Background: Chronic rhinosinusitis (CRS) is a heterogeneous group of inflammatory diseases of the nasal and paranasal cavities, either accompanied by polyp formation (CRSwNP) or without polyps (CRSsNP). The etiology and pathophysiology is unknown; some specialists define rhinitis and sinusitis as one clinical entity, whereas others regard both as separate dis-eases. We therefore investigated the immunological background of the chronically inflamed nasal and sinusal mucosa.
Methods: Protein levels of the inflammatory mediators ILl-beta, IL-5, ECP, INF-gamma, and TGF-beta were assessed in ethmoidal mucosal samples from CRSsNP and CRSwNP patients, and compared with the expression profile in nasal inferior turbinate (17) mucosa of the same patient groups. Nasal tissue of patients without disease served as control.
Results: In CRSwNP, increased levels of IL-5 and ECP were not only observed in ethmoidal samples, but also in the nasal IT-mucosa. TGF-beta levels were lower in polyps, reaching significance versus ethmoidal mucosa of CRSsNP. In CRSsNP, INF-gamma levels are up-regulated in both ethmoidal and nasal mucosa compared to control tissue.
Conclusion: On the basis of similar inflammatory mediator profiles, we conclude that rhinitis accompanies chronic sinusitis, supporting the consensus term "rhinosinusitis". On the other hand, CRSsNP and CRSwNP should be regarded as distinct clinical entities.