacerbation in the medium- to long-term following hospital discharge. Methods: We performed a retrospective chart review of children ≥6 years of age admitted to the ICU for a severe asthma exacerbation at a tertiary care center from January 1, 2000, to December 31, 2013. Lung function was ascertained during outpatient follow-up visits at 3-12 months and 12-24 months postdischarge. A total of 72 subjects met the inclusion criteria. Results: Subjects were predominantly boys (56.9%) and had a mean (standard deviation [SD]) age at admission of 10.3 years (3.4 years). The median (interquartile range) length of stay in the ICU was 1 day (1-3 days). Thirty-eight and 28 subjects performed pulmonary function tests with acceptable technique at the 3-12 months and 12-24 months postdischarge visits, respectively. At 3-12 months, the mean (SD) predicted forced expiratory volume in 1 s (FEV₁) and forced expiratory flow between 25% and 75% of vital capacity (FEF_25-75) percent were 95.9 (16.7) and 76.7 (25.8), respectively, and 97.4 (17.6) and 70.5 (24.9), respectively, at 12-24 months. FEV₁/forced vital capacity (FEV₁/FVC) was 81.7 (8.3) at 3-12 months and 79.3 (7.7) at 12-24 months. A paired t-test on 20 subjects who performed acceptable spirometry at both visits showed a significant intraindividual decrease in FEV₁ (P = 0.008), FEF_25-75 (P = 0.02), and FEV₁/FVC (P = 0.01) between the 2 time points. Conclusion: Although prospective studies are required to confirm our findings, our study suggests that children admitted to the ICU for severe asthma exacerbations may be at risk for declining pulmonary function in the medium- to long-term postdischarge.

Factors associated with wheezing among Lebanese children: Results of a cross-sectional study

BACKGROUND

In Lebanon, asthma is underdiagnosed due to low access to healthcare, particularly in rural areas, although asthma diagnosis in children is based mainly on clinical symptoms. Thus, wheezing might be more suggestive of undiagnosed respiratory diseases including asthma in Lebanese children. This study aimed to determine the factors associated with wheezing in Lebanese children without asthma diagnosis.

METHODS

This cross-sectional study was conducted between December 2015 and April 2016, enrolling a total of 1203 schoolchildren.

RESULTS

Out of 1500 prepared questionnaires, 1380 questionnaires were distributed in schools, and 1203 (87.17%) were collected back from the parents of children aged between 4-17 years old. The sample included 42 (3.5%) [95% CI 0.025-0.045] children with reported chronic wheezing. A multivariable analysis was performed taking the presence versus absence of wheezing in children as the dependent variable. The results showed that spraying pesticides at home (aOR=1.91), presence of humidity at home (aOR=2.21) and child reflux (aOR=2.60) were significantly associated with the presence of wheezing in children.

CONCLUSION

The findings of the study suggest that certain environmental factors, such as pesticides, humidity at home and reflux disease, might be associated with wheezing episodes in children. Those factors can be prevented through raising awareness by health care professionals.

Test for respiratory and asthma control in preschool kids in the emergency department as a predictor of wheezing exacerbations

OBJECTIVE

The test for respiratory and asthma control in kids (TRACK score) is a standardized questionnaire tool validated to identify poor symptom control in children with stable preschool wheeze. This study determined if TRACK score measured within 5 days of an Emergency Department (ED) visit for acute wheezing predicts a subsequent wheezing exacerbation requiring an ED visit and/or treatment with systemic corticosteroids within 3 months.

METHODS

This was a single-center prospective cohort study of children aged 36 to 71 months who presented to the ED with an acute episode of wheezing and had TRACK score measured at a clinic visit within 5 days of the index ED encounter, focused on information about symptoms occurring before the onset of the current acute episode. The outcomes were the independent association of a repeat wheezing exacerbation with the overall TRACK score (primary) and with mutually uncorrelated TRACK items (secondary), adjusted for sex and atopy.

RESULTS

We enrolled 102 children; median age 52.3 (44.1, 59.9) months, 59% males. Of these, 33 (32.4%) had further wheezing exacerbations. For each 10 unit decrease in TRACK, the odds of a future exacerbation was 1.38 (95% CI, 1.10-1.75); male sex demonstrated OR, 5.13 (1.84-14.33). A model that included TRACK items reflecting more than equal to 1 awakenings for wheezing in the past 4 weeks, receipt of more than equal to 2 courses of corticosteroids in the last year and male sex was predictive of wheezing exacerbations: OR, 6.43 (2.18-19.00).

CONCLUSION

In preschoolers with acute wheezing episodes in the ED, we have identified the TRACK score components which, together with male sex, can be used to identify children at risk of future exacerbations requiring referral for specialized care. These results need to be confirmed and validated in other populations enrolled at multiple sites before they can be implemented in practice.

Personal and early life factors associated with new-onset asthma, remission, and persistence of asthma in a 2-year follow-up of schoolchildren

OBJECTIVE

The natural course of childhood asthma, after its onset, is characterized by periods of persistence, relapse and remission. To investigate personal and early life factors associated with new-onset asthma, persistence and remission among children.

METHODS

The study was conducted in the province of Saskatchewan, Canada. Children in grades Kindergarten to Grade 8 (ages 5-14 years) participated in a cross-sectional study in 2013. In 2015, we approached those who gave consent in 2013 to be re-contacted, creating a prospective cohort. Data were collected using questionnaires in both years. Participants in 2013 who also had data in 2015 (25%: n = 324/1,348) had their asthma status reclassified and longitudinal descriptors were applied: "no asthma", "new-onset asthma", "persistent" or "remission". Personal and early life factors associations with asthma outcomes in 2015 were evaluated.

RESULTS

Among those without asthma in 2013 (n = 245), the incidence of new-onset asthma in 2015 was 7.2%. Among those with asthma in 2013 (n = 79), 47.1% had remission and 52.9% had persistent asthma in 2015. Parental history of asthma (adjusted odds ratio (aOR): 4.99; 95% confidence interval (CI): 1.88-28.27), early life respiratory infection (aOR: 1.92; 95%CI: 1.47-7.88), early life allergy [aOR: 6.39; 95%CI: 1.34-30.58) and early life infection (aOR: 4.99; 95%CI: 1.19-20.93) were associated with new onset asthma. Similarly, while parental history of asthma (aOR: 1.13; 95%CI: 0.29-4.34), early life respiratory infection (aOR: 2.71; 95%CI: 0.70-10.45), and early life ear infection (aOR: 1.34; 95%CI: 0.36-5.05) were also positively association with persistent asthma, the associations were not statistically significant.

CONCLUSION

Parental history of asthma, early life respiratory infection and allergy might not only influence the onset of childhood asthma but also be associated with asthma persistence.

Variability in Diagnosed Asthma in Young Children in a Large Pediatric Primary Care Network

OBJECTIVE

Our objectives were to 1) quantify the frequency of wheezing episodes and asthma diagnosis in young children in a large pediatric primary care network and 2) assess the variability in practice-level asthma diagnosis, accounting for common asthma risk factors and comorbidities. We hypothesized that significant variability in practice-level asthma diagnosis rates would remain after adjusting for associated predictors.

METHODS

We generated a retrospective longitudinal birth cohort of children who visited 1 of 31 pediatric primary care practices within the first 6 months of life from 1/2005 to 12/2016. Children were observed for up to 8 years or until the end of the observation window. We used multivariable discrete time survival models to evaluate predictors of asthma diagnosis by 3-month age intervals. We compared unadjusted and adjusted proportions of children diagnosed with asthma by practice.

RESULTS

Of the 161,502 children in the cohort, 34,578 children (21%) received at least 1 asthma diagnosis. In multivariable modeling, male gender, minority race/ethnicity, gestational age <34 weeks, allergic rhinitis, food allergy, and prior wheezing episodes were associated with asthma diagnosis. After adjusting for variation in these predictors across practices, the cumulative incidence of asthma diagnosis by practice by age 6 years ranged from 11% to 47% (interquartile range: 24%-29%).

CONCLUSIONS

Across pediatric primary care practices, adjusted incidence of asthma diagnosis by age 6 years ranged widely, though variation gauged by the interquartile range was more modest. Potential sources of practice-level variation, such as differing diagnosis thresholds and labeling of different wheezing phenotypes as "asthma," should be further investigated.

Parents know it best: Prediction of asthma and lung function by parental perception of early wheezing episodes

BACKGROUND

Childhood asthma is often preceded by early wheeze. Usually, wheezing episodes are recorded retrospectively, which may induce recall bias.

AIMS AND OBJECTIVES

The aim of this study was to investigate true-positive recall of parent-reported wheeze at 1 year of age, its determinants, and its implications for asthma and lung function at 6 years of age.

METHODS

The PASTURE (Protection Against Allergy-Study in Rural Environments) study followed 880 children from rural areas in 5 European countries from birth to age 6 years. Wheeze symptoms in the first year were asked weekly. At age 6, parent-reported asthma diagnosis was ascertained and lung function measurements were conducted. Correct parental recall of wheeze episodes at the end of the first year was assessed for associations with lung function, asthma, and the asthma risk locus on chromosome 17q21.

RESULTS

Parents correctly recalled wheeze after the first year in 54% of wheezers. This true-positive recall was determined by number of episodes, timing of the last wheeze episode, and parental asthma. Independently from these determinants, true-positive recall predicted asthma at age 6 years (odds ratio 4.54, 95% confidence interval (CI) [1.75-14.16]) and impaired lung function (β = -0.62, 95% CI [-1.12; -0.13], P-value = .02). Associations were stronger in children with asthma risk SNPs on chromosome 17q21.

CONCLUSION

Correct parental recall of wheezing episodes may reflect clinical relevance of early wheeze and its impact on subsequent asthma and lung function impairment. Questions tailored to parental perception of wheezing episodes may further enhance asthma prediction.

Maternal history of asthma modifies the risk of childhood persistent asthma associated with maternal age at birth: Results from a large prospective cohort in Canada

BACKGROUND

Asthma is a prevalent disease that affects many Canadians. Persistent asthma can affect quality of life, and has multiple health implications. Maternal age at birth has been associated with many adverse health outcomes in children. Conflicting study results exist regarding maternal age at birth and childhood asthma. The association between maternal age at birth and persistent asthma in children is still unknown.

OBJECTIVE

To investigate the relationship between maternal age at birth and persistent asthma in children at ten years of age.

METHODS

This is a prospective cohort study including all children aged 0-2 years who took part in the first cycle of the National Longitudinal Survey of Children and Youths (NLSCY) and were followed every two years until eight to ten years of age in Cycle 5. An interaction term between maternal age at birth and maternal asthma history was introduced in a multivariate model to examine modification effects of maternal asthma history on the association.

RESULTS

Multivariate logistic regression demonstrated that older maternal age at birth was significantly associated with an increased risk of childhood persistent asthma in mothers with a history of asthma (OR = 1.20, 95% CI: 1.04-1.40, p = .016). No relationship was found in mothers without a history of asthma.

CONCLUSION

Maternal history of asthma has an impact on the association between maternal age at birth and childhood persistent asthma in children by age ten. The finding may help explain the inconsistent results in the literature regarding the risk of asthma associated with maternal age at birth.

[Levels of airway inflammatory mediators in peripheral blood in infants and young children with wheezing]

OBJECTIVE

To examine the levels of airway inflammatory mediators in peripheral blood in infants and young children with wheezing and to study the possible pathogenesis of wheezing from the aspects of T helper cell 1 (Th1)/T helper cell 2 (Th2) imbalance and airway inflammation.

METHODS

A total of 50 children aged 1 month to 3 years with an acute wheezing episode were enrolled as the wheezing group, and 25 age-matched healthy infants were enrolled as the healthy control group. According to the number of wheezing episodes, the wheezing group was divided into a first-episode group (n=25) and a recurrent wheezing (number of episodes ≥2) group (n=25). According to the presence or absence of high-risk factors for asthma, the wheezing group was divided into a high-risk factor group (n=22) and a non-high-risk factor group (n=28). According to the results of pathogen detection, the wheezing group was divided into a positive pathogen group (n=23) and a negative pathogen group (n=27). Levels of interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), transforming growth factor-β1 (TGF-β1), and total IgE (TIgE) in peripheral blood were measured for each group. For children with wheezing, eosinophil (EOS) count in peripheral blood was measured, and related samples were collected for respiratory pathogen detection.

RESULTS

The wheezing group had significantly higher levels of IL-4, IL-5, IL-13, TGF-β1, and TIgE in peripheral blood than the healthy control group (P<0.05). There were no significant differences in the levels of IL-2, IL-4, IL-5, IL-13, TGF-β1, and TIgE in peripheral blood between the first-episode and recurrent wheezing groups, between the high-risk factor and non-high-risk factor groups, and between the positive pathogen and negative pathogen groups (P>0.05). The correlation analysis showed that in children with wheezing, EOS count was positively correlated with IL-4 level (P<0.01), IL-4 level was positively correlated with IL-5 and IL-13 levels (P<0.01), IL-5 level was positively correlated with IL-13 level (P<0.01), and IL-2 level was positively correlated with TGF-β1 level (P<0.05).

CONCLUSIONS

Th1/Th2 imbalance with a predominance of Th2 is observed in infants and young children with wheezing. IL-4, IL-5, IL-13, TGF-β1, and IgE are involved in the pathogenesis of wheezing in these children. Airway inflammation is also observed in these children with wheezing, but it is not associated with the number of wheezing episodes, presence or absence of high-risk factors for asthma, or results of pathogen detection.

Patterns of health care use related to respiratory conditions in early life: A birth cohort study with linked administrative data

OBJECTIVES

To identify distinctive patterns of respiratory-related health services use (HSU) between birth and 3 years of age, and to examine associated symptom and risk profiles.

METHODS

This study included 729 mother and child pairs enrolled in the Toronto site of the Canadian Healthy Infant Longitudinal Development study in 2009-2012; they were linked to Ontario health administrative databases (2009-2016). A model-based cluster analysis was performed to identify distinct groups of children who followed a similar pattern of respiratory-related HSU between birth and 3 years of age, regarding hospitalization, emergency department (ED) and physician office visits for respiratory conditions and total health care costs (2016 Canadian dollars).

RESULTS

The majority (estimated cluster weight = 0.905) showed a pattern of low and stable respiratory care use (low HSU) while the remainder (weight = 0.095) showed a pattern of high use (high HSU). From 0 to 3 years of age, the low- and high-HSU groups differed in mean trajectories of total health care costs ($783 per 6 months decreased to $114, vs $1796 to $177, respectively). Compared to low-HSU, the high-HSU group was associated with a constant risk of hospitalizations, early high ED utilization and physician visits for respiratory problems. The two groups differed significantly in the timing of wheezing (late onset in low-HSU vs early in high-HSU) and future total costs (stable vs increased).

CONCLUSIONS

One in ten children had high respiratory care use in early life. Such information can help identify high-risk young children in a large population, monitor their long-term health, and inform resource allocation.

Risk factors and prognosis of recurrent wheezing in Chinese young children: a prospective cohort study

Background

Nearly all the investigations into the risk factors for wheezing and asthma were conducted in developed countries with a high prevalence rate of asthma and allergy, but the studies in developing countries are limited. In this study, we aimed to investigate the risk factors for different wheezing phenotypes in Chinese young children and to explore the prognosis of recurrent wheezing.

Methods

This cohort study contained the recruitment stage and the follow-up stage conducted by phone questionnaire survey. According to the information collected at the follow-up for wheezing episodes and remission age, our cohort was divided into transient wheezing, persistent wheezing and late-onset wheezing. The wheezing symptoms and potential risk factors were compared between these three wheezing groups.

Results

From the initial 109 participants, 78.0% completed the follow-up survey. The frequency of current wheezing at followup was significantly reduced in all three groups compared to the recruitment stage (p < 0.01). We observe a trend that the rhinovirus (RV) and respiratory syncytial virus (RSV) infection rates were higher in the persistent wheezing group, and the overall infection rates appear to be the lowest in late-onset wheezing group at recruitment. At follow-up stage, the rates of rhinitis ever and current rhinitis were both higher in the persistent wheezing (63.0%, 50.0%) and late-onset wheezing groups (88.2%, 58.8%), compared to the transient wheezing group (14.3%, 14.3%). The incidence of current wheezing episodes increased cumulatively if the participant had concomitant risk factors of rhinitis ever, aeroallergens sensitization at recruitment, either alone or together with previous RV infection at the time of recruitment.

Conclusion

While the incidence of wheezing declined overall with age, but in addition to transient wheezers, additional subsets of children manifest persistent wheeze or late onset wheeze, and moreover the risk factors for wheezing display phenotypic variability between these subgroups. Rhinitis ever and aeroallergens sensitization, either alone or together with previous RV infection, were the most significant predictors for persistent wheezing in children in an eastern environment, such as in China.

Vitamin D status in pregnant women with asthma and its association with adverse respiratory outcomes during infancy

BACKGROUND

Vitamin D may influence pregnancy and infant outcomes, especially infant respiratory health. This study aimed to examine vitamin D status in pregnant women with asthma, and whether higher vitamin D levels are associated with fewer adverse respiratory outcomes in their infants.

METHODS

Pregnant women with asthma, recruited from John Hunter Hospital Newcastle Australia (latitude 33°S), had serum total 25-hydroxyvitamin-D (25(OH)D) measured at 16 and 35 weeks gestation. Infant respiratory outcomes were collected at 12 months by parent-report questionnaire. Mother-infant dyads were grouped by serum 25(OH)D during pregnancy: 25(OH)D < 75 nmol/L (at both time-points) versus 25(OH)D ≥ 75 nmol/L (at one or both time-points).

RESULTS

In 52 pregnant women with asthma, mean serum 25(OH)D levels were 61 (range 26-110) nmol/L at 16 weeks, and 65 (range 32-116) nmol/L at 35 weeks, gestation. Thirty-one (60%) women had 25(OH)D < 75 nmol/L at both time-points; 21 (40%) had 25(OH)D ≥ 75 nmol/L at one or both time-points. Maternal 25(OH)D < 75 nmol/L during pregnancy was associated with a higher proportion of infants with "wheeze ever" at 12 months, compared with 25(OH)D ≥ 75 nmol/L (71 versus 43%, p = .04). Infant acute-care presentations (45 versus 13%, p = .02) and oral corticosteroid use (26 versus 4%, p = .03) due to "asthma/wheezing" were higher in the maternal group with 25(OH)D < 75 nmol/L, versus ≥75 nmol/L.

CONCLUSIONS

Most pregnant women with asthma had low vitamin D status, which persisted across gestation. Low maternal vitamin D status was associated with greater risk of adverse respiratory outcomes in their infants, a group at high risk of developing childhood asthma.

Causes of variability in latent phenotypes of childhood wheeze

BACKGROUND

Latent class analysis (LCA) has been used extensively to identify (latent) phenotypes of childhood wheezing. However, the number and trajectory of discovered phenotypes differed substantially between studies.

OBJECTIVE

We sought to investigate sources of variability affecting the classification of phenotypes, identify key time points for data collection to understand wheeze heterogeneity, and ascertain the association of childhood wheeze phenotypes with asthma and lung function in adulthood.

METHODS

We used LCA to derive wheeze phenotypes among 3167 participants in the ALSPAC cohort who had complete information on current wheeze recorded at 14 time points from birth to age 16½ years. We examined the effects of sample size and data collection age and intervals on the results and identified time points. We examined the associations of derived phenotypes with asthma and lung function at age 23 to 24 years.

RESULTS

A relatively large sample size (>2000) underestimated the number of phenotypes under some conditions (eg, number of time points <11). Increasing the number of data points resulted in an increase in the optimal number of phenotypes, but an identical number of randomly selected follow-up points led to different solutions. A variable selection algorithm identified 8 informative time points (months 18, 42, 57, 81, 91, 140, 157, and 166). The proportion of asthmatic patients at age 23 to 24 years differed between phenotypes, whereas lung function was lower among persistent wheezers.

CONCLUSIONS

Sample size, frequency, and timing of data collection have a major influence on the number and type of wheeze phenotypes identified by using LCA in longitudinal data.

Occupational exposure to inhaled nanoparticles: Are young workers being left in the dust?

Objectives

Occupational exposure to inhaled nanoparticles (NPs) represents a significant concern for worker health. Adolescent workers may face unique risks for exposure and resulting health effects when compared with adult workers.

Methods

This manuscript discusses key differences in risks for occupational exposures to inhaled NPs and resulting health effects between young workers and adult workers via an examination of both physiological and occupational setting factors.

Results

Previous studies document how adolescents often face distinct and unique exposure scenarios to occupational hazards when compared to adults. Moreover, they also face different and unpredictable health effects because biological functions such as detoxification pathways and neurological mechanisms are still developing well into late adolescence. Early exposure also increases the chances of developing long‐latency disease earlier in life.

Taken together, adolescents’ rapid growth and development encompasses highly dynamic and complex processes. An aggravating factor is that these processes do not necessarily fall in line with legal classifications of adulthood, nor with occupational exposure limits created for adult workers.

Conclusions

The differences in exposures and health consequences from NPs on young workers are insufficiently understood. Research is needed to better understand what adolescent‐specific mitigation strategies may be most suitable to address these risk factors.

Preschool children with persistent asthmatic symptoms

Asthma is the most common chronic airway disease in children, with more than half the reported cases of persistent asthma starting in children below the age of 3 years. Asthma diagnosis in preschool children has proven to be challenging due to the heterogeneity of the disease, the continuing development of the immune system in such a young population, and lack of diagnostic options such as lung function measurement. Early diagnosis and treatment of asthmatic symptoms will improve patients' quality of life and help reduce disease morbidity. However, validated treatment options are scarce due to paucity of data and lack of conclusive studies in such a young patient population. Adjusting study design and endpoints to capture more reliable data with minimal risk of harm to patients is necessary. This thematic series review outlines the current position on preschool asthma, consolidates the current understanding of risk factors and diagnostic hurdles, and emphasizes the importance of early detection and management to help improve patients' quality of life, both present and future. Particular focus was given to anticholinergics and their emerging role in the treatment and control of asthma in pediatric patients.

Early Identification of Childhood Asthma: The Role of Informatics in an Era of Electronic Health Records

Emerging literature suggests that delayed identification of childhood asthma results in an increased risk of long-term and various morbidities compared to those with timely diagnosis and intervention, and yet this risk is still overlooked. Even when children and adolescents have a history of recurrent asthma-like symptoms and risk factors embedded in their medical records, this information is sometimes overlooked by clinicians at the point of care. Given the rapid adoption of electronic health record (EHR) systems, early identification of childhood asthma can be achieved utilizing (1) asthma ascertainment criteria leveraging relevant clinical information embedded in EHR and (2) innovative informatics approaches such as natural language processing (NLP) algorithms for asthma ascertainment criteria to enable such a strategy. In this review, we discuss literature relevant to this topic and introduce recently published informatics algorithms (criteria-based NLP) as a potential solution to address the current challenge of early identification of childhood asthma.

Asthma in the Preschool Age Child

Wheeze in preschool children (5 years of age and younger) is common. The majority of severe episodes are triggered by viral colds. Unlike atopic asthma in adults and young people, the underlying pathology of this condition is poorly understood, and the label of “preschool wheeze” should therefore not be regarded as a diagnosis but a description of symptoms. It is important to consider other causes of wheeze, but, for the most part, serious conditions such as cystic fibrosis and foreign body aspiration are associated with atypical features on careful history and examination. There remain significant uncertainties about the optimal management of children with this condition. Short-acting bronchodilators are indicated for the acute treatment of wheeze, and current evidence suggests that daily inhaled corticosteroid therapy is an effective preventive therapy, at least in a subgroup of children. Some trials suggest that preemptive therapy with inhaled corticosteroids may be as effective as regular inhaled corticosteroids. Since wheeze is intermittent for the majority of children, preemptive therapy is a logical approach. However, more studies are needed to confirm whether preemptive inhaled corticosteroids are as, or more, effective than regular preventer therapy.

Management of Recurrent Preschool, Doctor-Diagnosed Wheeze

Preschool wheeze occurs in half of the children before they reach 6 y of age and recurrence is also common. Recurrent preschool wheeze is classified as either typical or atypical. For typical recurrent preschool wheeze, the diagnoses are either asthma or bronchiolitis/bronchitis. Responsiveness to a properly administered bronchodilator confirms asthma, atopic or otherwise. All atypical preschool wheeze should be referred to pediatric respirologist for assessment. Lung function test by impulse oscillometry (IOS) before and after bronchodilator is helpful to confirm airway hyperresponsiveness, an essential feature of asthma. Assessment of atopy is important by either skin prick test or serum IgE level. Treatment of acute wheeze includes standard supportive care, bronchodilator for those diagnosed with asthma and hypertonic saline for those diagnosed as having acute bronchiolitis. Other treatments included nebulized adrenaline for acute bronchiolitis and systemic steroids for asthma. For those with significant respiratory distress, continuous positive airway pressure (CPAP) or heated humidified high flow should be considered. Daily or intermittent inhaled corticosteroid or intermittent montelukast would reduce asthma exacerbation rate. A significant proportion of preschool wheeze persists till school age. An early diagnosis of asthma would be important to allow early optimal management.

Wheezing phenotypes and risk factors in early life: The ELFE cohort

Objective

Different phenotypes of wheezing have been described to date but not in early life. We aim to describe wheezing phenotypes between the ages of two months and one year, and assess risk factors associated with these wheezing phenotypes in a large birth cohort.

Methods

We studied 18,041 infants from the ELFE (French Longitudinal Study of Children) birth cohort. Parents reported wheezing and respiratory symptoms at two and 12 months, and answered a complete questionnaire (exposure during pregnancy, parental allergy).

Results

Children with no symptoms (controls) accounted for 77.2%, 2.1% had had wheezing at two months but no wheezing at one year (intermittent), 2.4% had persistent wheezing, while 18.3% had incident wheezing at one year. Comparing persistent wheezing to controls showed that having one sibling (ORa = 2.19) or 2 siblings (ORa = 2.23) compared to none, nocturnal cough (OR = 5.2), respiratory distress (OR = 4.1) and excess bronchial secretions (OR = 3.47) at two months, reflux in the child at 2 months (OR = 1.55), maternal history of asthma (OR = 1.46) and maternal smoking during pregnancy (OR = 1.57) were significantly associated with persistent wheezing. These same factors, along with cutaneous rash in the child at 2 months (OR = 1.13) and paternal history of asthma (OR = 1.32) were significantly associated with increased odds of incident wheezing. Having one sibling (ORa = 1.9) compared to none, nocturnal cough at 2 months (OR = 1.76) and excess bronchial secretions at 2 months (OR = 1.65) were significantly associated with persistent compared to intermittent wheezing.

Conclusion

Respiratory symptoms (cough, respiratory distress, and excessive bronchial secretion) were significantly associated with a high risk of persistent wheezing at one year. Smoking exposure during pregnancy was also a risk factor for persistent and incident wheezing.

Impact of childhood wheezing on lung function in adulthood: A meta-analysis

BACKGROUND

A growing body of evidence shows that childhood wheezing may lead to recurrent or persistent symptoms in adulthood, such that persistent wheezing associated with lung function deficits often have their roots in the first few years of life.

OBJECTIVES

We summarized information from several prospective cohort studies following children with or without wheezing into adulthood, to estimate the effect of childhood wheezing on adulthood lung function.

METHODS

Medical literatures were searched in the Medline, PubMed, ScienceDirect, Web of Science and Embase databases up to October 31, 2016. The adulthood lung function was selected as primary outcome, and chronic obstructive pulmonary disease (COPD) prevalence was selected as secondary outcome. The meta-analysis was performed with the Stata Version 14.0. A random-effects model was applied to estimate standardized mean difference (SMD) of lung function, and relative risk (RR) of COPD.

RESULTS

Six articles enrolling 1141 and 1005 children with and without wheezing, respectively. Meta-analysis showed that childhood wheezing decreased adulthood lung function as compared with no-wheezing subjects (SMD = -0.365, 95% confidence interval (CI): -0.569~-0.161, P = 0.000). Subgroup analyses indicated that childhood atopic wheezing reduced adulthood FEV1/FVC and FEV1%pred when compared with no-wheezing subjects. In addition, childhood atopic wheezing was significantly associated with COPD prevalence (RR = 5.307, 95% CI:1.033~27.271, P = 0.046).

CONCLUSIONS

Our meta-analysis suggests that childhood wheezing may induce ongoing declined lung function that extends into adult life, as well as an increased risk of COPD prevalence when accompanied with atopy.

Pro-inflammatory mediator responses from neonatal airway epithelial cells and early childhood wheeze

BACKGROUND

Airway epithelial cell (AEC) function differs between children with and without asthma. Here, we associated neonatal AEC function with asthma symptoms at 4 years of age.

METHODS

Nasal AEC were collected from neonates within 48 h of birth. Cells were cultured and stimulated with tumor necrosis factor alpha/interleukin-1 beta (TNFα/IL-1β), lipopolysaccharide (LPS), or house dust mite (HDM). Absolute concentrations of pro-inflammatory mediators in the culture supernatant were quantified and expressed as median [interquartile range] in pg/mg protein. A parent-completed respiratory questionnaire was returned when the child was 4 years old.

RESULTS

AEC were successfully cultured in 139 neonates, of whom 120 were contacted at 4 years and 91 (76%) questionnaires were returned. Sixteen children had wheezed ever and 11 had recent wheeze. At birth, when compared to those with no recent wheeze, supernatants from cultured neonatal AEC from the children with recent wheeze had reduced median IL-8 (CXCL8) release after treatment with culture medium alone (P = 0.049), with TNFα/IL-1β (P < 0.001) and LPS (P = 0.004). Additionally, and when compared to those with no recent wheeze, 4 year olds with recent wheeze had reduced neonatal AEC release of IL-6 (P = 0.013), GMCSF (P = 0.012), and ICAM-1 (P = 0.017) after treatment with TNFα/IL-1β and reduced release of ICAM-1 (P = 0.038) and RANTES (P = 0.042) after treatment with HDM.

CONCLUSIONS

Abnormalities in AEC function are present at birth before the onset of childhood wheeze. The relationship between reduced AEC function at birth and wheeze at 4 years was not exclusive, suggesting that post-natal factors are required for the AEC abnormality to translate into symptoms.

Effect of enterovirus infections on asthma in young children: A national cohort study

BACKGROUND

We conducted a cohort study to determine the relationship between enterovirus (EV) infection and asthma.

MATERIALS AND METHODS

From the National Health Insurance Research Database of Taiwan, we identified patients who received a new diagnosis of asthma and concurrent treatment between January 2000 and December 2011 (EV cohort: n = 208 213; non-EV cohort: n = 208 213). Cox proportional hazards regression analysis was performed to determine and compare the adjusted hazard ratios (aHRs) of asthma between these 2 cohorts. Kaplan-Meier analysis was conducted to assess the differences in the cumulative incidence curves of asthma between the 2 cohorts.

RESULTS

The overall aHR of asthma was 1.48-fold higher in the EV cohort than in the non-EV cohort (95% confidence interval = 1.45-1.50). The aHR of asthma was higher in the EV cohort than in the non-EV cohort, comprising children aged ≤5 years, regardless of sex, sociodemographic factors (urbanization level and parental occupation) or comorbidities. The risk of asthma was higher in 1-3, 4-6, 7-9 and 10-12 months (all P < .001), particularly in those with a higher frequency of admission (>5 per year).

CONCLUSION

The incidence of asthma was higher in the EV cohort than in the non-EV cohort, comprising children aged ≤5 years, regardless of sex, urbanization level, parental occupation or season. In particular, the risk of asthma was higher in children with a higher frequency of admission, even in the absence of atopy or other respiratory infections.

The IL-4 rs2070874 polymorphism may be associated with the severity of recurrent viral-induced wheeze

BACKGROUND

Childhood recurrent wheezing and consequently asthma corresponds to various phenotypes. Our aim was to link genetic variants of asthma candidate genes to the phenotypes of early onset wheezing.

STUDY DESIGN

We included very young consecutive children presenting with recurrent wheezing who had been evaluated for the severity of wheezing, associated atopic comorbidities, and tested for biomarkers of atopy and inflammation. All were genotyped for 16 single nucleotide polymorphisms (SNPs) linked with asthma or atopy. An unsupervised hierarchical bottom-up method was used for clustering the phenotypes and a multinomial logistic regression was performed for each individual SNP.

RESULTS

We replicated the three phenotypes previously described Trousseau Asthma Program in 317 children aged 21.5 ± 7.9 months: cluster 1 (nonatopic uncontrolled severe wheeze), n = 207, a severe viral-induced wheeze, cluster 2 (atopic multiple trigger wheeze), n = 61, with multiple allergic comorbidities, and cluster 3 (episodic viral wheeze), n = 49, a mild viral-induced wheeze. The TT-genotype of the IL-4 rs2070874 polymorphism was significantly associated with the nonatopic uncontrolled severe wheeze compared to the episodic viral wheeze (OR 7.9; CI95% [2.5-25.3]; P = 0.001).

CONCLUSION

Association between the TT-genotype of IL-4 rs2070874 polymorphism and a severe phenotype of viral-induced wheeze further underlines the role IL-4 plays in the inflammation pathway leading to viral respiratory infections.

Beneficial Effects of Prebiotic Saccharomyces cerevisiae Mannan on Allergic Asthma Mouse Models

One of the unmet needs for asthma management is a new therapeutic agent with both anti-inflammatory and anti-smooth muscle (ASM) remodeling effects. The mannose receptor (MR) family plays an important role in allergen uptake and processing of major allergens Der p 1 and Fel d 1. We have previously reported that ASM cells express a mannose receptor (ASM-MR) and that mannan derived from Saccharomyces cerevisiae (SC-MN) inhibits mannosyl-rich lysosomal hydrolase-induced bovine ASM cell proliferation. Using a humanized transgenic mouse strain (huASM-MRC2) expressing the human MRC2 receptor in a SM tissue-specific manner, we have demonstrated that ASM hyperplasia/hypertrophy can occur as early as 15 days after allergen challenge in this mouse model and this phenomenon is preventable with SC-MN treatment. This proof-of-concept study would facilitate future development of a potential asthma therapeutic agent with dual function of anti-inflammatory and anti-smooth muscle remodeling effects.

Association of prenatal and early childhood stress with reduced lung function in 7-year-olds

BACKGROUND

No prior study has examined associations between prenatal and early-life stress on childhood lung function or identified critical windows of exposure.

OBJECTIVE

To prospectively examine associations between prenatal and early-life stress and childhood lung function.

METHODS

Stress was indexed by a maternal negative life events (NLEs) score ascertained during pregnancy and between 1 and 2 years post partum. Spirometry was performed when children were a mean (SD) of 6.99 (0.89) years old. Associations of prenatal and early postnatal stress with spirometry z scores were examined in 199 children using linear regression. Effect modification by child sex was explored.

RESULTS

Most mothers were minorities (65% Hispanic, 21% African American), had 12 years or less of education (67%), and did not smoke prenatally (78%). The highest level of prenatal stress (≥5 NLEs) was associated with lower levels of forced expiratory volume in 1 second (FEV₁) (z score = -0.53, P = .03), forced vital capacity (FVC) (z score = -0.49, P = .04), and forced expiratory flow between 25% and 75% (FEF_25%-75%) (z score = -0.68, P = .01) after covariate adjustment; effects were similar for postnatal stress considered separately. In sex-stratified analyses, high postnatal stress (≥5 NLEs) was associated with lower FEV₁ (z score = -0.76, P = .01), FVC (z score = -0.77, P = .01), and FEF_25%-75% (z score = -0.67, P = .02) in boys but not girls, although the interaction term was not significant (P for interaction >.10).

CONCLUSION

These are the first prospective data that link perinatal stress with reduced child lung function. High levels of stress in the prenatal and postnatal periods were associated with symmetric reductions in FEV₁ and FVC consistent with impaired lung growth. Given that lung function growth patterns are established by 7 years of age, these findings have lifelong implications.

Infantile wheeze: rethinking dogma

Wheeze is a common symptom in young children and is usually associated with viral illnesses. It is a major source of morbidity and is responsible for a high consumption of healthcare and economic resources worldwide. A few children have a condition resembling classical asthma. Rarer specific conditions may have a wheezy component and should be considered in the differential diagnosis. Over the last half century, there have been many circular discussions about the best way of managing preschool wheeze. In general, intermittent wheezing should be treated with intermittent bronchodilator therapy, and a controller therapy should be prescribed for a young child with recurrent wheezing only if positively indicated, and only then if carefully monitored for efficacy. Good multidisciplinary support, attention to environmental exposition and education are essential in managing this common condition. This article analyses the pathophysiological basis of wheezing in infancy and critically discusses the evolution of the scientific progress over time in this unique field of respiratory medicine.

Lung Function in Wheezing Infants after Acute Lower Respiratory Tract Infection and Its Association with Respiratory Outcome

Background:

Wheezing is common in early childhood and remains an important health concern. The aim of this study was to assess the lung function of wheezing infants and to investigate the relationship between lung function and respiratory outcome.

Methods:

Infants <2 years of age with acute lower respiratory tract infection (ALRTI) who had undergone lung function tests were included in the study. They were assigned to wheeze or no wheeze group based on physical examination. Infants without any respiratory diseases were enrolled as controls. Lung function was measured during the acute phase and 3 months after ALRTI. One-year follow-up for infants with ALRTI was achieved.

Results:

A total of 252 infants with ALRTI who had acceptable data regarding tidal breathing were included in the final analysis. Compared with the control and the no wheeze groups, infants in the wheeze group had significantly decreased time to peak tidal expiratory flow as a percentage of total expiratory time (TPTEF/TE) (20.1 ± 6.4% vs. 34.4 ± 6.2% and 26.4 ± 8.3%, respectively, P < 0.0001) and significantly increased peak tidal expiratory flow (PTEF) (90.7 ± 26.3 ml/s vs. 79.3 ± 18.4 ml/s and 86.1 ± 28.0 ml/s, respectively, P < 0.01), sReff and Reff. The infants in the wheeze group still had lower TPTEF/TE and volume to peak tidal expiratory flow as a percentage of total expiratory volume (VPTEF/VE) than the no wheeze infants 3 months after the ALRTI. Moreover, there was a significant inverse relationship between TPTEF/TE, VPTEF/VE, and the recurrence of wheezing and pneumonia.

Conclusions:

Impaired lung function was present in wheezing infants with ALRTI and the deficits persisted. In addition, the lower level of TPTEF/TE and VPTEF/VE was a risk factor for poor respiratory outcome.

Disaggregating asthma: Big investigation versus big data

We are facing a major challenge in bridging the gap between identifying subtypes of asthma to understand causal mechanisms and translating this knowledge into personalized prevention and management strategies. In recent years, "big data" has been sold as a panacea for generating hypotheses and driving new frontiers of health care; the idea that the data must and will speak for themselves is fast becoming a new dogma. One of the dangers of ready accessibility of health care data and computational tools for data analysis is that the process of data mining can become uncoupled from the scientific process of clinical interpretation, understanding the provenance of the data, and external validation. Although advances in computational methods can be valuable for using unexpected structure in data to generate hypotheses, there remains a need for testing hypotheses and interpreting results with scientific rigor. We argue for combining data- and hypothesis-driven methods in a careful synergy, and the importance of carefully characterized birth and patient cohorts with genetic, phenotypic, biological, and molecular data in this process cannot be overemphasized. The main challenge on the road ahead is to harness bigger health care data in ways that produce meaningful clinical interpretation and to translate this into better diagnoses and properly personalized prevention and treatment plans. There is a pressing need for cross-disciplinary research with an integrative approach to data science, whereby basic scientists, clinicians, data analysts, and epidemiologists work together to understand the heterogeneity of asthma.

Smoke-free legislation and child health

In this paper, we aim to present an overview of the scientific literature on the link between smoke-free legislation and early-life health outcomes. Exposure to second-hand smoke is responsible for an estimated 166 ,000 child deaths each year worldwide. To protect people from tobacco smoke, the World Health Organization recommends the implementation of comprehensive smoke-free legislation that prohibits smoking in all public indoor spaces, including workplaces, bars and restaurants. The implementation of such legislation has been found to reduce tobacco smoke exposure, encourage people to quit smoking and improve adult health outcomes. There is an increasing body of evidence that shows that children also experience health benefits after implementation of smoke-free legislation. In addition to protecting children from tobacco smoke in public, the link between smoke-free legislation and improved child health is likely to be mediated via a decline in smoking during pregnancy and reduced exposure in the home environment. Recent studies have found that the implementation of smoke-free legislation is associated with a substantial decrease in the number of perinatal deaths, preterm births and hospital attendance for respiratory tract infections and asthma in children, although such benefits are not found in each study. With over 80% of the world’s population currently unprotected by comprehensive smoke-free laws, protecting (unborn) children from the adverse impact of tobacco smoking and SHS exposure holds great potential to benefit public health and should therefore be a key priority for policymakers and health workers alike.

The Danish National Database for Asthma: establishing clinical quality indicators

Asthma is one of the most common chronic diseases worldwide affecting more than 300 million people. Symptoms are often non-specific and include coughing, wheezing, chest tightness, and shortness of breath. Asthma may be highly variable within the same individual over time. Although asthma results in death only in extreme cases, the disease is associated with significant morbidity, reduced quality of life, increased absenteeism, and large costs for society. Asthma can be diagnosed based on report of characteristic symptoms and/or the use of several different diagnostic tests. However, there is currently no gold standard for making a diagnosis, and some degree of misclassification and inter-observer variation can be expected. This may lead to local and regional differences in the treatment, monitoring, and follow-up of the patients. The Danish National Database for Asthma (DNDA) is slated to be established with the overall aim of collecting data on all patients treated for asthma in Denmark and systematically monitoring the treatment quality and disease management in both primary and secondary care facilities across the country. The DNDA links information from population-based disease registers in Denmark, including the National Patient Register, the National Prescription Registry, and the National Health Insurance Services register, and potentially includes all asthma patients in Denmark. The following quality indicators have been selected to monitor trends: first, conduction of annual asthma control visits, appropriate pharmacological treatment, measurement of lung function, and asthma challenge testing; second, tools used for diagnosis in new cases; and third, annual assessment of smoking status, height, and weight measurements, and the proportion of patients with acute hospital treatment. The DNDA will be launched in 2016 and will initially include patients treated in secondary care facilities in Denmark. In the nearby future, the database aims to include asthma diagnosis codes and clinical data registered by general practitioners and specialised practitioners as well.

Have Changing Palivizumab Administration Policies Led to More Respiratory Morbidity in Infants Born at 32-35 Weeks?

OBJECTIVES

To determine differences in the incidence of respiratory morbidity during the first year of life among infants born 32(0/7)-34(6/7) weeks' gestational age (GA) before and after the administration policy for palivizumab, as written by the American Academy of Pediatrics, was updated in 2009.

STUDY DESIGN

Secondary analysis of the dataset collected for the Gastrointestinal Risk Factors for Wheezing in Premature Infants study, which enrolled preterm infants without bronchopulmonary dysplasia and followed them by parental questionnaires at 3, 6, 9, and 12 months adjusted age for prematurity. Participants were included if they were enrolled in Gastrointestinal Risk Factors for Wheezing in Premature Infants, born 32(0/7)-34(6/7) weeks' GA, and completed the 12-month questionnaire. We compared rates of recurrent wheezing, respiratory medication use, and health care use before (Epoch 1) and after (Epoch 2) the 2009 administration policy change.

RESULTS

A total of 165 infants met inclusion criteria. There was a significant increase in recurrent wheezing in Epoch 2 (46.2%) vs Epoch 1 (28.8%) (OR 2.22 [95% CI 1.08-4.53], P = .03). There was a nonsignificant increase in visits to the emergency department in Epoch 2 (27.4%) vs Epoch 1 (15.3%) (OR 2.12 [95% CI 0.91-4.96], P = .08). There were no differences in hospital admissions or respiratory medication use.

CONCLUSIONS

Infants born 32(0/7)-34(6/7) weeks' GA treated after the American Academy of Pediatrics administration policy change in 2009 had a greater incidence of recurrent wheezing than those treated according to the previous policy. It will be important to track rates of recurrent wheezing after the 2014 administration policy, because it may be an important factor in future cost-effectiveness analyses.

Predicting asthma outcomes

This review addresses predictors of remission or persistence of wheezing and asthma from early childhood through adulthood. Early childhood wheezing is common, but predicting who will remit or have persistent childhood asthma remains difficult. By adding parental history of asthma and selected infant biomarkers to the history of recurrent wheezing, the Asthma Predictive Index and its subsequent modifications provide better predictions of persistence than simply the observation of recurrent wheeze. Sensitization, especially to multiple allergens, increases the likelihood of development of classic childhood asthma. Remission is more likely in male subjects and those with milder disease (less frequent and less severe symptoms), less atopic sensitization, a lesser degree of airway hyperresponsiveness, and no concomitant allergic disease. Conversely, persistence is linked strongly to allergic sensitization, greater frequency and severity of symptoms, abnormal lung function, and a greater degree of airway hyperresponsiveness. A genetic risk score might predict persistence more accurately than family history. Remission of established adult asthma is substantially less common than remission during childhood and adolescence. Loss of lung function can begin early in life and tracks through childhood and adolescence. Despite therapy which controls symptoms and exacerbations, the outcomes of asthma appear largely resistant to pharmacologic therapy.

Infections and Asthma

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Wheezing viral respiratory illnesses are the most common initial presentation of childhood asthma.

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Once asthma is established, viral infections, most notably rhinovirus (RV), are the most frequent trigger of severe asthma exacerbations. RV-C appears to be a particularly pathogenic virus in children with asthma.

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Evidence has recently emerged to suggest that bacterial pathogens in the lower airway may contribute to the expression of asthma. Ongoing studies are critical to our understanding of the role of the airway microbiome in asthma inception and exacerbation.

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Synergistic interactions between underlying allergy and virus infections play an important mechanistic role in asthma inception and exacerbation, and are an important therapeutic target.

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Novel therapies are needed to prevent and treat virus-induced wheezing and asthma exacerbations.

Minimally Invasive Sampling Method Identifies Differences in Taxonomic Richness of Nasal Microbiomes in Young Infants Associated with Mode of Delivery

To date, there is a limited understanding of the role of the airway microbiome in the early life development of respiratory diseases such as asthma, partly due to a lack of simple and minimally invasive sample collection methods. In order to characterize the baseline microbiome of the upper respiratory tract (URT) in infants, a comparatively non-invasive method for sampling the URT microbiome suitable for use in infants was developed. Microbiome samples were collected by placing filter paper in the nostrils of 33 healthy, term infants enrolled as part of the Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure (INSPIRE) study. After bacterial genomic DNA was extracted from the filters, amplicons were generated with universal primers targeting the V1-V3 region of the 16S rRNA gene. This method was capable of capturing a wide variety of taxa expected to inhabit the nasal cavity. Analyses stratifying subjects by demographic and environmental factors previously observed or predicted to influence microbial communities were performed. Microbial community richness was found to be higher in infants who had been delivered via Cesarean section and in those who had been formula-fed; an association was observed between diet and delivery, which confounds this analysis. We have established a baseline URT microbiome using a non-invasive filter paper nasal sampling for this population, and future studies will be performed in this large observational cohort of infants to investigate the relationship between viral infections, the URT microbiota, and the development of childhood wheezing illnesses.

Incident asthma and Mycoplasma pneumoniae: A nationwide cohort study

BACKGROUND

Previous studies investigating the relationship between Mycoplasma pneumoniae and incident asthma in the general population have been inconclusive.

OBJECTIVE

We conducted a nationwide cohort study to clarify this relationship.

METHODS

Using the National Health Insurance Research Database of Taiwan, we identified 1591 patients with M pneumoniae infection (International Classification of Diseases, Ninth Revision, Clinical Modification code 4830) given diagnoses between 2000 and 2008. We then frequency matched 6364 patients without M pneumoniae infection from the general population according to age, sex, and index year. Cox proportional hazards regression analysis was performed to determine the adjusted hazard ratio (aHR) of the occurrence of asthma in the M pneumoniae cohort compared with that in the non-M pneumoniae cohort.

RESULTS

Regardless of comorbidities and the use of antibiotic or steroid therapies, patients with M pneumonia infection had a higher risk of incident asthma than those without it. The aHR of asthma was 3.35 (95% CI, 2.71-4.15) for the M pneumoniae cohort, with a significantly higher risk when patients were stratified by age, sex, follow-up time, and comorbidities, including allergic rhinitis, atopic dermatitis, or allergic conjunctivitis. Patients with M pneumoniae infection had a higher risk of having early-onset (age, <12 years; aHR, 2.87) and late-onset (age, ≥12 years; aHR, 3.95) asthma. The aHR was also higher within the less than 2-year follow-up in the M pneumoniae cohort (aHR, 4.41; 95% CI, 3.40-5.74) than in the cohort without the infection.

CONCLUSION

This study found that incident cases of early-onset and late-onset asthma are closely related to M pneumoniae infection, even in nonatopic patients.