Impact of parental asthma, prenatal maternal asthma control, and vitamin D status on risk of asthma and recurrent wheeze in 3-year-old children

Discriminant analysis and logistic regression on genetic history and environmental factors in children with asthma

BACKGROUND

Asthma is known to be related to genetic and environmental factors, we aimed to identify the predictors discriminating between children with asthma and a control group in order to build typical profiles of these children.

METHODS

A multidimensional analysis covered children (58 with asthma and 217 as control group), under 17 years of age, involving environmental variables and medical history of these children and their families.

RESULTS

Chi-square tests highlighted significant links between variables as rhinitis and conjunctivitis (P<0.001). The results showed, in group of asthmatic children, significant high frequencies of allergies, mainly seasonal (P<0.001), rhinitis, family history more present in mothers (P=0.002) and in maternal aunts and uncles (P<0.02). Allergies were mostly present in mothers of asthmatic children (P=0.03). Children whose father, mother or both had asthma were significantly more numerous in asthmatic group (P=0.0007). A multiple correspondence analysis (MCA) identified two typical profiles of children, a first group of asthmatic children with positive modalities of family history, medical and environmental factors, a second, the control group (nA, non-asthmatic children), with essentially negative modalities of the variables. Logistic regression (LR) resulted in a final model which retained four significant predictors, rhinitis (P=0.01), atopic dermatitis (P=0.04), mother antecedents (P=0.03) and paternal uncle antecedents (P=0.008) with a globally appreciable predictive value (82%) of the Hosmer-Lemeshow Test.

CONCLUSIONS

These results allowed the drafting of a typical profile quantifying through a function of a few predictors, the variation of the probability for a child to develop an asthma.

The impact of maternal asthma on the fetal lung: Outcomes, mechanisms and interventions

Maternal asthma affects up to 17% of pregnancies and is associated with adverse infant, childhood, and adult respiratory outcomes, including increased risks of neonatal respiratory distress syndrome, childhood wheeze and asthma. In addition to genetics, these poor outcomes are likely due to the mediating influence of maternal asthma on the in-utero environment, altering fetal lung and immune development and predisposing the offspring to later lung disease. Maternal asthma may impair glucocorticoid signalling in the fetus, a process critical for lung maturation, and increase fetal exposure to proinflammatory cytokines. Therefore, interventions to control maternal asthma, increase glucocorticoid signalling in the fetal lung, or Vitamin A, C, and D supplementation to improve alveologenesis and surfactant production may be beneficial for later lung function. This review highlights potential mechanisms underlying maternal asthma and offspring respiratory morbidities and describes how pregnancy interventions can promote optimal fetal lung development in babies of asthmatic mothers.

Indoor environment in relation to recurrent childhood asthma in Yancheng, China: a hospital-based case-control study

This investigation explored the association between indoor environmental factors and childhood asthma in Yancheng, China. Asthma case (201 children with recurrent asthma) and control cohorts (242 healthy subjects) were recruited from a Traditional Chinese Medical (TCM) Hospital in Yancheng city, based on the results of an ISAAC questionnaire. Questionnaires regarding environmental risk factors were completed by the child's primary caregivers. To compare data on environmental VOCs and formaldehyde contents between asthma and control cohorts, we passively conducted a 10-day indoor and outdoor sampling. Breastfeeding was a major protective indoor environmental factor for recurrent asthma (adjusted odds ratio [aOR]: 0.368, 95% confidence interval [CI]: 0.216-0.627). Our analysis revealed that childhood recurrent asthma was intricately linked to a family history of asthma. Recurrent asthma was also associated with passive smoking [aOR2.115 (95%-CI 1.275-3.508)]. Analogous correlations were observed between household renovation or new furniture introduction and recurrent asthma [aOR3.129(95%-CI1.542-6.347)]. Benzene and formaldehyde were present in all examined homes. Enhanced benzene and formaldehyde concentrations were strongly evident among asthma versus control cohorts, and they were strongly correlated with augmented recurrent asthma risk. Home environment heavily regulates incidences of childhood recurrent asthma. Hence, actions against the indoor environmental risk factors described in this study may assist in the prevention of recurrent asthma among children.

Heritable vaginal bacteria influence immune tolerance and relate to early-life markers of allergic sensitization in infancy

Maternal asthma status, prenatal exposures, and infant gut microbiota perturbation are associated with heightened risk of atopy and asthma risk in childhood, observations hypothetically linked by intergenerational microbial transmission. Using maternal vaginal (n = 184) and paired infant stool (n = 172) samples, we identify four compositionally and functionally distinct Lactobacillus-dominated vaginal microbiota clusters (VCs) that relate to prenatal maternal health and exposures and infant serum immunoglobulin E (IgE) status at 1 year. Variance in bacteria shared between mother and infant pairs relate to VCs, maternal allergy/asthma status, and infant IgE levels. Heritable bacterial gene pathways associated with infant IgE include fatty acid synthesis and histamine and tryptophan degradation. In vitro, vertically transmitted Lactobacillus jensenii strains induce immunosuppressive phenotypes on human antigen-presenting cells. Murine supplementation with L. jensenii reduces lung eosinophils, neutrophilic expansion, and the proportion of interleukin-4 (IL-4)⁺ CD4⁺ T cells. Thus, bacterial and atopy heritability are intimately linked, suggesting a microbial component of intergenerational disease transmission.

Asthma and the Missing Heritability Problem: Necessity for Multiomics Approaches in Determining Accurate Risk Profiles

Asthma is ranked among the most common chronic conditions and has become a significant public health issue due to the recent and rapid increase in its prevalence. Investigations into the underlying genetic factors predict a heritable component for its incidence, estimated between 35% and 90% of causation. Despite the application of large-scale genome-wide association studies (GWAS) and admixture mapping approaches, the proportion of variants identified accounts for less than 15% of the observed heritability of the disease. The discrepancy between the predicted heritable component of disease and the proportion of heritability mapped to the currently identified susceptibility loci has been termed the ‘missing heritability problem.’ Here, we examine recent studies involving both the analysis of genetically encoded features that contribute to asthma and also the role of non-encoded heritable characteristics, including epigenetic, environmental, and developmental aspects of disease. The importance of vertical maternal microbiome transfer and the influence of maternal immune factors on fetal conditioning in the inheritance of disease are also discussed. In order to highlight the broad array of biological inputs that contribute to the sum of heritable risk factors associated with allergic disease incidence that, together, contribute to the induction of a pro-atopic state. Currently, there is a need to develop in-depth models of asthma risk factors to overcome the limitations encountered in the interpretation of GWAS results in isolation, which have resulted in the missing heritability problem. Hence, multiomics analyses need to be established considering genetic, epigenetic, and functional data to create a true systems biology-based approach for analyzing the regulatory pathways that underlie the inheritance of asthma and to develop accurate risk profiles for disease.

Breast milk-derived extracellular vesicle miRNAs are associated with maternal asthma and atopy

Background: Breast milk-derived extracellular vesicle (EV) miRNAs may program child health outcomes associated with maternal asthma and atopy. The authors investigated associations between maternal asthma/atopy and EV miRNAs in the Programming of Intergenerational Stress Mechanisms cohort. Methods: Breast milk-derived EV miRNAs collected 6.1 ± 5.9 weeks postnatally (n = 80 mothers) were profiled using the TaqMan OpenArray Human MicroRNA Panel. The authors assessed associations using adjusted robust regression. Results: Nine EV miRNAs were associated with asthma during pregnancy (a priori criteria: nominal p < 0.05; |B_regression| >0.2). miR-1290 was associated with asthma and atopy during pregnancy (p < 0.05; |B_regression| >0.2). Enriched Kyoto Encyclopedia of Genes and Genomes pathways included TGF-β signaling and extracellular matrix-receptor interaction (false discovery rate <0.05). Conclusion: In this study, maternal asthma and atopy were associated with breast milk-derived EV miRNAs. Additional studies are needed to understand whether EV miRNAs have direct effects on infant and child health.

Personalized Treatment of Asthma: The Importance of Sex and Gender Differences

An individual's sex (nominally male or female, based on biological attributes) and gender (a complex term referring to socially constructed roles, behaviors, and expressions of identity) influence the clinical course of asthma in several ways. The physiologic development of the lungs and effects of sex hormones may explain why more boys than girls have asthma, and after puberty, more women than men have asthma. Female sex hormones have an impact throughout the life span and are associated with poor asthma control. Gender may influence exposure to asthma triggers, and sex and gender can influence the prevalence of comorbidities and interactions with health care professionals. Despite widely reported sex- and gender-based differences in asthma and asthma management, these issues frequently are not considered by health care professionals. There is also inconsistency regarding the use of "sex" and "gender" in scientific discourse; research is needed to define sex- and gender-based differences better and how they might interact to influence asthma outcomes. This review outlines the impact an individual's sex and gender can have on the pathogenesis, clinical course, diagnosis, treatment, and management of asthma.

Vitamin D Levels in Asymptomatic Children and Adolescents with Atopy during the COVID-19 Era

This study assessed vitamin D status in asymptomatic children and adolescents in Greece, with and without atopy, and possible changes during the coronavirus disease 2019 (COVID-19) pandemic. Serum levels of 25-hydroxy-vitamin D (25(OH)D) and total immunoglobulin E (IgE), and eosinophil count were measured in 340 asymptomatic children and adolescents (155 males, 185 females), mean age 8.6 ± 4.6 years, recruited over a period of 24 months (February 2019–January 2021). Atopy, defined by high level of IgE for age, was associated with vitamin D deficient status (p = 0.041). Subjects with and without atopy showed similar rates of insufficient and normal levels of 25(OH)D. The median level of 25(OH)D was significantly higher in subjects recruited during the pandemic, when home confinement rules were observed, than before the pandemic, and significantly more children had normal levels of 25(OH)D (p < 0.001), but no differences were noticed for IgE levels or eosinophil count. These results support a link between vitamin D and allergic and infectious inflammations, and specifically the association of vitamin D deficiency with asymptomatic atopy, defined as increased IgE level for age.

Maternal active asthma in pregnancy influences associations between polyunsaturated fatty acid intake and child asthma

BACKGROUND

Studies evaluating effects of prenatal polyunsaturated fatty acid (PUFA) intake on childhood asthma reveal mixed results. Inconsistencies may result from not accounting for important modifying factors such as maternal asthma or child sex.

OBJECTIVE

To evaluate whether associations between prenatal PUFA intake and childhood asthma are modified by prenatal active maternal asthma or child sex in 412 mother-child dyads.

METHODS

Energy-adjusted prenatal dietary and supplement intakes of omega-3 (n-3) and omega-6 (n-6) PUFAs were estimated using the Block98 Food Frequency Questionnaire, administered during pregnancy. Mothers reported asthma in children followed prospectively to 4.0 plus or minus 1.7 years. Generalized additive models with smooth terms for PUFA (n-3, n-6, n-6/n-3 ratio) effects were used to investigate associations between PUFAs and child asthma, without prespecifying the form of these relationships, including effect modification by active maternal asthma or child sex.

RESULTS

Among mothers (40% Black, 31% Hispanic), 22% had active asthma in pregnancy; 17.5% of children developed asthma. Lower maternal n-3 PUFA intake was significantly associated with risk of childhood asthma (P = .03), in particular among children of mothers with active asthma and low n-3 PUFA intake (P = .01). This inverse association was more apparent in girls (P = .01) compared with boys (P = .30), regardless of maternal asthma status. For n-6 PUFA and the n-6/n-3 ratio, there was a lower risk of childhood asthma in the midrange of intake and increased risk at higher intake (n-6 PUFA P = .10, n-6/n-3 ratio P = .13).

CONCLUSION

Consideration of factors that modify effects of prenatal PUFA intake on childhood asthma has implications for designing intervention strategies tailored to impact those at greatest risk.

Effect of early and late prenatal vitamin D and maternal asthma status on offspring asthma or recurrent wheeze

BACKGROUND

Childhood asthma developmental programming is complex. Maternal asthma is a strong risk factor for childhood asthma, whereas vitamin D (VD) has emerged as a modifiable prenatal exposure.

OBJECTIVE

Our aim was to examine the combined effect of early and late prenatal VD status in during pregnancies in women with and without asthma on childhood asthma or recurrent wheeze development.

METHODS

We conducted a cohort study using prospectively collected data from the Vitamin D Antenatal Asthma Reduction Trial, a randomized, double-blinded, placebo-controlled VD supplementation trial in pregnant women at high risk of offspring asthma (N = 806 mother-offspring pairs). 25-Hydroxyvitamin-D (25(OH)D) level was measured in early and late pregnancy. Our main exposure was an ordered variable representing early and late prenatal VD sufficiency (25(OH)D level ≥ 30 ng/mL) status during pregnancy in women with and without asthma. The primary outcome was offspring with asthma or recurrent wheeze by age 3 years. We also examined the effect of prenatal VD level on early life asthma or recurrent wheeze progression to active asthma at age 6 years.

RESULTS

Among mothers with asthma versus among mothers with early and late prenatal VD insufficiency, those with early or late VD sufficiency (adjusted odds ratio = 0.56; 95% CI = 0.31-1.00) or early and late VD sufficiency (adjusted odds ratio = 0.36; 95% CI = 0.15-0.81) had a lower risk of offspring with asthma or recurrent wheeze by age 3 years (Pfor trend = .008). This protective trend was reiterated in asthma or recurrent wheeze progression to active asthma from age 3 to 6 years (Pfor trend = .04).

CONCLUSION

This study implies a protective role for VD sufficiency throughout pregnancy, particularly in attenuating the risk conferred by maternal asthma on childhood asthma or recurrent wheeze development.

The Asthma Family Tree: Evaluating Associations Between Childhood, Parental, and Grandparental Asthma in Seven Chinese Cities

Objective: To evaluate the associations between childhood, parental, and grandparental asthma. Methods: We studied 59,484 children randomly selected from 94 kindergartens, elementary, and middle schools in seven Chinese cities from 2012 to 2013, using a cross-sectional survey-based study design. Information on their and their family members' (parents, paternal grandparents, and maternal grandparents) asthma status were reported by children's parents or guardians. Mixed effects logistic regressions were used to assess hereditary patterns of asthma and mediation analysis was performed to estimate the potential mediation effect of parents on the association between grandparental asthma and childhood asthma. Results: The magnitude of ORs for childhood asthma increased as the number of family members affected by asthma increased. Among children who had one family member with asthma, childhood asthma was associated with asthma in maternal grandmothers (OR: 2.08, 95% CI: 1.67-2.59), maternal grandfathers (OR: 2.08, 95% CI: 1.71-2.53), paternal grandmothers (OR: 2.40, 95% CI: 1.93-2.99), and paternal grandfathers (OR: 2.59, 95% CI: 2.14-3.13). Among children who had two family members with asthma, the highest asthma risk was found when both parents had asthma (OR: 15.92, 95% CI: 4.66-54.45). Parents had a small proportion of mediation effect (9-12%) on the association between grandparental asthma and childhood asthma. Conclusions: Grandparents with asthma were associated with childhood asthma and parents with asthma partially mediated the association.

Vitamin D supplementation for term breastfed infants to prevent vitamin D deficiency and improve bone health

BACKGROUND

Vitamin D deficiency is common worldwide, contributing to nutritional rickets and osteomalacia which have a major impact on health, growth, and development of infants, children and adolescents. Vitamin D levels are low in breast milk and exclusively breastfed infants are at risk of vitamin D insufficiency or deficiency.

OBJECTIVES

To determine the effect of vitamin D supplementation given to infants, or lactating mothers, on vitamin D deficiency, bone density and growth in healthy term breastfed infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to 29 May 2020 supplemented by searches of clinical trials databases, conference proceedings, and citations.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs in breastfeeding mother-infant pairs comparing vitamin D supplementation given to infants or lactating mothers compared to placebo or no intervention, or sunlight, or that compare vitamin D supplementation of infants to supplementation of mothers.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial eligibility and risk of bias and independently extracted data. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 19 studies with 2837 mother-infant pairs assessing vitamin D given to infants (nine studies), to lactating mothers (eight studies), and to infants versus lactating mothers (six studies). No studies compared vitamin D given to infants versus periods of infant sun exposure. Vitamin D supplementation given to infants: vitamin D at 400 IU/day may increase 25-OH vitamin D levels (MD 22.63 nmol/L, 95% CI 17.05 to 28.21; participants = 334; studies = 6; low-certainty) and may reduce the incidence of vitamin D insufficiency (25-OH vitamin D < 50 nmol/L) (RR 0.57, 95% CI 0.41 to 0.80; participants = 274; studies = 4; low-certainty). However, there was insufficient evidence to determine if vitamin D given to the infant reduces the risk of vitamin D deficiency (25-OH vitamin D < 30 nmol/L) up till six months of age (RR 0.41, 95% CI 0.16 to 1.05; participants = 122; studies = 2), affects bone mineral content (BMC), or the incidence of biochemical or radiological rickets (all very-low certainty). We are uncertain about adverse effects including hypercalcaemia. There were no studies of higher doses of infant vitamin D (> 400 IU/day) compared to placebo. Vitamin D supplementation given to lactating mothers: vitamin D supplementation given to lactating mothers may increase infant 25-OH vitamin D levels (MD 24.60 nmol/L, 95% CI 21.59 to 27.60; participants = 597; studies = 7; low-certainty), may reduce the incidences of vitamin D insufficiency (RR 0.47, 95% CI 0.39 to 0.57; participants = 512; studies = 5; low-certainty), vitamin D deficiency (RR 0.15, 95% CI 0.09 to 0.24; participants = 512; studies = 5; low-certainty) and biochemical rickets (RR 0.06, 95% CI 0.01 to 0.44; participants = 229; studies = 2; low-certainty). The two studies that reported biochemical rickets used maternal dosages of oral D3 60,000 IU/day for 10 days and oral D3 60,000 IU postpartum and at 6, 10, and 14 weeks. However, infant BMC was not reported and there was insufficient evidence to determine if maternal supplementation has an effect on radiological rickets (RR 0.76, 95% CI 0.18 to 3.31; participants = 536; studies = 3; very low-certainty). All studies of maternal supplementation enrolled populations at high risk of vitamin D deficiency. We are uncertain of the effects of maternal supplementation on infant growth and adverse effects including hypercalcaemia. Vitamin D supplementation given to infants compared with supplementation given to lactating mothers: infant vitamin D supplementation compared to lactating mother supplementation may increase infant 25-OH vitamin D levels (MD 14.35 nmol/L, 95% CI 9.64 to 19.06; participants = 269; studies = 4; low-certainty). Infant vitamin D supplementation may reduce the incidence of vitamin D insufficiency (RR 0.61, 95% CI 0.40 to 0.94; participants = 334; studies = 4) and may reduce vitamin D deficiency (RR 0.35, 95% CI 0.17 to 0.72; participants = 334; studies = 4) but the evidence is very uncertain. Infant BMC and radiological rickets were not reported and there was insufficient evidence to determine if maternal supplementation has an effect on infant biochemical rickets. All studies enrolled patient populations at high risk of vitamin D deficiency. Studies compared an infant dose of vitamin D 400 IU/day with varying maternal vitamin D doses from 400 IU/day to > 4000 IU/day. We are uncertain about adverse effects including hypercalcaemia.

AUTHORS' CONCLUSIONS

For breastfed infants, vitamin D supplementation 400 IU/day for up to six months increases 25-OH vitamin D levels and reduces vitamin D insufficiency, but there was insufficient evidence to assess its effect on vitamin D deficiency and bone health. For higher-risk infants who are breastfeeding, maternal vitamin D supplementation reduces vitamin D insufficiency and vitamin D deficiency, but there was insufficient evidence to determine an effect on bone health. In populations at higher risk of vitamin D deficiency, vitamin D supplementation of infants led to greater increases in infant 25-OH vitamin D levels, reductions in vitamin D insufficiency and vitamin D deficiency compared to supplementation of lactating mothers. However, the evidence is very uncertain for markers of bone health. Maternal higher dose supplementation (≥ 4000 IU/day) produced similar infant 25-OH vitamin D levels as infant supplementation of 400 IU/day. The certainty of evidence was graded as low to very low for all outcomes.

Developments allergy in 2019 through the eyes of Clinical and Experimental Allergy, Part II clinical allergy

In the second of two linked articles, we describe the development in clinical as described by Clinical & Experimental Allergy and other journals in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered. In this article, we described the development in the field of allergy as described by Clinical and Experimental Allergy in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered.

The Effect of Vitamin D Supplementation on Clinical Outcomes of Asthmatic Children with Vitamin D Insufficiency

BACKGROUND

The extensive impacts of vitamin D on the immune system has gathered the attention of scholars in last years. In this regard, studies about vitamin D and incidence of asthma have showed various results. The aim of this study was to evaluate the effect of vitamin D supplements on clinical outcomes in asthmatic children with vitamin D insufficiency.

MATERIALS & METHODS

This before-after interventional study was conducted on all asthmatic children who attended the Be'sat Hospital, Iran. Serum levels of 25(OH)D, asthma severity and pulmonary function tests before and after therapeutic prescription of vitamin D were evaluated. Serum levels of 25(OH)D were measured by enzyme-linked immunosorbent assay.

RESULTS

The mean age of the samples was 10.69±9.78 years and 39 subjects (57.4%) were male. The primary mean level of serum 25(OH)D (18.21±8.22, ng/mL) has significantly (p<0.05) increased after treatment (35.45±9.35, ng/mL). Also, asthma severity, forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC indicators were significantly (p<0.05) increased after treatment.

CONCLUSION

We can conclude that therapeutic prescription of vitamin D is very effective in improving the clinical status of asthmatic children.

Serum 25 Hydroxyvitamin D Levels During Pregnancy in Women with Asthma: Associations with Maternal Characteristics and Adverse Maternal and Neonatal Outcomes

Low 25-hydroxyvitamin D (25(OH)D) levels are common in pregnancy and associated with adverse maternal/neonatal outcomes. In pregnant women with asthma, this study examined the association of lifestyle- and asthma-related factors on 25(OH)D levels and maternal/neonatal outcomes by vitamin D status. Serum 25(OH)D was measured at 16 and 35 weeks gestation in women with asthma (n = 103). Body mass index (BMI), gestational weight gain (GWG), smoking status, inhaled corticosteroid (ICS) use, asthma control, airway inflammation, and exacerbations, and maternal/neonatal outcomes were collected. Baseline and change (Δ) in 25(OH)D were modelled separately using backward stepwise regression, adjusted for season and ethnicity. Maternal/neonatal outcomes were compared between low (25(OH)D < 75 nmol/L at both time points) and high (≥75 nmol/L at one or both time points) vitamin D status. Fifty-six percent of women had low vitamin D status. Obesity was significantly associated with lower baseline 25(OH)D (Adj-R² = 0.126, p = 0.008); ICS and airway inflammation were not. Excess GWG and season of baseline sample collection were significantly associated with Δ25(OH)D (Adj-R² = 0.405, p < 0.0001); asthma-related variables were excluded (p > 0.2). Preeclampsia was more common in the low (8.6%) vs. high (0%) vitamin D group (p < 0.05). Obesity and excess GWG may be associated with gestational 25(OH)D levels, highlighting the importance of antenatal weight management.

Maternal asthma is associated with persistent changes in allergic offspring antibody glycosylation

BACKGROUND

Maternal asthma during pregnancy is considered an environmental risk factor for asthma development in children. Immunoglobulin G (IgG) antibodies that are transferred from the mother to the fetus are known to act in a pro- or anti-inflammatory manner depending on their glycosylation status.

OBJECTIVE

Using a mouse model, we examined how maternal allergic airway inflammation during pregnancy influenced offspring experimental asthma severity, as well as maternal and offspring serum IgG antibody glycosylation patterns. Additionally, the effects of maternal and offspring exposure to the same or different allergens were investigated.

METHODS

Female mice were either sham sensitized or sensitized to casein (CAS) or ovalbumin (OVA) before mating. Subsequently, allergic lung inflammation was induced in pregnant dams via aerosol allergen challenge (sham, CAS or OVA). After weaning, pups were subjected to an experimental asthma protocol using OVA. Asn-297 IgG glycosylation was analysed in maternal and offspring serum.

RESULTS

When mothers and offspring were sensitized to the same allergen (OVA-OVA), offspring had more severe experimental asthma. This was evidenced by altered antibody concentrations, increased bronchoalveolar lavage inflammatory cell influx and decreased lung tissue and lung draining lymph node regulatory T cell percentages. When mothers and offspring were sensitized to different allergens (CAS-OVA), this phenotype was no longer observed. Additionally, maternal serum from allergic mothers had significantly higher levels of pro-inflammatory IgG1, shown by decreased galactosylation and sialylation at the Asn-297 glycosylation site. Similar glycosylation patterns were observed in the serum of adult allergic offspring from allergic mothers.

CONCLUSIONS AND CLINICAL RELEVANCE

We observed a strong association between maternal experimental asthma during pregnancy, increased offspring airway inflammation and pro-inflammatory IgG glycosylation patterns in mothers and offspring. IgG glycosylation is not a standard measurement in the clinical setting, and we argue that it may be an important parameter to include in future clinical studies.

Targeting Vitamin D Deficiency to Limit Exacerbations in Respiratory Diseases: Utopia or Strategy With Potential?

Patients with respiratory diseases such as cystic fibrosis, chronic obstructive pulmonary disease, or asthma often experience an acute worsening of respiratory symptoms, termed exacerbations. Although the course of exacerbations is disease specific, they are mostly triggered by a respiratory infection. Exacerbations often require hospitalization and are an important cause of mortality. Treatments of exacerbations aim to minimize the negative impact and to prevent subsequent events. Despite many existing therapy options, many patients do not benefit from therapy and suffer from recurrent events. Vitamin D deficiency is a worldwide problem and is extremely prevalent in these patients. Vitamin D, known for its calcemic effects, also has immunomodulatory and anti-infectious actions and can therefore be a possible agent to treat or prevent exacerbations. This review will focus on vitamin D as a potential candidate to treat or prevent exacerbations in CF, COPD, and asthma.

Viral respiratory infections and the oropharyngeal bacterial microbiota in acutely wheezing children

Acute viral wheeze in children is a major cause of hospitalisation and a major risk factor for the development of asthma. However, the role of the respiratory tract microbiome in the development of acute wheeze is unclear. To investigate whether severe wheezing episodes in children are associated with bacterial dysbiosis in the respiratory tract, oropharyngeal swabs were collected from 109 children with acute wheezing attending the only tertiary paediatric hospital in Perth, Australia. The bacterial community from these samples was explored using next generation sequencing and compared to samples from 75 non-wheezing controls. No significant difference in bacterial diversity was observed between samples from those with wheeze and healthy controls. Within the wheezing group, attendance at kindergarten or preschool was however, associated with increased bacterial diversity. Rhinovirus (RV) infection did not have a significant effect on bacterial community composition. A significant difference in bacterial richness was observed between children with RV-A and RV-C infection, however this is likely due to the differences in age group between the patient cohorts. The bacterial community within the oropharynx was found to be diverse and heterogeneous. Age and attendance at day care or kindergarten were important factors in driving bacterial diversity. However, wheeze and viral infection were not found to significantly relate to the bacterial community. Bacterial airway microbiome is highly variable in early life and its role in wheeze remains less clear than viral influences.