Differentiation of chronic sinus diseases by measurement of inflammatory mediators

Background: Chronic rhinosinusitis (CRS) clinically is a heterogeneous group of sinus diseases, which may cover different disease entities, or may represent a disease continuum. Studying inflammatory cells and mediators in clearly defined disease subgroups may lead to a better differentiation of chronic sinus diseases. Methods: Sinonasal mucosal tissue from 10 nasal polyp (NP) patients, 13 cystic fibrosis patients (CF‐NP), eight CRS subjects without polyps, and nine control patients were stained for CD3, CD25, CD68, CD20, myeloperoxidase (MPO), CD138 and tissue homogenates were assayed for eotaxin, interleukin (IL)‐1 β , IL‐2sR α , IL‐5, interferon (IFN)‐ γ , IL‐8, transforming growth factor (TGF)‐ β 1, tumor necrosis factor‐ α , and MPO by enzyme‐linked immunosorbent assay or UNICAP system. Results: Nasal polyp and CF‐NP showed increased numbers and activation of T cells, while only NP displayed an increase in plasma cells. Nasal polyp had significantly higher levels of eosinophilic markers eosinophils, eotaxin, and eosinophil cationic protein (ECP) compared with CRS, controls and CF‐NP. Chronic rhinosinusitis was characterized by a Th1 polarization with high levels of IFN‐ γ and TGF‐ β , while NP showed a Th2 polarization with high IL‐5 and immunoglobulin (Ig) E concentrations. Nasal polyp and CF‐NP were discriminated by edema from CRS and controls, with CF‐NP displaying a very prominent neutrophilic inflammation. Conclusion: Based on cellular and mediator profiles, we suggest that CRS, NP, and CF‐NP are distinct disease entities within the group of chronic sinus diseases.