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

Longitudinal transcriptional immune profiles and persistent wheezing in moderate-to-late preterm infants

BACKGROUND

Prematurity is associated with an increased risk of persistent wheezing but the underlying mechanisms are not well defined. The aim of this study was to identify blood transcriptional profiles associated with the development of wheezing in a cohort of moderate to late preterm infants and to define immune gene expression changes associated with wheezing.

MATERIALS AND METHODS

A convenience sample of a multicenter birth cohort (SAREPREM) of moderate-late preterm children followed during the first 3 years of life was analyzed. Children were enrolled in the first 2 weeks of life (Y0) and longitudinally evaluated at 1 (Y1), 2 (Y2), and 3 years (Y3) of age, for the presence of wheezing and to obtain samples for transcriptional profile analysis. Samples were processed on Illumina HT12 chips and genomic expression analyses performed with R programming, modular analysis for biological function, and QuSAGE for quantitative gene expression.

RESULTS

Seventy-six children were included in the study; 33 were classified as non-wheezing and 43 (56.6%) in the wheezing group. At Y0, children who developed wheezing had decreased expression of interferon genes and increased expression of B cell genes compared with the non-wheezing group. These changes in IFN and B cell gene expression were especially significant in children with late/persistent wheezing compared with transient wheezers.

CONCLUSIONS

Changes in IFN and B lymphocyte gene expression identified in early life suggest the existence of specific immunological mechanisms that play an important role in the development of wheezing in late-preterm infants.

Epigenetics, hypersensibility and asthma: what do we know so far?

In this review, we describe recent advances in understanding the relationship between epigenetic changes, especially DNA methylation (DNAm), with hypersensitivity and respiratory disorders such as asthma in childhood. It is clearly described that epigenetic mechanisms can induce short to long-term changes in cells, tissues, and organs. Through the growing number of studies on the Origins of Health Development and Diseases, more and more data exist on how environmental and genomic aspects in early life can induce allergies and asthma. The lack of biomarkers, standardized assays, and access to more accessible tools for data collection and analysis are still a challenge for future studies. Through this review, the authors draw a panorama with the available information that can assist in the establishment of an epigenetic approach for the risk analysis of these pathologies.

The causal association between maternal smoking around birth on childhood asthma: A Mendelian randomization study

To explore the causal relationship between maternal smoking around birth and childhood asthma using Mendelian randomization (MR). Using the data from large-scale genome-wide association studies, we selected independent genetic loci closely related to maternal smoking around birth and maternal diseases as instrumental variables and used MR methods. In this study, we considered the inverse variance weighted method (MR-IVW), weighted median method, and MR-Egger regression. We investigated the causal relationship between maternal smoking around birth and maternal diseases in childhood asthma using the odds ratio (OR) as an evaluation index. Multivariable MR (MVMR) included maternal history of Alzheimer's disease, illnesses of the mother: high blood pressure and illnesses of the mother: heart diseaseas covariates to address potential confounding. Sensitivity analyses were evaluated for weak instrument bias and pleiotropic effects. It was shown with the MR-IVW results that maternal smoking around birth increased the risk of childhood asthma by 1.5% (OR = 1.0150, 95% CI: 1.0018-1.0283). After the multivariable MR method was used to correct for relevant covariates, the association effect between maternal smoking around birth and childhood asthma was still statistically significant (P < 0.05). Maternal smoking around birth increases the risk of childhood asthma.

Microarray-Based Analyses of Rhinovirus Species-Specific Antibody Responses in Exacerbated Pediatric Asthma in a German Pediatric Cohort

Rhinoviruses (RV) account for a significant number of asthma exacerbations, and RV species C may be associated with a severe course in vulnerable patient groups. Despite important evidence on the role of RV reported by clinicians and life scientists, there are still unanswered questions regarding their influence on asthma exacerbation in young patients. Thus, we measured the RVspecies-specific IgG titers in our German pediatric exacerbation cohort using a microarray-based technology. For this approach, human sera of patients with exacerbated asthma and wheeze, as well as healthy control subjects (n = 136) were included, and correlation analyses were performed. Concordantly with previously published results, we observed significantly higher cumulative levels of RV species A-specific IgG (p = 0.011) and RV-C-specific IgG (p = 0.051) in exacerbated asthma group compared to age-matched controls. Moreover, atopic wheezers had increased RV-specific IgG levels for species A (p = 0.0011) and species C (p = 0.0009) compared to non-atopic wheezers. Hypothesizing that bacterial infection positively correlates with immune memory against RV, we included nasopharyngeal swab results in our analyses and detected limited correlations. Interestingly, the eosinophil blood titer positively correlated with RV-specific IgG levels. With these observations, we add important observations to the existing data regarding exacerbation in pediatric and adolescent medicine. We propose that scientists and clinicians should pay more attention to the relevance of RV species in susceptible pediatric patients.

[Management of asthma during pregnancy]

Asthma is the most common chronic condition in pregnant women. The risks of complications associated with asthma for the mother, the foetus and the pregnancy are mainly due to uncontrolled asthma and the occurrence of exacerbations. These events are promoted by the patient's difficulty in complying with treatment or by prescription insufficiency for an unjustified fear of teratogenicity. The challenge of the management of asthma during pregnancy is to ensure optimal maternal asthma control in order to prevent foetal hypoxia and thus, reduce the risk of complications. Preventing the occurrence of asthma symptoms and exacerbations, ensuring optimal lung function and managing the risk factors of poor asthma outcomes and comorbidities are the principles necessary to achieve this goal. Because of the low or non-existent risks of the main treatments of asthma for the foetus and the mother, it is widely recommended that all therapies initiated before conception are continued, in particular inhaled corticosteroids, and to adjust the dosage to the minimum effective dose. During the preconception period and throughout pregnancy, coordination of the different healthcare professionals (general practitioner, respiratory specialist and gynecologist) is essential, with the mother-to-be playing a central role in the management of her asthma.

Medical care and treatment of children with asthmatic or wheezing health outcomes and urban-rural differences in Bavaria - a cross-sectional study

Introduction: Asthma is among the most common chronic conditions in children. The aim of this publication is to describe prevalence rates and factors associated with asthmatic or wheezing preschoolers and to evaluate medical care and treatment with regard to urban-rural differences.Methods: Data for this cross-sectional study were collected through a questionnaire, which was distributed to parents within the Health Monitoring Units in Bavaria (HMU), Germany. Data from 4767 children were available (2016/17). Those children were classified into four diagnostic groups: Unremitting Wheeze, International Study of Asthma and Allergies in Children (ISAAC) Asthma, Physician-diagnosed Asthma, and healthy control group. Urban-rural differences were tested by Pearson's chi-squared test or by Fisher's exact test. Independent variables were factors associated with health outcomes, for example, residency or migrant status. To examine associations between independent and outcome variables multivariate logistic regression analysis was performed.Results: Prevalence rates were 6.3% for 'Unremitting Wheeze', 5.2% for 'ISAAC Asthma', and 1.2% for 'Physician-diagnosed Asthma'. Factors associated with health outcomes were the occurrence of asthma in first-degree relatives, male sex, and migrant status. Generally, higher rates of doctor's visits, positive allergy tests, and corticosteroids intake in the diagnostic groups in rural compared to urban areas were observed. Rates of performed allergy tests were 55.6% for 'ISAAC Asthma' and 74.6% for 'Physician-diagnosed Asthma'.Conclusions: Prevalence rates of the diagnostic groups decreased compared to the HMU 2014/15. According to previous studies, factors associated with asthmatic or wheezing health outcomes could be confirmed. Children in rural areas generally received more medical care.Key pointsChildren's prevalence rates of asthma or wheezing disorders decreased in the past 2 years within Bavaria.This study is consistent with risk factors for asthma from the literature: asthma in the family, male gender, and migrant status.Children in rural areas receive more medical care than children in urban areas.There should me more allergy tests among children with medical diagnosis in Bavaria as low rates indicate gaps in care.

Maternal Prenatal Hair Cortisol Is Associated with Child Wheeze among Mothers and Infants with Tobacco Smoke Exposure and Who Face High Socioeconomic Adversity

The association of co-occurring prenatal stress and tobacco exposures on childhood wheezing and asthma are not well established. In this study, we compared maternal prenatal hair cortisol concentration (HCC) to the maternal report of infant wheezing (y/n) in the first year of life among mother-infant dyads exposed to tobacco smoke and socioeconomic adversity. Data were obtained from the Vitamin C to Decrease Effects of Smoking in Pregnancy on Infant Lung Function study. Maternal adversity was defined by the level of education, household income, and health insurance provider. Hair was collected at delivery, representing average circulating third-trimester cortisol levels. HCC was log transformed and dichotomized into high/low cortisol groups that were placed into a multivariate model predicting wheeze. Subjects (n = 132) were primarily White with ≤high school education and receiving government-provided health insurance. Forty-five percent of infants wheezed. Average HCC was 3.39 pg/mg hair. Women with HCC > 3.55 pg/mg were more than twice as likely to report having a child who wheezed (odds ratio 2.56, 95% confidence interval 1.22-5.40; p = 0.01), adjusting for insurance provider and maternal asthma. Among this sample of dyads with prenatal smoke exposure, elevated maternal HCC was associated with child wheeze that was not diminished after consideration of covariates.

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.

Negative influence of maternal smoking during pregnancy on infant outcomes

BACKGROUND

According to the INPES 2014 health barometer, the prevalence of smoking in pregnant women in France is the highest in Europe : 17.8% of expectant mothers who smoke continue to do so during pregnancy. Several epidemiological studies have confirmed multiple risks for tobacco-exposed infants (low birth weight; digestive, respiratory, neurological, and psychological disorders; obesity; type 1 diabetes).

PURPOSE

This study compared a cohort of infants exposed to tobacco in utero (T+) with those unexposed (T-). Birth weight, diet, presence of colic (ROME III criteria) and regurgitations (Vandenplas scale) were specifically analyzed.

METHODS

This observational, cross-sectional, and multicenter survey was conducted in France by pediatricians and general practitioners from September 2016 to February 2017. Infants with a chronic pathology and those with parents under 18 years of age were excluded. The data were collected by the physician and by the mother through a self-administered questionnaire.

RESULTS

A total of 452 physicians recruited 759 T+ and 741 T- infants in the study. The mean birth weight of T+ infants was significantly lower (3.1±0.5 kg [WHO z-score -0.476±1.081]) than that of T- infants (3.3±0.5 kg [0.033±0.965]; P<0.001). At the time of leaving the maternity facility, 47.7% of T+ infants were breastfed by their mother compared with 70.1% of T- infants. The median reported duration of breastfeeding was 1 month vs. 2 months for T+ and T- infants, respectively. Colic was significantly more common in T+ than in T- infants: 25.6% vs. 12.3% according to the ROME III criteria, and 45.7% vs. 29.7% according to the doctor's opinion (P<0.001 for both). In the T+ group, cases of regurgitation (63.6% vs. 56.5%; P=0.005), respiratory disorder (6.3% vs. 2.4%, P<0.001), and bronchiolitis (6.5% vs. 3.0%; P=0.001) were also more frequent.

CONCLUSION

This study confirms that maternal smoking during pregnancy is associated with health risks; exposed infants had significantly more digestive/respiratory symptoms and lower birth weight than unexposed infants. Preventive and educational actions need to be further strengthened in the face of this public health problem.

Phenotypes of wheezing and asthma in preschool children

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of the identified phenotypes of preschool wheezing.

RECENT FINDINGS

Early life wheezing patterns have been described in multiple populations, with several commonalities found between cohorts. Early life environmental exposures have been found to be differentially associated with preschool wheezing phenotypes and their future trajectories. These include allergen and microbe exposure, environmental tobacco smoke exposure, and maternal stress and depression. Elevated IgE in early life may also influence future asthma risk.

SUMMARY

Preschool wheezing phenotypes are heterogeneous and complex, with trajectories that are related to factors including environmental exposures. More research is needed to characterize these relationships, hopefully leading to targeted prevention strategies.

Dietary meat intake and risk of asthma in children: evidence from a meta-analysis

BACKGROUND

Many studies have been reported that dietary meat intake may be associated with the risk of asthma in children, but the results are inconsistent. Therefore, we performed a meta-analysis to evaluate the effect of meat on the risk of asthma in children.

METHODS

The databases PubMed, Embase, and Web of Science were searched. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated with random-effect model using Stata software.

RESULTS

A total of 9 articles were included in this meta-analysis. Results from our study suggest that dietary meat intake 3 or more times per week compared with never/occasionally intake has no significant association with asthma risk among children (OR = 1.27, 95% CI = 0.80-2.01, P = .308). Similarly, daily intake of meat did not affect the risk of asthma in children when compared with never/occasionally intake (OR = 1.13, 95% CI = 0.93-1.37, P = 0.234). In addition, no publication biases were detected in our meta-analysis.

CONCLUSION

Dietary meat intake most probably is not a risk factor for asthma in children. Due to some limitations that exist in our study, more studies are needed to further assess the association between meat intake and asthma risk in children.

The Association Between Female Smoking and Childhood Asthma Prevalence-A Study Based on Aggregative Data

Aims: Socioeconomic and environmental factors influence childhood asthma prevalence across the world. In-depth epidemiological research is necessary to determine the association between asthma prevalence and socio-environmental conditions, and to develop public health strategies to protect the asthmatic children against the environmental precipitators. Our research was based on aggregative data and sought to compare the asthma prevalence between children of two different age-groups across the world and to identify the association among the key socio-environmental conditions with increased childhood asthma prevalence.

Method: We included forty countries with available data on various socio-environmental conditions (2014–2015). Childhood asthma prevalence of two different age groups (6–7 and 13–14 years) were obtained from global asthma report 2014. Because of significant diversities, the selected countries were divided into two groups based on human developmental index (HDI), a well-recognized parameter to estimate the overall socioeconomic status of a country. Robust linear regression was conducted using childhood asthma prevalence as the dependent variable and female smoking prevalence, tertiary school enrollment (TSE), PM₁₀ (particulate matter ≤10 μm in diameter) and gross domestic product (GDP) as predictors.

Results: Asthma prevalence was not different between two age groups. Among all predictors, only female smoking prevalence (reflecting maternal smoking) was associated with asthma prevalence in the countries with lower socio-economic conditions (HDI), but not in the higher HDI group. The results were unchanged even after randomization.

Conclusions: Childhood asthma prevalence did not change significantly with age. Female smoking may have a positive correlation with childhood asthma prevalence in lower HDI countries.