Endotoxin exposure in asthmatic children and matched healthy controls: results of IPEADAM study

Abstract

This study has demonstrated that the home environments of English children (4-17) with asthma and without the disease do not differ greatly. With the exception of endotoxin, the parameters examined in this study, including house dust mite allergens, nitrogen dioxide, ETS and damp are unlikely to be related to the development of asthma. Avoidance of these pollutants may not be beneficial in preventing asthma in this age group.

Respiratory health and indoor air pollutants based on quantitative exposure assessments

“…In a cohort of 1,884 German newborns, a two-fold increased risk of wheezing during the first 6 months of life was found in children exposed to high endotoxin concentrations (OR 2.37, 95% CI 1.40-4.03) [78]. Such associations have been confirmed in other longitudinal studies [79,80,84], as well as in case-control or crosssectional studies [81][82][83]. Moreover, exposure to endotoxins has been linked to asthma severity and morbidity [86,87].…”

“…Findings from epidemiological studies are less consistent [74]. Whereas some reports suggest a protective effect of endotoxins on the development of allergies [57,[75][76][77], others found that the exposure to endotoxins constitutes a risk factor for respiratory symptoms [78][79][80][81][82][83][84], which might depend on the amount of exposure [85].…”

“…The first studies that evaluated the respiratory effects of endotoxin exposure in an urban environment observed positive associations with asthma and wheezing [78][79][80][81][82][83][84]. In a cohort of 1,884 German newborns, a two-fold increased risk of wheezing during the first 6 months of life was found in children exposed to high endotoxin concentrations (OR 2.37, 95% CI 1.40-4.03) [78].…”

The hygiene hypothesis in allergy and asthma

“…For example, one birth cohort found that early endotoxin exposure was associated with an increased risk of atopy at the age of 2 years [32], whereas two similar birth cohort studies found a protective effect on atopy in 2-year-olds [28] and asthma symptoms in 4-year-olds [30]. Endotoxin exposure has also been shown to be a risk factor for asthma as demonstrated in inner city urban environments [33,34].…”

Chemical and microbial components of urban air PM cause seasonal variation of toxicological activity

“…It is known that endotoxins increase the risk for asthma development (Tavernier et al, 2005) and occupational respiratory symptoms (Douwes et al, 2003). In the toxicological studies, endotoxin has been linked to increased inflammatory responses (e.g.…”