alpha(2)-macroglobulin and eosinophil cationic protein in the allergic airway mucosa in seasonal allergic rhinitis

As previously demonstrated in seasonal allergic rhinitis, increased microva scular permeability and eosinophil activation are key features of allergic airway inflammation. In the present study, the hypothesis that exudation of alpha(2)-macroglobulin may cause the appearance of eosinophil cationic pro tein (ECP) in the airway lumen was explored. Nasal lavages were carried out using the nasal pool device before and durin g the pollen season both at baseline and after histamine challenge in 10 ch ildren with allergic rhinitis. Nasal lavage fluid levels of alpha(2)-macrog lobulin and ECP were determined. All patients experienced nasal symptoms of allergic rhinitis during the pol len season (p<0.01-0.05), Baseline nasal lavage fluid levels of alpha(2)-ma croglobulin and ECP were increased during the season (p<0.01-0.05) and were found to be well correlated (p<0.0001). Histamine produced concentration-d ependent plasma exudation before and during the pollen season, but it was o nly during the pollen season that this caused an increase in the lavage flu id levels of ECP (p<0.05). These data suggest that exudation of plasma and increased tissue levels and output of eosinophil cationic protein characterize nasal mucosal inflammat ion in children with seasonal allergic rhinitis, The plasma exudation proce ss in part may account for lumenal entry of eosinophil cationic protein mol ecules that have been released in mucosal tissue compartments. A combinatio n of induced exudation and nasal lavage may improve the yield of important markers of inflammation in studies of nasal diseases.