Immune imbalance in nasal polyps of Caucasian chronic rhinosinusitis patients is associated with a downregulation of E-selectin.

Chronic rhinosinusitis with nasal polyps (CRSwNP) in Caucasians is a chronic Th2 inflammatory disease of the nasal and paranasal mucosa and the recruitment of leukocytes to the site of inflammation is poorly understood. We studied mRNA and protein expression profiles of adhesion molecules in nasal polyp and associated inferior turbinate tissues using molecular, biochemical, and immunohistological methods. Analysis showed a strongly decreased E-selectin expression in nasal polyps with a significant difference between eosinophil and neutrophil counts in nasal polyps and balanced counts in inferior turbinates. E-selectin expression is known to be downregulated in a Th2 milieu and has an essential role in immunosurveillance by locally activating neutrophil arrest and migratory function. A downregulation of E-selectin may come along with an immune imbalance in Caucasian nasal polyps due to a significant inhibition of neutrophil recruitment. Therefore, we suggest that an upregulation of E-selectin and the associated influx of neutrophils may play a significant role in the resolution of inflammation as well as for the pathophysiology of nasal polyps of Caucasian chronic rhinosinusitis patients.