Azithromycin's effects on post-RSV bronchiolitis recurrent wheezing: a randomized trial

Published Online: July 24, 2015

Childhood asthma carries a significant burden on affected individuals and society. Therefore, investigation of asthma prevention strategies is highly desirable. The population of young infants hospitalized due to Respiratory syncytial virus (RSV) bronchiolitis is an attractive population to explore such prevention strategies because up to 75% of these infants experience at least three additional wheezing episodes, and almost 50% are diagnosed with asthma by the age of seven years. Up to now, no effective strategies have been identified which can reduce post-RSV recurrent wheeze.

In a study recently published in The Journal of Allergy and Clinical Immunology (JACI), Beigelman and colleagues reported the results of a randomized, double-masked, placebo-controlled, proof-of-concept trial in 40 otherwise healthy infants hospitalized with RSV bronchiolitis. The authors investigated the utility of azithromycin for the prevention of post-RSV recurrent wheeze in infants.

Study participants were treated with azithromycin or placebo for 14 days. The investigators evaluated the effect of the interventions on a marker of neutrophilic inflammation, the levels of the cytokine IL-8, in upper airway secretions and serum. Clinical outcomes, including the occurrence of recurrent wheeze were assessed monthly over the following year. Azithromycin treatment in infants hospitalized with RSV bronchiolitis reduced IL-8 levels in nasal lavage, but not in serum. The intervention significantly decreased the likelihood of subsequent recurrent wheeze, as evidenced by a prolonged time to a third wheezing episode. In addition, azithromycin-treated infants had fewer days with respiratory symptoms over the subsequent year.

The results of this proof-of-concept study suggest that azithromycin therapy during acute bronchiolitis may be an effective intervention to attenuate the outcome of post-RSV recurrent wheeze and potentially asthma. As up to 13% of childhood asthma cases are attributable to severe (i.e., disease requiring hospitalization) RSV bronchiolitis, the utility of azithromycin as a potential disease modifying approach to attenuate post-RSV recurrent wheeze should be investigated in a more definitive trial.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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