Distribution of RANTES and interleukin-5 in allergic nasal mucosa and nasal polyps

Eosinophil-chemoattracting cytokines are thought to be important in the pat hogenesis of allergic inflammation. However, little is known about the pres ence and significance of RANTES in nasal allergy and nasal polyps, two well -known rhinologic disorders characterized by eosinophil infiltration in the tissue, in order to evaluate the role of RANTES in eosinophil infiltration in vivo, the tissue distributions of RANTES and interleukin-5 (IL-5) and t heir correlation with eosinophil infiltration were investigated. Nasal muco sa specimens were obtained from 9 allergic and 12 control subjects, and nas al polyps from 6 allergic and 9 nonallergic subjects. All the subjects were divided into 4 groups: normal mucosa, allergic mucosa, nonallergic polyps, and allergic polyps. To identify the cellular localizations of RANTES and IL-5, we used specific immunohistochemical staining. We also investigated t he differences in cytokine expression among the 4 groups, and the correlati on between cytokine expression and eosinophil infiltration in the tissue. R ANTES was expressed in the epithelium, endothelium, and some submucosal cel ls, while IL-5 was confined to the cells in the submucosa. Expression of bo th RANTES and IL-5 significantly increased in allergic mucosa and nasal pol yps compared to normal mucosa; however, there was no significant difference in their expression between allergic and nonallergic polyps. Both cytokine s had a significant correlation between their expression and either total o r activated eosinophil numbers. The results of this study suggest that RANT ES, as well as IL-5, plays a role in eosinophil recruitment in allergic nas al mucosa and nasal polyps in vivo.