Effect of day care attendance on sensitization and atopic wheezing differs by Toll-like receptor 2 genotype in 2 population-based birth cohort studies.

Background: Variation in the Toll-like receptor 2 gene (TLR2/-16934) is associated with allergic diseases among farmers' children but not among children not living on farms.

Objective: To test the hypothesis that the same genetic variant conferring protection in the farming environment is associated with reduced risk of developing allergic phenotypes among urban children attending day care in early life.

Methods: In 2 population-based birth cohorts (Manchester, United Kingdom, Manchester Asthma and Allergy Study [MAAS]; Tucson, Ariz, Tucson Infant Immune Study [IIS]), participants were recruited prenatally and followed prospectively (MAAS: 3, 5, 8 and 11 years; IIS: 1, 2, 3 and 5 years).

Day-care attendance, position in sibship, and early childhood wheezing: a population-based birth cohort study.

Background: There are conflicting data on the effect of day-care attendance and position in sibship on the development of wheezing.

Objective: To investigate the relationship between day-care attendance and position in sibship with early childhood wheeze.

Methods: Prospective population-based birth cohort.

Exhaled breath condensate pH and childhood asthma: unselected birth cohort study.

Rationale: Exhaled breath condensate pH (EBC-pH) may be useful noninvasive marker for evaluation of patients with asthma.

Objectives: To investigate the relationship between EBC-pH and symptoms suggestive of childhood asthma in an epidemiologic setting and examine its relation to lung function, airway hyperresponsiveness (AHR), and airway inflammation.

Methods: Within the context of a prospective population-based birth cohort, EBC was collected from 630 children at age 8 yr using the RTube (pH measured after deaeration with argon).