Eotaxin and impaired lung function in asthma

We performed an association study of plasma eotaxin levels, eosinophil coun ts, total IgE levels, asthma diagnosis, and lung function in an ethnically diverse and geographically dispersed population. We studied 515 asthmatic a nd 519 normal subjects, none of whom was taking inhaled or oral corticoster oids. Logistic regression analysis demonstrated a direct relationship betwe en asthma diagnosis and eotaxin levels (p < 0.0001). The odds of an asthma diagnosis increased with eotaxin quartile, with the highest quartile having an odds ratio of 5.4 (95% CI 3.2 to 9.2, p < 0.001) compared with the lowe st eotaxin quartile. Eotaxin levels were inversely related to lung function (p < 0.001), with the mean percent predicted FEV1 in the highest eotaxin q uartile being 13.5 percentage paints (SEM 2.1, p < 0.001) less than that in the lowest quartile, Plasma eotaxin levels were associated with asthma and inversely related to lung function independent of age, race, sex, or smoki ng status. When combined with eosinophil counts and IgE levels, eotaxin lev els contributed to the odds of an asthma diagnosis and of impaired lung fun ction. Our results are the first to associate eotaxin levers with asthma di agnosis and compromised lung function in a large geographically and ethnica lly diverse population.