Allergic profiles in unilateral nasal polyps of bilateral chronic rhinosinusitis

Background: Bilateral chronic rhinosinusitis (CRS), with unilateral nasal polyps (NPs), is a good model for study, being characterized by a similar inflammatory reaction and environment in both nasal cavities of a subject, although NPs exist in only one nasal cavity. It may be feasible to identify specific pathological factors responsible for the disparities by comparing the differences between the nasal cavities. Methods: In patients with bilateral CRS, polyp tissue and the middle turbinate tissue on the side of the polyp were examined and compared with contralateral nonpolyp middle turbinate tissue. Tissue and serum-specific immunoglobulin E (sIgE) levels were measured, and eosinophilic infiltration, interleukin (IL)-5 and IL-1-beta were assessed also in the polyp tissue. Results: The presence of allergic symptoms correlated well with a positive serum CAP test but poorly with a positive tissue CAP test. There were no obvious differences between tissue sIgE levels on the NP side compared with the nonpolyp side. Tissue eosinophilia was a general characteristic of NPs, whether there was allergy or not. IL-5 and IL-1-beta levels were elevated in NPs, regardless of allergy. There were no differences in the specimens on the nonpolyp side between allergy and nonallergy groups. Conclusion: With this model, we have more precise, however, not new results. Localized allergic reaction is not a major factor for the development of a unilateral polyp. Inflammation associated with eosinophilic infiltration and the presence of proinflammatory cytokines, including IL-5 and IL-1-beta, are more important in the pathogenesis of NPs than the allergic reaction.