Relationship between allergen and endotoxin exposure and allergic sensitization in Cyprus

Abstract

RATIONALE: Sensitisation to indoor allergens is a risk factor for asthma. A dose-response relationship between Der p 1 exposure and sensitisation to mite has been shown in some populations but not others. The aim of this study was to identify risk factors for allergic sensitisation amongst children in Cyprus. METHODS: We measured exposure to endotoxin and allergens (mite, cat and dog) in the homes of 128 children aged 15-16 years. Participants were skin tested to mite, cat and dog, and sensitization defined as a weal diameter 3mm greater than the negative control. We analyzed the data using multivariate logistic regression (adjusting for gender, area of residence and family history) and presented the outcomes as odds ratios and 95% confidence intervals. RESULTS: A total of 19% of children were sensitized to mite, 15% to cat and 7% to dog. Factors associated with mite sensitisation were increasing levels of Der p 1 (OR 1.28, 95% CI 1.01-1.62, p=0.04), increasing levels of endotoxin (1.76, 1.01-3.08, p=0.05) and living in an urban rather than a rural area (6.74, 1.37-33.67, p=0.02). Sensitisation to domestic pets was associated only with paternal atopy (Cat: 5.68, 1.37-23.56, p=0.02; dog: 13.5, 1.79-101.73, p=0.01), but not with pet ownership or specific allergen or endotoxin exposure. CONCLUSIONS: Mite allergen exposure was associated with sensitisation to mite, but there was no association between cat and dog allergen exposure and specific sensitizations. Surprisingly, in this area increasing endotoxin level was associated with an increased risk of sensitization to mite.