MIP-1α level in nasopharyngeal aspirates at the first wheezing episode predicts recurrent wheezing.

Background: Respiratory virus-induced wheezing, such as that induced by respiratory syncytial virus (RSV) and human rhinovirus, is an important risk factor for recurrent wheezing and childhood asthma. However, no biomarkers for predicting recurrent wheezing have been identified.

Objective: We searched for predictors of recurrent wheezing using nasopharyngeal aspirates obtained from patients during the first wheezing episode who were hospitalized with an acute lower respiratory tract illness.

Methods: We enrolled 82 infants during the first wheezing episode (median age, 5.0 months) who were hospitalized for acute lower respiratory tract 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 by using RT-PCR and sequencing. Levels of 33 cytokines, tryptase, IgE, anti-RSV IgE, and anti-RSV IgG were measured by using ELISAs or the Bio-Plex multiplex assay. Predictors of recurrent wheezing were examined by using a stepwise logistic regression model with backward elimination.

Results: Sixty percent of the patients experienced recurrent wheezing episodes. One or more viruses were detected in the nasopharynxes of 93% of the patients during the first wheezing episode. IFN-γ, IL-2, IL-9, MIP-1α, and MIP-1β levels were significantly higher among patients with recurrent wheezing than among those without recurrent wheezing (P < .05 or .01). The stepwise model demonstrated that the MIP-1α level (odds ratio, 7.72; 95% CI, 1.50-39.77; P = .015) was the strongest independent predictor of the occurrence of recurrent wheezing.

Conclusion: An increased MIP-1α level in nasopharyngeal aspirates from patients with acute respiratory symptoms during the first wheezing episode caused by viral infections might predict recurrent wheezing.