Sensitization to individual allergens and bronchial responsiveness in the ECRHS

Little is known about the relation of bronchial responsiveness (BHR) to sen sitization to individual allergens, or its variation between countries. Data were obtained for BHR, specific immunoglobulin E and confounding varia bles from 11.,215 subjects, aged 20-44 Srs at the start of the European Com munity Respiratory Health Survey, in 34 centres in 15 countries. The relati on of BHR tb sensitization to cat, house dust mite, timothy grass and Clado sporium was estimated by means of multiple regression for each centre, and combined across centres by random effects meta-analysis sis, controlling fo r baseline lung function, height, sea, season of testing, age, smoking and age/sex and age/smoking interactions. BHR was greater, on average, in those sensitized to rat (p=0.02,3), house d ust mite (p<0.001) and timothy grass (p=0.018), but not to Cladospopium (p= 0.60), and increased with degree of sensitization (p<0.001). All relations shelved heterogeneity between centres, although to a lesser extent in the r elation to sensitization to house dust mite. More variation in bronchial responsiveness was explained by sensitization a nd degree of sensitization to the individual allergens than by atopy define d as an!: positive test in each centre, but the relative importance of each allergen varied. The use of atopy as a single variable in relation to bron chial hyperresponsiveness may be misleading.