The aim of this study was to evaluate the impact of urban air pollution, assessed through reliable indicators of exposure, on asthma and allergies in schoolchildren. A validated dispersion model ...combining data on traffic conditions, topography, meteorology and background pollution was used to relate 3-yrs averaged concentrations of major urban pollutants at the sites of schools to skin prick tests, exercise-induced asthma and reported asthma and allergies in 6,683 children (9-11 yrs) attending 108 schools randomly selected in six French communities. For the 4,907 children who had resided at their current address for the past 3 yrs, asthma (exercise induced, past year and lifetime) was significantly positively associated with benzene, SO(2), particles with a 50% cut-off aerodynamic diameter of 10 microm (PM(10)), nitrogen oxides (NO(x)) and CO. In the same children, eczema (lifetime and past year) was significantly positively associated with benzene, PM(10), NO(2), NO(x) and CO, lifetime allergic rhinitis with PM(10) and sensitisation to pollens with benzene and PM(10). Among the 2,213 children residing at their current address since birth, the associations persisted for lifetime asthma with benzene (adjusted OR per interquartile range (95% CI) 1.3 (1.0-1.9)) and PM(10 )(1.4 (1.0-2.0)), and for sensitisation to pollens with volatile organic compounds (1.3 (1.0-1.9)) and PM(10) (1.2 (1.0-1.9)). Accurately modelled urban air pollution was associated with some measures of childhood asthma and allergies.
Les venins d’hyménoptères contiennent de nombreuses substances à propriétés toxiques responsables des phénomènes inflammatoires observés lors de l’envenimation. Des amines biogènes, des enzymes et ...des peptides à propriétés histaminolibératrices ont été isolés dans le venin des apidés et des vespidés. Chez les formicidés, on insiste sur le rôle d’alcaloïdes. Ces substances ont également des propriétés hémolytiques, cytolytiques et, pour certaines, une action neurotoxique. De nombreux allergènes sont répertoriés surtout dans le venin d’abeille. La phospholipase A2 (Api m 1) est un allergène majeur, de même que la hyaluronidase (Api m 2). D’autres allergènes jouent un rôle important dans la sensibilisation au venin d’abeille, en particulier la mellitine (Api m 4), une dipeptidylpeptidase (Api m 5) et surtout l’icarapine (Api m 10). Au total, douze allergènes ont été inscrits dans la nomenclature. Chez les vespidés, les allergènes majeurs sont la phospholipase A1, la hyaluronidase et les antigènes 5. Ces allergènes sont plus ou moins partagés entre guêpes Vespula, guêpes Polistes et frelons Vespa, ce qui rend le diagnostic de sensibilisation sérologique spécifique difficile. Les venins de fourmis sont moins bien connus, essentiellement représentés par une phospholipase A1 (Sol i 1) chez la fourmi Solenopsis. Concernant les arthropodes hématophages, la composition des salives est moins explorée, sauf pour le moustique où 9 allergènes salivaires ont été identifiés. Ces allergènes sont souvent communs entre différentes espèces, ce qui explique la fréquence de réactions croisées aussi bien in vivo qu’in vitro. Ces communautés antigéniques expliquent aussi des co-sensibilisations entre diptères hématophages et hyménoptères.
Hymenoptera venoms contain many substances with toxic properties causing inflammation at sting location. Biogenic amines, enzymes and mast cell degranulating peptides are identified in Apidae and Vespidae venoms. In Formicidae, alkaloids are involved. These substances have also hemolytic, cytolytic and for some of them neurotoxic properties. Numerous allergens are identified especially in bee venom. Phospholipase A 2 (Api m 1) and hyaluronidase (Api m 2) are major allergens. Other allergens playing a major role in bee venom sensitization are mellitin (Api m 4), dipeptidylpeptidase (Api m 5) and the more recently described icarapin (Api m 10). In total, twelve bee venom allergens are registered in the international nomenclature. In Vespidae, major allergens are phospholipase A 1, hyaluronidase and the antigens 5. These allergens are more or less shared between Vespula, Polistes and Vespa species, which makes accurate diagnosis by means of serology particularly difficult. Ant venoms are less studied: essentially a phospholipase (Sol i 1) is described in the venom of Solenopsis species. The saliva of blood-sucking arthropods contains also many less well known components, except for mosquito where nine salivary allergens have been identified. All these allergens are often common to different species, explaining the high frequency of cross reactions observed in studies, as well in vivo as in vitro. These allergenic similarities may also explain cases of co-sensitization between hymenoptera and diptera..
Summary
Background
The impact of air pollution on asthma and allergies still remains a debate.
Objective
Our cross‐sectional study was intended to analyse the associations between long‐term exposure ...to background air pollution and atopic and respiratory outcomes in a large population‐based sample of schoolchildren.
Methods
Six thousand six hundred and seventy‐two children aged 9–11 years recruited from 108 randomly schools in six French cities underwent a clinical examination including a skin prick test (SPT) to common allergens, exercise‐induced bronchial reactivity (EIB) and skin examination for flexural dermatitis. The prevalence of asthma, allergic rhinitis (AR) and atopic dermatitis was assessed by a standardized health questionnaire completed by the parents. Three‐year‐averaged concentrations of air pollutants (NO2, SO2, PM10 and O3) were calculated at children' schools using measurements of background monitoring stations.
Results
After adjusting for confounders, EIB, lifetime asthma and lifetime AR were found to be positively related to an increase in the exposure to SO2, PM10 and O3. The adjusted odds ratios (aOR) per increase of 5 μg/m3 of SO2 was 1.39 (95% confidence interval (CI)=1.15–1.66) for EIB and 1.19 (1.00–1.41) for lifetime asthma. The aOR for lifetime AR per increase of 10 μg/m3 of PM10 was 1.32 (CI=1.04–1.68). Moreover, SPT positivity was associated with O3 (aOR=1.34; CI=1.24–1.46). Associations with past year symptoms were consistent, even if not always statistically significant. Results persisted in long‐term resident (current address for at least 8 years) children. However, no consistent positive association was found with NO2.
Conclusions
A moderate increase in long‐term exposure to background ambient air pollution was associated with an increased prevalence of respiratory and atopic indicators in children.
Background
The management of severe occupational asthma (OA) remains problematic and new alternative treatments providing better disease control are required, ideally enabling affected individuals to ...remain in their job.
Methods
Ten patients with severe uncontrolled OA were treated with the monoclonal anti‐IgE antibody omalizumab. In six cases the causative agent was a high molecular weight (HMW) compound and in four cases it was a low molecular weight (LMW) chemical. All of the patients had well documented OA despite workplace adjustments.
Results
During treatment, nine patients exhibited a lower rate of asthma exacerbations and used less oral or inhaled corticosteroids. Seven patients were able to continue working at the same workplace as before treatment.
Conclusion
We have demonstrated that omalizumab is a potential treatment for severe uncontrolled OA and enabled seven of the ten patients in the study to remain in their job.
Summary
Background
Exercise‐induced bronchospasm (EIB) is frequent among asthmatic children. However, opinions differ on the relation between EIB and rhinitis in the absence of asthma.
Objectives
We ...assessed the relationship between EIB and various phenotypes of rhinitis according to asthmatic status at the general population level in the Six Cities Study.
Methods
Of 7781 schoolchildren with a mean age of 10 years underwent an EIB test and skin prick test to assess allergic sensitization. Their parents completed a standardized questionnaire recording asthma‐like symptoms and past‐year rhinoconjunctivitis, ever hay fever (EHF), and a score for allergic rhinitis (SFAR) ≥7 as a marker of ‘past‐year allergic rhinitis’. Exercise‐induced bronchospasm was defined as a fall in peak expiratory flow rate ≥15% after exercise.
Results
Of the 6813 schoolchildren retained for analysis, 227 (3.33%) experienced EIB after exercise. Odds ratios 95% confidence intervals between EIB and allergic rhinitis phenotypes in the absence of asthma were 1.56 0.92–2.63 for EHF, 1.97 1.16–3.35 for past‐year rhinoconjunctivitis, and 1.84 1.16–2.91 for a SFAR ≥7. Results were unchanged after adjustment for confounders. Multiple correspondence analysis showed that EIB, although related to asthma, constitutes a separate entity. Exercise‐induced bronchospasm was not significantly related to familial history of asthma.
Conclusion
In our large population‐based sample of children, different phenotypes of atopic rhinitis were associated with EIB, independently of asthma. Exercise‐induced bronchospasm, although related to asthma, seems to constitute a separate entity.
Clinical relevance
In this large (6813) sample of 10‐year children drawn from the general population, EIB is associated with rhinitis phenotypes in the absence of asthma. Furthermore, it constitutes an entity independent from asthma and is not related to a familial history of asthma. Thus, investigating these symptoms could be important in this disease, as a specific nasal treatment might improve EIB in these children.
Background: Food allergy (FA) is an important health problem. However, epidemiological studies at the population level are scarce. We assessed the prevalence of FA and its associations with ...respiratory manifestations among schoolchildren.
Methods: A total of 6672 schoolchildren aged 9–11 years recruited from 108 randomly chosen schools in six French cities underwent a clinical examination including skin prick test (SPT) to common food and aeroallergens and the standardized protocol of the run test to assess exercise‐induced bronchial hyper‐responsiveness (EIB). Asthma, allergic rhinitis (AR) and clinical symptoms of FA were determined using a standardized questionnaire completed by parents.
Results: About 2.1% of the children reported symptoms of FA, 1.9% were sensitized to food allergens, and 0.1% had SP‐tested FA. The AR was more prevalent than asthma (20.0% lifetime, 11.9% past year vs 9.8%, 8.7% respectively). Reported FA, food sensitization and SP‐tested FA were all positively associated with asthma and AR (P < 0.001). These associations persisted also for FA not manifesting as respiratory symptoms (P < 0.001). Asthma and AR remained significantly associated with reported symptoms of FA and allergic sensitization to food allergens after adjustment for confounders as well as for sensitization to aeroallergens. No relationship existed between EIB (9.0%) and FA.
Conclusion: The relationships between FA and asthma and AR could be totally explained neither by the existence of respiratory manifestations of FA nor by sensitization to aeroallergens. The FA might intervene differently in asthma and AR.
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