Nasal tissue eosinophils in allergic rhinitis.

The density characteristics and functional heterogeneity of nasal tissue eosinophils were studied. The density distribution profiles of eosinophils from patients with allergic rhinitis (AR) showed peaks at densities of 1.068 to 1.084 g/ml, significantly lower than the densities of eosinophils in non-allergic patients with nasal polyps and chronic sinusitis (p < 0.01). The proportion of hypodense eosinophils in patients with AR was 43%; this was significantly greater than that in non-allergic subjects (p < 0.001). Patients with AR tended to have more EG2-positive tissue eosinophils. Furthermore, normodense eosinophils in nasal tissue tended to show a higher percentage of EG2-positive cells than hypodense eosinophils. On the other hand, circulating hypodense eosinophils showed a higher percentage of EG2-positive cells than normal density eosinophils. These results suggest that tissue eosinophils may be activated, and that the functional heterogeneity of eosinophils is dependent on factors other than cell density.