Document Detail


Multiple microbial exposures in the home may protect against asthma or allergy in childhood.
MedLine Citation:
PMID:  20412140     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Experimental animal data on the gram-negative bacterial (GNB) biomarker endotoxin suggest that persistence, dose, and timing of exposure are likely to influence its effects on allergy and wheeze. In epidemiologic studies, endotoxin may be a sentinel marker for a microbial milieu, including gram-positive bacteria (GPB) as well as GNB, that may influence allergy and asthma through components (pathogen-associated molecular patterns) that signal through innate Toll-like receptor pathways.
OBJECTIVE: To determine the influence of current GNB and GPB exposures on asthma and allergic sensitization in school-aged children.
METHODS: We examined the relationship between bacterial biomarkers and current asthma and allergic sensitization in 377 school-aged children in a birth cohort study. We then evaluated the effects of school-aged endotoxin, after controlling for exposure in early life.
RESULTS: Exposure to GNB was inversely associated with asthma and allergic sensitization at school age [for >median endotoxin: prevalence odds ratio (POR)=0.34, 95% CI=0.2-0.7, for current asthma and prevalence ratio=0.77, 95% CI=0.6-0.97, for allergic sensitization]. In contrast, elevated GPB in the bed was inversely associated with current asthma (POR=0.41, 95% CI=0.2-0.9) but not with allergic sensitization (POR=1.07, 95% CI=0.8-1.4). School-aged endotoxin exposure remained protective in models for allergic disease adjusted for early-life endotoxin.
CONCLUSION: Both GNB and GPB exposures are associated with decreased asthma symptoms, but may act through different mechanisms to confer protection. Endotoxin exposure in later childhood is not simply a surrogate of early-life exposure; it has independent protective effects on allergic disease.
Authors:
J E Sordillo; E B Hoffman; J C Celedón; A A Litonjua; D K Milton; D R Gold
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2010-04-13
Journal Detail:
Title:  Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology     Volume:  40     ISSN:  1365-2222     ISO Abbreviation:  Clin. Exp. Allergy     Publication Date:  2010 Jun 
Date Detail:
Created Date:  2010-06-18     Completed Date:  2010-10-14     Revised Date:  2013-04-26    
Medline Journal Info:
Nlm Unique ID:  8906443     Medline TA:  Clin Exp Allergy     Country:  England    
Other Details:
Languages:  eng     Pagination:  902-10     Citation Subset:  IM    
Affiliation:
Channing Laboratory, Boston, MA, USA. rejoa@channing.harvard.edu
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MeSH Terms
Descriptor/Qualifier:
Allergens / immunology
Asthma* / epidemiology,  immunology,  prevention & control
Child
Child, Preschool
Cohort Studies
Dust / immunology
Endotoxins / immunology*
Environmental Exposure*
Female
Gram-Negative Bacteria / immunology
Gram-Positive Bacteria / immunology
Housing*
Humans
Hypersensitivity* / epidemiology,  immunology,  prevention & control
Male
Muramic Acids / immunology
Grant Support
ID/Acronym/Agency:
AI35786/AI/NIAID NIH HHS; ES07036/ES/NIEHS NIH HHS
Chemical
Reg. No./Substance:
0/Allergens; 0/Dust; 0/Endotoxins; 0/Muramic Acids

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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