INFLAMMATORY CYTOKINE EXPRESSION ON NASAL POLYPS DEVELOPED IN ALLERGIC AND INFECTIOUS RHINITIS

To investigate the expression of cytokine mRNAs in nasal polyps and th e role of allergy in the pathogenesis of nasal polyposis, we studied t he expression of IL-4, IL-5, and IFN-gamma mRNAs using the RT-PCR and Southern blot. Nasal polyp specimens were obtained from 14 patients wi th infectious rhinitis and 5 patients with perennial allergic rhinitis . Turbinate mucosa specimens were obtained from 10 patients with aller gic rhinitis and from 10 healthy subjects as controls. IL-4, IL-5 and IFN-gamma mRNA were expressed in most specimens of allergic turbinate mucosa. The expression of these cytokines was less frequent in normal healthy turbinate mucosa. The density ratios of IL-4, IL-5 and IFN-gam ma to P-actin were individually determined in both polyp and turbinate tissues. The density ratio for each cytokine was relatively higher in polyp tissues than in healthy turbinate mucosa; however, there was no significant difference in the density ratios determined for polyps as sociated with allergic rhinitis as compared with polyps associated wit h infectious rhinitis. These findings indicate that nasal polyposis ma y differ from allergic rhinitis in the mechanism by which IL-4 and IL- 5 are increased. It is concluded that allergy may have an insignifican t role in the development of nasal polyps.