Do Baseline Asthma and Allergic Sensitization Characteristics Predict Responsiveness to Mouse Allergen Reduction?

Abstract

Background: Mouse allergen reduction is associated with improvements in asthma among sensitized and exposed children, but whether clinical characteristics predict responsiveness to allergen reduction is unclear.

Objective: To examine the effects of clinical characteristics on relationships between mouse allergen reduction and asthma outcomes.

Methods: We performed a secondary analysis of data from a randomized clinical trial of a mouse allergen intervention, examining the effects of atopy, demographic characteristics, lung function, asthma control, and asthma severity on relationships between mouse allergen reduction and asthma outcomes.

Results: Participants were predominantly low-income and minority (78% black, 22% Hispanic), and had persistent asthma. Among less atopic participants (<6 positive skin prick test results), each 50% reduction in mouse allergen was associated with fewer symptoms (incidence rate ratio [95% CI]: maximal symptoms: 0.94 [0.92-0.96]). There was little effect of mouse allergen reduction on symptoms among more atopic participants (P > .05). The interactions between atopic status and mouse allergen reduction were statistically significant for all symptom outcomes; however, there was no evidence that atopic status influenced the effect of mouse allergen reduction on exacerbation-related outcomes. Older children (≥9 years) tended to experience greater improvement in some asthma outcomes with reduction in mouse allergen exposure than younger children. There was no evidence that either mouse-specific IgE or lung function influenced the effect of mouse allergen reduction on any asthma outcomes.

Conclusions: Although there may be variability in the clinical response to mouse allergen reduction among low-income, minority children with asthma, there were no clinical characteristics that clearly identified a subgroup at which the intervention should be targeted.

Trial registration: ClinicalTrials.gov NCT01251224.

Keywords: Allergen exposure; Allergen exposure reduction; Allergen sensitization; Allergic asthma; Atopy; Mouse allergen exposure.