Background Eotaxin-1 (CCL11) is a CC chemokine whose nasal eosinophilic chemotactic activity in vivo and in vitro has been demonstrated primarily using nasal allergen challenge models. The extension of these challenge findings to the in vivo setting has been limited.
Objective To obtain nasal lavage fluid from volunteers with perennial and seasonal (in- and out-of-season) allergic rhinitis (AR) and non-atopic non-rhinitic controls for the measurement of eotaxin-1 concentrations and to relate these findings to the symptomatic disease severity, the percentage of lavage eosinophils, and to α2-macroglobulin (α2-MG) lavage concentrations, as a marker of vascular permeability and an index of airway inflammation.
Methods Thirty-seven volunteers with AR (16 seasonal and 21 perennial) and 20 non-atopic non-rhinitic volunteers were recruited and phenotyped. Nasal lavage fluid was obtained by standardized protocol. The nasal lavage fluid concentrations of eotaxin and α2-MG were measured by ELISA, and differential cell counts performed on cytospins.
Results Eotaxin-1 nasal lavage fluid concentrations were significantly higher in both the perennial and seasonal (in-season) AR groups compared with the controls, and significantly related to the severity of symptom expression and to the percentage of lavage eosinophils. The lavage eosinophil counts were significantly higher in both the symptomatic rhinitis groups compared with the control groups and correlated with the lavage concentrations of α2-MG. α2-MG levels were significantly increased in seasonal (in-season) rhinitics compared with both non-atopic controls and seasonal (out-of-season) rhinitics. A significant correlation was observed between the levels of α2-MG and levels of eotaxin in the symptomatic allergic rhinitic groups.
Conclusions This study clearly demonstrates the relevance of eotaxin-1 to the pathogenesis of naturally occurring AR.