Mucosal output of eotaxin in allergic rhinitis and its attenuation by topical glucocorticosteroid treatment

Background Eotaxin is a chemokine that attracts and activates eosinophils. The present study examines the occurrence of eotaxin in nasal mucosal surfa ce liquids in patients with seasonal allergic rhinitis without allergen exp osure and during repeat allergen challenge with and without topical glucoco rticosteroid treatment. The number of subepithelial eosinophils and mucosal outputs of bulk plasma (alpha (2)-macroglobulin) and eosinophil cationic p rotein (ECP) are also examined. Methods Twelve patients underwent daily allergen challenges for 6 days. Sep arately, 14 patients, who were receiving budesonide and placebo in a parall el group design, also underwent allergen challenge for 6 days. Nasal biopsi es were obtained before and 24 h after the allergen challenge series, and l avages were carried out before and 15 min after selected allergen challenge s. Results At baseline nasal lavage fluid levels of eotaxin correlated to leve ls Of alpha (2)-macroglobulin and ECP. After the first allergen challenge t here was a correlation between nasal lavage fluid levels of eotaxin and ECP . Repeat allergen exposure increased the mucosal output of eotaxin (P < 0.0 5) and ECP (P < 0.01) as well as eosinophil numbers (P < 0.01), but no corr elation was found between increased eosinophil numbers and eotaxin. Budeson ide reduced eotaxin levels during repeat allergen challenge (P < 0.05). Conclusions Repeat allergen exposure in allergic rhinitis is associated wit h increased mucosal output of eotaxin. Topical budesonide attenuates this e ffect, suggesting the possibility that inhibitory effects on mucosal eotaxi n may contribute to anti-eosinophilic actions of topical glucocorticosteroi ds.