Methods: We enrolled 82 first-wheezing-episode infants (median age, 5.0 months) hospitalized for acute lower respiratory illness between August 2009 and June 2012 and followed these patients for 2.5 years. Nasopharyngeal aspirates and blood samples were obtained on the first day of hospitalization. Viral genomes were identified using RT-PCR and sequencing. The levels of 33 cytokines, tryptase, IgE, anti-RSV IgE, and anti-RSV IgG in nasopharyngeal aspirates were measured using enzyme-linked immunosorbent assays or Bio-Plex multiplex assay. Predictors of recurrent wheezing were examined using a stepwise logistic regression model with backward elimination.
Results: Sixty percent of the patients experienced recurrent wheezing episodes. In the nasopharynx of 93% of the first-wheezing-episode patients, one or more viruses were detected. The IFN-γ, IL-2, IL-9, MIP-1α, and MIP-1β levels were significantly higher with recurrent wheezing than among patients without recurrent wheezing (P < 0.05 or 0.01). The stepwise model demonstrated that the log MIP-1α level (OR, 7.72; 95% CI, 1.50 – 39.77; P = 0.015) was the strongest independent predictor of the occurrence of recurrent wheezing.
Conclusions: The measurement of MIP-1α levels in nasopharyngeal aspirates from first-wheezing-episode patients with acute lower respiratory illness may be useful for predicting recurrent wheezing and initiating early intervention.