Respiratory syncytial virus infection in children hospitalized for wheezing: virus-specific studies from infancy to preschool years.
OBJECTIVE
To evaluate whether the presence of immunoglobulin G (IgG) antibodies against respiratory syncytial virus (RSV) in early childhood is associated with later asthma, and to evaluate a new diagnostic test for RSV, reverse-transcription polymerase chain reaction (RT-PCR), comparing it to the antigen and antibody assays initially used in RSV diagnostics in the present cohort.


METHODS
At the start of the study in 1992-1993, RSV was studied by antigen detection (using time-resolved fluoroimmunoassay) and complement-fixing antibody assay. Advances in methodology allowed us to supplement RSV studies by RT-PCR in frozen nasopharyngeal aspirates obtained on admission, and by specific IgG antibodies (using enzyme immunoassay) in frozen serum samples obtained during the follow-up.


RESULTS
On admission, 29 of the 100 children hospitalized for wheezing at <2 y of age were RSV positive. When compared with conventional methods, the sensitivity of RT-PCR was 83% (100% w.r.t. antigen detection) and its specificity was 92% in diagnosing RSV infection. RSV-specific IgG antibody concentrations rose with age, but were not predictive of asthma at any age. In the present cohort, wheezing without RSV was particularly associated with increased risk for later childhood asthma.


CONCLUSIONS
Hospitalization for wheezing in infancy is associated with increased risk for later childhood asthma, particularly in children without RSV infection on admission, although children with RSV have also slightly increased risk for later asthma. However, mere serological evidence of RSV infection is not associated with the development of asthma. In addition to RSV, more attention should be paid to less virulent agents in order to find those wheezing infants who are at particular risk of later childhood asthma.
Kotaniemi-Syrjänen
Anne
A
Department of Paediatrics, University of Kuopio and Kuopio University Hospital, Kuopio, Finland. kotaniem@hytti.uku.fi
Laatikainen
Aino
A
Waris
Matti
M
Reijonen
Tiina M
TM
Vainionpää
Raija
R
Korppi
Matti
M
D001249:Asthma / Q000453:epidemiology* / Q000276:immunology / Q000821:virology; D002675:Child, Preschool; D005500:Follow-Up Studies; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D012135:Respiratory Sounds; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis* / Q000453:epidemiology* / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D018709:Statistics, Nonparametric
D007074:Immunoglobulin G