574:
Reduction in mouse allergen exposure is associated with greater lung function growth in mouse sensitized and exposed children and adolescents with persistent asthma
Sunday, March 4, 2018: 2:15 PM
S330GH (Convention Center)
Torie L. Grant, MD, , , , , , , , , , ,
RATIONALE: The effect of reducing allergen exposure on the trajectory of lung function among sensitized/exposed asthmatic children is unknown.

METHODS: 350 mouse-sensitized/exposed asthmatic children (5-17y) were enrolled in a randomized trial of integrated pest management+education versus education alone. Pre-/post-bronchodilator (BD) spirometry was performed at baseline, 6 and 12 months, and bedroom floor mouse allergen was measured every 3 months for one year. Mouse allergen reduction was defined as ≥90% decrease in mouse allergen at any point. Because there were no differences in exposure or clinical outcomes between treatment groups, they were combined for analyses. Generalized estimating equations were used to model change in lung function over time. Models were adjusted for age, gender, race, atopy (number of +SPTs), group, and included an interaction term (allergen reduction*time).

RESULTS: The study population was predominantly black (79.4%) and low-income (66.3% <$30,000). At baseline, median (IQR) mouse allergen level was 5.7ug/g (1.5-22.8); mean (SD) pre-BD FEV1/FVC% was 80.2%(8.9). 151 (44%) participants had ≥90% mouse allergen reduction. There was a greater increase in pre-BD-FEV1, but not pre-BD-FVC, among those who experienced allergen reduction (pint=0.005& 0.20, respectively). Using models stratified by allergen reduction, a 10 yo with versus without ≥90% allergen reduction is predicted to have pre-BD-FEV1 growth of 211mL/y (95%CI: -77-503mL/y) versus 139mL/y (-154-433mL/y) and pre-BD-FVC growth of 255mL/y (95%CI: -136-646mL/y) versus 224mL/y (-49-498mL/y), respectively. Effects of allergen reduction on post-BD lung function growth were not statistically significant.

CONCLUSIONS: Reduction in mouse allergen is associated with greater growth in lung function over 1-year among sensitized and exposed asthmatic children.