Early exposure to bio-contaminants and asthma up to 10 years of age: results of the HITEA study

Abstract

Inverse associations have been found between exposure to bio-contaminants and asthma and allergies. The aim of this study was to prospectively assess whether early exposure to bio-contaminants in dust is associated with asthma and allergy later in childhood among children from (sub)-urban areas.In subsets of three European birth cohorts (PIAMA: n=553; INMA: n=481; and LISAplus: n=395), endotoxin, (1,3,)-β-D-glucan and extracellular polysaccharide were measured in dust from living rooms shortly after birth. Current asthma at 6 years and 10 years of age and ever asthma up to 10 years of age were assessed by parental questionnaires. Specific IgE levels at 8 years (PIAMA) and 10 years (LISAplus) were available. Adjusted, cohort-specific logistic regression analyses were performed.Higher endotoxin concentrations were positively associated with current asthma at 6 years of age in PIAMA (adjusted OR 1.96, 95% CI 1.07-3.58), but were inversely related with ever asthma up to 10 years of age in INMA (adjusted OR 0.39,. No associations with asthma were found for LISAplus. No associations were observed with atopic sensitisation in all cohorts. All associations with (1,3)-β-D-glucan and extracellular polysaccharide were statistically nonsignificant.The suggested immunological mechanisms of early exposure to bio-contaminants with regards to asthma and allergy might be different for children growing up in (sub)-urban environments. @ERSpublications Immunological mechanisms of early exposure to bio-contaminants might be different in children from urban environments

Early‐life house dust mite allergens, childhood mite sensitization, and respiratory outcomes

“…In addition, the long‐term implications of these results are not clear. The association between early‐life exposure to microbial markers (endotoxin, EPS, or β‐glucan) and asthma up to the age of 10 years has been investigated in INMA, a subsample of LISAplus participants, and in the PIAMA intervention study participants . Like for the exposure to allergens reported in our study, no significant associations were observed between early‐life exposure to high concentrations of microbial markers and asthma.…”

Indoor bacterial microbiota and development of asthma by 10.5 years of age

“…2 Accordingly, intimate exposure to environments rich in microbes, such as those associated with traditional farming practices, might decrease the risk of asthma and other allergic diseases. 3 Earlier epidemiologic studies on home microbial exposure and asthma were based on characterization of exposure through measures of general microbial markers, [4][5][6][7] such as endotoxin in dust samples (reviewed by Doreswamy and Peden 8 ). We have previously shown in this cohort that the quantity of exposure to bacterial and fungal cell-wall components in early life has a bell-shaped association with asthma at the age of 6 years.…”

Role of timing of exposure to pets and dampness or mould on asthma and sensitization in adolescence

“…Another limitation is that asthma status was assessed from questionnaires and not based on lung function tests. However, the questionnaire-based outcome is used in large birth cohort studies 54,55 and it offers data for many subjects, while lung function measurements are more costly and therefore often not feasible for all participants.…”