Airways hyperresponsiveness is a hallmark of asthma. Inhaled corticosteroids improve hyperresponsiveness, but the extent of improvement may vary considerably between patients. This study was designed to determine which patient characteristics predict these differences in response.

Children with atopic asthma (n=71) received inhaled budesonide (800ug per day) regularly for 12 weeks, and methacholine PC20 was measured before and after the treatment. Baseline clinical characteristics of children were analyzed with regard to their response to budesonide therapy.

The children were divided into high (n=36) and low responder (n=35) on the basis of the median value of the doubling doses (change in PC20). There were no differences observed between the two groups with respect to age, sex, eosinophil counts, and pretreatment FEV1 or methacholine PC20. Among the allergic parameters, serum total IgE was higher in the high responder group than in the low responder group, whereas Dermatophagoides-specific IgE levels or skin test wheal sizes were not different between the two groups. There was a significant correlation between total IgE level and change in PC20.

Total serum IgE was found to be the most important and single predictor of change in PC20 with inhaled corticosteroids.