Nasal polyps in patients with and without cystic fibrosis: a differentiation by innate markers and inflammatory mediators

Abstract

Background: The dysfunction of the mucosal interface of the upper respiratory tract in cystic fibrosis (CF) patients is clinically visible by the development of nasal polyps (NP) at a young age. Innate defence markers and inflammatory mediators in NP from patients with CF were compared with non-cystic fibrosis nasal polyps (non-CF-NP) to determine a possible different immunological background in macroscopically similar tissue.

Methods: Surgical samples were obtained from patients with non-CF-NP, cystic fibrosis patients with nasal polyps (CF-NP) and control patients (CO). With real time PCR, the mRNA expression of human beta defensins (HBD) 2 and 3, toll-like receptors (TLR) 2 and 4 and the macrophage mannose receptor (MMR) were measured. On homogenates of the surgical samples eotaxin, myeloperoxidase (MPO), IL-5 and IL-8 protein content was measured using commercial ELISA kits; IgE and eosinophilic cationic protein (ECP) were measured by the Unicap system.

Results: In CF-NP we found a statistically significant higher mRNA expression of HBD 2 compared with non-CF-NP and CO and of TLR 2 compared with non-CF-NP. In the non-CF-NP group, MMR mRNA expression was significantly elevated compared with CO and CF-NP. For TLR 4 mRNA expression no statistically significant differences were found between groups. IL-5 was below detection level in all CO and CF-NP, but was measurable in 80% of the non-CF-NP. MPO and IL-8 concentrations were significantly higher in CF-NP compared with CO and non-CF-NP, whereas ECP, eotaxin and IgE were significantly higher in the non-CF-NP group.

Conclusions: We here demonstrate that CF-NP and non-CF-NP not only differ in terms of inflammatory mediator profile, but also in terms of innate markers.