Prenatal origins of allergic disease

Childhood atopic disorders in relation to placental changes-A systematic review and meta-analysis

Fetal programming may arise from prenatal exposure and increase the risk of diseases later in life, potentially mediated by the placenta. The objective of this systematic review was to summarize and critically evaluate publications describing associations between human placental changes and risk of atopic disorders during childhood. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The inclusion criteria were original research articles or case reports written in English describing a human placental change in relation to disease occurring in offspring during childhood. The MEDLINE and EMBASE databases were searched for eligible studies. Risk of bias (RoB) was assessed using the ROBINS-I tool. The results were pooled both in a narrative way and by a meta-analysis. Nineteen studies were included (n = 12,997 participants). All studies had an overall serious RoB, and publication bias could not be completely ruled out. However, five studies showed that histological chorioamnionitis in preterm-born children was associated with asthma-related problems (pooled odds ratio = 3.25 (95% confidence interval = 2.22-4.75)). In term-born children, a large placenta (≥750 g) increased the risk of being prescribed anti-asthma medications during the first year of life. Placental histone acetylation, DNA methylation, and gene expression differences were found to be associated with different atopic disorders in term-born children. There is some evidence supporting the idea that the placenta can mediate an increased risk of atopic disorders in children. However, further studies are needed to validate the findings, properly control for confounders, and examine potential mechanisms.

Association between maternal gestational diabetes and allergic diseases in offspring: a birth cohort study

BACKGROUND

Previous studies have linked gestational diabetes (GDM) with allergies in offspring. However, the effect of specific glucose metabolism metrics was not well characterized, and the role of polyunsaturated fatty acids (PUFAs), a modifier of metabolism and the immune system, was understudied. We aimed to investigate the association between maternal GDM and allergic diseases in children and the interaction between glucose metabolism and PUFAs on allergic outcomes.

METHODS

This prospective cohort study included 706 mother-child dyads from Guangzhou, China. Maternal GDM was diagnosed via a 75-g oral glucose tolerance test (OGTT), and dietary PUFAs were assessed using a validated food frequency questionnaire. Allergic disease diagnoses and the age of onset were obtained from medical records of children within three years old.

RESULTS

Approximately 19.4% of women had GDM, and 51.3% of children had any allergic diseases. GDM was positively associated with any allergic diseases (hazard ratio [HR] 1.40; 95% confidence interval (CI) 1.05-1.88) and eczema (HR 1.44; 95% CI 1.02-1.97). A unit increase in OGTT after two hours (OGTT-2 h) glucose was associated with an 11% (95% CI 2%-21%) higher risk of any allergic diseases and a 17% (95% CI 1-36%) higher risk of food allergy. The positive associations between OGTT-2 h glucose and any allergic diseases were strengthened with decreased dietary a-linolenic acid (ALA) and increased n-6 PUFAs, linoleic acid (LA), LA/ALA ratio, and n-6/n-3 PUFA ratio.

CONCLUSIONS

Maternal GDM was adversely associated with early-life allergic diseases, especially eczema. We were the first to identify OGTT-2 h glucose to be more sensitive in inducing allergy risk and that dietary PUFAs might modify the associations.

Identifying sensitive windows of prenatal household air pollution on birth weight and infant pneumonia risk to inform future interventions

BACKGROUND

Prenatal household air pollution impairs birth weight and increases pneumonia risk however time-varying associations have not been elucidated and may have implications for the timing of public health interventions.

METHODS

The Ghana Randomized Air Pollution and Health Study (GRAPHS) enrolled 1,414 pregnant women from Kintampo, Ghana and measured personal carbon monoxide (CO) exposure four times over pregnancy. Birth weight was measured within 72-hours of birth. Fieldworkers performed weekly pneumonia surveillance and referred sick children to study physicians. The primary pneumonia outcome was one or more physician-diagnosed severe pneumonia episode in the first year of life. We employed reverse distributed lag models to examine time-varying associations between prenatal CO exposure and birth weight and infant pneumonia risk.

RESULTS

Analyses included n = 1,196 mother-infant pairs. In models adjusting for child sex; maternal age, body mass index (BMI), ethnicity and parity at enrollment; household wealth index; number of antenatal visits; and evidence of placental malaria, prenatal CO exposures from 15 to 20 weeks gestation were inversely associated with birth weight. Sex-stratified models identified a similar sensitive window in males and a window at 10-weeks gestation in females. In models adjusting for child sex, maternal age, BMI and ethnicity, household wealth index, gestational age at delivery and average postnatal child CO exposure, CO exposure during 34-39 weeks gestation were positively associated with severe pneumonia risk, especially in females.

CONCLUSIONS

Household air pollution exposures in mid- and late- gestation are associated with lower birth weight and higher pneumonia risk, respectively. These findings support the urgent need for deployment of clean fuel stove interventions beginning in early pregnancy.

Prenatal IgE as a Risk Factor for the Development of Childhood Neurodevelopmental Disorders

Background: Few studies have examined if maternal allergic disease is associated with an offspring's neurodevelopment. We hypothesized that Th-2 biased maternal immune function assessed as total serum immunoglobulin (Ig) E is associated with attention deficit hyperactivity disorder (ADHD). Methods: Data are from the Wayne County Health, Environment, Allergy, and Asthma Longitudinal Study (WHEALS), a racially and socioeconomically diverse birth cohort in metropolitan Detroit, Michigan. Maternal total IgE was measured prenatally and at 1-month postpartum. Child total IgE was assessed at birth, 6 months, and 2 years of age. ADHD diagnosis was based on the parental report at the 10-12-year study visits or medical chart abstraction. Total IgE was log2 transformed. Poisson regression models with robust error variance were used to calculate the risk ratios (RR). Inverse probability weighting was used to correct for potential bias due to a loss to follow-up and non-response. Results: Of the 636 maternal-child pairs in the analysis, 513 children were neurotypical and 123 had ADHD. Maternal prenatal total IgE was significantly associated with ADHD even after adjustment for potential confounders (RR = 1.08, 95% CI 1.03-1.13). Maternal and child IgE measures were positively and significantly correlated, but child total IgE was not associated with ADHD at any time point. Conclusions: Maternal prenatal IgE may influence neurodevelopment, but additional studies are needed to confirm and expand these findings.

Identification of modifiable pre- and postnatal dietary and environmental exposures associated with owner-reported canine atopic dermatitis in Finland using a web-based questionnaire

A cross-sectional hypothesis generating study was performed to investigate modifiable exposures such as whether feeding pattern (a non-processed meat based diet, NPMD, or an ultra-processed carbohydrate based diet, UPCD), certain environmental factors and their timing of exposure might be associated with the development of canine atopic dermatitis (CAD). Also, genetic and demographic factors were tested for associations with CAD. The data was collected from the validated internet-based DogRisk food frequency questionnaire in Finland. A total of 2236 dogs were eligible for the study (the owners reported 406 cases and 1830 controls). Our main interest was to analyze modifiable early risk factors of CAD, focusing on nutritional and environmental factors. We tested four early life periods; prenatal, neonatal, early postnatal and late postnatal periods. Twenty-two variables were tested for associations with CAD using logistic regression analysis. From the final models we identified novel dietary associations with CAD: the NPMD during the prenatal and early postnatal periods had a significant negative association with the incidence of CAD in adult dogs (age above 1 year). Oppositely, UPCD was associated with a significantly higher risk for CAD incidence. Other variables that were associated with a significantly lower risk for CAD were maternal deworming during pregnancy, sunlight exposure during early postnatal period, normal body condition score during the early postnatal period, the puppy being born within the same family that it would stay in, and spending time on a dirt or grass surface from 2 to 6 months. Also, the genetic factors regarding maternal history of CAD, allergy-prone breeds and more than 50% white-colored coat all showed a significant positive association with CAD incidence in agreement with previous findings. Although no causality can be established, feeding NPMD early in life seemed to be protective against CAD, while UPCD could be considered a risk factor. Prospective intervention studies are needed to establish the causal effects of the protective role of NPMD on prevalence of CAD during the fetal and early postnatal life.

The fetal/placental weight ratio is associated with the incidence of atopic dermatitis in female infants during the first 14 months: The Hamamatsu Birth Cohort for Mothers and Children (HBC Study)

Background

Among atopic diseases, atopic dermatitis is the most common allergic disease in children and influences both infantile and parental quality of life.

Objective

The present study investigated the sex-specific relationship between the fetal/placental weight ratio and The incidence of atopic dermatitis in infants during the first 14 months of life.

Methods

Study participants were 922 infants (462 female and 460 male) from singleton pregnancies enrolled in the Hamamatsu Birth Cohort for Mothers and Children (HBC Study) after the exclusion of 298 with missing data on atopic dermatitis. The enrollment of infants with atopic dermatitis was based on a positive response from parents regarding whether a physician had ever diagnosed their child with atopic dermatitis by 14 months of age. The two-sample Wilcoxon rank-sum test or χ² test was adopted for descriptive analyses where appropriate. Unadjusted odds ratios and 95% confidence intervals for the infantile incidence of atopic dermatitis were compared using logistic regression analyses.

Results

Maternal and perinatal factors did not correlate with the incidence of infantile atopic dermatitis. Fetal/placental weight ratio, but not birth or placental weight, correlated with the incidence of atopic dermatitis in female, but not male, infants. A correlation was still observed after adjustments for maternal allergies, gestational age at birth, maternal smoking during pregnancy, and household income at birth (odds ratio: 1.57; 95% confidence interval, 1.05-2.33).

Conclusion

We speculated that the intrauterine fetal environment, represented by a relatively small placenta, programs a predisposition in only female infants to atopic dermatitis during the first 14 months of life.

Role of early life immune regulation in asthma development

Development of childhood asthma is complex with a strong interaction of genetic, epigenetic, and environmental factors. Ultimately, it is critical how the immune system of a child responds to these influences and whether effective strategies for a balanced and healthy immune maturation can be assured. Pregnancy and early childhood are particularly susceptible for exogenous influences due to the developing nature of a child’s immune system. While endogenous influences such as family history and the genetic background are immutable, epigenetic regulations can be modulated by both heredity and environmental exposures. Prenatal influences such as a mother’s nutrition, smoking, or infections influence the complex interplay of innate and adaptive immune regulation as well as peri- and postnatal influences including mode of delivery. Early in life, induction and continuous training of healthy maturation include balanced innate immunity (e.g., via innate lymphoid cells) and an equilibrium of T-cell subpopulations (e.g., via regulatory T cells) to counter-regulate potential pro-inflammatory or exuberant immune reactions. Later in childhood, rather compensatory immune mechanisms are required to modulate deviant regulation of a child’s already primed immune trajectory. The specific effects of exogenous and endogenous influences on a child’s maturing immune system are summarized in this review, and its importance and potential intervention for early prevention and treatment strategies are delineated.

Preconception immunization can modulate intracellular Th2 cytokine profile in offspring: in vivo influence of interleukin 10 and B/T cell collaboration

Introduction

In the last few years our group has been studying the mechanisms involved in the inhibition of allergy in offspring mediated by preconception maternal immunization, but these mechanisms are not fully understood. Such mechanisms that we have studied aimed at the passive transfer of maternal antibodies and its influence on offspring immune status.

Aim of the study

To evaluate whether maternal immunization could modulate intracellular Th1/Th2 profiles in offspring.

Material and methods

C57BL/6 female wild type mice (WT), interleukin (IL)-10^-/- or CD28^-/- mice were immunized or not with ovalbumin (OVA) and were mated with respective lineage males and offspring were evaluated at 3 days old (d.o.), 20 d.o., or 20 d.o. after neonatal immunization.

Results

Preconception OVA immunization induced a marked reduction in IL-4 secretion by TCD4+ cells of WT offspring when compared with offspring from non-immunized mothers. The maternal immunization of IL-10^-/- mice induced an increase in the TCD4+IL-4+ percentage in offspring and a reduction in TCD4+IFN-γ+ cells. The maternal immunization in CD28^-/- mice induced augment IL-4 intensity in 3 and 20 d.o. offspring TCD4+ cells.

Conclusions

Our results reveal that maternal immunization with OVA can down-regulate the Th2 pattern in offspring and this regulation is dependent on IL-10 and B/T cell collaboration.

Aeroallergens in Canada: Distribution, Public Health Impacts, and Opportunities for Prevention

Aeroallergens occur naturally in the environment and are widely dispersed across Canada, yet their public health implications are not well-understood. This review intends to provide a scientific and public health-oriented perspective on aeroallergens in Canada: their distribution, health impacts, and new developments including the effects of climate change and the potential role of aeroallergens in the development of allergies and asthma. The review also describes anthropogenic effects on plant distribution and diversity, and how aeroallergens interact with other environmental elements, such as air pollution and weather events. Increased understanding of the relationships between aeroallergens and health will enhance our ability to provide accurate information, improve preventive measures and provide timely treatments for affected populations.

The Influence of LPS-Induced Maternal Inflammation on Postnatal Collagen-Induced Arthritis

Maternal health and nutritional status influence offspring health and the diseases that may develop in them. The effects of maternal inflammation on offspring from the perspective of the inflammatory response and immune changes are not fully understood. We hypothesized that maternal inflammation modulates immune and metabolic functions, affecting the pathophysiology of inflammatory diseases in offspring. This study investigated whether maternal inflammation affects the onset of collagen-induced arthritis (CIA), a murine model of human rheumatoid arthritis. Female DBA/1J mice received a single intraperitoneal injection of lipopolysaccharide (LPS) 5 days before conception. Male offspring of LPS-treated dams were placed in the maternal LPS group (MLG). To induce CIA, type II collagen (CII) was emulsified with Freund's complete adjuvant and injected twice into each mouse, at 13 and 16 weeks. The offspring were sacrificed at 26 weeks to analyze immunological and metabolic parameters. The degree of joint swelling at an early stage of CIA was lower in the MLG than in the control group. From histological analysis, the severity of joint destruction (severity of arthritis score) and CII-specific IgG titer were significantly lower in the MLG. However, at 26 weeks, serum interleukin (IL)-6 levels, an index of CIA disease activity, were significantly higher in the MLG. Moreover, serum leptin levels were lower in the MLG, and a negative correlation between leptin and serum IL-6 was observed. In conclusion, maternal inflammation does not merely suppress inflammation; it may delay CIA in offspring. The analysis of inflammatory cytokines and leptin concentrations at 26 weeks suggests that the pathophysiology of arthritis was worsening. This study also suggests that maternal inflammation modulates postnatal inflammatory response patterns in offspring.

Pregnancy diet and offspring asthma risk over a 10-year period: the Lifeways Cross Generation Cohort Study, Ireland

OBJECTIVE

The association of maternal pregnancy diet with offspring asthma risk have been reported. However, literature on longitudinal patterns of asthma risk relative to intrauterine nutrient exposure is limited. We aimed to establish whether vegetable, oily fish and vitamin D intake during pregnancy are associated with childhood asthma risk over a 10-year period in the Irish Republic.

DESIGN

Mother-child pairs (n=897) from the Lifeways prospective birth cohort, with data on nutrient intake during pregnancy and asthma status, respectively, were eligible for inclusion in the analysis. Data on socioeconomic and morbidity indicators over 10 years of follow-up on mothers and the index child were collected through self-administered questionnaires. Asthma status as diagnosed by the general practitioner at any time point over 10 years was related to maternal vegetable, oily fish and vitamin D intake during pregnancy, while adjusting for gestational age, socioeconomic status, smoking at delivery, breast feeding, season of birth and supplement use. Data were modelled with a marginal model on correlated observations over time within individuals.

RESULTS

In the fully adjusted model, asthma was inversely associated with higher daily average intake of oily fish (OR 0.23 per serving/day, 95% CI 0.04 to 1.41) and of vegetables (OR 0.96 per serving/day, 95% CI 0.88 to 1.05), but the confidence limits overlapped 1. A higher daily vitamin D intake was associated with reduced odds of asthma (OR 0.93 per μg/day, 95% CI 0.89 to 0.98).

CONCLUSION

This analysis suggests higher daily average intake of vitamin D in pregnancy is associated with asthma risk in offspring over the first 10 years of life.

In Utero Exposure to Aspirin and Risk of Asthma in Childhood

BACKGROUND

Aspirin is widely used in general population and low-dose aspirin is commonly prescribed to prevent recurrent pregnancy loss associated with antiphospholipid syndrome and preeclampsia, often used throughout pregnancy. But aspirin is associated with asthma pathogenesis. We aim to examine whether in utero exposure to aspirin at different fetal stages is associated with asthma in childhood.

METHODS

We used data from the Collaborative Perinatal Project. Maternal exposure to aspirin before and during pregnancy was recorded at each prenatal visit. Children were followed up to 7 years of age. A total of 19,928 singleton children without maternal history of asthma were included. We used multilevel multiple logistic regression models to control for potential confounders.

RESULTS

In utero exposure to aspirin was associated with an increased risk of childhood asthma (adjusted odds ratio [aORs] = 1.3, 95% confidence interval [CI] = 1.1, 1.6). aORs for exposure in first, second, and third trimesters were 1.1 (95% CI = 0.87, 1.3), 1.2 (95% CI = 1.0, 1.4), and 1.4 (95% CI = 1.1, 1.6), respectively. Furthermore, aORs of asthma were 1.3 (95% CI = 1.0, 1.7) and 1.3 (95% CI = 1.0, 1.7) for aspirin use for 2 to 7 days or more than 7 days in third trimester, respectively.

CONCLUSION

In utero exposure to therapeutic dose of aspirin even just briefly in late pregnancy is associated with childhood asthma by 7 years of age. More research is needed to carefully examine the association between low-dose aspirin with extended exposure period and long-term child outcomes.

Inducing maternal inflammation promotes leptin production in offspring but does not improve allergic symptoms in a mouse model of allergic rhinitis

AIMS

The intrauterine environment is considered to affect immunological development in fetus, leading to an increased risk of developing allergy. In particular, maternal lipopolysaccharides (LPS) administration might regulate the development of allergic disease in offspring. Several studies have shown that being obese relates to a higher prevalence of allergic diseases compared to normal weight. The present study explored the effects of inducing maternal inflammation with LPS before pregnancy on body weight, physical composition including body fat, adipokine production, and pathology of allergic rhinitis in offspring.

MAIN METHODS

Female mice received a single intraperitoneal injection of LPS (2 μg/g BW). After 5 days of LPS administration, female mice were mated with males, and experimental allergic rhinitis was induced in female offspring. Immunization and nasal challenge with ovalbumin (OVA) were performed at 7 and 8 weeks of age. Allergic rhinitis-like symptoms, OVA-specific IgE and adipokines in sera, body weight, fat pad weight, and cytokine production by splenocytes in these 9-week-old offspring.

KEY FINDINGS

Maternal LPS administration results in a significant increase in body weight, visceral fat accumulation, and serum leptin concentration, and the dominance of Th1 in Th balance. Nevertheless, there was no statistical difference in OVA-specific IgE titer and allergic-like symptoms between the groups.

SIGNIFICANCE

In conclusion, maternal LPS promoted leptin production and altered Th balance in mice offspring, but not improved allergic symptoms in a mouse model of allergic rhinitis. It might suggest that inflammation during pregnancy plays a role in the adipose tissue function which could diversely influence allergic inflammation in offspring.

Intrauterine sensitization of ovalbumin in the third trimester increases the risk of food allergy in progeny

Intrauterine sensitization caused by food allergens plays an important role in the food allergy development in progeny. The aim of our study was to determine the critical period of intrauterine sensitization during pregnancy. Female mice were exposed to ovalbumin (OVA) during different trimesters of pregnancy. Lymphocytes from their offspring were isolated and cultured, and proliferation was evaluated by CCK-8 assay. The levels of IFN-γ and IL-4 in serum were measured using ELISA. In addition, the expressions of IFN-γ and IL-4 mRNAs and proteins were detected by real-time PCR and western blot. The mice were divided into the first trimester pregnancy (FTP1 and FTP2) group, the second trimester pregnancy (STP1 and STP2) group, and the third trimester pregnancy (TTP1 and TTP2) group based on the stages of pregnancy in which their mothers were exposed to OVA and their ages. The OVA-specific lymphocyte proliferation of the TTP1 group was statistically significantly greater that in the FTP1 and STP1 groups. The serum level of IFN-γ in the TTP1 group was significantly decreased, and the serum level of IL-4 in the TTP1 group was significantly increased compared with the levels in the FTP1 and STP1 groups. The mRNA and protein expression levels of IFN-γ in the TTP1 group were significantly decreased and the mRNA and protein expression levels of IL-4 in this group were significantly increased compared with the levels in the FTP1 and STP1 groups. Our results suggest that OVA-induced intrauterine sensitization in the third trimester may increase the risk of food allergy after birth.

Vitamin D supplementation during pregnancy and infancy reduces aeroallergen sensitization: a randomized controlled trial

BACKGROUND

Vitamin D has immune-modulating effects. We determined whether vitamin D supplementation during pregnancy and infancy prevents aeroallergen sensitization and primary care respiratory illness presentations.

METHODS

A randomized, double-blind, placebo-controlled parallel-group trial. We assigned pregnant women, from 27-week gestation to birth, and then their infants, from birth to 6 months, to placebo or one of two dosages of daily oral vitamin D. Woman/infant pairs were randomized to: placebo/placebo, 1000 IU/400 IU or 2000 IU/800 IU. When the children were 18 months old, we measured serum-specific IgE antibodies and identified acute primary care visits described by the doctor to be due to a cold, otitis media, an upper respiratory infection, croup, asthma, bronchitis, bronchiolitis, a wheezy lower respiratory infection or fever and cough.

RESULTS

Specific IgE was measured on 185 of 260 (71%) enrolled children. The proportion of children sensitized differed by study group for four mite antigens: Dermatophagoides farinae (Der-f1, Der-f2) and Dermatophagoides pteronyssinus (Der-p1, Der-p2). With results presented for placebo, lower dose, and higher dose vitamin D, respectively (all P < 0.05): Der-f1 (18%, 10%, 2%), Der-f2 (14%, 3%, 2%), Der-p1 (19%, 14%, 3%) and Der-p2 (12%, 2%, 3%). There were study group differences in the proportion of children with primary care visits described by the doctor as being for asthma (11%, 0%, 4%, P = 0.002), but not for the other respiratory diagnoses.

CONCLUSIONS

Vitamin D supplementation during pregnancy and infancy reduces the proportion of children sensitized to mites at age 18 months. Preliminary data indicate a possible effect on primary care visits where asthma is diagnosed.

Longitudinal pattern of multiplexed immunoglobulin E sensitization from prenatal stage to the first year of life

BACKGROUND

The longitudinal pattern of allergen-specific IgE levels from the prenatal stage to early life has remained largely unexplored.

METHODS

One-hundred and three mother-infant pairs, which were part of an ongoing population-based prospective birth cohort study of early childhood allergic diseases in Tainan, Taiwan, were included in this study. We examined the relationship of 20 allergen-specific IgE levels with blood samples of mothers, cord blood, and infants at 12 months of age using Spearman rank correlation, Kenal τ and McNemar test, respectively.

RESULTS

Certain degree of IgE sensitization against most 20 examined specific allergens was observed in blood samples of mothers, cord blood, and infants at 12 months of age. When we further examined the association between allergy-related risk factors and atopy in infants at the first year of life, we found positive association between colic pain and atopy in infants at 12 months of age [adjusted odds ratios (AOR) = 3.51; 95% confidence interval (CI): 1.13-10.96; p = 0.03], and borderline significance between wheezing and atopy in infants at 12 months of age (AOR = 4.58; 95% CI: 0.89-23.50; p = 0.07).

CONCLUSION

The findings from this study suggest that influence of maternal allergen-specific IgE levels on infant immune response might occur at birth and then wane in infants at 12 months of age. Positive association of colic pain and wheezing with atopy in infants at 12 months of age provides supportive evidence for the 'Allergy March' theory of allergy development in an Asian birth cohort.

A review of Vitamin D effects on common respiratory diseases: Asthma, chronic obstructive pulmonary disease, and tuberculosis

Despite the classic role of Vitamin D in skeletal health, new aspects of Vitamin D have been discovered in tissues and organs other than bones. Epidemiological and observational studies demonstrate a link between Vitamin D deficiency and risk of developing respiratory diseases including asthma, chronic obstructive pulmonary disease (COPD), and tuberculosis (TB). To review the literature, we searched the terms "Vitamin D" (using the set operator) and "asthma," "COPD" and "TB" in electronic databases, including PubMed/MEDLINE, Scopus, and Google Scholar until July 2015. Non-English articles or articles with unavailable full text were excluded. Both in vivo and in vitro studies were included. All the reviewed articles state that Vitamin D deficiency is very common among patients with respiratory diseases. The present data regarding Vitamin D and asthma is still controversial, but data about COPD and TB are more encouraging. The relevant studies have been conducted in different populations therefore it is not particularly possible to compare the data due to genetic variations. In order to point out a role for Vitamin D, large clinical trials with Vitamin D deficient subjects and sufficient Vitamin D supplementation are needed.

Maternal PUFA status and offspring allergic diseases up to the age of 18 months

Studies have suggested that maternal PUFA status during pregnancy may influence early childhood allergic diseases, although findings are inconsistent. We examined the relationship between maternal PUFA status and risk of allergic diseases in early childhood in an Asian cohort. Maternal plasma samples from the Growing Up in Singapore Towards Healthy Outcomes mother–offspring cohort were assayed at 26–28 weeks of gestation for relative abundance of PUFA. Offspring (n 960) were followed up from 3 weeks to 18 months of age, and clinical outcomes of potential allergic diseases (rhinitis, eczema and wheezing) were assessed by repeated questionnaires. Skin prick testing (SPT) was also performed at the age of 18 months. Any allergic disease with positive SPT was defined as having any one of the clinical outcomes plus a positive SPT. The prevalence of a positive SPT, rhinitis, eczema, wheezing and any allergic disease with positive SPT was 14·1 % (103/728), 26·5 % (214/808), 17·6 % (147/833), 10·9 % (94/859) and 9·4 % (62/657), respectively. After adjustment for confounders, maternal total n-3, n-6 PUFA status and the n-6:n-3 PUFA ratio were not significantly associated with offspring rhinitis, eczema, wheezing, a positive SPT and having any allergic disease with positive SPT in the offspring (P>0·01 for all). A weak trend of higher maternal n-3 PUFA being associated with higher risk of allergic diseases with positive SPT in offspring was observed. These findings do not support the hypothesis that the risk of early childhood allergic diseases is modified by variation in maternal n-3 and n-6 PUFA status during pregnancy in an Asian population.

Vitamin D in asthma and future perspectives

Humans have the ability to synthesize vitamin D during the action of ultraviolet (UV) radiation upon the skin. Apart from the regulation of calcium and phosphate metabolism, another critical role for vitamin D in immunity and respiratory health has been revealed, since vitamin D receptors have also been found in other body cells. The term "vitamin D insufficiency" has been used to describe low levels of serum 25-hydroxyvitamin D that may be associated with a wide range of pulmonary diseases, including viral and bacterial respiratory infection, asthma, chronic obstructive pulmonary disease, and cancer. This review focuses on the controversial relationship between vitamin D and asthma. Also, it has been found that different gene polymorphisms of the vitamin D receptor have variable associations with asthma. Other studies investigated the vitamin D receptor signaling pathway in vitro or in experimental animal models and showed either a beneficial or a negative effect of vitamin D in asthma. Furthermore, a range of epidemiological studies has also suggested that vitamin D insufficiency is associated with low lung function. In the future, clinical trials in different asthmatic groups, such as infants, children of school age, and ethnic minorities are needed to establish the role of vitamin D supplementation to prevent and/or treat asthma.

Developmental programming for allergy: a secondary analysis of the Mothers, Omega-3, and Mental Health Study

OBJECTIVE

Fetal dysregulation of T helper cell pathways may predispose to allergy, as high cord blood T helper 2/T helper 1 ratios have been shown to precede development of allergic diseases. We aimed to determine whether prenatal eicosapentaenoic acid and docosahexaenoic acid supplementation reduces T helper 2 to T helper 1-associated chemokine ratios. We also explored the effect of mode of delivery on T helper 2/T helper 1 ratios.

STUDY DESIGN

We conducted a secondary analysis of a randomized placebo controlled trial initially performed to assess the effects of docosahexaenoic acid or eicosapentaenoic acid supplementation on pregnancy-related depressive symptoms among 126 participants. Cord plasma specimens from 98 newborns were assayed for chemokines associated with T helper 2 (thymus and activation-regulated chemokine [CCL17], macrophage-derived chemokine [CCL22], eotaxin [CCL 11]) and T helper 1 (interferon-inducible protein-10 [CXCL 10]) by enzyme-linked immunosorbent assay and Multiplex immunoassays. Ratios of log-transformed chemokines macrophage-derived chemokine/interferon-inducible protein-10 and thymus and activation-regulated chemokine/interferon-inducible protein-10 were compared between groups by analyses of variance. Multiple linear regression was performed to examine associations between treatments and chemokine ratios, adjusting for covariates.

RESULTS

After adjusting for gestational age at delivery, birthweight, and mode of delivery, both omega-3 supplementation groups were associated with lower macrophage-derived chemokine/interferon-inducible protein-10 ratios than placebo (eicosapentaenoic acid: coefficient -1.8; 95% confidence interval [CI], -3.6 to -0.05; P = .04; docosahexaenoic acid: -2.0; 95% CI, -3.9 to -0.07; P = .04). Similar associations were found for thymus and activation-regulated chemokine/interferon-inducible protein-10 (eicosapentaenoic acid: -1.5; 95% CI, -3.0 to 0.06; P = .06; docosahexaenoic acid -2.2; 95% CI, -3.8 to -0.52; P = .01). Cesarean delivery was associated with higher macrophage-derived chemokine/interferon-inducible protein-10 (1.6; 95% CI, 0.01-3.3; P = .049) and thymus and activation-regulated chemokine/interferon-inducible protein-10 (1.5; 95% CI, 0.1-2.9; P = .042) ratios than vaginal delivery.

CONCLUSION

Prenatal supplementation with eicosapentaenoic acid and docosahexaenoic acid resulted in decreased cord blood T helper 2/T helper 1 chemokine ratios. Cesarean delivery was associated with a pronounced T helper 2 deviation at birth.

Milk allergy in the neonatal intensive care unit: comparison between premature and full-term neonates

BACKGROUND

There have been several reports on neonates with milk allergy in a neonatal ward. This type of allergy is mostly categorized as a non-IgE-mediated food allergy. Although most cases of milk allergy occur in the first few months of life, the differences in clinical characteristics between premature and full-term neonates are still unclear.

OBJECTIVE

This study aimed to clarify the differences in clinical characteristics of milk allergy between premature and full-term neonates.

METHODS

We retrospectively evaluated 2,116 neonates admitted to the Department of Neonatology, Chiba Kaihin Municipal Hospital, between 2001 and 2007.

RESULTS

We identified 24 neonates strongly suspected of having milk allergy because of symptoms, such as bloody stools, repeated vomiting, diminished sucking and abdominal distension, as well as objective laboratory findings of eosinophilia in stool cytology and/or positive results for a rectal milk challenge test. Twelve of these 24 neonates were premature (median gestational age, 31 ± 3 weeks; median birth weight, 1,656 ± 592 g) and the other 12 were full-term (median gestational age, 38 ± 1 weeks; median birth weight, 2,760 ± 560 g). There were no differences in symptoms and time to start of feeding between premature and full-term neonates, but there was a significant difference in the median postnatal age at onset (premature neonates: 23 days; vs. full-term neonates: 3.5 days; p < 0.01).

CONCLUSION

All premature neonates developed a milk allergy after 32 weeks of corrected gestational age, suggesting that the development of milk allergy requires a certain degree of immunological maturation.

Low vegetable intake is associated with allergic asthma and moderate-to-severe airway hyperresponsiveness

BACKGROUND

In recent decades, children's diet quality has changed and asthma prevalence has increased, although it remains unclear if these events are associated.

OBJECTIVE

To examine children's total and component diet quality and asthma and airway hyperresponsiveness (AHR), a proxy for asthma severity.

METHODS

Food frequency questionnaires adapted from the Nurses' Health Study and supplemented with foods whose nutrients which have garnered interest of late in relation to asthma were administered. From these data, diet quality scores (total and component), based on the Youth Healthy Eating Index (YHEI adapted) were developed. Asthma assessments were performed by pediatric allergists and classified by atopic status: Allergic asthma (≥1 positive skin prick test to common allergens >3 mm compared to negative control) versus non-allergic asthma (negative skin prick test). AHR was assessed via the Cockcroft technique. Participants included 270 boys (30% with asthma) and 206 girls (33% with asthma) involved in the 1995 Manitoba Prospective Cohort Study nested case-control study. Logistic regression was used to examine associations between diet quality and asthma, and multinomial logistic regression was used to examine associations between diet quality and AHR.

RESULTS

Four hundred seventy six children (56.7% boys) were seen at 12.6 ± 0.5 years. Asthma and AHR prevalence were 26.2 and 53.8%, respectively. In fully adjusted models, high vegetable intake was protective against allergic asthma (OR 0.49; 95% CI 0.29-0.84; P < 0.009) and moderate/severe AHR (OR 0.58; 0.37-0.91; P < 0.019).

CONCLUSIONS

Vegetable intake is inversely associated with allergic asthma and moderate/severe AHR.

Local and systemic immunological parameters associated with remission of asthma symptoms in children

The immunological and clinical parameters that are associated with asthma remission are poorly understood. The cytokine and local mediator changes associated with the resolution of asthma symptoms were examined in three groups of subjects 12-18 years of age (n = 15 in each group): (a) continuing asthma group (CA) who had persistent symptoms since early childhood, (b) an age, sex and atopic status-matched group who had persistent symptoms in early childhood but in whom these had resolved (RA), and (c) a non-atopic, non-asthmatic control group. Clinical parameters, sputum cell counts, peripheral blood mononuclear cell (PBMC) cytokine production and activation marker expression were determined. All of the CA had methacholine airway hyperresponsiveness compared with only half of the RA subjects. The CA showed elevated numbers of eosinophils and increased ECP and IL-5 in sputum, which were not observed in the RA. PBMC cytokine studies revealed increased production of the type 1 cytokines IL-12, IFN-γ and TNF-α in the CA group compared with the RA group, under a range of activation conditions, however, the production of IL-4 and IL-5 were unchanged. These findings suggest that decreased type 1 cytokine expression as well as decreased eosinophilic inflammation is associated with the resolution of asthma symptoms.

Maternal allergen exposure reprograms the developmental lung transcriptome in atopic and normoresponsive rat pups

The "fetal origins hypothesis" argued that physiological changes consequent to in utero exposures ultimately contribute to disease susceptibility in later life. The dramatic increase in asthma prevalence is attributed to early exposures acting on preexisting asthma-susceptible genotypes. We showed previously that distinct transcriptome signatures distinguish the developmental respiratory phenotype of atopic (Brown Norway, BN) and normoresponsive (Lewis) rats. We aimed to determine whether maternal allergen exposure would influence asthma pathogenesis by reprogramming primary patterns of developmental lung gene expression. Postnatal offspring of dams sensitized to ovalbumin before mating and challenged during pregnancy were assessed for lung function, inflammatory biomarkers, and respiratory gene expression. Although maternal ovalbumin exposure resulted in characteristic features of an allergic response (bronchoalveolar lavage neutrophils, IgE, methacholine-induced lung resistance) in offspring of both strains, substantial strain-specific differences were observed in respiratory gene expression. Of 799 probes representing the top 5% of transcriptomic variation, only 112 (14%) were affected in both strains. Strain-specific gene signatures also exhibited marked differences in enrichment for gene ontologies, with immune regulation and cell proliferation being prominent in the BN strain, cell cycle and microtubule assembly gene sets in the Lewis strain. Multiple ovalbumin-specific probes in both strains were also differentially expressed in lymphoblastoid cell lines from human asthmatic vs. nonasthmatic sibling pairs. Our data point to the existence of distinct, genetically programmed responses to maternal exposures in developing lung. These different response patterns, if recapitulated in human fetal development, can contribute to long-term pulmonary health including interindividual susceptibility to asthma.

How changes in nutrition have influenced the development of allergic diseases in childhood

The increasing prevalence of allergic diseases in childhood in the last decades could be linked to concomitant dietary changes, especially with the modified and lower consumption of fruit, vegetables and minerals. The consumption of these foods by pregnant women and children in the first years of life seems to be associated with a reduced risk of asthma and related symptoms. Foods that can prevent the development of wheezing through their antioxidant effects contain vitamin C and selenium; blood levels of these elements correlate negatively with the risk of wheezing. Intake of vitamin E during pregnancy also appears to be correlated with a reduced risk of wheezing for the unborn child. Similarly, low intake of zinc and carotenoids by pregnant women is associated with an increased risk of wheezing and asthma in childhood. Fiber also has anti-inflammatory properties and protective effects against allergic diseases such as atopic dermatitis and asthma. The consumption of fat influences the development of the airways. Populations in Western countries have increased their consumption of n-6 PUFAs and, in parallel, reduced n-3 PUFAs. This has led to decreased production of PGE2, which is believed to have a protective effect against inflammation of the airways. Conflicting hypotheses also concern vitamin D; both an excess and a deficiency of vitamin D, in fact, have been associated with an increased risk of asthma. Further studies on the role of these substances are necessary before any conclusions can be drawn on a clinical level.

The effect of perinatal omega-3 fatty acid supplementation on inflammatory markers and allergic diseases: a systematic review

BACKGROUND

Maternal supplementation with omega-3 polyunsaturated fatty acids (n-3 PUFA) may modulate immune responses and allergy in neonates and children.

OBJECTIVE

To determine if n-3 PUFA supplementation during pregnancy and lactation reduces risk for childhood allergic disease.

SEARCH STRATEGY

We searched Medline and all evidence-based medicine reviews for randomised controlled trials comparing the effects of n-3 PUFA and placebo supplementation during pregnancy and/or lactation on childhood allergic diseases and inflammatory cytokines.

SELECTION CRITERIA

We included studies reporting on food allergy, response to the egg skin prick test (SPT), atopy and asthma in infancy and childhood as well as production of interleukin-13 and interferon-gamma, two cytokines involved in the pathogenesis of asthma. For assessment of inclusion, two authors reviewed all abstracts for suitability and independently extracted data.

DATA COLLECTION AND ANALYSIS

Two-by-two tables were constructed and odds ratios (OR) were calculated for the outcomes: response to the SPT, food allergy, atopy and asthma in childhood. The assays differed so data on inflammatory markers were reported in narrative form.

MAIN RESULTS

Five randomised controlled trials (n = 949) were included. n-3 PUFA supplementation during pregnancy reduced 12-month prevalence of positive egg SPT (two trials, 12/87 versus 32/100, OR 0.33, 95% CI 0.16, 0.70) and childhood asthma (two trials, 10/303 versus 17/179, OR 0.349, 95% CI 0.154, 0.788) and significantly reduced cord blood interleukin-13 levels. Supplementation during lactation did not prevent asthma, food allergy or atopy.

CONCLUSION

n-3 PUFA supplementation during pregnancy decreases childhood asthma and response to SPT.

Feasibility of neonatal dried blood spot retrieval amid evolving state policies (2009-2010): a Children's Oncology Group study

Dried blood spots (DBS) are collected uniformly from US newborns to test for metabolic and other disorders. Because evidence exists for prenatal origins of some diseases, DBS may provide unique prenatal exposure records. Some states retain residual DBS and permit their use in aetiological studies. The primary study aim was to assess the feasibility of obtaining residual DBS from state newborn screening programmes for paediatric and adolescent cancer patients nationwide with parental/subject consent/assent. Families of leukaemia and lymphoma patients aged ≤21 years diagnosed from 1998 to 2007 at randomly selected Children's Oncology Group institutions across the US were questioned (n = 947). Parents/guardians and patients aged ≥18 years were asked to release DBS to investigators in spring 2009. DBS were then requested from states. Overall, 299 families (32%) released DBS. Consenting/assenting patients were born in 39 US states and 46 DBS were obtained from five states; 124 DBS were unobtainable because patients were born prior to dates of state retention. State policies are rapidly evolving and there is ongoing discussion regarding DBS storage and secondary research uses. Currently, population-based DBS studies can be conducted in a limited number of states; fortunately, many have large populations to provide reasonably sized paediatric subject groups.

Allergic disease in infants up to 2 years of age in relation to plasma omega-3 fatty acids and maternal fish oil supplementation in pregnancy and lactation

We have previously reported a protective effect of maternal omega-3 long-chain polyunsaturated fatty acids (ω-3 LCPUFA) supplementation in pregnancy and lactation on IgE-associated eczema and food allergy in the infant during the first year of life. Here we investigate whether the effects of the LCPUFA supplementation on IgE-associated diseases last up to 2 yr of age and assess the relationship between plasma proportions of ω-3 PUFAs and the frequency and severity of infant allergic disease. 145 pregnant women, at risk of having an allergic infant, were randomized to daily supplementation with 1.6 g eicosapentaenoic acid (EPA) and 1.1 g docosahexaenoic acid (DHA) or placebo starting in the 25th gestational week and continuing through 3.5 months of breastfeeding. Clinical examinations, skin prick tests and analysis of maternal and infant plasma phospholipid fatty acids and infant specific IgE were performed. No difference in the prevalence of allergic symptoms was found between the intervention groups. The cumulative incidence of IgE-associated disease was lower in the ω-3-supplemented group (6/54, 13%) compared with the placebo group (19/62, 30%, p=0.01). Higher maternal and infant proportions of DHA and EPA were associated with lower prevalence of IgE associated disease (p=0.01-0.05) in a dose-dependent manner. Higher maternal and infant proportions of DHA and EPA were found if the infants presented none, when compared with multiple allergic symptoms, (p<0.05) regardless of sensitization. In summary, the ω-3 supplementation offered no obvious preventive effect on the prevalence of clinical symptoms of allergic disease, but the decrease in cumulative incidence of IgE-associated disease seen during the first year still remained until 2 yr of age. Furthermore, high proportions of DHA and EPA in maternal and infant plasma phospholipids were associated with less IgE-associated disease and a reduced severity of the allergic phenotype.

Anthelminthic treatment during pregnancy is associated with increased risk of infantile eczema: randomised-controlled trial results

BACKGROUND

Allergy is commoner in developed than in developing countries. Chronic worm infections show inverse associations with allergy, and prenatal exposures may be critical to allergy risk.

OBJECTIVE

To determine whether anthelminthic treatment during pregnancy increases the risk of allergy in infancy.

METHODS

A randomised, double-blind, placebo-controlled trial on treatment in pregnancy with albendazole versus placebo and praziquantel versus placebo was conducted in Uganda, with a 2 × 2 factorial design; 2507 women were enrolled; infants' allergy events were recorded prospectively. The main outcome was doctor-diagnosed infantile eczema.

RESULTS

Worms were detected in 68% of women before treatment. Doctor-diagnosed infantile eczema incidence was 10.4/100 infant years. Maternal albendazole treatment was associated with a significantly increased risk of eczema [Cox HR (95% CI), p: 1.82 (1.26-2.64), 0.002]; this effect was slightly stronger among infants whose mothers had no albendazole-susceptible worms than among infants whose mothers had such worms, although this difference was not statistically significant. Praziquantel showed no effect overall but was associated with increased risk among infants of mothers with Schistosoma mansoni [2.65 (1.16-6.08), interaction p = 0.02]. In a sample of infants, skin prick test reactivity and allergen-specific IgE were both associated with doctor-diagnosed eczema, indicating atopic aetiology. Albendazole was also strongly associated with reported recurrent wheeze [1.58 (1.13-2.22), 0.008]; praziquantel showed no effect.

CONCLUSIONS

The detrimental effects of treatment suggest that exposure to maternal worm infections in utero may protect against eczema and wheeze in infancy. The results for albendazole are also consistent with a direct drug effect. Further studies are required to investigate mechanisms of these effects, possible benefits of worms or worm products in primary prevention of allergy, and the possibility that routine deworming during pregnancy may promote allergic disease in the offspring.

Th1 and Th2 chemokines, vaccine-induced immunity, and allergic disease in infants after maternal ω-3 fatty acid supplementation during pregnancy and lactation

We investigated whether the previously reported preventive effect of maternal ω-3 fatty acid supplementation on IgE-associated allergic disease in infancy may be mediated by facilitating a balanced circulating Th2/Th1 chemokine profile in the infant. Vaccine-induced immune responses at 2 y of age were also evaluated. Pregnant women, at risk of having an allergic infant, were randomized to daily supplementation with 1.6 g eicosapentaenoic acid and 1.1 g docosahexaenoic acid or placebo from the 25th gestational week through 3.5 mo of breastfeeding. Infant plasma was analyzed for chemokines (cord blood, 3, 12, 24 mo) and anti-tetanus and anti-diphtheria IgG (24 mo). High Th2-associated CC-chemokine ligand 17 (CCL17) levels were associated with infant allergic disease (p < 0.05). In infants without, but not with, maternal history of allergy, the ω-3 supplementation was related to lower CCL17/CXC-chemokine ligand 11 (CXCL11) (Th2/Th1) ratios (p < 0.05). Furthermore, in nonallergic, but not in allergic infants, ω-3 supplementation was linked with higher Th1-associated CXCL11 levels (p < 0.05), as well as increased IgG titers to diphtheria (p = 0.01) and tetanus (p = 0.05) toxins. Thus, the prospect of balancing the infant immune system toward a less Th2-dominated response, by maternal ω-3 fatty acid supplementation, seems to be influenced by allergic status.

Maternal fatty acid status in pregnancy and childhood atopic manifestations: KOALA Birth Cohort Study

BACKGROUND

Prevalence of atopic disorders has increased rapidly, but aetiological factors responsible for this increase are still largely unknown. Prenatal exposure to a pro-inflammatory fatty acid status is hypothesized although little research has been carried out.

OBJECTIVE

To investigate whether prenatal fatty acid exposures are associated with atopy in childhood.

METHODS

In the KOALA Birth Cohort Study, maternal blood samples (n=1275) at 34-36 weeks of pregnancy were assayed for n-6 and n-3 long-chain polyunsaturated fatty acids (LCPs). The full spectrum of offspring atopic manifestations (wheeze, asthma, allergic rhinoconjunctivitis, eczema, atopic dermatitis, allergic sensitization, and high total IgE) until the age of 6-7 years was assessed by repeated parental questionnaires and measurements of total and specific IgE. Associations of maternal fatty acid status with child atopic outcomes were analysed using multivariable logistic regression and generalized estimating equations for repeated measurements.

RESULTS

High ratio of maternal n-6 vs. n-3 LCPs was associated with a lower risk of eczema in the child (P for trend 0.012). More specifically, we found a decreased risk of eczema in the first 7 months of life with increasing arachidonic acid levels (P for trend 0.013). No associations were found between maternal fatty acids and offspring airway-related atopic manifestations, sensitization, or high total IgE.

CONCLUSION AND CLINICAL RELEVANCE

The development of atopic disorders in early childhood is associated with prenatal exposure to n-6 vs. n-3 fatty acids, but with inconsistencies between different manifestations. Further exploration of associations with maternal diet and genetic variants in genes regulating fatty acid metabolism are required. This study shows that the influence of prenatal exposure to fatty acids on the risk of eczema in the child is limited to the first year of life.

Childhood socioeconomic status and adult health

Socioeconomic status (SES) exposures during childhood are powerful predictors of adult cardiovascular morbidity, cardiovascular mortality, all-cause mortality, and mortality due to a range of specific causes. However, we still know little about when childhood SES exposures matter most, how long they need to last, what behavioral, psychological, or physiological pathways link the childhood SES experience to adult health, and which specific adult health outcomes are vulnerable to childhood SES exposures. Here, we discuss the evidence supporting the link between childhood and adolescent SES and adult health, and explore different environmental, behavioral, and physiological pathways that might explain how early SES would influence adult health. We also address the ages when SES exposures matter most for setting adult health trajectories as well as the role of exposure duration in SES influences on later health. While early childhood exposures seem to be potent predictors of a range of health outcomes, we emphasize that later childhood and adolescent exposures are risks for other health outcomes.

Season of birth and risk for adult onset glioma

Adult onset glioma is a rare cancer which occurs more frequently in Caucasians than African Americans, and in men than women. The etiology of this disease is largely unknown. Exposure to ionizing radiation is the only well established environmental risk factor, and this factor explains only a small percentage of cases. Several recent studies have reported an association between season of birth and glioma risk. This paper reviews the plausibility of evidence focusing on the seasonal interrelation of farming, allergies, viruses, vitamin D, diet, birth weight, and handedness. To date, a convincing explanation for the occurrence of adult gliomas decades after a seasonal exposure at birth remains elusive.

Induction of interleukin-4 production in neonatal IgE+ cells after crosslinking of maternal IgE

Transfer of maternal IgE antibodies to the neonate with the colostrum has been described in different mammalian species. Previous work in horses has shown that IgE bound to the surface of neonatal basophils is solely of maternal origin. However, the functional role of the maternal IgE transfer remained unclear. We hypothesized that maternal IgE mediates the onset of innate IL-4 production in equine neonatal basophils. Intracellular IL-4 production was measured in PBMC of newborn and older foals by flow cytometric analysis. A small population of IL-4(+) cells was observed in the peripheral blood at days 3-5 after birth. Phenotyping of the IL-4(+) cells showed that they were IgE(+)/MHCII(low)/CD4(-) cells. Magnetic cells sorting of the IgE(+)/MHCII(low) cells identified them as basophils. Anti-IgE stimulation in vitro induced IL-4 in IgE(+)/MHCII(low) basophils, but not in MHCII(+) cells or cells collected before colostrum ingestion. In conclusion, stimulation via maternal IgE antibodies mediated innate IL-4 production in neonatal basophils which might provide a paragenetic mechanism to promote the development of adaptive T-cell responses in the neonate after birth.

Genetic influences on asthma susceptibility in the developing lung

Asthma is the leading serious pediatric chronic illness in the United States, affecting 7.1 million children. The prevalence of asthma in children under 4 years of age has increased dramatically in the last 2 decades. Existing evidence suggests that this increase in prevalence derives from early environmental exposures acting on a pre-existing asthma-susceptible genotype. We studied the origins of asthma susceptibility in developing lung in rat strains that model the distinct phenotypes of airway hyperresponsiveness (Fisher rats) and atopy (brown Norway [BN] rats). Postnatal BN rat lungs showed increased epithelial proliferation and tracheal goblet cell hyperplasia. Fisher pups showed increased lung resistance at age 2 weeks, with elevated neutrophils throughout the postnatal period. Diverse transcriptomic signatures characterized the distinct respiratory phenotypes of developing lung in both rat models. Linear regression across age and strain identified developmental variation in expression of 1,376 genes, and confirmed both strain and temporal regulation of lung gene expression. Biological processes that were heavily represented included growth and development (including the T Box 1 transcription factor [Tbx5], the epidermal growth factor receptor [Egfr], the transforming growth factor beta-1-induced transcript 1 [Tgfbr1i1]), extracellular matrix and cell adhesion (including collagen and integrin genes), and immune function (including lymphocyte antigen 6 (Ly6) subunits, IL-17b, Toll-interacting protein, and Ficolin B). Genes validated by quantitative RT-PCR and protein analysis included collagen III alpha 1 Col3a1, Ly6b, glucocorticoid receptor and Importin-13 (specific to the BN rat lung), and Serpina1 and Ficolin B (specific to the Fisher lung). Innate differences in patterns of gene expression in developing lung that contribute to individual variation in respiratory phenotype are likely to contribute to the pathogenesis of asthma.

Maternal TLR signaling is required for prenatal asthma protection by the nonpathogenic microbe Acinetobacter lwoffii F78

The pre- and postnatal environment may represent a window of opportunity for allergy and asthma prevention, and the hygiene hypothesis implies that microbial agents may play an important role in this regard. Using the cowshed-derived bacterium Acinetobacter lwoffii F78 together with a mouse model of experimental allergic airway inflammation, this study investigated the hygiene hypothesis, maternal (prenatal) microbial exposure, and the involvement of Toll-like receptor (TLR) signaling in prenatal protection from asthma. Maternal intranasal exposure to A. lwoffii F78 protected against the development of experimental asthma in the progeny. Maternally, A. lwoffii F78 exposure resulted in a transient increase in lung and serum proinflammatory cytokine production and up-regulation of lung TLR messenger RNA. Conversely, suppression of TLRs was observed in placental tissue. To investigate further, the functional relevance of maternal TLR signaling was tested in TLR2/3/4/7/9^−/− knockout mice. The asthma-preventive effect was completely abolished in heterozygous offspring from A. lwoffii F78–treated TLR2/3/4/7/9^−/− homozygous mother mice. Furthermore, the mild local and systemic inflammatory response was also absent in these A. lwoffii F78–exposed mothers. These data establish a direct relationship between maternal bacterial exposures, functional maternal TLR signaling, and asthma protection in the progeny.

Antioxidants and allergic disease: a case of too little or too much?

Speculation persists as to the possible role, if any, of dietary antioxidants in allergic disease. While it has been hypothesized that the recent increase in allergic disease is a consequence of declining dietary antioxidant intake, an alternative hypothesis proposes that the increase in allergic disease is due to increasing antioxidant intake. Dietary trends are conflicting; the intake of some antioxidants has declined, for others intakes are likely to have increased. Animal model studies demonstrate that antioxidant supplementation at the time of primary and subsequent allergen exposure attenuates allergic inflammatory responses. The data from human studies are less clear. Observational epidemiological studies of humans are beset by several methodological limitations associated with the assessment of diet and predominantly focus on asthma. Most observational studies report potentially beneficial associations between dietary antioxidants and allergic outcomes, but a small minority report potentially adverse associations. Human intervention studies suggest that single antioxidant supplements confer minimal, if any clinical benefit in adults with asthma, however, there is still scope for studies in children, atopic dermatitis, allergic rhinitis (AR) and of antioxidant combinations. More recently, it has been suggested that dietary antioxidants in the developmental context of fetal and infant development influence the development childhood asthma and atopic sensitization possibly by affecting the first interactions between the neonatal immune system and allergens. While a small number of birth cohort studies have reported potentially beneficial associations between maternal intake of some antioxidants during pregnancy and childhood asthma, there is very limited data suggesting associations between maternal antioxidant intake and childhood atopic dermatitis and AR. The available epidemiological, animal, molecular and immunological data suggest that there are associations between antioxidants and asthma and to a much lesser extent, atopic dermatitis and AR. However, the exact nature of the relationships and the potential for therapeutic intervention remain unclear.

Vacuum-assisted delivery is associated with late-onset asthma

BACKGROUND

Perinatal factors during delivery might modulate fetal immunological development and thereby be associated with the development of allergic diseases and asthma later.

METHODS

Perinatal data was recorded during pregnancy and at the time of delivery in regard to 5823 children who were born in Northern Finland in 1985-1986. Data from self-administered questionnaires were available at the ages of 7 and 15-16 years and skin prick tests for four main allergens were carried out at the age of 15-16 years. Only singletons delivered by the vaginal route were analyzed.

RESULTS

There was a higher prevalence of doctor-diagnosed asthma at any time of life among children who were delivered by vacuum extraction (RR 1.80, 95% CI 1.27-2.56; P < 0.001) in comparison with spontaneously delivered children. In particular, this risk was increased as regards late-onset asthma (RR 2.41, 95% CI 1.52-3.81; P < 0.001). Perinatal effects had less impact on the development of other asthma, atopy or hay fever.

CONCLUSIONS

The delivery by vacuum extraction had significant impact on the development of late-onset asthma compared with spontaneously delivered children.

Prevalence of asthma and other allergic diseases in children born after in vitro fertilisation

BACKGROUND

Children born after in vitro fertilisation (IVF) are under greater risk of development of some health problems than those children born after spontaneous conception. Yet it is not exactly known what the prevalence of asthma and other allergic diseases among these children is.

AIMS OF THE STUDY

To investigate the prevalence of asthma, allergic rhinitis and atopic dermatitis in children born after IVF, and controls born after spontaneous pregnancy using questionnaires of International Study of Asthma and Allergies in Children (ISAAC).

METHODS

We recruited 158 children (mean age: 4.60 +/- 2.14 years) born after IVF pregnancies and 102 children (mean age: 5.27 +/- 2.8 years) as control group to investigate the prevalences of asthma, atopic dermatitis and allergic rhinitis. The questions in the questionnaire were asked to the parents by telephone or face to face.

RESULTS

Wheezing ever has been reported in 19 % of the children born after IVF and in 17.6 % of the control group (p > 0.05). No significant differences were found between groups, in terms of use of any anti-asthma drugs, physician diagnosed asthma and admission to emergency room with wheezing (p > 0.05). In addition, prevalence of allergic rhinitis and atopic dermatitis were also comparable between two groups (p > 0.05).

CONCLUSIONS

Prevalences of asthma, allergic rhinitis and atopic dermatitis are similar in children born after IVF and children born after spontaneous conception.

Fish oil supplementation in pregnancy and lactation may decrease the risk of infant allergy

Maternal intake of omega-3 (omega-3) polyunsaturated fatty acids (PUFAs) during pregnancy has decreased, possibly contributing to a current increased risk of childhood allergy.

AIM

To describe the effects of maternal omega-3 long-chain PUFA supplementation during pregnancy and lactation on the incidence of allergic disease in infancy.

METHODS

One hundred and forty-five pregnant women, affected by allergy themselves or having a husband or previous child with allergies, were included in a randomized placebo-controlled trial. Daily maternal supplementation with either 1.6 g eicosapentaenoic acid and 1.1 g docosahexaenoic acid or placebo was given from the 25(th) gestational week to average 3-4 months of breastfeeding. Skin prick tests, detection of circulating specific immunoglobulin E (IgE) antibodies and clinical examinations of the infants were performed.

RESULTS

The period prevalence of food allergy was lower in the omega-3 group (1/52, 2%) compared to the placebo group (10/65, 15%, p < 0.05) as well as the incidence of IgE-associated eczema (omega-3 group: 4/52, 8%; placebo group: 15/63, 24%, p < 0.05).

CONCLUSION

Maternal omega-3 fatty acid supplementation may decrease the risk of food allergy and IgE-associated eczema during the first year of life in infants with a family history of allergic disease.

Early intervention with suplatast tosilate for prophylaxis of pediatric atopic asthma: a pilot study

The onset of asthma may be related to Th2 cytokine dominance at the time when food allergies occur several months after birth. This study investigated the effectiveness of early intervention with a Th2 cytokine inhibitor (suplatast tosilate) for prevention of asthma in infants with food allergies and atopic dermatitis. Suplatast tosilate dry syrup (6 mg/kg daily) or a histamine H(1)-blocker (ketotifen fumarate dry syrup: 0.06 mg/kg daily) was administered randomly to 53 infants with atopic dermatitis caused by food allergies. The primary endpoints were the incidence of asthma and the time to the onset of wheezing. The peripheral blood Th1/Th2 ratio, total IgE level, and eosinophil count were measured before and after treatment. After 24 months of treatment, the prevalence of asthma was significantly lower in the suplatast group (20.8%) than in the ketotifen group (65.6%, p < 0.01). Additionally, the time from the start of treatment to the initial episode of wheezing for infants who developed asthma was significantly longer in the suplatast group than the ketotifen group (p < 0.01). Furthermore, the eosinophil count was significantly decreased by suplatast treatment (p < 0.05), and there was a significant difference between the suplatast and ketotifen groups with respect to both the eosinophil count (p < 0.01) and the Th1/Th2 ratio (p < 0.05). The results of the present pilot study suggest that suplatast tosilate is useful for the primary prevention of wheezing and asthma in children.

Effects of winter birth season and prenatal cockroach and mouse allergen exposure on indoor allergen-specific cord blood mononuclear cell proliferation and cytokine production

BACKGROUND

Season of birth has been associated with the development of atopy and asthma. Relationships among a particular birth season, maternal allergen exposure during the birth season, and childhood development of allergies to allergens in higher concentration during the birth season may be important.

OBJECTIVE

To investigate the effects of winter birth (January 1 to March 31) and prenatal cockroach and mouse allergens in settled dust on indoor allergen-specific cord blood mononuclear cell (CBMC) proliferation, TH2 production, and cord blood IgE concentration.

METHODS

As part of an ongoing prospective study, 350 cord blood samples were collected. The CBMCs were cultured with cockroach, dust mite, and mouse protein extracts, and proliferation was measured. Interleukin 5, interferon-delta, and total IgE levels were measured. Home dust samples were analyzed for cockroach and mouse allergens.

RESULTS

An isolated association was observed between winter birth and a greater mean (SD) cockroach interleukin 5 ratio (winter vs nonwinter birth: 26,043 [11,403] vs 11,344 [3,701]; P = .02). Other associations between winter birth and increased CBMC proliferation, T-helper cytokines, or cord blood IgE levels were not detected. Higher mouse allergen levels were associated with decreased mouse-induced proliferation (winter vs nonwinter birth: mean [SD] stimulation index, 1.72 [0.12] vs 2.02 [0.11]; P = .04).

CONCLUSIONS

Winter birth and increased cockroach or mouse allergen levels during pregnancy were not consistently associated with greater CBMC proliferation, T-helper cytokine production, or cord blood IgE levels. Greater indoor allergen exposure during pregnancy does not seem to affect the development of cockroach or mouse immune responses in utero.

A EuroPrevall review of factors affecting incidence of peanut allergy: priorities for research and policy

Peanuts are extensively cultivated around the world, providing a foodstuff that is both cheap to produce and nutritious. However, allergy to peanuts is of growing global concern, particularly given the severity of peanut-allergic reactions, which can include anaphylaxis and death. Consequently, it is important to understand the factors related to the prevalence of peanut allergy in order to inform efforts to ameliorate or pre-empt the condition. In this article we review evidence for the relevance of factors hypothesized to have some association with allergy prevalence, including both genetic and environmental factors. Although our analysis does indicate some empirical support for the importance of a number of factors, the key finding is that there are significant data gaps in the literature that undermine our ability to provide firm conclusions. We highlight these gaps, indicating questions that need to be addressed by future research.

Increased activation of GATA-3, IL-2 and IL-5 of cord blood mononuclear cells in infants with IgE sensitization

Risk of allergic diseases has been linked to abnormal patterns of fetal immune development, suggesting that priming of the immune system may occur in utero. The aim of the study was to investigate whether the pattern of immune response in cord blood mononuclear cells (CBMC) shows association with allergic diseases and IgE sensitization at 2 yr of age, and to study the effect of maternal probiotic supplementation on CBMC immune responses. CBMC were isolated from 98 neonates in a randomized double-blinded intervention study. CBMC were stimulated with beta-lactoglobulin, and phytohemaglutinin (PHA). Secretion of interferon-gamma (IFN-gamma), interleukin-5 (IL-5), and IL-13 was measured by an ELISA; IL-2, IL-4, and IL-10 by a cytokine bead assay. T-cell polarization-associated IL-4 receptor and IL-12R expressions, and the respective transcription factors GATA-3 and T-bet were analyzed with RT-PCR. The above responses were compared with the development of allergic diseases and IgE sensitization at 2 yr of age, and with the maternal probiotic or placebo supplementation. PHA-stimulated GATA-3 expression and IL-2 secretion in CBMC were higher in IgE-sensitized children at an age of 2 yr than in the non-sensitized, non-allergic children (p = 0.03 and 0.026). PHA-induced expression of GATA-3 correlated with IL-5 (p = 0.003, r = 0.300) and IL-13 (p = 0.007, r = 0.278) secretion of CBMC, and IL-5 secretion of beta-lactoglobulin-stimulated CBMC was higher in IgE-sensitized children at 2 yr of age than in the non-sensitized, non-allergic children (p = 0.013). Probiotic bacteria had no effect on CBMC immune responses. In CBMC-enhanced induction of GATA-3, which activates several Th2 cytokines genes, was a risk factor for IgE sensitization. The immune deviation towards Th2-type immunity developed already in utero and seemed to modulate the pattern of immune response favoring an IgE response to environmental antigens.

Fetal Programming

Research on young animals and humans has demonstrated the critical importance of the fetal stage as a formative period in normal development. However, the significance of these findings has not always been incorporated into our thinking when trying to elucidate the origins of health and disease. It is not only that babies react to the state of the mother and to salient environmental events while still in the uterus. This stimulation and priming seems to be essential for guiding the optimal maturation of the nervous, endocrine, and immune systems. Experiences during prenatal life also program the regulatory set points that will govern physiology in adulthood. During this malleable maturational phase, these biological processes should be viewed as flexible “learning systems” that guide the developmental trajectory toward health or derail it toward pathology. Our studies on infant primates have shown that the competence of their immune responses and the structure and activity of certain brain regions, as well as many aspects of behavior and emotional reactivity, are strongly affected by the pregnancy conditions of their mothers.

Fetal cord blood: aspects of heightened immune responses

Neonatal immune responses have been associated with the development of atopy in childhood. We assessed in cord blood mononuclear cells (CBMC) whether increased allergen/mitogen-induced lymphoproliferation (LP) is associated with pro-allergic Th2 cytokine IL-13 or Th1 cytokine IFN-gamma secretion. We determined whether LP to one allergen is related to heightened lymphocyte function to other allergens/mitogen. CBMC from 135 neonates were stimulated with house dust mite (Derf1), cockroach, ovalbumin, or mitogen. LP to one allergen was associated with significantly increased LP to other allergens/mitogen. Increased Derf1-LP was associated with increased Derf1-induced IL-13 secretion (r = 0.21, p = 0.01). After adjusting for neonatal gender, race, and maternal smoking, Derf1-LP remained associated with Derf1-IL-13 (OR 3.08, 95% CI 1.56-6.10). Increased mitogen-induced proliferation was associated with increased mitogen-induced IL-13 secretion (r = 0.37, p < 0.001). For some individuals, a predisposition to a heightened immune response is already evident at birth. Whether this phenotype results in atopy in childhood warrants further investigation.