Upregulation of RANTES in nasal polyps from patients with cystic fibrosis

Abstract

Background: Nasal polyps in patients with cystic fibrosis (CF) are believed to be phenotypically different than polyps affecting non-CF patients. The objective of this study was to characterize the expression of inflammatory cytokines within nasal polyps from CF and non-CF, aspirin-tolerant patients. "Regulated on activation, normal T-cell expressed and secreted" (RANTES) is a chemotactic cytokine involved in the recruitment and activation of eosinophils. Multiple molecular studies of non-CF polyps have established that RANTES may play an important role in nasal polyposis. Our study suggests RANTES may be upregulated in CF polyps relative to non-CF polyps.

Methods: Nasal polyps were prospectively obtained from CF and non-CF, aspirin-tolerant patients. The Quantibody™ Human Cytokine Array I from RayBiotech, Inc., was used to identify differences in cytokine expression between protein extracts of two polyp groups. Four CF polyp extracts and 4 non-CF, aspirin-tolerant polyp extracts were each incubated on identical antibody subarrays, each containing 20 human cytokines in quadruplicate. Western blot analysis confirmed expression of RANTES.

Results: The protein microarray suggests a greater than 4-fold upregulation of RANTES in CF polyps relative to non-CF polyps. Western blot analysis confirmed expression of RANTES in CF polyps.

Conclusion: Chemokines such as RANTES are responsible for the activation of inflammatory cells within the lamina propria of nasal polyps. We have demonstrated that RANTES may be an important cytokine associated with CF polyps.