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| - BACKGROUND: The relevance of allergic sensitization, judged by titers of serum IgE antibodies, to the risk of an asthma exacerbation caused by rhinovirus is unclear. OBJECTIVE: To examine the prevalence of rhinovirus infections in relation to the atopic status of children treated for wheezing in Costa Rica, a country with an increased asthma burden. METHODS: The children enrolled (n=287) were 7 through 12 years old. They included 96 with acute wheezing, 65 with stable asthma, and 126 non-asthmatic controls. PCR methods, including gene sequencing to identify rhinovirus strains, were used to identify viral pathogens in nasal washes. Results were examined in relation to wheezing, total IgE, allergen-specific IgE antibody, and levels of expired nitric oxide (FE(NO)). RESULTS: Sixty-four percent of wheezing children compared to 13% of children with stable asthma and 17% of the non-asthmatic controls tested positive for rhinovirus (p<0.001 for both comparisons). Among wheezing subjects, 75% of the rhinoviruses detected were Group C strains. High titers of IgE antibodies to dust mite allergen (especially Dermatophagoides sp) were common and correlated significantly with levels of total IgE and FE(NO). The greatest risk for wheezing was observed among children with titers of IgE antibodies to dust mite ≥17.5 IU/ml who tested positive for rhinovirus (odds ratio for wheezing: 31.5; 95% CI 8.3–108, p<0.001). CONCLUSIONS: High titers of IgE antibody to dust mite allergen were common and significantly increased the risk for acute wheezing provoked by rhinovirus among asthmatic children.
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