Preterm babies are given the monoclonal antibody palivizumab to prevent respiratory syncytial virus
(RSV) infection. These babies also appear less likely to develop recurrent wheeze, at least
until the age of six, revealed a new research published online, ahead
of print in the American Thoracic Society's American Journal of Respiratory and Critical Medicine.
In "Palivizumab Prophylaxis in Preterm Infants and Subsequent Recurrent Wheezing: 6 Year Follow-up Study,"
researchers report on multicenter case-control study of 444 Japanese
infants born at 33-35 weeks gestation.
‘Preterm infants who received at least three doses of palivizumab had about half the incidence of physician-diagnosed wheeze by age six, compared to those who did not receive the drug.’
The primary goal of the study was
to determine if palivizumab prophylaxis would prevent the onset of
atopic asthma. The drug did not, but it did significantly reduce
physician-diagnosed recurrent wheezing up to six years of age.
"Our findings suggests two independent phenotypes of recurrent
wheezing in young children: one that is dependent and one that is
independent of RSV lower respiratory infection," said lead study author
Hiroyuki Mochizuki, professor and chairman of pediatrics at
Tokai University in Japan.
The researchers found that infants who received at least three doses
of palivizumab according to standard medical practice had about half
the incidence of physician-diagnosed wheeze by age six, compared to those
who did not receive the drug (15.3% vs. 31.6%).
A strength of the study was that it was long-term prospective study
in 52 centers with a high follow-up rate. The latter was achieved using
an innovative method involving QR codes on mobile phones for
photographing physician documentation of wheezing during outpatient and
Study limitations include potential bias due to nonrandomized
design. The authors noted that there were only minimal differences in
family history of asthma, birth weight and gestational age among those
who were treated and those who were not. Children in the untreated
group, however, were more likely to live in a home with a smoker and
have a family member with a history of allergy - factors that would
"These results suggest that atopic asthma in children up to age six
is probably not due to RSV, but a significant proportion of recurrent
wheeze is," Dr. Mochizuki said. "Long-term observation of these subjects is planned to consider the impact of RSV infection on lung function in later life."