Increased expression of the chemokine CCL23 in eosinophilic chronic rhinosinusitis with nasal polyps

Background Chronic rhinosinusitis (CRS) is a heterogeneous chronic disease characterized by local inflammation of the sinonasal tissues. The pathogenesis of CRS remains controversial, but it has been associated with the accumulation of various immune and inflammatory cells in sinus tissue. Objectives The objective of this study was to investigate the expression of the chemokine CCL23, which is known to bind to CCR1 and recruit monocytes, macrophages, and dendritic cells, in patients with CRS. Methods We collected nasal tissue from patients with CRS and control subjects. We assayed mRNA for CCL23 by using real-time PCR and measured CCL23 protein by means of ELISA, immunohistochemistry, and immunofluorescence. Results CCL23 mRNA levels were significantly increased in nasal polyps (NPs) from patients with CRS with nasal polyps (CRSwNP; P + inflammatory cells occurred only in NPs. Immunofluorescence data showed CCL23 colocalization with eosinophil cationic protein–positive eosinophils. The concentration of CCL23 in NPs positively correlated with the concentration of eosinophil cationic protein, suggesting that eosinophils are major CCL23-producing cells in NPs. Finally, we found that CCL23 protein levels were significantly increased in NPs from patients with CRSwNP with aspirin sensitivity. Conclusion Overproduction of CCL23 in NPs might contribute to the pathogenesis of eosinophilic CRSwNP through the recruitment of CCR1 + inflammatory cells, including monocytes and macrophages, and the amplification of local inflammation.