Proinflammatory Cytokines: Measurement in Nasal Secretion and Induction of Adhesion Receptor Expression

Abstract

We recently demonstrated that interleukin (IL)-1β tumor necrosis factor (TNF)-α IL-6 and IL-8 can be found in nasal secretions from allergic rhinitis patients under artificial and natural conditions. By ELISA measurements, significantly elevated baseline levels for IL-1β, IL-6 and IL-8 were found in seasonal allergic compared to control subjects. Within the first 2 h after nasal allergen challenge, IL-1β and TNF are secreted, whereas IL-6 and IL-8 showed a slow increase over 6–8 h. All cytokine levels returned to baseline within 24 h after exposure. Repeated measurements at 4-week intervals in perennial allergic rhinitis subjects (n = 27) showed significant correlations between IL-1 and IL-8, IL-6 and IL-8 and IL-6 and the symptom score (visual analogue scale). The IL-1 receptor antagonist IL-1ra was found in great molar excess in the secretions and correlated significantly with IL-8, but not IL-1β. In an in vitro assay using fresh nasal mucosa of grass-pollen-allergic subjects, we were able to demonstrate a strong and rapid induction of E-selectin adhesion receptor expression on endo-thelial cells by allergen, IL-1β and TNF. The adhesion receptor expression was markedly inhibited by soluble IL-1 receptors, sTNF-R and IL-1ra. These data indicate a key role for inflammatory cytokines in the regulation of allergic inflammation.