Eosinophilia and cell activation mediators in nasal secretions

In rhinologic disorders such as polyposis or rhinitis, nasal cytology allows differentiation between patients according to the degree of eosinophilia in nasal secretions. The egress of eosinophil and/or neutrophil polymorphonuclears from the underlying mucosa might correlate with the release of soluble mediators of cell activation such as the chemokine IL-8, and such molecules of the innate immunity as the LPS-receptor CD14 or lysozyme. We assayed the levels of these three molecules in nasal secretions in correlation with cytologic findings and especially the degree of eosinophilia.

Fifty-four patients from a prospective study of nasal secretions were enrolled in this work. They constituted two groups of 27 patients each, respectively, with or without more than 20% eosinophils in nasal secretions. Nasal secretions were collected by aspiration, weighed and diluted in a fixed amount of buffer. Classic cytologic analyses were performed on the pelleted cells and IL-8, sCD14, and lysozyme levels were assayed in the cell-free supernatants.

Cytologic analyses included cell-enumeration in Neubauer's chambers, and differentials performed on May-Grünwald Giemsa-stained cytospins. ELISA tests were used to assay the levels of IL-8 and sCD14. Lysozyme concentrations were assayed in immuno-nephelometry.

Significantly lower levels of IL-8 and sCD14 were observed in patients with eosinophilia than in patients with a predominance of neutrophils, whereas no difference was observed in lysozyme concentrations.

These data show that the egress of neutrophils in nasal secretions is associated with high levels of IL-8 and sCD14.