Maternal transmission of asthma risk

Epidemiological characterization and risk factors of rhinitis and rhinoconjunctivitis among preschool children in Shanghai, China

BACKGROUND

Previous studies have reported an increasing prevalence of childhood allergic rhinitis in developing countries. There is still a lack of the recent epidemiology of allergic rhinitis among Chinese preschool children. Therefore, this study explored the prevalence of rhinitis symptoms and identified their associations with potential risk factors among children at the age of 3-6 in Shanghai, China.

METHODS

Validated International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was adopted to collect information about rhinitis symptoms and potential risk factors. Univariate and multivariate logistic regression analyses were used to assess associations between risk factors and allergic rhinitis and rhinoconjunctivitis.

RESULTS

A total of 6183 questionnaires were included in our study. The prevalence of rhinitis ever, current rhinitis, and physician-diagnosed rhinitis were 32.6%, 29.2%, and 14.3%, respectively, while the prevalence of current rhinoconjunctivitis was 11.3%. The higher prevalence was observed in boys than in girls in terms of rhinitis ever, current rhinitis, current rhinoconjunctivitis and doctor-diagnosed rhinitis. Autumn had the highest prevalence among four seasons. In our multivariate logistic regression analyses, history of allergic diseases and paracetamol use in the last year showed positive associations with the increased risk of both current rhinitis and rhinoconjunctivitis, and antibiotic use was an independent significant risk factor only for current rhinitis. Genetic factors, including maternal and paternal rhinitis, asthma, and eczema, were significantly associated with the prevalence of current rhinitis. Similar associations were seen between these factors and current rhinoconjunctivitis, except for paternal eczema. Among environmental factors, smoking exposure at home, heavy truck traffic in home's street, floor heating system were independent risk factors for both current rhinitis and rhinoconjunctivitis in the adjusted model, while cleaning the house less than once a week was only associated with current rhinitis.

CONCLUSION

The prevalence of current rhinitis was 29.2% among children aged 3-6 in Shanghai, China. Sex differences and seasonal variations were observed in the prevalence of rhinitis symptoms. The identified risk factors would provide a basis for policy makers and medical experts to take intervention measures to prevent allergic rhinitis and rhinoconjunctivitis.

Catching Our Breath: Updates on the Role of Dendritic Cell Subsets in Asthma

Dendritic cells (DCs), as potent antigen presenting cells, are known to play a central role in the pathophysiology of asthma. The understanding of DC biology has evolved over the years to include multiple subsets of DCs with distinct functions in the initiation and maintenance of asthma. Furthermore, asthma is increasingly recognized as a heterogeneous disease with potentially diverse underlying mechanisms. The goal of this review is to summarize the role of DCs and the various subsets therein in the pathophysiology of asthma and highlight some of the crucial animal models shaping the field today. Potential future avenues of investigation to address existing gaps in knowledge are discussed.

Dysbiotic lung microbial communities of neonates from allergic mothers confer neonate responsiveness to suboptimal allergen

In humans and animals, offspring of allergic mothers have increased responsiveness to allergens. This is blocked in mice by maternal supplementation with α-tocopherol (αT). Also, adults and children with allergic asthma have airway microbiome dysbiosis with increased Proteobacteria and may have decreased Bacteroidota. It is not known whether αT alters neonate development of lung microbiome dysbiosis or whether neonate lung dysbiosis modifies development of allergy. To address this, the bronchoalveolar lavage was analyzed by 16S rRNA gene analysis (bacterial microbiome) from pups of allergic and non-allergic mothers with a basal diet or αT-supplemented diet. Before and after allergen challenge, pups of allergic mothers had dysbiosis in lung microbial composition with increased Proteobacteria and decreased Bacteroidota and this was blocked by αT supplementation. We determined whether intratracheal transfer of pup lung dysbiotic microbial communities modifies the development of allergy in recipient pups early in life. Interestingly, transfer of dysbiotic lung microbial communities from neonates of allergic mothers to neonates of non-allergic mothers was sufficient to confer responsiveness to allergen in the recipient pups. In contrast, neonates of allergic mothers were not protected from development of allergy by transfer of donor lung microbial communities from either neonates of non-allergic mothers or neonates of αT-supplemented allergic mothers. These data suggest that the dysbiotic lung microbiota is dominant and sufficient for enhanced neonate responsiveness to allergen. Importantly, infants within the INHANCE cohort with an anti-inflammatory profile of tocopherol isoforms had an altered microbiome composition compared to infants with a pro-inflammatory profile of tocopherol isoforms. These data may inform design of future studies for approaches in the prevention or intervention in asthma and allergic disease early in life.

Cord blood sphingolipids are associated with atopic dermatitis and wheeze in the first year of life

Background

Allergen-sensitized pregnant mice have increased plasma levels of the lipids β-glucosylceramides (βGlcCers) that are transplacentally transferred to the fetus, increased subsets of proinflammatory dendritic cells in the fetal liver and pup lung, and increased allergen-induced offspring lung inflammation.

Objective

Our aim was to determine whether these preclinical observations extend to a human association of βGlcCers with wheeze and allergic disease in the prospective Wisconsin Infant Study Cohort.

Methods

We measured 74 lipids in cord blood plasma by using mass spectrometry detection of sphingolipids, eicosanoids, and docosinoids, as well as an ELISA for 13-hydroxyoctadecadienoic acid. Lipid profiles were determined by unbiased Uniform Manifold Approximation and Projection dimensional reduction machine learning. Lipid profiles and a proinflammatory lipid index were analyzed for association with maternal allergy and childhood outcomes of wheeze, atopic dermatitis, cord blood leukocytes, and total IgE level at age 1 year.

Results

Uniform Manifold Approximation and Projection analysis of lipids defined 8 cluster-specific plasma lipid profiles. Cluster 6 had significantly lower levels of plasma βGlcCers and a higher frequency of cord blood plasmacytoid dendritic cells that mediate anti-inflammatory responses, which is consistent with an anti-inflammatory profile. For clusters and for each infant, a proinflammatory lipid index was calculated to reflect the sum of the proinflammatory lipids minus the anti-inflammatory lipids that were significantly different than in cluster 6. The cluster proinflammatory lipid index was associated with cord blood basophil frequency and with wheeze and atopic dermatitis in the first year of life. The infant inflammatory lipid index was associated with increased risk of wheeze in the first year of life.

Conclusion

The cord blood proinflammatory lipid index is associated with early-life atopic dermatitis and wheezing.

Asthma, allergy and vitamin E: Current and future perspectives

Asthma and allergic disease result from interactions of environmental exposures and genetics. Vitamin E is one environmental factor that can modify development of allergy early in life and modify responses to allergen after allergen sensitization. Seemingly varied outcomes from vitamin E are consistent with the differential functions of the isoforms of vitamin E. Mechanistic studies demonstrate that the vitamin E isoforms α-tocopherol and γ-tocopherol have opposite functions in regulation of allergic inflammation and development of allergic disease, with α-tocopherol having anti-inflammatory functions and γ-tocopherol having pro-inflammatory functions in allergy and asthma. Moreover, global differences in prevalence of asthma by country may be a result, at least in part, of differences in consumption of these two isoforms of tocopherols. It is critical in clinical and animal studies that measurements of the isoforms of tocopherols be determined in vehicles for the treatments, and in the plasma and/or tissues before and after intervention. As allergic inflammation is modifiable by tocopherol isoforms, differential regulation by tocopherol isoforms provide a foundation for development of interventions to improve lung function in disease and raise the possibility of early life dietary interventions to limit the development of lung disease.

Inherent maternal type 2 immunity: Consequences for maternal and offspring health

An inherent elevation in type 2 immunity is a feature of maternal and offspring immune systems. This has diverse implications for maternal and offspring biology including influencing success of pregnancy, offspring immune development and maternal and offspring ability to control infection and diseases such as allergies. In this review we provide a broad insight into how this immunological feature of pregnancy and early life impacts both maternal and offspring biology. We also suggest how understanding of this axis of immune influence is and may be utilised to improve maternal and offspring health.

A model of perinatal stress and childhood wheezing: ELSPAC-CZ cohort

BACKGROUND

Prenatal origins of wheezing are not fully understood. This study develops a model of mechanisms linking perinatal stress exposure to wheeze phenotypes in children.

METHODS

Data were obtained from 1880 mother-child dyads participating in ELSPAC-CZ birth cohort. Wheeze phenotypes assessed between birth and age 7 years included "never wheeze," "early-onset transient (EOT) wheeze," "early-onset persistent (EOP) wheeze," and "late-onset (LO) wheeze." Prenatal and postnatal stress exposures were assessed in mid-pregnancy and 6 months after delivery, respectively, using an inventory of 42 life events.

RESULTS

In adjusted models, children in the highest tercile (high) versus lowest tercile (low) for prenatal life events had a 38% higher risk of EOT wheeze (relative risk ratio [RRR] = 1.38; 95% confidence interval [CI] = 1.01-1.88; p = .041) and 50% higher risk of LO wheeze (RRR = 1.50; 95% CI = 1.00-2.25; p = .047). High versus low exposure to postnatal life events predicted a 60% increase in relative risk of EOT wheeze (RRR = 1.60; 95% CI = 1.17-2.19; p = .003) and medium versus low exposure was related to an 85% increase in relative risk of EOP wheeze (RRR = 1.85; 95% CI = 1.16-2.95; p = .010). Lower respiratory tract infections and postpartum depression partially mediated between postnatal life events and any wheeze (indirect effects 1.06, 95% CI = 1.02-1.09, p = .003 and odds ratio [OR] = 1.08, 95% CI = 1.02-1.15, p = .012, respectively), while postnatal events mediate for prenatal events (indirect effect OR = 1.11; 95% CI = 1.03-1.18; p = .005).

CONCLUSIONS

Exposures to prenatal and postnatal life events are risk factors for the development of wheezing. Prenatal stress contributes to wheeze directly and also through postnatal life events, respiratory infections, and maternal depression.

β-Glucosylceramide From Allergic Mothers Enhances Offspring Responsiveness to Allergen

In animals and humans, offspring of allergic mothers have increased responsiveness to allergen and the allergen-specificity of the offspring can be different than that of the mother. In our preclinical models, the mother's allergic responses influence development of the fetus and offspring by elevating numbers of cells in dendritic cell subsets. A major question is the identity of maternal factors of allergic mothers that alter offspring development of responsiveness to allergen. Lipids are altered during allergic responses and lipids are transported to the fetus for growth and formation of fetal membranes. We hypothesized that pro-inflammatory lipids, that are elevated in allergic mothers, are transported to the fetus and regulate fetal immune development. We demonstrate in this report that there was a significant 2-fold increase in β-glucosylceramides (βGlcCer) in allergic mothers, the fetal liver and her offspring. The βGlcCer were transported from mother's plasma, across the placenta, to the fetus and in breastmilk to the offspring. Administration of βGlcCer to non-allergic mothers was sufficient for offspring responses to allergen. Importantly, maternal administration of a clinically relevant pharmacological inhibitor of βGlcCer synthase returned βGlcCer to normal levels in the allergic mothers and her offspring and blocked the offspring increase in dendritic cell subsets and offspring allergen responsiveness. In summary, allergic mothers had increased βGlcCer that was transported to offspring and mediated increases in offspring DCs and responsiveness to allergen. These data have a significant impact on our understanding of mechanisms for development of allergies in offspring of allergic mothers and have the potential to lead to novel interventions that significantly impact risk for allergic disease early in life.

Prevalence and Risk Factors of Asthma in Preschool Children in Shanghai, China: A Cross-Sectional Study

BACKGROUND

Previous studies have shown the increasing prevalence of childhood asthma around the world as well as in China. Nevertheless, little is known about the epidemiology of asthma in preschool children. Thus, the present study investigated the prevalence and severity of asthma in Shanghai, China, and identified related risk factors for asthma in children at the age of 3-6.

METHODS

Information was obtained through the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Risk factor analysis was carried out using univariate and multivariate logistic regression. The odds ratio (OR)/adjusted odds ratio (aOR) and the 95% confidence interval (CI) were determined.

RESULTS

A total of 6,183 children (3,165 boys and 3,018 girls) covering 12 communities were included in our study, with an average age of 4.2 ± 0.7 years. The prevalence of ever asthma, current asthma, and physician-diagnosed asthma was 16.0, 11.2, and 5.3%, respectively. Parental allergic history, including rhinitis and asthma, was significantly associated with asthma symptoms. The strongest association with current asthma was paternal asthma (aOR = 5.91, 95% CI 3.87-9.01), and maternal asthma had the second strongest association with current asthma (3.85; 2.40-6.17). Among personal factors, allergic rhinitis history, eczema history, food allergy history, and antibiotic use in the first year of life were significantly associated with current asthma (aOR = 1.89, 95% CI 1.52-2.34; aOR = 1.34, 95% CI 1.09-1.64; aOR = 1.68, 95% CI 1.37-2.06; aOR = 1.53, 95% CI 1.25-1.87, respectively). More than once paracetamol use per year and per month were associated with current asthma in a dose-response manner. Additionally, female sex was an independent protective factor for ever asthma (0.82; 0.70-0.96). Among environmental factors, dampness or mildew at home was an independent risk factor for ever asthma (1.50; 1.15-1.97) and current asthma (1.63; 1.21-2.19). Floor heating system was significantly associated with ever asthma (1.57; 1.25-1.98) and current asthma (1.36; 1.04-1.78). Furthermore, dampness or mildew, infrequent house cleaning, and truck traffic in residential streets were significantly associated with asthma symptoms only in old communities, while paracetamol use in the first year of life and flooring materials were significant factors only in new communities.

CONCLUSION

The prevalence of asthma has increased among preschool children in Shanghai over the past three decades. The identified risk factors indicated the combined effects of genetic, personal, and environmental factors on asthma symptoms. Differentiated strategies should be taken for preventing asthma in old and new communities.

Childhood wheeze trajectory-specific risk factors: A systematic review and meta-analysis

BACKGROUND

There is growing interest in the use of latent trajectory methodology to identify wheeze patterns in heterogeneous populations of children. This study systematically reviewed and meta-analyzed childhood wheeze trajectory studies to identify childhood wheeze trajectory group-specific risk factors among children from birth through to adolescence.

METHODS

We included studies that used latent trajectory methodology to identify wheeze trajectories and associated risk factors. We searched PubMed, EMBASE, and Google Scholar from 2000 through September 30, 2019, for relevant studies. The study was conducted according to the PRISMA recommendations.

RESULTS

Thirteen cohort studies conducted in eleven high-income countries were included in our meta-analysis with the length of follow-up ranging from 3 to 18 years. Five distinct latent wheeze trajectory groups were identified: Never/Infrequent, Early-Transient, Early-Persistent, Intermediate-Onset, and Late-Onset. We found moderate-to-strong evidence that family history of asthma predicted persistent childhood wheezing among male children but with lower risk among first-born children. There was weak-to-moderate evidence for childhood atopy, male sex, short duration of breastfeeding, tobacco exposure, daycare attendance, and having siblings as risk factors for Early-Transient wheezing; except for breastfeeding, these factors were also associated with intermediate and Late-Onset wheezing with varying effect sizes in high-risk vs general population cohorts.

CONCLUSIONS

Our findings confirm the consistency of wheeze trajectory groups defined by onset, peak prevalence, and duration; we also suggest a common nomenclature for future trajectory studies. With the exception of the relationship between a family history of asthma and persistent childhood wheezing, commonly suspected wheeze risk factors (childhood atopy, male sex, short duration of breastfeeding, tobacco exposure, daycare attendance, and having siblings) are not trajectory-specific and have varying effects in high-risk vs general population cohorts. Delineation of time-varying risk factor effects may be critical to the specificity of wheeze trajectory group prediction to better inform prognosis and targeted early preventive intervention among at-risk children.

Associations of α- and γ-tocopherol during early life with lung function in childhood

BACKGROUND

Tocopherol isoforms may regulate child lung growth and spirometric measures.

OBJECTIVE

Our aim was to determine the extent to which plasma α-tocopherol (α-T) or γ-tocopherol (γ-T) isoform levels in early childhood or in utero are associated with childhood lung function.

METHODS

We included 622 participants in the Project Viva cohort who had lung function at a mid-childhood visit (age 6-10 years). Maternal and child tocopherol isoform levels were measured by HPLC at the second trimester and 3 years of age, respectively. Multivariable linear regression models (adjusted for mid-childhood body mass index z scores, maternal education, smoking in pregnancy, and prenatal particulate matter with diameter of <2.5 micrometers (PM_2.5) particulate exposure) stratified by tertiles of child γ-T level were used to assess the association of α-T levels with FEV₁ and forced vital capacity (FVC) percent predicted. Similarly, models stratified by child α-T tertile evaluated associations of γ-T levels with lung function. We performed similar analyses with maternal second trimester tocopherol isoform levels.

RESULTS

The median maternal second trimester α-T level was 63 μM (interquartile range = 47-82). The median early-childhood level was 25 μM (interquartile range = 20-33 μM). In the lowest tertile of early-childhood γ-T, children with a higher α-T level (per 10 μM) had a higher mid-childhood FEV₁ percent predicted (β = 3.09; 95% CI = 0.58-5.59 and a higher FVC percent predicted (β = 2.77; 95% CI = 0.47-5.06). This protective association of α-T was lost at higher γ-T levels. We did not see any consistent associations of second trimester levels of either α-T or γ-T with mid-childhood FEV₁ or FVC.

CONCLUSION

When γ-T levels were in the lowest tertile, a higher early-childhood α-T level was associated with better lung function at mid-childhood. Second trimester maternal plasma α-T concentration was 3-fold higher than in the adult nonpregnant female population.

Role for Maternal Asthma in Severe Human Metapneumovirus Lung Disease Susceptibility in Children

Background

Severity of human metapneumovirus (hMPV) lower respiratory illness (LRTI) is considered similar to that observed for respiratory syncytial virus (RSV). However, differences in severity between these pathogens have been noted, suggesting the degree of illness may vary in different populations. Moreover, a potential association between hMPV and asthma also suggests that hMPV may preferentially affect asthmatic subjects.

Methods

In a population-based surveillance study in children aged <2 years admitted for severe LRTI in Argentina, nasopharyngeal aspirates were tested by RT-PCR for hMPV, RSV, influenza A, and human rhinovirus.

Results

Of 3947 children, 383 (10%) were infected with hMPV. The hospitalization rate for hMPV LRTI was 2.26 per 1000 children (95% confidence interval [CI], 2.04–2.49). Thirty-nine (10.2%) patients infected with hMPV experienced life-threatening disease (LTD; 0.23 per 1000 children; 95% CI, .16–.31/1000), and 2 died (mortality rate 0.024 per 1000; 95% CI, .003–.086). In hMPV-infected children birth to an asthmatic mother was an increased risk for LTD (odds ratio, 4.72; 95% CI, 1.39–16.01). We observed a specific interaction between maternal asthma and hMPV infection affecting risk for LTD.

Conclusions

Maternal asthma increases the risk for LTD in children <2 years old hospitalized for severe hMPV LRTI.

A three-generation study on the association of tobacco smoking with asthma

Background

Mothers’ smoking during pregnancy increases asthma risk in their offspring. There is some evidence that grandmothers’ smoking may have a similar effect, and biological plausibility that fathers’ smoking during adolescence may influence offspring’s health through transmittable epigenetic changes in sperm precursor cells. We evaluated the three-generation associations of tobacco smoking with asthma.

Methods

Between 2010 and 2013, at the European Community Respiratory Health Survey III clinical interview, 2233 mothers and 1964 fathers from 26 centres reported whether their offspring (aged ≤51 years) had ever had asthma and whether it had coexisted with nasal allergies or not. Mothers and fathers also provided information on their parents’ (grandparents) and their own asthma, education and smoking history. Multilevel mediation models within a multicentre three-generation framework were fitted separately within the maternal (4666 offspring) and paternal (4192 offspring) lines.

Results

Fathers’ smoking before they were 15 [relative risk ratio (RRR) = 1.43, 95% confidence interval (CI): 1.01–2.01] and mothers’ smoking during pregnancy (RRR = 1.27, 95% CI: 1.01–1.59) were associated with asthma without nasal allergies in their offspring. Grandmothers’ smoking during pregnancy was associated with asthma in their daughters [odds ratio (OR) = 1.55, 95% CI: 1.17–2.06] and with asthma with nasal allergies in their grandchildren within the maternal line (RRR = 1.25, 95% CI: 1.02–1.55).

Conclusions

Fathers’ smoking during early adolescence and grandmothers’ and mothers’ smoking during pregnancy may independently increase asthma risk in offspring. Thus, risk factors for asthma should be sought in both parents and before conception.

Funding

European Union (Horizon 2020, GA-633212).

Mechanism for initiation of food allergy: Dependence on skin barrier mutations and environmental allergen costimulation

BACKGROUND

Mechanisms for the development of food allergy in neonates are unknown but clearly linked in patient populations to a genetic predisposition to skin barrier defects. Whether skin barrier defects contribute functionally to development of food allergy is unknown.

OBJECTIVE

The purpose of the study was to determine whether skin barrier mutations, which are primarily heterozygous in patient populations, contribute to the development of food allergy.

METHODS

Mice heterozygous for the filaggrin (Flg)ft and Tmem79ma mutations were skin sensitized with environmental and food allergens. After sensitization, mice received oral challenge with food allergen, and then inflammation, inflammatory mediators, and anaphylaxis were measured.

RESULTS

We define development of inflammation, inflammatory mediators, and food allergen-induced anaphylaxis in neonatal mice with skin barrier mutations after brief concurrent cutaneous exposure to food and environmental allergens. Moreover, neonates of allergic mothers have increased responses to suboptimal sensitization with food allergens. Importantly, responses to food allergens by these neonatal mice were dependent on genetic defects in skin barrier function and on exposure to environmental allergens. ST2 blockade during skin sensitization inhibited the development of anaphylaxis, antigen-specific IgE, and inflammatory mediators. Neonatal anaphylactic responses and antigen-specific IgE were also inhibited by oral pre-exposure to food allergen, but interestingly, this was blunted by concurrent pre-exposure of the skin to environmental allergen.

CONCLUSION

These studies uncover mechanisms for food allergy sensitization and anaphylaxis in neonatal mice that are consistent with features of human early-life exposures and genetics in patients with clinical food allergy and demonstrate that changes in barrier function drive development of anaphylaxis to food allergen.

Oxidative Stress: Harms and Benefits for Human Health

Oxidative stress is a phenomenon caused by an imbalance between production and accumulation of oxygen reactive species (ROS) in cells and tissues and the ability of a biological system to detoxify these reactive products. ROS can play, and in fact they do it, several physiological roles (i.e., cell signaling), and they are normally generated as by-products of oxygen metabolism; despite this, environmental stressors (i.e., UV, ionizing radiations, pollutants, and heavy metals) and xenobiotics (i.e., antiblastic drugs) contribute to greatly increase ROS production, therefore causing the imbalance that leads to cell and tissue damage (oxidative stress). Several antioxidants have been exploited in recent years for their actual or supposed beneficial effect against oxidative stress, such as vitamin E, flavonoids, and polyphenols. While we tend to describe oxidative stress just as harmful for human body, it is true as well that it is exploited as a therapeutic approach to treat clinical conditions such as cancer, with a certain degree of clinical success. In this review, we will describe the most recent findings in the oxidative stress field, highlighting both its bad and good sides for human health.

Vitamin E: Emerging aspects and new directions

The discovery of vitamin E will have its 100th anniversary in 2022, but we still have more questions than answers regarding the biological functions and the essentiality of vitamin E for human health. Discovered as a factor essential for rat fertility and soon after characterized for its properties of fat-soluble antioxidant, vitamin E was identified to have signaling and gene regulation effects in the 1980s. In the same years the cytochrome P-450 dependent metabolism of vitamin E was characterized and a first series of studies on short-chain carboxyethyl metabolites in the 1990s paved the way to the hypothesis of a biological role for this metabolism alternative to vitamin E catabolism. In the last decade other physiological metabolites of vitamin E have been identified, such as α-tocopheryl phosphate and the long-chain metabolites formed by the ω-hydroxylase activity of cytochrome P-450. Recent findings are consistent with gene regulation and homeostatic roles of these metabolites in different experimental models, such as inflammatory, neuronal and hepatic cells, and in vivo in animal models of acute inflammation. Molecular mechanisms underlying these responses are under investigation in several laboratories and side-glances to research on other fat soluble vitamins may help to move faster in this direction. Other emerging aspects presented in this review paper include novel insights on the mechanisms of reduction of the cardiovascular risk, immunomodulation and antiallergic effects, neuroprotection properties in models of glutamate excitotoxicity and spino-cerebellar damage, hepatoprotection and prevention of liver toxicity by different causes and even therapeutic applications in non-alcoholic steatohepatitis. We here discuss these topics with the aim of stimulating the interest of the scientific community and further research activities that may help to celebrate this anniversary of vitamin E with an in-depth knowledge of its action as vitamin.

γ-Tocopherol supplementation of allergic female mice augments development of CD11c+CD11b+ dendritic cells in utero and allergic inflammation in neonates

γ-Tocopherol increases responses to allergen challenge in allergic adult mice, but it is not known whether γ-tocopherol regulates the development of allergic disease. Development of allergic disease often occurs early in life. In clinical studies and animal models, offspring of allergic mothers have increased responsiveness to allergen challenge. Therefore, we determined whether γ-tocopherol augments development of allergic responses in offspring of allergic female mice. Allergic female mice were supplemented with γ-tocopherol starting at mating. The pups from allergic mothers developed allergic lung responses, whereas pups from saline-treated mothers did not respond to allergen challenge. The γ-tocopherol supplementation of allergic female mice increased the numbers of eosinophils twofold in the pup bronchoalveolar lavage and lungs after allergen challenge. There was also about a twofold increase in pup lung CD11b(+) subsets of CD11c(+) dendritic cells and in numbers of these dendritic cells expressing the transcription factor IRF4. There was no change in several CD11b(-) dendritic cell subsets. Furthermore, maternal supplementation with γ-tocopherol increased the number of fetal liver CD11b(+)CD11c(+) dendritic cells twofold in utero. In the pups, γ-tocopherol increased lung expression of the inflammatory mediators CCL11, amphiregulin, activin A, and IL-5. In conclusion, maternal supplementation with γ-tocopherol increased fetal development of subsets of dendritic cells that are critical for allergic responses and increased development of allergic responses in pups from allergic mothers. These results have implications for supplementation of allergic mothers with γ-tocopherol in prenatal vitamins.

Maternal influences over offspring allergic responses

Asthma occurs as a result of complex interactions of environmental and genetic factors. Clinical studies and animal models of asthma indicate offspring of allergic mothers have increased risk of development of allergies. Environmental factors including stress-induced corticosterone and vitamin E isoforms during pregnancy regulate the risk for offspring development of allergy. In this review, we discuss mechanisms for the development of allergic disease early in life, environmental factors that may impact the development of risk for allergic disease early in life, and how the variation in global prevalence of asthma may be explained, at least in part, by some environmental components.

Inter- and transgenerational epigenetic inheritance: evidence in asthma and COPD?

Evidence is now emerging that early life environment can have lifelong effects on metabolic, cardiovascular, and pulmonary function in offspring, a concept also known as fetal or developmental programming. In mammals, developmental programming is thought to occur mainly via epigenetic mechanisms, which include DNA methylation, histone modifications, and expression of non-coding RNAs. The effects of developmental programming can be induced by the intrauterine environment, leading to intergenerational epigenetic effects from one generation to the next. Transgenerational epigenetic inheritance may be considered when developmental programming is transmitted across generations that were not exposed to the initial environment which triggered the change. So far, inter- and transgenerational programming has been mainly described for cardiovascular and metabolic disease risk. In this review, we discuss available evidence that epigenetic inheritance also occurs in respiratory diseases, using asthma and chronic obstructive pulmonary disease (COPD) as examples. While multiple epidemiological as well as animal studies demonstrate effects of 'toxic' intrauterine exposure on various asthma-related phenotypes in the offspring, only few studies link epigenetic marks to the observed phenotypes. As epigenetic marks may distinguish individuals most at risk of later disease at early age, it will enable early intervention strategies to reduce such risks. To achieve this goal further, well designed experimental and human studies are needed.

Supplementation of Mice with Specific Nondigestible Oligosaccharides during Pregnancy or Lactation Leads to Diminished Sensitization and Allergy in the Female Offspring

BACKGROUND

The maternal environment and early life exposure affect immune development in offspring.

OBJECTIVE

We investigated whether development of food allergy in offspring is affected by supplementing pregnant or lactating sensitized or nonsensitized mice with a mixture of nondigestible oligosaccharides.

METHODS

Dams were sensitized intragastrically with ovalbumin before mating, with use of cholera toxin (CT) as an adjuvant. Nonsensitized dams received CT only. Dams were fed a control diet or a diet supplemented with short-chain galacto oligosaccharides (scGOSs), long-chain fructo oligosaccharides (lcFOSs), and pectin-derived acidic oligosaccharides (pAOSs) in a ratio of 9:1:2 at a dose of 2% during pregnancy or lactation, resulting in 7 experimental groups. After weaning, offspring were fed a control diet and ovalbumin-CT sensitized. Acute allergic skin responses (ASRs), shock symptoms, body temperature, and specific plasma immunoglobulins were measured upon intradermal ovalbumin challenge. Th2/Th1- and regulatory T cells were analyzed with use of quantitative polymerase chain reaction and flow cytometric analysis in spleen, mesenteric lymph nodes, and blood.

RESULTS

Supplementing sensitized pregnant or lactating dams with scGOS/lcFOS/pAOS resulted in lower ASRs in the offspring [offspring of sensitized female mice fed experimental diet during pregnancy (S-Preg): 48 ± 2.1 μm; offspring of sensitized female mice fed experimental diet during lactation (S-Lact): 60 ± 6.2 μm] compared with the sensitized control group (119 ± 13.9 μm). In the S-Lact group, this coincided with an absence of shock symptoms compared with the offspring of sensitized female mice fed control food during pregnancy and lactation (S-Con) and S-Preg groups, and lower ovalbumin-IgG1 [S-Con: 3.8 ± 0.1 arbitrary units (AUs); S-Preg: 3.3 ± 0.1 AUs; S-Lact: 2.4 ± 0.1 AUs] and higher ovalbumin-IgG2a concentrations (S-Con: 1.1 ± 0.1 AUs; S-Preg: 0.8 ± 0.1 AUs; S-Lact: 2.0 ± 0.1 AUs). Supplementing nonsensitized pregnant or lactating dams with scGOS/lcFOS/pAOS resulted in lower plasma ovalbumin-IgE [offspring of nonsensitized female mice fed experimental diet during pregnancy (NS-Preg): 1.6 ± 0.4 AUs; offspring of nonsensitized female mice fed experimental diet during lactation (NS-Lact): 0.3 ± 0.1 AUs vs. offspring of nonsensitized female mice fed control food during pregnancy and lactation (NS-Con): 3.1 ± 0.6 AUs] and ovalbumin-IgG1 (NS-Lact: 2.3 ± 0.3 AUs vs. NS-Con: 3.4 ± 0.3 AUs) concentrations in offspring. Ovalbumin-IgG2a plasma concentrations were higher in offspring of scGOS/lcFOS/pAOS-supplemented dams (NS-Preg: 1.1 ± 0.1 AUs; NS-Lact: 1.1 ± 0.1 AUs) than in those of unsupplemented, nonsensitized controls (0.4 ± 0.0 AUs).

CONCLUSIONS

These data show impaired sensitization in offspring of scGOS/lcFOS/pAOS-supplemented mice. A number of the analyzed variables are differentially affected by whether supplementation occurs during pregnancy or lactation, and the outcome of dietary supplementation is affected by whether the mother has been sensitized to ovalbumin and CT.

Maternal Antiasthma Simplified Herbal Medicine Intervention therapy prevents airway inflammation and modulates pulmonary innate immune responses in young offspring mice

BACKGROUND

Maternal asthma is a risk factor for asthma in offspring; however, transmission of the risk for allergic asthma without direct offspring sensitization has not been explored.

OBJECTIVE

To determine whether offspring from mothers with ovalbumin (OVA)-sensitized asthma would develop airway disease at first-ever exposure to OVA and whether preconception maternal treatment with the Antiasthma Simplified Herbal Medicine Intervention (ASHMI) or dexamethasone (DEX) could modify this risk in offspring.

METHODS

Female BALB/c mice (F0) with OVA-induced asthma were generated using established protocols. Mice with asthma were treated with ASHMI, DEX, or water for 6 to 7 weeks. Naive mice served as controls. Subsequently, mice were mated. Twelve-day-old F1 offspring received 3 consecutive intranasal low- or high-dose OVA exposures without sensitization. Forty-eight hours later, airway inflammation, mucus hypersecretion, serum antibodies, and cytokines were evaluated.

RESULTS

Offspring from OVA-sensitized mothers, but not naive mothers, showed eosinophilic and neutrophilic airway inflammation, and mucus hyperplasia after OVA exposure and he presence of OVA-specific IgG1 and IgG2a. Offspring of ASHMI- and DEX-treated mothers showed decreased airway inflammation and mucus hypersecretion after low-dose OVA (P < .05-.001 for the 2 comparisons vs offspring of OVA/Sham mothers). Offspring of ASHMI-treated, but not DEX-treated, mothers were protected after the high-dose OVA challenge (P < .05-.01 vs offspring OVA/Sham). Maternal ASHMI therapy was associated with increased IgG2a (P < .01 vs offspring of OVA/Sham mothers) and decreased bronchoalveolar lavage fluid CXCL-1 and eotaxin-1 levels (P < .01 and P < .05, respectively, vs offspring of OVA/Sham mothers).

CONCLUSION

Offspring of mothers with OVA-induced asthma developed airway inflammation and mucus to first-ever OVA exposure without prior sensitization. Maternal therapy with ASHMI was superior to DEX in decreasing offspring susceptibility to airway disease and could be a strategy to lower asthma prevalence.

The interaction between mother and fetus and the development of allergic asthma

The rising prevalence of asthma and atopic disease in industrialized countries in the last 50 years has raised important questions about how and why the disease develops in susceptible populations. Most asthma begins in childhood in association with allergic sensitization and the development of a TH2 phenotype. It is recognized that asthma arises in the context of a complex interaction between genetic factors and the evolving immune system of the infant and the environment to which it is exposed, which now includes its in utero exposure. Early life exposures that lead to allergen sensitization and airway damage, especially in the form of viral respiratory tract infections, may lead to disease induction that commence the process that leads in some to asthma. Asthma models and early life observations suggest that repeated exposure to allergens and viral infection perpetuate a state of chronic airway inflammation leading to a maladaptive innate immune response that fails to resolve, characterized by chronic airway inflammation, airway remodeling and airway hyperresponsiveness. This article will concentrate on the development of asthma in the context of early life and maternal influences, including the effect of asthma on both the fetus and the mother.

α-Tocopherol supplementation of allergic female mice inhibits development of CD11c+CD11b+ dendritic cells in utero and allergic inflammation in neonates

α-Tocopherol blocks responses to allergen challenge in allergic adult mice, but it is not known whether α-tocopherol regulates the development of allergic disease. Development of allergic disease often occurs early in life. In clinical studies and animal models, offspring of allergic mothers have increased responsiveness to allergen challenge. Therefore, we determined whether α-tocopherol blocked development of allergic responses in offspring of allergic female mice. Allergic female mice were supplemented with α-tocopherol starting at mating. The pups from allergic mothers developed allergic lung responses, whereas pups from saline-treated mothers did not respond to the allergen challenge, and α-tocopherol supplementation of allergic female mice resulted in a dose-dependent reduction in eosinophils in the pup bronchoalveolar lavage and lungs after allergen challenge. There was also a reduction in pup lung CD11b(+) dendritic cell subsets that are critical to development of allergic responses, but there was no change in several CD11b(-) dendritic cell subsets. Furthermore, maternal supplementation with α-tocopherol reduced the number of fetal liver CD11b(+) dendritic cells in utero. In the pups, there was reduced allergen-induced lung mRNA expression of IL-4, IL-33, TSLP, CCL11, and CCL24. Cross-fostering pups at the time of birth demonstrated that α-tocopherol had a regulatory function in utero. In conclusion, maternal supplementation with α-tocopherol reduced fetal development of subsets of dendritic cells that are critical for allergic responses and reduced development of allergic responses in pups from allergic mothers. These results have implications for supplementation of allergic mothers with α-tocopherol.

Prenatal adverse life events increase the risk for atopic diseases in children, which is enhanced in the absence of a maternal atopic predisposition

BACKGROUND

There is evidence to suggest an association between prenatal maternal stress and the development of asthma or other atopic diseases in offspring. Yet, insights on the lasting effect of multiple, common prenatal stressors are rare, and the effects of prenatal timing are poorly understood. Further, it remains elusive if prenatal life events modify the risk for atopic diseases in the context of a parental predisposition to atopy.

OBJECTIVE

We tested whether women's experiences of common, adverse life events during the first or second half of pregnancy predicted the risk of developing atopic diseases in their children and whether a reported parental atopic disease moderated this association.

METHODS

We calculated the odds of a child developing asthma, eczema, and/or allergic rhinitis at ages 6 or 14 years, depending on maternal prenatal exposure to negative life events in a sample of 1587 children from the Western Australian Pregnancy Cohort (Raine) Study by using multivariable logistic regression.

RESULTS

We observed that the likelihood of asthma and eczema at age 14 years was significantly increased in children of mothers who had experienced adverse life events during the second half of gestation (1 life event: adjusted odds ratio for asthma, 2.08 [95% CI, 1.22-3.54]). A stronger increase in the odds to develop asthma upon prenatal life events was present in children of mothers without asthma compared with mothers with asthma.

CONCLUSIONS

Maternal adverse life events during the second half of gestation are linked to an increased risk for the development of atopic disorders, asthma, and eczema, in the case of asthma, particularly in the absence of a maternal asthma.

Pre- and perinatal characteristics and breast milk immune markers

BACKGROUND

Maternal allergy and gestational exposures can alter the concentration of type-1/type-2/T-regulatory markers in breast milk. We tested whether maternal risk factors are related to breast milk immune markers.

METHODS

Expecting mothers were enrolled in 2008-2010 in South Carolina in prenatal clinics and classes. Interferon (IFN)-γ-induced protein 10 (CXCL10), CCL11, interleukin (IL)-1β, IL-4, IL-5, IL-6, CXCL8, IL-10, IL-12(p70), IL-13, transforming growth factor (TGF)-β1, and immunoglobulin (Ig)A in 115 whey samples were measured by immunoassays. Maternal asthma, eczema, rhinitis, smoking, urogenital infections during gestation, pet exposure, education, race/ethnicity, age, body mass, and the child's birth date and sex were ascertained. The effects of these risk factors on immune markers were estimated using general linear models.

RESULTS

Maternal asthma was linked to higher levels of IL-5, rhinitis to lower levels of IL-5 and INF-γ, and eczema to lower levels of IL-6. Gestational smoking was related to increased concentrations of CXCL8 and IL-6. African-American mothers had markedly higher levels of IL-6, IFN-γ, and CXCL8. Urogenital infections, maternal age, body mass, child's sex, and season of birth contributed to the variation.

CONCLUSION

The impact of maternal allergies on immune markers in breast milk was small compared with that of maternal nondisease characteristics.

Perinatal factors in neonatal and pediatric lung diseases

Wheezing and asthma are significant clinical problems for infants and young children, particularly following premature birth. Recurrent wheezing in infants can progress to persistent asthma. As in adults, altered airway structure (remodeling) and function (increased bronchoconstriction) are also important in neonatal and pediatric airway diseases. Accumulating evidence suggests that airway disease in children is influenced by perinatal factors including perturbations in normal fetal lung development, postnatal interventions in the intensive care unit (ICU) and environmental and other insults in the neonatal period. Here, in addition to genetics, maternal health, environmental processes, innate immunity and impaired lung development/function can all influence pathogenesis of airway disease in children. We summarize current understanding of how prenatal and postnatal factors can contribute to development of airway diseases in neonates and children. Understanding these mechanisms will help identify and develop novel therapies for childhood airway diseases.

Offspring IgE responses are influenced by levels of maternal IgG transferred in early life

PROBLEM

Maternal immune responses may interfere with offspring allergy development as maternal immunization may suppress IgE development, while maternal allergy may promote allergy. Therefore, we investigated the effect of two different maternal treatments on airway allergy in female and male offspring.

METHOD OF STUDY

Pregnant mice were immunized (IMM) with ovalbumin (OVA) or immunized and airway-challenged (IMM+AI). At different ages, airway allergy to OVA was induced in offspring by intranasal sensitization.

RESULTS

Maternal IgG1 was found at higher levels in IMM+AI than in IMM offspring. After sensitization, the suppression of OVA-specific IgE and IgG1 was complete in juvenile offspring but waned with age concurrently with maternal IgG1 levels. Cytokine secretion, lung inflammation, and B cell priming were not suppressed although IgE responses were.

CONCLUSIONS

High compared with low levels of maternal IgG1 were associated with lower TH 2 antibody production after adult offspring were re-exposed to OVA. Thus, offspring allergy-related responses appeared to be shaped by maternal antibody levels.

Asthma phenotyping, therapy, and prevention: what can we learn from systems biology?

Asthma has a high prevalence worldwide, and contributes significantly to the socioeconomic burden. According to a classical paradigm, asthma symptoms are attributable to an allergic, Th2-driven airway inflammation that causes airway hyperresponsiveness and results in reversible airway obstruction. Diagnosis and therapy are based mainly on these pathophysiologic concepts. However, these have increasingly been challenged by findings of recent studies, and the frequently observed failure in controlling asthma symptoms. Important recent findings are the protective "farm effect" in children, the possible prenatal mechanisms of this protection, the recognition of many different asthma phenotypes in children and adults, and the partly disappointing clinical effects of new targeted therapeutic approaches. Systems biology approaches may lead to a more comprehensive view of asthma pathophysiology and a higher success rate of new therapies. Systems biology integrates clinical and experimental data by means of bioinformatics and mathematical modeling. In general, the "-omics" approach, and the "mathematical modeling" approach can be described. Recently, several consortia have been attempting to bring together clinical and molecular data from large asthma cohorts, using novel experimental setups, biostatistics, bioinformatics, and mathematical modeling. This "systems medicine" approach to asthma will help address the different asthma phenotypes with adequate therapy and possibly preventive strategies.

Suppression of allergen-specific IgE in offspring after preconceptional immunisation: maternal, paternal and genetic influences

Immunisation of female mice with the allergen ovalbumin (OVA) during pregnancy reduces the OVA-specific IgE response in adult offspring. To approach primary prevention strategies for allergy, we investigated to what extent genetic, paternal and maternal factors influence this suppressive effect on allergic sensitisation in offspring and investigated the possibility of pregestational immunisation. Maternal allergen immunisation reduced OVA-specific IgE levels in immunised offspring, even after maternal immunisation up to 8 weeks before conception without further allergen exposure. Immunisation of immunodeficient BALB/c severe combined immune deficiency (SCID) dams mated with wild type males did not lead to IgE suppression in offspring, indicating the importance of a functional maternal immune system. Immunisation of male mice before the relevant spermatogenesis did not cause antibody suppression in offspring. OVA-specific IgG1, presumably of maternal origin, was present in naïve offspring only from immunised dams and was associated with suppressed IgE responses after offspring immunisation. The IgE-suppressive effect of maternal immunisation was demonstrated in all three immunocompetent strains tested (NIH/OlaHsd, BALB/cA and C57BL/6 mice). In conclusion, suppression of allergen-specific IgE production in offspring could not be induced by paternal immunisation, and genetic factors were of minor importance. In contrast, we demonstrate the necessity of maternal factors, possibly allergen-specific IgG1, resulting from a functional adaptive immune response, for the IgE-suppressive effect in offspring. These maternal factors could be induced by immunisation of female mice even before conception.

A life course model of self-rated health through adolescence and young adulthood

This paper proposes and tests a life course model of self-rated health (SRH) extending from late childhood to young adulthood, drawing on three waves of panel data from the National Longitudinal Study of Adolescent Health (Add Health). Very little research has examined SRH during the early decades, or whether and how these self-assessments reflect experiences in the family of origin. Background characteristics (parental education, income, and family structure), parental health conditions (asthma, diabetes, obesity, migraines), and early health challenges (physical abuse, presence of a disability, and parental alcoholism and smoking) predict SRH from adolescence to young adulthood. These experiences in the family-of-origin are substantially mediated by the young person's health and health behaviors (as indicated by obesity, depression, smoking, drinking, and inactivity), although direct effects remain (especially for early health challenges). Associations between SRH and these mediators (especially obesity) strengthen with age. In turn, efforts to promote healthy behaviors in young adulthood, after the completion of secondary school, may be especially strategic in the promotion of health in later adulthood.

Prenatal and postnatal maternal stress and wheeze in urban children: effect of maternal sensitization

RATIONALE

Critical periods for programming early wheeze risk may include pregnancy and infancy. Effects of timing remain poorly understood.

OBJECTIVES

Associations among prenatal and postnatal maternal stress and children's wheeze were prospectively examined in 653 families. Effect modification by maternal sensitization was also examined.

METHODS

Stress was indexed by a maternal negative life events (NLEs) score (range, 0-9) ascertained during pregnancy and between 1 and 2 years postpartum. Mothers reported child wheeze every 3 months up to age 2 years. Relationships of prenatal and postnatal maternal NLEs with repeated wheeze (≥2 episodes) were examined using logistic regression adjusting for covariates. Penalized splines were implemented to explore possible nonlinear associations. We also examined the interaction between prenatal stress and maternal sensitization indexed by allergen-specific IgE from maternal prenatal serum.

MEASUREMENTS AND MAIN RESULTS

Adjusted models considering prenatal or postnatal NLEs alone both showed an exposure-response relationship between higher stress and child wheeze. When considering prenatal and postnatal stress concurrently, only children of mothers with high stress in both periods were significantly more likely to wheeze (adjusted odds ratio, 3.04; 95% confidence interval, 1.67-5.53) than children of mothers reporting low stress in both periods. Associations between high prenatal stress and wheeze were significant in children born to nonsensitized mothers (any IgE <0.35 kU/L) but not in the sensitized group (P for interaction = 0.03).

CONCLUSIONS

Although children have heightened sensitivity to maternal stress in utero and in early childhood, those with higher stress in both periods were particularly at risk for wheeze. The prenatal maternal immune milieu modified effects.

Particular characteristics of allergic symptoms in tropical environments: follow up to 24 months in the FRAAT birth cohort study

Background

Early wheezing and asthma are relevant health problems in the tropics. Mite sensitization is an important risk factor, but the roles of others, inherent in poverty, are unknown. We designed a birth-cohort study in Cartagena (Colombia) to investigate genetic and environmental risk factors for asthma and atopy, considering as particular features perennial exposure to mites, parasite infections and poor living conditions.

Methods

Pregnant women representative of the low-income suburbs of the city were randomly screened for eligibility at delivery; 326 mother-infant pairs were included at baseline and biological samples were collected from birth to 24 months for immunological testing, molecular genetics and gene expression analysis. Pre and post-natal information was collected using questionnaires.

Results

94% of families were from the poorest communes of the city, 40% lacked sewage and 11% tap-water. Intestinal parasites were found as early as 3 months; by the second year, 37.9% of children have had parasites and 5.22% detectable eggs of Ascaris lumbricoides in stools (Median 3458 epg, IQR 975-9256). The prevalence of "wheezing ever" was 17.5% at 6 months, 31.1% at 12 months and 38.3% at 24 months; and recurrent wheezing (3 or more episodes) 7.1% at 12 months and 14.2% at 24 months. Maternal rhinitis [aOR 3.03 (95%CI 1.60-5.74), p = 0.001] and male gender [aOR 2.09 (95%CI 1.09 - 4.01), p = 0.026], increased risk for wheezing at 6 months. At 24 months, maternal asthma was the main predisposing factor for wheezing [aOR 3.65 (95%CI 1.23-10.8), p = 0.01]. Clinical symptoms of milk/egg allergy or other food-induced allergies were scarce (1.8%) and no case of atopic eczema was observed.

Conclusions

Wheezing is the most frequent phenotype during the first 24 months of life and is strongly associated with maternal asthma. At 24 months, the natural history of allergic symptoms is different to the "atopic march" described in some industrialized countries. This cohort is representative of socially deprived urban areas of underdeveloped tropical countries. The collection of biological samples, data on exposure and defined phenotypes, will contribute to understand the gene/environment interactions leading to allergy inception and evolution.

Paternal heredity and housing characteristics affect childhood asthma and allergy morbidity

A birth cohort was initiated when each pregnant woman was asked for her own and her husband's history of asthma and allergic diseases at the time of recruitment. They were further inquired to verify their housing conditions, and current health status of children 3 to 5 years old at the time of interview. Paternal history was the most significant risk factor associated with reporting childhood morbidities at age of 3 to 5 years. Housing characteristics became meaningful variables only if the fathers were asthmatic or atopic. A 9-fold increase of risk was found if children with paternal history and also exposed to incense burning and water damage at home. This is the first epidemiological evidence of East Asia suggesting paternal heredity, with concurrent indoor hazardous exposures, as a predominant risk on developing childhood asthma and allergy.

Mitochondrial genetic background plays a role in increasing risk to asthma

A number of studies suggest that mitochondrial dysfunction plays a role in the pathogenesis of asthma. To shed light for the first time on the role of the mitochondrial genome in the etiology of asthma we analyzed the mitochondrial tRNA genes and part of their flanking regions in patients with asthma compared with a set of healthy controls. We found a total of 10 mutations in 56 out of 76 asthmatic patients. Four of these mutations were not found in the control group, five were observed at a significantly lower frequency in controls, but none of the combinations of mutations detected in asthma patients was observed in the controls. Furthermore, we observed that 27.6% of the asthma patients (vs. 4% of the controls) belonged to the haplogroup U (Fisher test P = 0.00) and a positive significant correlation was found between the occurrence of the haplogroup U and the severity of the disease (Fisher test P = 0.02). Whereas further studies in larger cohorts are needed to confirm these observations we suggest that the mitochondrial genetic background plays a key role in asthma development.

Maternal allergy acts synergistically with cigarette smoke exposure during pregnancy to induce hepatic fibrosis in adult male offspring

Maternal environmental exposures during pregnancy are known to affect disease onset in adult offspring. For example, maternal asthma exacerbations during pregnancy can worsen adult asthma in the offspring. Cigarette smoking during pregnancy is associated with future onset of cardiovascular disease, obesity and diabetes. However, little is known about the effect of maternal environmental exposures on offspring susceptibility to liver disease. This pilot study examined the long-term effect of maternal allergen challenge and/or cigarette smoking during pregnancy on hepatic inflammation and fibrosis in adult mouse offspring. Ovalbumin (OVA) or phosphate-buffered saline (PBS)-sensitized/challenged CD-1 dams were exposed to mainstream cigarette smoke (MCS) or filtered air from gestational day 4 until parturition. Eight weeks postnatally, offspring were sacrificed for comparison of hepatic histology and mRNA expression. Adult male offspring of OVA-sensitized/challenged dams exposed to MCS (OSM) displayed significantly increased liver fibrosis (9.2% collagen content vs. <4% for all other treatment groups). These mice also had 1.8-fold greater collagen 1A1 mRNA levels. From the results here, we concluded that maternal allergen challenge in combination with cigarette smoke exposure during pregnancy may be an important risk factor for liver disease in adult male offspring.

The role of epigenetics in the developmental origins of allergic disease

OBJECTIVE

To review current research findings in the field of epigenetics pertaining to the developmental origins of allergic disease.

DATA SOURCES

We examined original research and review articles identified from MEDLINE, OVID, and PubMed that addressed the topic of interest, using the search terms atopy, allergy, asthma, development, IgE, origins, and cord blood paired with epigenetic(s). Relevant references from each article were also procured for review.

STUDY SELECTION

Articles were selected based on their relevance to the contributory role of epigenetic modifications in asthma and other atopic diseases.

RESULTS

There is increasing evidence pointing to the influence of prenatal and early life exposures on the development of allergic disease. A growing body of literature supports the theory that transient environmental pressures can have permanent effects on gene regulation and expression through epigenetic mechanisms. Histone modifications have been associated with degree of bronchial hyperresponsiveness and corticosteroid resistance in asthma. Epigenetic mechanisms can operate independently in various cell types; recent studies have suggested a role in the differentiation of human T cells. Murine studies have revealed that a maternal diet rich in methyl donors can enhance susceptibility to allergic inflammation in the offspring, mediated through increased DNA methylation. Murine studies have also implicated epigenetically modified dendritic cells in the transmission of allergic risk from mothers to offspring.

CONCLUSION

The current literature offers exciting data to support a role for epigenetics in the development and persistence of asthma and allergic rhinitis. However, further human studies are necessary to explore these mechanisms and assess future clinical applicability.

Risk for asthma in offspring of asthmatic mothers versus fathers: a meta-analysis

BACKGROUND

Many human epidemiologic studies demonstrate that maternal asthma confers greater risk of asthma to offspring than does paternal disease. However, a handful have shown the opposite. Given this disparity, a meta-analysis is necessary to determine the veracity and magnitude of the "maternal effect."

METHODOLOGY/PRINCIPAL FINDINGS

We screened the medical literature from 1966 to 2009 and performed a meta-analysis to compare the effect of maternal asthma vs. paternal asthma on offspring asthma susceptibility. Aggregating data from 33 studies, the odds ratio for asthma in children of asthmatic mothers compared with non-asthmatic mothers was significantly increased at 3.04 (95% confidence interval: 2.59-3.56). The corresponding odds ratio for asthma in children of asthmatic fathers was increased at 2.44 (2.14-2.79). When comparing the odds ratios, maternal asthma conferred greater risk of disease than did paternal asthma (3.04 vs. 2.44, p = 0.037). When analyzing the studies in which asthma was diagnosed by a physician the odds ratios were attenuated and no significant differences were observed (2.85 vs. 2.48, N = 18, p = 0.37). Similarly, no significant differences were observed between maternal and paternal odds ratios when analyzing the studies in which the patient population was 5 years or older (3.15 vs. 2.60, p = 0.14). However, in all cases the trend remained the same, that maternal asthma was a greater risk factor for asthma than paternal.

CONCLUSIONS/SIGNIFICANCE

The results show that maternal asthma increases offspring disease risk to a greater extent than paternal disease.

Maternal allergen immunisation to prevent sensitisation in offspring: Th2-polarising adjuvants are more efficient than a Th1-polarising adjuvant in mice

Background

Allergy has been an increasing problem in several parts of the world. Prenatal exposure to allergen and microbial components may affect the development of allergies in childhood, as indicated by epidemiological and experimental studies. We investigated the capacity for allergic sensitisation in offspring after induction of a Th1- or a Th2-polarised immune response to the same allergen in mothers during pregnancy.

Results

During pregnancy, mice were immunised with ovalbumin (OVA) given with either one of the Th2-adjuvants pertussis toxin (PT) or Al(OH)₃ (aluminium hydroxide), or with the Th1 adjuvant CpG. Offspring were immunised with OVA in Al(OH)₃ as young adults. Serum and supernatants from ex vivo stimulated or non-stimulated spleen cells from mothers and offspring were analysed for OVA-specific antibodies and cytokines, respectively. Mothers immunised with OVA together with either Al(OH)₃ or PT had increased levels of OVA-specific IgE and IgG1 compared to naive mothers, whereas mothers immunised with OVA together with CpG had increased levels of OVA-specific IgG2a compared to naive mothers. In general the highest levels of IL-5, IL-10, and IFNγ were observed in spleen cells from mothers immunised with PT and OVA. Upon immunisation, offspring from mothers immunised with OVA and either PT or Al(OH)₃ showed reduced levels of OVA-specific IgE and IgG1 and increased levels of OVA-specific IgG2a antibodies compared to offspring from naive mothers. Maternal immunisation with CpG and OVA did not affect antibody responses in offspring.

Conclusion

Allergic sensitisation in the offspring was affected by the type of adjuvant used for immunisation of the mothers with the same allergen. Th2 polarisation of the immune response in the mothers was found to give reduced IgE levels upon sensitisation of the offspring, whereas no reduction was achieved with Th1 polarisation in the mothers.

Maternal exposure to particulate matter increases postnatal ozone-induced airway hyperreactivity in juvenile mice

RATIONALE

Epidemiologic studies implicate air pollutant exposure during pregnancy as a risk factor for wheezing in offspring. Ozone exposure is linked to exacerbations of wheezing in children.

OBJECTIVES

To determine if maternal pulmonary exposure to traffic-related particles during pregnancy augments ozone-induced airway hyperresponsiveness in offspring.

METHODS

C57BL6 time-mated mice were given NIST SRM#1648 (particulate matter [PM]) 0.48 mg, saline vehicle, or no treatment by tracheal insufflation twice weekly for 3 weeks. PM exposure augmented maternal lung inflammation and placental TNF-alpha, Keratinocyte-derived cytokine (KC), and IL-6 (measured at gestation Day 18). After parturition, dams and litters were exposed to air or ozone 1 ppm 3 h/d, every other day, thrice weekly for 4 weeks. Respiratory system resistance in pups was measured at baseline and after administration of nebulized methacholine.

MEASUREMENTS AND MAIN RESULTS

Ozone increased airway hyperresponsiveness, but the increase was greatest in pups born to PM-treated dams. Whole-lung TNF-alpha, IL-1beta, KC, IL-6, and MCP-1 were increased in ozone-treated pups, with the greatest increase in pups born to dams given PM. Airway epithelial mucous metaplasia estimated by periodic acid-Schiff Alcian blue staining was increased in ozone-exposed pups born to PM-treated dams. Alveolar development, determined by morphometry, and airway smooth muscle bulk, estimated using alpha-actin histochemistry, were unaffected by prenatal or postnatal treatment.

CONCLUSIONS

Maternal pulmonary exposure to PM during pregnancy augments placental cytokine expression and postnatal ozone-induced pulmonary inflammatory cytokine responses and ozone-induced airway hyperresponsiveness without altering airway structure.

Soothing signals: transplacental transmission of resistance to asthma and allergy

The progressive rise in the prevalence of allergic diseases since the 1970s is widely attributed to diminished exposure to microbial stimuli, resulting in dysregulated immune functions during early life. Most studies investigating the mechanism behind this phenomenon have focused on postnatal microbial exposure. But emerging evidence suggests that such programming may also occur in the developing fetus as a result of microbial stimulation of the pregnant mother.

Maternal peanut exposure during pregnancy and lactation reduces peanut allergy risk in offspring

BACKGROUND

Maternal allergy is believed to be a risk factor for peanut allergy (PNA) in children. However, there is no direct evidence of maternal transmission of PNA susceptibility, and it is unknown whether maternal peanut exposure affects the development of PNA in offspring.

OBJECTIVE

To investigate the influence of maternal PNA on offspring reactions to the first peanut exposure, and whether maternal low-dose peanut exposure during pregnancy and lactation influences these reactions and peanut sensitization in a murine model.

METHODS

Five-week-old offspring of PNA C3H/HeJ mothers (PNA-Ms) were challenged intragastrically with peanut (first exposure), and reactions were determined. In a subset of the experiment, PNA-Ms were fed a low dose of peanut (PNA-M/PN) or not fed peanut (PNA-M/none) during pregnancy and lactation. Their 5-week-old offspring were challenged intragastrically with peanut, and reactions were determined. In another subset of the experiment, offspring of PNA-M/PN or PNA-M/none were sensitized with peanut intragastrically for 6 weeks, and serum peanut-specific antibodies were determined.

RESULTS

PNA-M offspring exhibited anaphylactic reactions at first exposure to peanut that were associated with peanut-specific IgG(1) levels and prevented by a platelet activation factor antagonist. In a subset experiment, PNA-M/PN offspring showed significantly reduced first-exposure peanut reactions, increased IgG(2a), and reduced mitogen-stimulated splenocyte cytokine production compared with PNA-M/none offspring. In an additional experiment, PNA-M/PN offspring showed reduction of peanut-specific IgE to active peanut sensitization.

CONCLUSION

We show for the first time maternal transmission of susceptibility to first-exposure peanut reactions and active peanut sensitization. Low-dose peanut exposure during pregnancy and lactation reduced this risk.