RSV infection appears related to recurrent wheeze in preterm infants

A study conducted in the Netherlands shows that the monoclonal antibody palivizumab significantly reduces wheezing days during premature infants’ first year of life, in addition to preventing severe respiratory syncytial virus (RSV) infection in these high-risk children.

Investigators assigned 429 preterm infants, who were no more than 6 months old and born at a gestational age of 33 to 35 weeks, to receive either palivizumab injections or placebo during RSV season. Until their infants reached their first birthdays, parents reported on the number of days their babies wheezed, along with airway symptoms, doctor or hospital visits, and use of airway drugs. Parents also took a nasopharyngeal swab from infants who had respiratory symptoms that lasted more than 1 day; investigators tested the swabs for the presence of RSV. Median follow-up was 10 months in both study groups.

Infants in the palivizumab group wheezed fewer days than those in the placebo group, with rates of wheezing in the palivizumab group 2.7 percentage points lower than in the placebo group (1.8% vs 4.5%), for a relative reduction of 61%. These effects persisted during the postprophylaxis period, for a relative reduction of 73%. Similarly, the palivizumab group experienced decreased wheezing days outside the RSV season. In addition, the proportion of infants with recurrent wheeze was 10 percentage points lower in patients treated with palivizumab (11% vs 21%). Similarly, the proportion of infants using bronchodilators was lower in the treatment group than in the placebo group (13% vs 23%).

As expected, the study confirmed that infants who were treated with palivizumab had a lower incidence both of RSV-related hospitalization and of medically attended nonhospitalized RSV infection than those who received placebo. Among children with any proven RSV infection, however, no significant differences were seen between the 2 groups in the incidence of wheezing or in the mean number of wheezing days during the first year of life (Blanken MO, et al. N Engl J Med. 2013;368[19]:1791-1799).

COMMENTARY  This investigation addresses pediatricians’ age-old, chicken-or-egg question: Does early RSV infection cause later wheezing in childhood or are infants who develop severe symptoms with early RSV preprogrammed to be wheezers? This prospective, randomized, controlled study offers evidence that RSV is the egg rather than the chicken. -Michael Burke, MD

DR BURKE, section editor for Journal Club, is chairman of the Department of Pediatrics at Saint Agnes Hospital, Baltimore, Maryland. He is a contributing editor for Contemporary Pediatrics. He has nothing to disclose in regard to affiliations with or financial interests in any organizations that may have an interest in any part of this article.