Preventive treatment of intranasal fluticasone propionate reduces cytokinemRNA expressing cells before and during a single nasal allergen provocation

Background The local production and release of a number of cytokines regula te allergic upper airway inflammation. Medication is usually used at the pr esentation of the first symptoms. There are, however, clues that it is advi sable to start taking the corticosteroid before the grass pollen season beg ins. Methods This single allergen provocation study was conducted in autumn, out of the hay fever season. Nasal mucosa biopsies were taken twice before pro vocation (before and after 4 weeks of preventive treatment) and three times after allergen provocation (1 h, 24 h and 1 week). The preventive treatmen t used was fluticasone propionate aqueous nasal spray (FPANS) (n = 10) or a placebo (n = 9). Eosinophils and mRNA positive cells (in situ hybridizatio n for IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, IFN gamma, RANTES a nd TNF alpha) were counted in the biopsies. Results Preventive treatment with FPANS out of season resulted in a decreas e in eosinophils and mRNA positive cells for IL-5 and IL-6. After allergen provocation, levels of most of the measured cytokines (IL-3, IL-5, IL-6, IL -13, IFN gamma, RANTES and TNF alpha) and eosinophils were reduced using co rticosteroids. The numbers of cells (eosinophils, IL-3, IL-6 and IL-8) corr elated with nasal symptoms. Significant correlations in the early and late allergic phase were found between eosinophils and cytokines (IL-3, IL-10 an d IL-13). Conclusion These results indicate that preventive treatment with FPANS prio r to contact with grass pollen is effective in reducing the increase of cyt okine mRNA positive cells in reaction to grass pollen contact.