Integrating Clinical and Epidemiologic Data on Allergic Diseases Across Birth Cohorts: A Harmonization Study in the Mechanisms of the Development of Allergy Project

Organic Food Consumption Might Protect Against Sensitisation to Inhalant Allergens at School Age: The PARIS Cohort

BACKGROUND

Interest has grown recently in childhood diet's role in allergy development. However, the studies focusing on organic food consumption are scarce. We address the relationships between such consumption and respiratory/allergic morbidity at school age in the PARIS (Pollution and asthma risk: An infant study) cohort.

METHODS

Diet was assessed using a food frequency questionnaire completed by the parents at 8 years. Dietary patterns were identified by cluster analysis based on the consumption frequency of 30 foods (either organic or conventional) and 19 organic foods. Associations between dietary patterns and respiratory/allergic morbidity (asthma, rhinitis, eczema and sensitisation) were studied using multivariable logistic regression models adjusted for potential confounders, including family socioeconomic status and adherence to the Mediterranean diet as a proxy for dietary balance.

RESULTS

Among 1258 children, three dietary patterns were identified, which differed significantly in terms of organic food consumption frequency: low frequency in G0 (51% of children), moderate in G1 (28%) and high in G2 (21%). No association was found between dietary patterns and asthma, eczema, rhinitis or sensitisation to food allergens. Children in G2 had lower likelihood of sensitisation to any allergen than those in G0 (adjusted odds ratio [aOR] = 0.60; 95% confidence interval [CI]: 0.40-0.91), particularly to inhalant allergens (aOR = 0.64; 95% CI: 0.42-0.99).

CONCLUSIONS

Our findings suggest that frequent organic food consumption may be protective against allergic sensitisation at school age, based on the assumption that organic food consumption at the age of eight reflects consumption at earlier ages. Further research is warranted to explore the underlying mechanisms for this association, including nutritional and environmental exposures.

Advancing Understanding of Childhood Asthma: Lessons Learned from Birth Cohort Studies

Asthma and allergies are some of the most common chronic disorders affecting children, the prevalence of which has been increasing in countries and regions undergoing rapid development like China. To curb the rising tide of allergies and safeguard the health of future generations, it is of critical importance to understand how asthma inception is influenced by factors acting at different life stages. Birth cohorts represent a powerful tool to investigate the temporal sequence of exposures along the natural course of asthma. We examined recent evidence on birth cohort studies of asthma and allergic diseases and evaluated their strengths and weaknesses. Essential elements for a successful birth cohort are proposed to further elucidate asthma etiology and pathogenies. Initiating new cohorts in understudied populations with the application of advanced analytical approaches will be needed. Moreover, fostering collaborative networks using standardized methodologies should be prioritized to enable integration of findings across diverse cohorts. There remains an urgent and unmet need to further translate the seminal findings from asthma birth cohort studies into targeted primary prevention strategies to eradicate the disease.

Life course of retrospective harmonization initiatives: key elements to consider

Optimizing research on the developmental origins of health and disease (DOHaD) involves implementing initiatives maximizing the use of the available cohort study data; achieving sufficient statistical power to support subgroup analysis; and using participant data presenting adequate follow-up and exposure heterogeneity. It also involves being able to undertake comparison, cross-validation, or replication across data sets. To answer these requirements, cohort study data need to be findable, accessible, interoperable, and reusable (FAIR), and more particularly, it often needs to be harmonized. Harmonization is required to achieve or improve comparability of the putatively equivalent measures collected by different studies on different individuals. Although the characteristics of the research initiatives generating and using harmonized data vary extensively, all are confronted by similar issues. Having to collate, understand, process, host, and co-analyze data from individual cohort studies is particularly challenging. The scientific success and timely management of projects can be facilitated by an ensemble of factors. The current document provides an overview of the 'life course' of research projects requiring harmonization of existing data and highlights key elements to be considered from the inception to the end of the project.

Sex specific associations between in utero exposure to persistent organic pollutants and allergy-related outcomes in childhood: The Rhea Mother-Child Cohort (Crete, Greece)

Accumulating evidence suggests that in utero exposures can influence the development of the immune system. Few studies have investigated whether prenatal exposure to persistent organic pollutants (POPs) is associated with allergy-related phenotypes in childhood, nor explored sex differences. We examined the association between prenatal exposure to POPs and offspring allergic outcomes in early and mid-childhood. We included 682 mother-child pairs from the prospective birth cohort Rhea. We measured dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and 6 polychlorinated biphenyl (PCB) congeners in maternal first trimester serum. Parents completed the questionnaires adapted from the International Study on Asthma and Allergy in Childhood (ISAAC) for allergy-related phenotypes when their children were 4 and 6 years old. We used Poisson regression models to estimate Risk Ratios. Prenatal HCB was associated with increased risk for rhinoconjunctivitis at 6 years (RR (95% CI): 2.5; (1.3, 4.8) for a doubling in the exposure). Among girls, prenatal DDE was associated with increased risk for current wheeze, current asthma and current rhinoconjunctivitis at 4 years (RR (95%CI): 1.4 (0.8, 2.6), 1.6 (1.1, 2.4) and 1.8 (1.0, 3.3) and p-interaction = 0.035, 0.027 and 0.059, respectively), with increased risk for current rhinoconjunctivitis at 6 years (RR (95%CI): 1.7 (0.7, 3.8) and p-interaction = 0.028) and total PCBs were associated with increased risk for current eczema at 4 years (RR (95%CI): 2.1 (1.1, 4.2) and p-interaction = 0.028). In boys, prenatal DDE was associated with decreased risk for current wheeze and current asthma at 4 years. Our findings suggest that even low levels of exposure to POPs prenatally may affect the development of childhood allergy-related outcomes in a sex and age-specific manner.

The continuing evolution of birth cohort studies: achievements and challenges

Well-designed birth cohorts are able to estimate prevalence/distribution of various health events/outcomes, and to link early-life origins with adult health and function. The past two decades have seen a surge in the establishment of new birth cohorts and their accompanying research. We discussed distinct designs of current birth cohort studies, reviewed their achievements, and highlighted insights obtained from birth cohort studies, as well as challenges we are facing. Birth cohort studies are providing increasing opportunities to identify determining factors for short- and long-term health, yielding substantial evidence to uncover biological mechanisms of diseases and phenotypes, and providing further insights for public health. Dynamic monitoring, accurate measurements, long-term follow-ups and collaborative efforts are warranted in new birth cohorts to elucidate the nature of life course relationships in contemporary generation.

Establishing the value of genomics in medicine: the IGNITE Pragmatic Trials Network

PURPOSE

A critical gap in the adoption of genomic medicine into medical practice is the need for the rigorous evaluation of the utility of genomic medicine interventions.

METHODS

The Implementing Genomics in Practice Pragmatic Trials Network (IGNITE PTN) was formed in 2018 to measure the clinical utility and cost-effectiveness of genomic medicine interventions, to assess approaches for real-world application of genomic medicine in diverse clinical settings, and to produce generalizable knowledge on clinical trials using genomic interventions. Five clinical sites and a coordinating center evaluated trial proposals and developed working groups to enable their implementation.

RESULTS

Two pragmatic clinical trials (PCTs) have been initiated, one evaluating genetic risk APOL1 variants in African Americans in the management of their hypertension, and the other to evaluate the use of pharmacogenetic testing for medications to manage acute and chronic pain as well as depression.

CONCLUSION

IGNITE PTN is a network that carries out PCTs in genomic medicine; it is focused on diversity and inclusion of underrepresented minority trial participants; it uses electronic health records and clinical decision support to deliver the interventions. IGNITE PTN will develop the evidence to support (or oppose) the adoption of genomic medicine interventions by patients, providers, and payers.

Associations between air pollution and pediatric eczema, rhinoconjunctivitis and asthma: A meta-analysis of European birth cohorts

BACKGROUND

Uncertainly continues to exist regarding the role of air pollution on pediatric asthma and allergic conditions, especially as air pollution levels have started to decrease in recent decades.

OBJECTIVE

We examined associations of long-term air pollution levels at the home address with pediatric eczema, rhinoconjunctivitis and asthma prevalences in five birth cohorts (BIB, EDEN, GASPII, RHEA and INMA) from seven areas in five European countries.

METHODS

Current eczema, rhinoconjunctivitis and asthma were assessed in children aged four (N = 6527) and eight years (N = 2489). A multi-morbidity outcome (≥2 conditions versus none) was also defined. Individual outdoor levels of nitrogen dioxide (NO₂), nitrogen oxides, mass of particulate matter with an aerodynamic diameter <10 μm (PM₁₀), 10-2.5 μm (PM_coarse) and <2.5 μm (PM_2.5), and PM_2.5 absorbance were assigned to the birth, four- and eight-year home addresses using highly defined spatial air pollution exposure models. Cohort-specific cross-sectional associations were assessed using logistic regression models adjusted for demographic and environmental covariates and combined in a random effects meta-analysis.

RESULTS

The overall prevalence of pediatric eczema, rhinoconjunctivitis and asthma at four years was 15.4%, 5.9% and 12.4%. We found no increase in the prevalence of these outcomes at four or eight years with increasing air pollution exposure. For example, the meta-analysis adjusted odds ratios (95% confidence intervals) for eczema, rhinoconjunctivitis and asthma at four years were 0.94 (0.81, 1.09), 0.90 (0.75, 1.09), and 0.91 (0.74, 1.11), respectively, per 10 μg/m³ increase in NO₂ at the birth address, and 1.00 (0.81, 1.23), 0.70 (0.49, 1.00) and 0.88 (0.54, 1.45), respectively, per 5 μg/m³ increase in PM_2.5 at the birth address.

DISCUSSION

In this large meta-analysis of five birth cohorts, we found no indication of adverse effects of long-term air pollution exposure on the prevalence of current pediatric eczema, rhinoconjunctivitis or asthma.

Prioritizing research challenges and funding for allergy and asthma and the need for translational research-The European Strategic Forum on Allergic Diseases

The European Academy of Allergy and Clinical Immunology (EAACI) organized the first European Strategic Forum on Allergic Diseases and Asthma. The main aim was to bring together all relevant stakeholders and decision-makers in the field of allergy, asthma and clinical Immunology around an open debate on contemporary challenges and potential solutions for the next decade. The Strategic Forum was an upscaling of the EAACI White Paper aiming to integrate the Academy's output with the perspective offered by EAACI's partners. This collaboration is fundamental for adapting and integrating allergy and asthma care into the context of real-world problems. The Strategic Forum on Allergic Diseases brought together all partners who have the drive and the influence to make positive change: national and international societies, patients' organizations, regulatory bodies and industry representatives. An open debate with a special focus on drug development and biomedical engineering, big data and information technology and allergic diseases and asthma in the context of environmental health concluded that connecting science with the transformation of care and a joint agreement between all partners on priorities and needs are essential to ensure a better management of allergic diseases and asthma in the advent of precision medicine together with global access to innovative and affordable diagnostics and therapeutics.

Sex-specific incidence of asthma, rhinitis and respiratory multimorbidity before and after puberty onset: individual participant meta-analysis of five birth cohorts collaborating in MeDALL

Introduction

To understand the puberty-related sex shift in the prevalence of asthma and rhinitis as single entities and as respiratory multimorbidities, we investigated if there is also a sex-specific and puberty-related pattern of their incidences.

Methods

We used harmonised questionnaire data from 18 451 participants in five prospective observational European birth cohorts within the collaborative MeDALL (Mechanisms of the Development of Allergy) project. Outcome definitions for IgE-associated and non-IgE-associated asthma, rhinitis and respiratory multimorbidity (first occurrence of coexisting asthma and rhinitis) were based on questionnaires and the presence of specific antibodies (IgE) against common allergens in serum. For each outcome, we used proportional hazard models with sex–puberty interaction terms and conducted a one-stage individual participant data meta-analysis.

Results

Girls had a lower risk of incident asthma (adjusted HR 0.67, 95% CI 0.61 to 0.74), rhinitis (0.73, 0.69 to 0.78) and respiratory multimorbidity (0.58, 0.51 to 0.66) before puberty compared with boys. After puberty onset, these incidences became more balanced across the sexes (asthma 0.84, 0.64 to 1.10; rhinitis 0.90, 0.80 to 1.02; respiratory multimorbidity 0.84, 0.63 to 1.13). The incidence sex shift was slightly more distinct for non-IgE-associated respiratory diseases (asthma 0.74, 0.63 to 0.87 before vs 1.23, 0.75 to 2.00 after puberty onset; rhinitis 0.88, 0.79 to 0.98 vs 1.20, 0.98 to 1.47; respiratory multimorbidity 0.66, 0.49 to 0.88 vs 0.96, 0.54 to 1.71) than for IgE-associated respiratory diseases.

Discussion

We found an incidence ‘sex shift’ in chronic respiratory diseases from a male predominance before puberty to a more sex-balanced incidence after puberty onset, which may partly explain the previously reported sex shift in prevalence. These differences need to be considered in public health to enable effective diagnoses and timely treatment in adolescent girls.