João Cavaleiro Rufo1,2,3,4, Joana Madureira3, Inês Paciência1,2,3,4, Lívia Aguiar4,5, Cristiana Pereira4,5, Diana Silva1,2, Patrícia Padrão6, Pedro Moreira6, Luís Delgado1,2, Isabella Annesi-Maesano7, Eduardo Oliveira Fernandes3, João Paulo Teixeira4,5, André Moreira1,2,4,6. 1. Basic and Clinical Immunology, Faculty of Medicine, University of Porto, Porto, Portugal. 2. Centro Hospitalar São João, Porto, Portugal. 3. INEGI - Institute of Science and Innovation in Mechanical Engineering and Industrial Management, Porto, Portugal. 4. Epidemiology Research Unit, Institute of Public Health (EPIUnit), University of Porto, Porto, Portugal. 5. National Institute of Health Dr Ricardo Jorge, Porto, Portugal. 6. Faculty of Nutrition and Food Sciences, University of Porto, Porto, Portugal. 7. Epidemiology of Allergic and Respiratory Diseases Department, Institut Pierre Louis d'Epidémiologie et de Santé Publique, INSERM and UPC, Paris, France.
Abstract
BACKGROUND: Childhood exposure to microbiologic agents may influence the development of allergic and respiratory diseases. Apart from home, children spend most of their time at school, which represents an environment of significant exposure to indoor air microbes. Therefore, we aimed to assess how the prevalence of allergic sensitization and asthma in schoolchildren is affected by microbiologic exposure within classrooms. METHODS: Spirometry with bronchodilation, exhaled nitric oxide measurements and skin-prick tests data were retrieved from 858 children aged 8-10 years attending 71 classrooms in 20 primary schools. Air samples were collected in all classrooms using a single-stage microbiologic air impactor through agar plates. Gram-negative endotoxins were collected using flow control pumps and analysed by limulus amebocyte lysate assay. Diversity scores were established as the number of different fungal species found in each classroom. RESULTS: Classrooms with increased diversity scores showed a significantly lower prevalence of children with atopic sensitization, but not asthma. The risk of sensitization increased with increasing endotoxin exposure in classrooms. Similarly, significantly higher concentrations of Penicillium spp were found in classrooms with a higher number of children with atopic sensitization. CONCLUSIONS: Although no causal relationships could be established, exposure to higher fungal diversity was protective against allergic sensitization but this was not seen for asthma. In contrast, higher exposure to Gram-negative endotoxins and Penicillium spp in primary school's classrooms was associated with increasing odds of allergic sensitization in children.
BACKGROUND: Childhood exposure to microbiologic agents may influence the development of allergic and respiratory diseases. Apart from home, children spend most of their time at school, which represents an environment of significant exposure to indoor air microbes. Therefore, we aimed to assess how the prevalence of allergic sensitization and asthma in schoolchildren is affected by microbiologic exposure within classrooms. METHODS: Spirometry with bronchodilation, exhaled nitric oxide measurements and skin-prick tests data were retrieved from 858 children aged 8-10 years attending 71 classrooms in 20 primary schools. Air samples were collected in all classrooms using a single-stage microbiologic air impactor through agar plates. Gram-negative endotoxins were collected using flow control pumps and analysed by limulus amebocyte lysate assay. Diversity scores were established as the number of different fungal species found in each classroom. RESULTS: Classrooms with increased diversity scores showed a significantly lower prevalence of children with atopic sensitization, but not asthma. The risk of sensitization increased with increasing endotoxin exposure in classrooms. Similarly, significantly higher concentrations of Penicillium spp were found in classrooms with a higher number of children with atopic sensitization. CONCLUSIONS: Although no causal relationships could be established, exposure to higher fungal diversity was protective against allergic sensitization but this was not seen for asthma. In contrast, higher exposure to Gram-negative endotoxins and Penicillium spp in primary school's classrooms was associated with increasing odds of allergic sensitization in children.
Authors: Sachin N Baxi; William J Sheehan; Joanne E Sordillo; Michael L Muilenberg; Christine A Rogers; Jonathan M Gaffin; Perdita Permaul; Peggy S Lai; Margee Louisias; Carter R Petty; Chunxia Fu; Diane R Gold; Wanda Phipatanakul Journal: Ann Allergy Asthma Immunol Date: 2019-03-20 Impact factor: 6.347
Authors: J Bousquet; C A Akdis; C Grattan; P A Eigenmann; K Hoffmann-Sommergruber; P W Hellings; I Agache Journal: Clin Transl Allergy Date: 2018-11-27 Impact factor: 5.871