FeNO Response to Oral Corticosteroids in Children with Mild to Moderate Asthma: Influence of Race.

Background Fraction exhaled nitric oxide (FeNO) is a non-invasive biomarker of type-2 asthma that can predict response to inhaled corticosteroid(ICS) therapy. Little is known regarding the magnitude of FeNO reduction following an oral corticosteroid(OCS) course and less is known whether there are differential responses based on race in children with mild-to-moderate asthma. Objective To assess the effect of a short course of OCS on FeNO in asthmatic children and to determine if the effect is influenced by race. Methods Children presenting with an acute asthma exacerbation, who had a FeNO measurement within the last six months when clinically stable, were enrolled. Spirometry and FeNO were obtained at the time of exacerbation and following a short course of prednisone. Results 92 children were identified [age 11±3.3years; white,n=46(50%), Hispanics,n=30(33%), AAs,n=16(17%)]. At baseline, AAs were more atopic and had higher mean FeNO values than both white (48.9vs.25.6 ppb;p Conclusion FeNO levels fell over 50% following an OCS course. AA children had a greater degree of type-2 driven airway inflammation at baseline, during an exacerbation and following a short course of OCS compared to non-AAs, although the relative reduction in FeNO was similar between the groups.