Preconceptional exposure to oral contraceptive pills and the risk of wheeze, asthma and rhinitis in children

Overviewing allergy epidemiology in Japan - Findings from birth cohorts (JECS and T-Child study)

The escalating global allergy epidemic has emerged as a pressing and persistent challenge, exerting a profound impact on human health systems across centuries. This burgeoning predicament can be attributed to contemporary lifestyles, environmental influences, and genetic predispositions. The manifestation of allergy-related factors exhibits dynamic fluctuations contingent on temporal shifts, geographical distinctions, cultural variances, and diverse demographic strata. In this review, we present recent epidemiological insights derived from two distinct birth cohorts: the Japan Environment and Children's Study (JECS), encompassing the entirety of Japan, and the Tokyo Children's Health, Illness, and Development Study (T-Child Study) within Tokyo. Through this comprehensive review, we offer a comprehensive overview of the latest epidemiological discoveries stemming from these pivotal Japanese birth cohorts, thereby affording a unique opportunity to deliberate on imperative strategies for the optimal management of the allergy epidemic.

Preconception origins of asthma, allergies and lung function: The influence of previous generations on the respiratory health of our children

Emerging research suggests that exposures occurring years before conception are important determinants of the health of future offspring and subsequent generations. Environmental exposures of both the father and mother, or exposure to disease processes such as obesity or infections, may influence germline cells and thereby cause a cascade of health outcomes in multiple subsequent generations. There is now increasing evidence that respiratory health is influenced by parental exposures that occur long before conception. The strongest evidence relates adolescent tobacco smoking and overweight in future fathers to increased asthma and lower lung function in their offspring, supported by evidence on parental preconception occupational exposures and air pollution. Although this literature is still sparse, the epidemiological analyses reveal strong effects that are consistent across studies with different designs and methodologies. The results are strengthened by mechanistic research from animal models and (scarce) human studies that have identified molecular mechanisms that can explain the epidemiological findings, suggesting transfer of epigenetic signals through germline cells, with susceptibility windows in utero (both male and female line) and prepuberty (male line). The concept that our lifestyles and behaviours may influence the health of our future children represents a new paradigm. This raises concerns for future health in decades to come with respect to harmful exposures but may also open for radical rethinking of preventive strategies that may improve health in multiple generations, reverse the imprint of our parents and forefathers, and underpin strategies that can break the vicious circle of propagation of health inequalities across generations.

Eczema phenotypes and IgE component sensitization in adolescents: A population-based birth cohort

BACKGROUND

Eczema patients are commonly immunoglobulin (Ig)E polysensitized. Although atopic dermatitis (AD) phenotypes have been recognized, IgE sensitization patterns based on AD phenotypes have not been well illustrated. We aimed to investigate how eczema phenotypes impact IgE component sensitization patterns.

METHODS

This birth cohort study investigated a general population in the Tokyo Children's Health, Illness, and Development Study (T-Child Study) until children reached the age of 13 years. Eczema was assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Allergen component specific IgE antibody titers were measured using a multiplex array ImmunoCAP ISAC.

RESULTS

Persistent eczema phenotype until adolescence was strongly associated with allergic march symptoms, such as wheezing and hay fever, and oral allergy symptoms, and IgE component sensitizations of airborne (Japanese cedar, house dust mite, Timothy, cat, and dog) and cross-reactive allergens (Bet v 1 family) compared to early-remission and late-onset eczema. On the other hand, late-onset eczema did not show any strong associations with allergic symptoms and IgE sensitization. Adolescents with persistent eczema have high comorbidity of symptoms of pollen-food allergy syndrome.

CONCLUSIONS

Early-onset eczema is deeply connected with the later allergic march, and late-onset eczema differs from the phenotype of allergic march. Early-onset eczema characterizing IgE sensitization was likely to be an extrinsic type, and late-onset eczema, which was not related to IgE sensitization, was likely an intrinsic type. Pollen-Food Allergy Syndrome is one of the allergic features in allergic march.

Population-based study of the association between asthma and exogenous female sex hormone use

OBJECTIVES

Several studies have suggested the influence of exogenous hormones on asthma, but the results are still conflicting. Moreover, there has been little associated research on Asian population. This study aimed to assess the association between use of exogenous female sex hormones and asthma in Korean women.

DESIGN

Korea National Health and Nutrition Examination Survey (KNHANES) is a nationwide programme to assess national health and nutritional status in Korea. A population-based study was conducted to analyse the relationship between self-reported asthma and exogenous hormones using the KNHANES between 2007 and 2012.

PARTICIPANTS

The study sample included 6874 premenopausal and 4912 postmenopausal women aged 30-65.

OUTCOME MEASURES

KNHANES data comprised health interviews and physical examinations. Questionnaires regarding asthma, reproductive factors and exogenous hormones were included.

RESULTS

Among postmenopausal women, 3.4% reported doctor-diagnosed asthma. Hormone replacement therapy (HRT) was associated with increased odds of doctor-diagnosed asthma (OR 1.56; 95% CI 1.04 to 2.35), while the association between HRT and wheeze in the last 1 year was not significant (OR 1.37; 95% CI 0.95 to 1.96). In premenopausal women, the prevalence of asthma was 2.3%. Use of oral contraceptives (OCs) was associated with an increased odds of doctor-diagnosed asthma (OR 1.67; 95% CI 1.01 to 2.76) and wheeze in the last 1 year (OR 1.88; 95% CI 1.31 to 2.69). These associations were dominant among non-obese women (body mass index <25 kg/m²; OR 2.36; 95% CI 1.34 to 4.17 for asthma and OR 2.15; 95% CI 1.43 to 3.23 for wheeze).

CONCLUSIONS

HRT and OCs were associated with increased asthma in postmenopausal and premenopausal women, respectively. The association between OC use and asthma was strong in non-obese premenopausal women.

The Exposome Approach in Allergies and Lung Diseases: Is It Time to Define a Preconception Exposome?

Emerging research suggests environmental exposures before conception may adversely affect allergies and lung diseases in future generations. Most studies are limited as they have focused on single exposures, not considering that these diseases have a multifactorial origin in which environmental and lifestyle factors are likely to interact. Traditional exposure assessment methods fail to capture the interactions among environmental exposures and their impact on fundamental biological processes, as well as individual and temporal factors. A valid estimation of exposure preconception is difficult since the human reproductive cycle spans decades and the access to germ cells is limited. The exposome is defined as the cumulative measure of external exposures on an organism (external exposome), and the associated biological responses (endogenous exposome) throughout the lifespan, from conception and onwards. An exposome approach implies a targeted or agnostic analysis of the concurrent and temporal multiple exposures, and may, together with recent technological advances, improve the assessment of the environmental contributors to health and disease. This review describes the current knowledge on preconception environmental exposures as related to respiratory health outcomes in offspring. We discuss the usefulness and feasibility of using an exposome approach in this research, advocating for the preconception exposure window to become included in the exposome concept.

Impact of swimming school attendance in 3-year-old children with wheeze and rhinitis at age 5 years: A prospective birth cohort study in Tokyo

Background

In Japan, swimming school attendance is promoted as a form of therapy or as a prophylactic measure against asthma in young children. However, the putative beneficial effects have not been sufficiently verified.

Objective

The aim of the present study was to clarify whether or not swimming school attendance at age 3 years affects the onset and/or improvement of wheeze and rhinitis at age 5 years.

Methods

This study was a single-center, prospective, general, longitudinal cohort study (T-CHILD Study). Between November 2003 and December 2005, 1776 pregnant women were enrolled, and their offspring were followed up until age 5 years. Swimming school attendance at age 3 years and the presence of wheeze and/or rhinitis in the previous one year were examined using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. The relationship between swimming school attendance and wheeze and/or rhinitis was analyzed using multivariable logistic regression analysis.

Results

Data on the 1097 children were analyzed. At age 3 years, 126 (11.5%) children attended a swimming school, and at age 5 years, the prevalence of wheeze was 180 (16.4%) while that of rhinitis was 387 (35.3%). Swimming school attendance at age 3 showed no significant relationship with the development of either wheeze (aOR 0.83, 95% CI (0.43–1.60) or rhinitis (aOR 0.80, 95% CI (0.43–1.60) at age 5.

Conclusions

Swimming school attendance at age 3 years showed neither a preventive nor therapeutic effect on wheeze or rhinitis at age 5 years. There is thus no scientific evidence yet that swimming school attendance has a positive impact on the development of childhood wheeze or rhinitis.

Maternal oral contraceptive pill use and the risk of atopic diseases in the offspring: A systematic review and meta-analysis

Studies of maternal oral contraceptive pill (OCP) exposure and the offspring's risk of atopic diseases are of current interest due to concerns about widespread use of OCP before or during pregnancy.We evaluated whether maternal OCP exposure is associated with an increased risk of atopic diseases by reviewing the literature and performing a meta-analysis. The PubMed and Embase databases were searched to identify potential studies for inclusion. Three common atopic outcomes were included: asthma, eczema, and rhinitis.We found 693 titles, abstracts, and citations, and 6 studies were included in this analysis. A meta-analysis revealed that maternal OCP exposure was associated with higher odds of asthma (odds ratio [OR] 1.1; 95% confidence interval [CI] 1.02-1.19; P = .014), rhinitis (OR 1.34; 95% CI 1.07-1.68; P = .011) during childhood, whereas there was no association with eczema (OR 1.17; 95% CI 0.81-1.68; P = .383). This analysis was limited by the small number of studies included and the limited adjustments for the possible confounders in the studies.Current evidence suggests that maternal OCP exposure increases the risk for respiratory allergic diseases (asthma and rhinitis) in the offspring, but not for eczema. Given the few studies included, future larger, prospective studies that control for important confounders are needed to verify our findings.

Exploratory analysis of plasma cytokine/chemokine levels in 6-year-old children from a birth cohort study

This study aimed to reveal a new dimension of allergy profiles in the general population by using machine learning to explore complex relationships among various cytokines/chemokines and allergic diseases (asthma and atopic dermatitis; AD). We examined the symptoms related to asthma and AD and the plasma levels of 72 cytokines/chemokines obtained from a general population of 161 children at 6 years of age who participated in a pilot birth cohort study of the Japan Environment and Children's Study (JECS). The children whose signs and symptoms fulfilled the criteria of AD, which are mostly based on questionnaire including past symptoms, tended to have higher levels of the two chemokine ligands, CCL17 and CCL27, which are used for diagnosis of AD. On the other hand, another AD-related chemokine CCL22 level in plasma was higher only in children with visible flexural eczema, which is one of AD diagnostic criteria but was judged on the same day of blood examination unlike other criteria. Here, we also developed an innovative method of machine learning for elucidating the complex cytokine/chemokine milieu related to symptoms of allergic diseases by using clustering analysis based on the random forest dissimilarity measure that relies on artificial intelligence (AI) technique. To our surprise, the majority of children showing at least any asthma-related symptoms during the last month were divided by AI into the two clusters, either cluster-2 having elevated levels of IL-33 (related to eosinophil activation) or cluster-3 having elevated levels of CXCL7/NAP2 (related to neutrophil activation), among the total three clusters. Future studies will clarify better approach for allergic diseases by endotype classification.

IgE responses to multiple allergen components among school-aged children in a general population birth cohort in Tokyo

BACKGROUND

Response patterns to allergen components among Japanese children have not been studied extensively.

OBJECTIVE

Our aim was to examine the differences in sensitization patterns at ages 5 years and 9 years to identify longitudinal changes in the degree and patterns of sensitization in a birth cohort of Japanese children.

METHODS

Our study enrolled 984 children at aged 5 years between 2008 and 2010, and 729 children aged 9 years between 2012 and 2014. Allergic diseases were assessed using the ISAAC and UK Working Party's Diagnostic Criteria. Serum-specific IgE titers to allergen components were measured by multiplex array ImmunoCAP ISAC when the children were aged 5 and 9 years. Principal component analysis (PCA) was performed to characterize IgE sensitization to allergen components.

RESULTS

The prevalence of allergic rhinitis increased considerably over time (10.6%-31.2%). Furthermore, the sensitization prevalence to allergen-specific IgE (sIgE) also increased from 57.8% at age 5 years to 74.8% at age 9 years. IgE sensitization prevalence to Der f 1 (mites) was 42.1% at age 5 years and 54.3% at age 9 years. Furthermore, children were highly sensitized to Cry j 1 (Japanese cedar) (32.8% at age 5 years and 57.8% at age 9 years). Principle component analysis showed that sensitization to PR-10 cross-reactive components was independent of sensitization to mite and that no children acquired sensitization to pollen before acquiring sensitization to mite.

CONCLUSIONS

The prevalence of allergic rhinitis and related allergen components increased from age 5 years to age 9 years in Japanese children.

Influence of antibiotic use in early childhood on asthma and allergic diseases at age 5

BACKGROUND

In the past few decades, the prevalence of allergic diseases has increased rapidly worldwide. At the same time, the overuse of antibiotics has been observed, especially in Japan.

OBJECTIVE

To elucidate the association of early childhood antibiotic use with allergic diseases in later childhood at 5 years of age.

METHODS

Relevant data were extracted from the hospital-based birth cohort study, the Tokyo Children's Health, Illness and Development Study. To identify signs of asthma and allergic diseases in children, the International Study of Asthma and Allergies in Childhood questionnaire was used. Logistic regression models were applied to estimate the effect of antibiotic use on outcomes in later life.

RESULTS

Antibiotic exposure in children within the first 2 years of life was associated with current asthma (adjusted odds ratio [aOR] 1.72, 95% confidence interval [CI] 1.10-2.70), current atopic dermatitis (aOR 1.40, 95% CI 1.01-1.94), and current allergic rhinitis (aOR 1.65, 95% CI 1. 05-2.58) at 5 years of age. Analysis of the associations by type of antibiotics showed that cephem was associated with current asthma (aOR 1.97, 95% CI 1.23-3.16) and current rhinitis (aOR 1.82, 95% CI 1.12-2.93), and macrolide was associated with current atopic dermatitis (aOR 1.58, 95% CI 1.07-2.33).

CONCLUSION

Our findings suggest that antibiotic use within the first 2 years of life was a risk factor for current asthma, current atopic dermatitis, and current allergic rhinitis in 5-year-old children.

Periconception endogenous and exogenous maternal sex steroid hormones and risk of asthma and allergy in offspring: protocol for a systematic review and meta-analysis

INTRODUCTION

Pregnancy is associated with several hormonal changes which influence the developing fetus. Variations in maternal endogenous hormones and prepregnancy use of hormonal preparations have been linked to asthma and allergy in the offspring, but findings are inconsistent. We plan to undertake a systematic review to synthesise the evidence on the association between endogenous and exogenous maternal sex hormones and the risk of asthma and allergy in the offspring.

METHODS AND ANALYSIS

We will search Medline, Embase, Cochrane Library, Institute of Scientific Information Web of Science, Cumulative Index of Nursing and Allied Health, Scopus, Google Scholar, Allied and Complementary Medicine Database, Global Health, Psychological Information (PsycINFO), Centre for Agriculture and Bioscience (CAB) International and WHO Global Health Library from inception until 2016 to identify relevant studies on the topic. Additional studies will be identified by searching databases of proceedings of international conferences, contacting international experts in the field and searching the references cited in identified studies. We will include analytical epidemiological studies. Two researchers will independently screen identified studies, undertake data extraction and assess risk of bias in eligible studies, while a third reviewer will arbitrate any disagreement. We will use the Effective Public Health Practice Project tool to assess the risk of bias in the studies. We will perform a random-effects meta-analysis to synthesise the evidence. We will use the Grading of Recommendations Assessment, Development and Evaluation approach to rate the strength and quality of the overall evidence with respect to each outcome.

ETHICS AND DISSEMINATION

Ethical approval is not required since the study is a systematic review of published literature. Our findings will be reported in a peer-reviewed scientific journal.

PROSPERO REGISTRATION NUMBER

CRD42016048324.

Timing of eczema onset and risk of food allergy at 3 years of age: A hospital-based prospective birth cohort study

BACKGROUND

Although recent studies suggest that eczema in early childhood is important in the development of food allergy, the importance of the timing of eczema onset has not been fully clarified.

OBJECTIVE

This study aim to identify an association between the timing of eczema onset and development of food allergy in a prospective birth cohort study.

METHODS

Data were obtained from the Tokyo Children's Health, Illness and Development (T-CHILD) study, which is a hospital-based birth cohort study currently in progress in Japan. A total of 1550 children were born to the recruited women. Outcome data for children were collected from questionnaires completed at 6 months, 1 and 3 years of age. Association between the timing of eczema onset and development of food allergy was estimated by logistic regression analyses. All analysis were performed using SPSS software with a two-sided 5% significance level.

RESULTS

Eczema in the first year of life was a significant risk factor in multivariate analysis (aOR 3.90, 95% CI 2.34-6.52, p<0.001). In each age (by month) stratum, infants with onset of eczema within the first 1-2 months after birth had the highest risk of food allergy at 3 years of age (aOR 6.61, 95% CI 3.27-13.34, p<0.001).

CONCLUSION

Infants with early eczema onset (especially within the first 1-4 months after birth) were found to have an increased risk of developing food allergy at 3 years of age. Our findings may contribute to a better understanding of the timing of eczema onset as a potentially modifiable risk factor and to defining those who may need to be on guard for food allergy.