Farming in childhood, diet in adulthood and asthma history.

The decrease in the number of children living on traditional farms in France during early childhood and changes in diet could both play a role in the increase in asthma prevalence over the last decades. This study aimed to assess 1) the association of farming lifestyle in childhood and asthma, and 2) whether diet in adulthood modifies the association between farming lifestyle in childhood and adult-onset asthma. In the French Etude Epidemiologique des Femmes de la Mutuelle Générale de l'Education Nationale (E3N) study (54,018 females; age 43-68 yrs), three indicators of farming lifestyle were defined: one using individual data (having farmer parents) and two using ecological data (born in a rural area and exposure to cattle).

Phenotypic determinants of uncontrolled asthma.

Background: Although uncontrolled asthma remains frequent, determinants of asthma control are poorly studied.

Objectives: The aim was to estimate the distribution and the phenotypic characteristics of asthma control in 2 groups of subjects defined by the use of inhaled corticosteroids (ICS) in the past 12 months, in the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA).

Methods: Five hundred one adult current patients with asthma who participated in the follow-up of the EGEA study were included.

Cat sensitization according to cat window of exposure in adult asthmatics.

Background: In adults, there is limited information on tolerance to cat, which may be reflected by high IgG4 without IgE sensitization. Early exposure to cat may play a critical role.

Objective: The aim was to assess among adults the association of Fel d 1 IgG4, Fel d 1 IgE, skin prick test (SPT) response to cat and pet-related symptoms in relation to exposure to cat considering the period of exposure.

Heterogeneity of asthma according to blood inflammatory patterns.

Rationale: There is increasing interest regarding asthma heterogeneity in relation to inflammatory patterns.

Objectives: To assess phenotypic characteristics, in particular clinical presentation of the disease, in 381 well-characterised adults with asthma from the French Epidemiological study on the Genetics and Environment of Asthma (EGEA) according to their blood inflammatory pattern.

Methods: Four blood inflammatory patterns were defined according to eosinophil (EOS) and neutrophil (NEU) count cut-off points.

CD14 and toll-like receptor gene polymorphisms, country living, and asthma in adults.

Rationale: It has been shown that country living protects against asthma, which may be explained by microbial exposures.

Objectives: To study whether single nucleotide polymorphisms (SNPs) in CD14 and Toll-like receptor (TLR) 2, TLR4 and TLR9 genes are associated with asthma in adults, and whether these SNPs modify associations between country living and asthma.

Methods: Twenty-five SNPs in CD14, TLR2, TLR4, and TLR9 genes were genotyped in adult subjects from the French Epidemiological study on the Genetics and Environment of Asthma, Bronchial Hyperresponsiveness, and Atopy (EGEA).

Total serum IgE levels are associated with ambient ozone concentration in asthmatic adults.

Background: Effects of air pollution exposure on IgE-mediated response in asthmatics are poorly investigated. The aim was to examine the relationship between air pollution concentrations and total IgE levels in adult asthmatics.

Methods: The present study relates to the 369 asthmatic adults from the French Epidemiological study on Genetics and Environment of Asthma (EGEA), with availability of data on both total serum IgE measurements and air pollution concentrations.

Evidence for linkage of a new region (11p14) to eczema and allergic diseases.

Asthma, allergic rhinitis (AR) and atopic dermatitis also called eczema are allergic co-morbidites, which are likely to depend on pleiotropic genetic effects as well as on specific genetic factors. After a previous genome-wide linkage screen conducted for asthma and AR in a sample of 295 French EGEA families ascertained through asthmatic subjects, the aim here was to search for genetic factors involved in eczema and more particularly the ones shared by the three allergic diseases using the same EGEA data. In this sake, eczema and phenotypes of "allergic disease" accounting for the joint information on the presence/absence of the three diseases were examined by linkage analyses using the maximum likelihood binomial method.

[Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA) - First results of a multi-disciplinary study].

The French co-operative epidemiological study EGEA realised in 1991/95 combines a case control study and a study of the families of asthmatic cases. A synthesis of the results already obtained is presented. Smoking was related to IgE, even in asthmatics and was clearly related to the clinical severity of asthma, an aspect insufficiently taken into account.

[Environmental factors for asthma severity and allergy: results from the EGEA study].

Introduction: EGEA (Epidemiological study on the genetics and environment of asthma, bronchial hyperresponsiveness and atopy), a case control and family study including 2048 individuals, was initiated to look for environmental and genetic risk factors for asthma. A synthesis of the results obtained since 2002 on phenotypic and environmental aspects of asthma severity and allergy are presented in this article.

Methods And Results: The results support a role for hormonal factors in asthma severity and in various allergic markers of asthma.

Evidence for a locus in 1p31 region specifically linked to the co-morbidity of asthma and allergic rhinitis in the EGEA study.

Objective: A recent genome scan conducted in French EGEA families led to detect linkage of 1p31 to either asthma or allergic rhinitis (AR) and more significantly to asthma associated with AR. The goal of the present study was to assess formally whether 1p31 is a linkage region shared by two different diseases, asthma and AR, or whether it is specific to the co-morbidity asthma plus AR.

Methods: We used two different statistical approaches: the Triangle Test Statistic (TTS) and the Predivided Sample Test (PST), to search for heterogeneity of linkage to 1p31 according to the affection status being defined by either the presence of the two diseases (asthma plus AR) or the presence of only one disease ('asthma only' or 'AR only' or 'asthma only or AR only').

Interrelationships of quantitative asthma-related phenotypes in the Epidemiological Study on the Genetics and Environment of Asthma, Bronchial Hyperresponsiveness, and Atopy.

Background: Delineating asthma subphenotypes is of interest to understand the cause of the disease. Few studies have addressed the interrelationships of quantitative asthma-related traits.

Objective: We sought to study the interrelationships of allergy markers and FEV(1) in relation to asthma and sex in children and adults.

Does childhood immunization against infectious diseases protect from the development of atopic disease?

The argument of whether early immunization against infections promotes allergy or protects from it is presently under debate. The relationship between childhood immunization and the development of atopic diseases (asthma, allergic rhinitis and eczema) was examined in a population-based sample of 718 adolescents by taking individual data drawn from personal paediatric records on the schedule and the type of vaccination into account. Atopic diseases were determined using a standardized questionnaire.

Genome screen in the French EGEA study: detection of linked regions shared or not shared by allergic rhinitis and asthma.

In the sample of 295 French EGEA families with at least one asthmatic subject, a genome screen was conducted to identify potential linkage regions specific either to allergic rhinitis (AR) or to asthma as well as those shared by the two diseases. Two binary rhinitis phenotypes based on (1) diagnosis (ARbin1) and (2) symptoms (ARbin2) and a categorical ordered trait (ARcat) were considered. Asthma phenotype was based on answers to a standardized questionnaire plus the presence of bronchial hyper-responsiveness.

Clustering patterns of LOD scores for asthma-related phenotypes revealed by a genome-wide screen in 295 French EGEA families.

A genome-wide scan for asthma phenotypes was conducted in the whole sample of 295 EGEA families selected through at least one asthmatic subject. In addition to asthma, seven phenotypes involved in the main asthma physiopathological pathways were considered: SPT (positive skin prick test response to at least one of 11 allergens), SPTQ score being the number of positive skin test responses to 11 allergens, Phadiatop (positive specific IgE response to a mixture of allergens), total IgE levels, eosinophils, bronchial responsiveness (BR) to methacholine challenge and %predicted FEV(1). Four regions showed evidence for linkage (P View Article and Find Full Text PDF

Influence of asthma on the validity of reported lifelong environmental tobacco smoke in the EGEA study.

The aim of this study was to assess the short-term reproducibility and the validity of reported ETS (environmental tobacco smoke) exposure, with a special emphasis on the potential misclassification related to personal or family history of asthma. Analyses were based on the data on the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA), a case-control study of asthma that included first degree relatives of asthmatic cases. The study was comprised of 348 families of asthmatics recruited in six chest clinics throughout France and 416 population-based controls.

Role of gender and hormone-related events on IgE, atopy, and eosinophils in the Epidemiological Study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy.

Background: The pattern of asthma over the lifespan is different in male and female patients, but etiologic differences according to gender are only partially understood. In women, information regarding factors explaining perimenstrual asthma and the role of hormone-related aspects on asthma-related phenotypes is scanty.

Objective: To assess the relationships of eosinophils, IgE, and atopy with (1) asthma according to gender and age of onset and (2) hormone-related events.

Increased prevalence of asthma and allied diseases among active adolescent tobacco smokers after controlling for passive smoking exposure. A cause for concern?

Background: Whereas effects on allergic and respiratory health have been established for passive tobacco smoking, contradictory results still exist for active tobacco smoking.

Objective: Whether adolescents with asthma and allied diseases have higher rates of active smoking compared with adolescents without asthma was assessed after controlling for environmental tobacco smoking exposure.

Methods: A population-based sample of 14,578 adolescents was enrolled in an epidemiological survey on allergies in France.

Familial correlations and inter-relationships of four asthma-associated quantitative phenotypes in 320 French EGEA families ascertained through asthmatic probands.

Asthma is a complex disease, associated with biological and physiological phenotypes including immunoglobulin E (IgE) levels, sum of positive skin prick tests to allergens (SPTQ), eosinophil counts (EOS) and percent predicted forced expiratory volume in 1 s (%FEV1). We investigated the patterns of familial correlations and the inter-relationships of these four quantitative phenotypes, using the general class D regressive model, in 320 French EGEA nuclear families ascertained through 204 offspring (set A) and 116 parents (set B). Familial correlations of IgE and SPTQ were consistent with a model including no spouse correlation and equal parent-offspring and sib-sib correlations (rhoPO = rhoSS = 0.

Allergy markers in adults in relation to the timing of pet exposure: the EGEA study.

Background: Studies suggest that early childhood exposure to pets may protect from the development of atopy, but limited information is available on adults. The association of allergy markers in adulthood with current and childhood exposure to pets was studied considering retrospectively the window of exposure.

Methods: Immunoglobulin E (IgE), skin prick tests (SPT), eosinophils were related to exposure to pets in 187 adult asthmatic cases and 243 controls from the Epidemiological Study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA) study.

Relationships of allergic sensitization, total immunoglobulin E and blood eosinophils to asthma severity in children of the EGEA Study.

Background: Although allergy is highly associated with childhood asthma, it is not well known if there is a relationship between the intensity of allergic sensitization and asthma severity.

Objective: The objectives of the study were to examine the relationships between several markers of allergy and asthma severity in asthmatic children included in the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyper-responsiveness and atopy (EGEA).

Methods: The population comprised 216 asthmatic children below 16 years of age.

Methodologic aspects of the quantification of skin prick test responses: the EGEA study.

Background: The expression of responses of allergy skin prick tests is not standardized. Usual definitions of atopy are not quantitative.

Objective: We sought to perform a biometric analysis of responses to various allergens to propose synthetic, quantitative indices independent of the heterogeneity of responses to various allergens.

The protective role of country living on skin prick tests, immunoglobulin E and asthma in adults from the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyper-responsiveness and atopy.

Background: Farming environment and traditional lifestyle seem to protect from childhood allergy.

Objective: The aim is to analyse the relationships of living in the country to asthma, positive skin prick tests and IgE among adults considering various windows of exposure over the life-span.

Methods: The study concerns 805 adults drawn from the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyper-responsiveness and atopy (EGEA) (asthmatic cases, non-asthmatic controls, and parents of cases with and without asthma).

Allergy markers in respiratory epidemiology.

Assessing allergy by measurement of serum immunoglobulin (Ig) E antibodies is fast and safe to perform. Serum antibodies can preferably be assessed in patients with dermatitis and in those who regularly use antihistamines and other pharmacological agents that reduce skin sensitivity. Skin tests represent the easiest tool to obtain quick and reliable information for the diagnosis of respiratory allergic diseases.