RATIONALE: To assess the effect of fluticasone propionate (FP) or FP/salmeterol (FSC) on the risk reduction of asthma exacerbation and impairment associated with fall respiratory viral infections in a pediatric population.
METHODS: This was a 16-week study in pediatric subjects with a recent history of severe asthma exacerbation. Subjects (n=339) treated with FP or FSC were randomized prior to starting the 2010 school year. Subjects collected mucus samples upon self-report of moderate to severe cold symptoms and/or meeting worsening asthma criteria. Mucus amples were analyzed by PCR.Viral-associated severe exacerbations were defined as positive viral sample occurring within the 5 days prior to exacerbation of a or up to 2 days following the start of the exacerbation.
RESULTS: Of the 537 mucus samples collected 344 were positive for at least one respiratory virus and 276 were rhinovirus (HRV) positive. Forty-one subjects experienced 49 severe exacerbations (FSC=24; FP=25) during treatment. Twenty (FSC=6; FP=14) of the 49 exacerbations were viral-associated and 14 (FSC=5; FP=9) of those viral-associated exacerbations were associated with HRV.
CONCLUSIONS: This prospective study collected mucus samples from subjects receiving FP or FSC during the fall viral period, a period when this age group (4-11 years) is most susceptible to viral-induced exacerbations. While colds and/or episodes of worsening asthma were associated with positive viral samples, the lower than expected number of virus-associated severe exacerbations suggests that FP and FSC therapy may preferentially prevent viral-induced severe exacerbation.
