Eotaxin in exhaled breath condensate of allergic asthma patients with exercise-induced bronchoconstriction

Eosinophils are the key inflammatory cells in asthma, and more and more evidence suggests their crucial role in exercise-induced bronchoconstriction (EIB). Eotaxin, as the most important chemotactic factor for eosinophils, plays an important role in the pathogenesis of asthma.

The aim of the study was to evaluate the changes in eotaxin levels in exhaled breath condensate (EBC) following intensive exercise in allergic asthmatics.

The study was performed in a group of 27 asthmatics (17 with EIB, 13 without EIB) and 9 healthy volunteers. Changes induced by intensive exercise in the concentrations of eotaxin in EBC during the 24 h after an exercise test were assessed. The possible correlations of these measurements with the results of other tests commonly associated with eosinophilic airway inflammation were also determined.

In asthmatic patients with EIB, a statistically significant increase in eotaxin concentrations in EBC collected during the first 24 h after an exercise test - with maximal increase after 6 h - was revealed. A statistically significant correlation between the maximum increase in eotaxin concentrations in EBC after exercise, and an increase in either serum eosinophil cationic protein or F(ENO) 24 h after exercise in the group of asthmatics with EIB, was observed.

Our results confirm connections between EIB and airway eosinophilic inflammation. The increase of eotaxin in asthmatic airways, by promoting the migration and activation of eosinophils, may play an important role in upregulation and sustaining of the airway inflammation observed in EIB in asthmatic patients.