Asthma Phenotypes In Children Research Articles

Genetic aspects of the realization of the severity of the bronchial asthma phenotype in children

Genetic aspects of the realization of the severity of the bronchial asthma phenotype in children

Contribution of Gestational Weight Gain to Childhood Asthma Phenotypes: A Prospective Cohort Study

BackgroundThe contribution of prenatal anthropometric measures to the development of specific childhood asthma phenotypes is not known. ObjectiveWe aimed to evaluate associations between prepregnancy body mass index (BMI) and gestational weight gain (GWG) with allergic and non-allergic asthma phenotypes in childhood. MethodsOur study population included term, healthy infants in the middle Tennessee region of the United States. Prepregnancy BMI and GWG were ascertained from questionnaires administered during early infancy and categorized based on World Health Organization (WHO) and Institute of Medicine (IOM) recommendations, respectively. Allergic asthma was defined as 5-year current asthma and a positive skin test or specific IgE to aeroallergen(s). We used multivariable logistic regression models for asthma and multinomial logistic regression models for non-asthma, allergic asthma, and non-allergic asthma. ResultsA total of 1,266 children were included. At the 5-year follow-up, 194 (15.3%) had asthma; among them, 102 (52.6%) had allergic asthma. Both inadequate and excessive GWG, compared to adequate GWG, were associated with increased odds of asthma (inadequate: aOR 1.76 [95% CI: 1.03–2.98]; excessive: aOR 1.70 [95% CI: 1.12–2.57]) and increased odds of allergic asthma compared to no asthma (inadequate: aOR 3.49 [95% CI: 1.66–7.32]; excessive: aOR 2.55 [95% CI: 1.34–4.85]). Prepregnancy BMI was not associated with asthma nor with asthma phenotypes. ConclusionBoth inadequate and excessive GWG were associated with allergic asthma risk. These results support the benefits of optimal GWG during pregnancy on child health outcomes.

Viral and non-viral episodes of wheezing in early life and the development of asthma and respiratory phenotypes among urban children.

Viral wheezing is an important risk factor for asthma, which comprises several respiratory phenotypes. We sought to understand if the etiology of early-life wheezing illnesses relates to childhood respiratory and asthma phenotypes. Data were collected prospectively on 429 children in the Urban Environment and Childhood Asthma (URECA) birth cohort study through age 10 years. We identified wheezing illnesses and the corresponding viral etiology (PCR testing of nasal mucus) during the first 3 years of life. Six phenotypes of respiratory health were identified at 10 years of age based on trajectories of wheezing, allergic sensitization, and lung function. We compared the etiology of early wheezing illnesses to these wheezing respiratory phenotypes and the development of asthma. In the first 3 years of life, at least one virus was detected in 324 (67%) of the 483 wheezing episodes documented in the study cohort. Using hierarchical partitioning we found that non-viral wheezing episodes accounted for the greatest variance in asthma diagnosed at both 7 and 10 years of age (8.0% and 5.8% respectively). Rhinovirus wheezing illnesses explained the most variance in respiratory phenotype outcome followed by non-viral wheezing episodes (4.9% and 3.9% respectively) at 10 years of age. Within this high-risk urban-residing cohort in early life, non-viral wheezing episodes were frequently identified and associated with asthma development. Though rhinovirus wheezing illnesses had the greatest association with phenotype outcome, the specific etiology of wheezing episodes in early life provided limited information about subsequent wheezing phenotypes.

Comparative characterization of interleukin genotypes and risks of bronchial asthma phenotypes in children

The present paper analyses genetic predictors of various endotypes and phenotypes of bronchial asthma in children. The review of data on the structure and prevalence of single-nucleotide polymorphisms of interleukin genes demonstrates their correlation with the risk of virus-induced and allergen-induced phenotypes of bronchial asthma. Significant differences in genotypes correlate with aberrant production of interleukin and the risks for developing various phenotypes of the disease. The studies into genetic factors indicate the significance of functional polymorphisms of interleukin genes as predictors associated with phenotypes and risk of the disease.

Characterization of asthma phenotypes in children of the tropics

Determine the main asthma phenotypes in a population of asthmatic children in Cartagena, Colombia. 107 children (7 to 17 years old) with a previous diagnosis of asthma were recruited. Biomarkers of T2 inflammation were evaluated by measuring FeNO, eosinophil count in peripheral blood by hemocytometry, and determination of specific IgE to mite allergens by ELISA. The study was approved by the ethics committee of the University of Cartagena (SGR, Grant BPIN2020000100405). The average age of patients was 10,9 years. 19,6% of the children did not show elevation of any of the T2 inflammation biomarkers evaluated (FeNO<20ppb, eos<300/ul, negative specific IgE), so they were considered patients with non-allergic asthma (non-T2). 71,9% of all patients were sensitized to at least one allergen, this phenotype was considered allergic asthma. 30,8% of the patients presented the three elevated biomarkers (FeNO>20ppb + eos >300/ul + positive specific IgE), this phenotype was classified as high T2 allergic asthma. A moderate correlation (Spearman rho=0,44, p<0,0001) was found between FeNO values and eosinophil counts. In this study, the following phenotypes were found: allergic asthma, high T2 asthma, and non-allergic asthma. Most patients presented a type 2 inflammatory phenotype with allergic sensitization. In addition to the measurement of specific IgE, the use of FeNO and eosinophil count in peripheral blood help to accurately determine those patients with high T2 asthma phenotypes.

Obesity-associated asthma phenotype in children

Obesity-associated asthma phenotype in children

Maternal vitamin D–related metabolome and offspring risk of asthma outcomes

Gestational vitamin D deficiency is implicated in development of respiratory diseases in offspring, but the mechanism underlying this relationship is unknown. We sought to study the link between gestational vitamin D exposure and childhood asthma phenotypes using maternal blood metabolomics profiling. Untargeted blood metabolic profiles were acquired using liquid chromatography-mass spectrometry at 1 week postpartum from 672 women in the Copenhagen Prospective Studies on Asthma in Childhood2010 (COPSAC2010) mother-child cohort and at pregnancy weeks 32 to 38 from 779 women in the Vitamin D Antenatal Asthma Reduction Trial (VDAART) mother-child cohort. In COPSAC2010, we employed multivariate models and pathway enrichment analysis to identify metabolites and pathways associated with gestational vitamin D blood levels and investigated their relationship with development of asthma phenotypes in early childhood. The findings were validated in VDAART and in cellular models. In COPSAC2010, higher vitamin D blood levels at 1 week postpartum were associated with distinct maternal metabolome perturbations with significant enrichment of the sphingomyelin pathway (P< .01). This vitamin D-related maternal metabolic profile at 1 week postpartum containing 46 metabolites was associated with decreased risk of recurrent wheeze (hazard ratio [HR]= 0.92 [95% CI 0.86-0.98], P= .01) and wheeze exacerbations (HR= 0.90 [95% CI 0.84-0.97], P= .01) at ages 0 to 3 years. The same metabolic profile was similarly associated with decreased risk of asthma/wheeze at ages 0 to 3 in VDAART (odds ratio= 0.92 [95% CI 0.85-0.99], P= .04). Human bronchial epithelial cells treated with high-dose vitamin D3 showed an increased cytoplasmic sphingolipid level (P< .01). This exploratory metabolomics study in 2 independent birth cohorts demonstrates that the beneficial effect of higher gestational vitamin D exposure on offspring respiratory health is characterized by specific maternal metabolic alterations during pregnancy, which involves the sphingomyelin pathway.

Exposures to perfluoroalkyl substances and asthma phenotypes in childhood: an investigation of the COPSAC2010 cohort.

Exposure to perfluoroalkyl substances may affect offspring immune development and thereby increase risk of childhood asthma, but the underlying mechanisms and asthma phenotype affected by such exposure is unknown. In the Danish COPSAC2010 cohort of 738 unselected pregnant women and their children plasma PFOS and PFOA concentrations were semi-quantified by untargeted metabolomics analyses and calibrated using a targeted pipeline in mothers (gestation week 24 and 1 week postpartum) and children (age ½, 1½ and 6 years). We examined associations between pregnancy and childhood PFOS and PFOA exposure and childhood infections, asthma, allergic sensitization, atopic dermatitis, and lung function measures, and studied potential mechanisms by integrating data on systemic low-grade inflammation (hs-CRP), functional immune responses, and epigenetics. Higher maternal PFOS and PFOA exposure during pregnancy showed association with a non-atopic asthma phenotype by age 6, a protection against sensitization, and no association with atopic asthma or lung function, or atopic dermatitis. The effect was primarily driven by prenatal exposure. There was no association with infection proneness, low-grade inflammation, altered immune responses or epigenetic changes. Prenatal exposure to PFOS and PFOA, but not childhood exposure, specifically increased the risk of low prevalent non-atopic asthma, whereas there was no effect on atopic asthma, lung function, or atopic dermatitis. All funding received by COPSAC are listed on www.copsac.com. The Lundbeck Foundation (Grant no R16-A1694); The Novo Nordic Foundation (Grant nos NNF20OC0061029, NNF170C0025014, NNF180C0031764); The Ministry of Health (Grant no 903516); Danish Council for Strategic Research (Grant no 0603-00280B); and The Capital Region Research Foundation have provided core support to the COPSAC research center. COPSAC acknowledges the National Facility for Exposomics (SciLifeLab, Sweden) for supporting calibration of the untargeted metabolomics PFAS data. BC and AS has received funding for this project from the European Union's Horizon 2020 research and innovation programme (BC: grant agreement No. 946228 DEFEND; AS: grant agreement No. 864764 HEDIMED).

Role of adiponectin, resistin and monocyte chemo-attractant protein-1 in overweight/obese asthma phenotype in children

BackgroundAsthma is a chronic inflammatory disorder of the airways with diverse overlapping pathologies and phenotypes contributing to a significant heterogeneity in clinical manifestations. Obesity may modify asthma risk, phenotype, and prognosis. A suggested mechanism linking obesity and asthma is through systemic inflammation. Adipokines secreted by adipose tissue were suggested to provide a link between obesity and asthma.ObjectiveTo have an understanding for the contribution of adiponectin, resistin and MCP-1 to development of distinct asthma phenotype in overweight/obese children through assessment of their serum level and correlation to pulmonary function tests.Subjects and methodsThe study included 29 normal weight asthmatics, 23 overweight/obese asthmatic children and 30 controls. All cases were subjected to detailed history taking, thorough examination and pulmonary function tests. Serum adiponectin, resistin, MCP-1 and IgE were assessed to all recruited subjects.ResultsAdiponectin level was significantly higher in overweight/obese asthmatics (24900 ± 1600 ng/ml) compared to normal weight asthmatics (21700 ± 1700 ng/ml) and control (23000 ± 3200 ng/ml), (p < 0.001 & 0.051 respectively). Normal weight asthmatics had significantly lower adiponectin level than control, (p = 0.039). A significant low level of MCP-1 in overweight/obese asthmatics (149.5 (20—545) ng/L) compared to control (175 (28 -1123.5) ng/L), p = 0.037. No significant difference was found regarding resistin. Normal weight asthmatics had significantly lower FEV1% and FVC% compared to overweight/obese asthmatics (p = 0.036, 0.016 respectively). A significant positive correlation was found between (FEV1%, FVC) and BMI in normal weight asthmatics (P = 0.01, < 0.01 respectively) and a significant negative correlation between PEF and BMI (-0.42, p = 0.05) in obese/overweight asthmatics. Resistin/adiponectin ratio was not affected by sex, degree of asthma severity or level of asthma control in either normal weight or overweight/obese asthmatic.ConclusionThis work could suggest that adiponectin may play a role in overweight/obese asthma phenotype where it is possible to have a dual action (pro & anti- inflammatory). It seems that resistin had no role in asthma pathogenesis.

Application of Metabolomics in Obesity-Related Childhood Asthma Subtyping: A Narrative Scoping Review.

Obesity-related asthma is a heterogeneous childhood asthma phenotype with rising prevalence. Observational studies identify early-life obesity or weight gain as risk factors for childhood asthma development. The reverse association is also described, children with asthma have a higher risk of being obese. Obese children with asthma have poor symptom control and an increased number of asthma attacks compared to non-obese children with asthma. Clinical trials have also identified that a proportion of obese children with asthma do not respond as well to usual treatment (e.g., inhaled corticosteroids). The heterogeneity of obesity-related asthma phenotypes may be attributable to different underlying pathogenetic mechanisms. Although few childhood obesity-related asthma endotypes have been described, our knowledge in this field is incomplete. An evolving analytical profiling technique, metabolomics, has the potential to link individuals' genetic backgrounds and environmental exposures (e.g., diet) to disease endotypes. This will ultimately help define clinically relevant obesity-related childhood asthma subtypes that respond better to targeted treatment. However, there are challenges related to this approach. The current narrative scoping review summarizes the evidence for metabolomics contributing to asthma subtyping in obese children, highlights the challenges associated with the implementation of this approach, and identifies gaps in research.

Type 2-High Airway Inflammation in Childhood Asthma Distinguishes a More Severe Phenotype

There is a limited number of biomarkers to identify different phenotypes of childhood asthma, most reflecting type 2-high (T2-high) airway inflammation. It is largely unknown whether such phenotyping can distinguish disease persistency and trajectories.

The maternal prenatal and offspring early-life gut microbiome of childhood asthma phenotypes.

The infant fecal microbiome is known to impact subsequent asthma risk, but the environmental exposures impacting this association, the role of the maternal microbiome, and how the microbiome impacts different childhood asthma phenotypes are unknown. Our objective was to identify associations between features of the prenatal and early-life fecal microbiomes and child asthma phenotypes. We analyzed fecal 16 s rRNA microbiome profiling and fecal metabolomic profiling from stool samples collected from mothers during the third trimester of pregnancy (n=120) and offspring at ages 3-6months (n=265), 1 (n=436) and 3 years (n=506) in a total of 657 mother-child pairs participating in the Vitamin D Antenatal Asthma Reduction Trial. We used clinical data from birth to age 6 years to characterize subjects with asthma as having early, transient or active asthma phenotypes. In addition to identifying specific genera that were robustly associated with asthma phenotypes in multiple covariate-adjusted models, we clustered subjects by their longitudinal microbiome composition and sought associations between fecal metabolites and relevant microbiome and clinical features. Seven maternal and two infant fecal microbial taxa were robustly associated with at least one asthma phenotype, and a longitudinal gut microenvironment profile was associated with early asthma (Fisher exact test p=.03). Though mode of delivery was not directly associated with asthma, we found substantial evidence for a pathway whereby cesarean section reduces fecal Bacteroides and microbial sphingolipids, increasing susceptibility to early asthma. Overall, our results suggest that the early-life, including prenatal, fecal microbiome modifies risk of asthma, especially asthma with onset by age 3 years.

Evaluation of serum levels of interferon beta (INF-Ɓ) and nucleotide-binding oligomerization domain 2 (NOD2) gene polymorphism in relation to asthma phenotypes in children

Evaluation of serum levels of interferon beta (INF-Ɓ) and nucleotide-binding oligomerization domain 2 (NOD2) gene polymorphism in relation to asthma phenotypes in children

Childhood asthma: pathogenesis and phenotypes.

In the pathogenesis of asthma in children there is a pivotal role for a type 2 inflammatory response to early life exposures or events. Interactions between infections, atopy, genetic susceptibility and environmental exposures (such as farmyard environment, air pollution and tobacco smoke exposure) influence the development of wheezing illness and the risk of progression to asthma. The immune system, lung function and the microbiome in gut and airways develop in parallel, and dysbiosis of the microbiome may be a critical factor in asthma development. Increased infant weight gain and preterm birth are other risk factors for development of asthma and reduced lung function. The complex interplay between these factors explains the heterogeneity of asthma in children. Subgroups of patients can be identified as phenotypes, based on clinical parameters, or endotypes, based on a specific pathophysiological mechanism. Paediatric asthma phenotypes and endotypes may ultimately help to improve diagnosis of asthma, prediction of asthma development and treatment of individual children, based on clinical, temporal, developmental or inflammatory characteristics. Unbiased, data-driven clustering, using a multidimensional or systems biology approach may be needed to better define phenotypes. The present knowledge on inflammatory phenotypes of childhood asthma has now been successfully applied in the treatment with biologicals of children with severe therapy-resistant asthma, and it is to be expected that more personalised treatment options may become available.

Biologics in the Treatment of Severe Uncontrolled Asthma in Children

Asthma is the most common chronic disease in children, currently affecting about 7 million children. Severe uncontrolled asthma is rare in children with a prevalence of about 2.1% to 5%, but inflicts a disproportionate health burden. Children with severe asthma have increased risk of life threatening exacerbations, frequent hospitalization, worsening health-related quality of life, and impaired physical activity. Severe asthma in childhood is associated with long-term morbidities, such as bronchiolitis obliterans, impaired airway development, and development of chronic obstructive pulmonary disease in adulthood. Childhood asthma like adult-onset asthma, is classified into four cellular inflammatory phenotypes using induced sputum cytometry. The four phenotypes of asthma include eosinophilic asthma, neutrophilic asthma, paucigranulocytic asthma, and mixed cellularity asthma. The pathophysiological mechanisms of asthma involve airway inflammation and remodeling. Inflammatory mediators such as cytokines, chemokines, adhesion molecules, and growth factors play a key role in orchestration airway remodeling. During airway inflammation, cytokines secreted by type 2 helper (Th2) lymphocytes, such as interleukin-5 (IL-5), IL-4, IL-13, IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) play a key role in the pathogenesis of eosinophilic asthma. Whereas, the Th17 axis cytokines, including IL-17, IL-23, and IL-8 are responsible for the pathophysiology of neutrophilic asthma. The airway structural changes due to airway remodeling lead to thickening of the airway wall, narrowing of the bronchiolar lumen, airway obstruction, and decline in pulmonary function. Most of the children with asthma respond to low and medium inhaled corticosteroids, however a significant proportion still have severe asthma uncontrolled on the standard of care. The most common asthma phenotype in children is eosinophilic asthma, which responds superbly to biologic therapy. Children with severe asthma require add-on targeted interleukin antagonists (ILA), such as mepolizumab (anti-IL-5), benralizumab (anti-IL-5Rα), and dupilumab (anti-4Rα). ILAs have been shown to ameliorate asthma symptoms, reduce moderate and severe exacerbations, and improve pulmonary function. Additionally, ILAs have been demonstrated to improve the health-related quality of life, and have steroid sparing effect.

Treatment outcome clustering patterns correspond to discrete asthma phenotypes in children

Despite widely and regularly used therapy asthma in children is not fully controlled. Recognizing the complexity of asthma phenotypes and endotypes imposed the concept of precision medicine in asthma treatment. By applying machine learning algorithms assessed with respect to their accuracy in predicting treatment outcome, we have successfully identified 4 distinct clusters in a pediatric asthma cohort with specific treatment outcome patterns according to changes in lung function (FEV1 and MEF50), airway inflammation (FENO) and disease control likely affected by discrete phenotypes at initial disease presentation, differing in the type and level of inflammation, age of onset, comorbidities, certain genetic and other physiologic traits. The smallest and the largest of the 4 clusters- 1 (N = 58) and 3 (N = 138) had better treatment outcomes compared to clusters 2 and 4 and were characterized by more prominent atopic markers and a predominant allelic (A allele) effect for rs37973 in the GLCCI1 gene previously associated with positive treatment outcomes in asthmatics. These patients also had a relatively later onset of disease (6 + yrs). Clusters 2 (N = 87) and 4 (N = 64) had poorer treatment success, but varied in the type of inflammation (predominantly neutrophilic for cluster 4 and likely mixed-type for cluster 2), comorbidities (obesity for cluster 2), level of systemic inflammation (highest hsCRP for cluster 2) and platelet count (lowest for cluster 4). The results of this study emphasize the issues in asthma management due to the overgeneralized approach to the disease, not taking into account specific disease phenotypes.

IL-8 gene expression and bronchial asthma phenotypes in children

Asthma is a common chronic illness among school children, where different cytokines, including IL-8 play a role in its pathogenesis. IL-8 induces chemotaxis and migration of immune cells, especially neutrophils to the site of inflammation. IL-8 level was significantly increased in sputum of severely asthmatic patients, but can it be linked to some asthma phenotypes. Our aim of the study was to detect the IL 8 gene expression in different asthma phenotypes and to determine its relation to asthma severity. This case control study included 320 subjects (160 asthmatic and 160 matched controls) aged from 5 to 16 years old in Beni-Suef governorate. IL-8 gene expression was assessed by a real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and studied regarding its level in cases versus controls and its relations to severity, phenotype and other laboratory parameters. IL-8 gene expression was statistically higher in asthmatic cases (P<0.001) and was significantly correlated to the phenotype (presence of other allergy as urticaria and drug eruption) and degree of asthma symptoms (r=0.869, P<0.001), FEV1(r=0.757, P<0.001) and serum IgE level (r=0.789, P<0.001). IL-8 gene expression level is increased with the degree of severity in asthmatic children and can be looked for in certain asthma phenotypes especially in presence of other atopic manifestation.

Different childhood asthma phenotypes based on humidifier disinfectant exposure

Exposure to humidifier disinfectants can increase the risk of asthma but the characteristics of humidifier disinfectant-related asthma are currently unclear. To investigate the characteristics of polyhexamethylene guanidine hydrochloride (PHMG)-induced asthma.

Low gestational vitamin D level and childhood asthma are related to impaired lung function in high-risk children

Lung function impairment in early life often persists into adulthood. Therefore, identifying risk factors for low childhood lung function is crucial. We examined the effect of 25-hydroxyvitamin D (25[OH]D) level and childhood asthma phenotype on childhood lung function in the Vitamin D Antenatal Asthma Reduction Trial (VDAART). The 25(OH)D level was measured at set time points in mothers during pregnancy and in children during early life. On the basis of parental reports, children were categorized into 3 clinical phenotypes: asymptomatic/infrequent wheeze, early transient wheeze, and asthma at age 6 years. Lung function was assessed with impulse oscillometry at ages 4, 5, and 6 years and with spirometry at ages 5 and 6 years. A total of 570 mother-child pairs were included in this post hoc analysis. Mean gestational 25(OH)D-level quartiles were negatively associated with child respiratory resistance at 5 Hz (R5) from age 4 to 6 years (β, -0.021 kPa/L/s; 95% CI, -0.035 to -0.007; P= .003) and positively associated with FEV1 (β, 0.018 L; 95% CI, 0.005-0.031; P= .008) and forced vital capacity (β, 0.022 L; 95% CI, 0.009-0.036; P= .002) from age 5 to 6 years. Children with asthma at age 6 years had lower lung function from age 4 to 6 years than the asymptomatic/infrequent wheeze group (β, 0.065 kPa/L/s; 95% CI, 0.028 to 0.102; P< .001 for R5 and β, -0.063 L; 95% CI, -0.099 to -0.028; P< .001 for FEV1). Low gestational 25(OH)D level and childhood asthma are important risk factors for decreased lung function in early childhood.

Effects of low exposure to traffic related air pollution on childhood asthma onset by age 10 years

Although NO2, a major traffic related air pollutant, has been associated with onset of childhood asthma, young children may be more susceptible to traffic related air pollution exposure compared to other individuals. We linked data from National Longitudinal Survey of Children and Youths Cycle 1–5 (1994–2003) and the National Air Pollution Surveillance Program to determine the association between NO2 exposure and either early or late onset childhood asthma phenotypes. Children diagnosed with asthma from age 0–3 were defined as having early onset asthma. Children diagnosed with asthma from age 4–9 were defined as having late onset asthma. Mean NO2 exposure for each quartile was 6.31 ppb, 9.45 ppb, 11.83 ppb, and 17.9 ppb. Higher levels of NO2 exposure were more strongly associated with early childhood asthma (Quartile 3 OR: 2.11, 95% CI: 1.29, 3.44, Quartile 4 OR: 2.16, 95% CI: 1.27, 3.68) compared to the lowest level of NO2 exposure (Quartile 1). No such association was observed with risk of late childhood asthma onset. Asthma susceptibility to NO2 exposure may vary with the childhood developmental stage, and young children may be susceptible to NO2 exposure at levels well below national and international guidelines. Our study emphasizes the importance of considering the timing of childhood asthma onset in future studies and confirms the increased risk of early onset of childhood asthma associated even with relatively low NO2 exposure levels.