RANTES, macrophage-inhibitory protein 1 alpha, and the eosinophil product major basic protein are released into upper respiratory secretions during virus-induced asthma exacerbations in children

The presence of cytokines and the toxic eosinophil granule product major ba sic protein (MBP) was investigated in nasal aspirates from children with na turally occurring virus-induced asthma exacerbations and compared with leve ls in nasal aspirates taken from the same children when asymptomatic. Incre ased levels of MBP accompanied by increased levels of the chemokines RANTES and macrophage-inhibitory protein lot were observed in nasal aspirates fro m children during the virus-induced exacerbations. Granulocyte-macrophage c olony-stimulating factor was mostly undetectable in samples obtained during both symptomatic and asymptomatic periods. Interleukin-5 levels were low, but tended to increase in samples from symptomatic children, These data con firm that the eosinophil product MBP and the eosinophil chemoattractant che mokines RANTES and macrophage-inhibitory protein la are increased in upper respiratory viral infections associated with asthma exacerbations and sugge st an important role for these chemokines in regulating eosinophil influx a nd activation. These chemokines may represent targets for therapeutic inter vention in virus-induced asthma exacerbations.