Effect of fluticasone on neuropeptides in nasal lavage in persistent allergic rhinitis.

OBJECTIVE Recent guidelines reveal that allergic rhinitis impairs quality of life. Neuropeptides play a central role in allergy-related nasal inflammation. The objective of this study was to analyze the release of neuropeptides (substance P, neurokinin A, and vasoactive intestinal peptide) in nasal lavage and their modification by intranasal fluticasone propionate as an established therapy in patients with allergic rhinitis. METHODS Eleven patients with proven allergic rhinitis induced by house dust mite were challenged before and after administration of fluticasone propionate nasal spray. Nasal lavage samples were collected after allergen challenge, and neuropeptides were measured using enzyme-linked immunosorbent assay. Values for histamine, protein, and human serum albumin were also recorded. Eight healthy individuals were included as nonatopic controls. RESULTS The neuropeptides investigated were detectable in nasal lavage fluid in both patients and controls. Treatment with fluticasone propionate significantly decreased clinical response to allergen challenge (P < .01) compared with the controls and led to a decrease in values for substance P, neurokinin A, vasoactive intestinal peptide, histamine release, human serum albumin, and total protein after allergen challenge (P < .01). CONCLUSIONS The demonstration of proinflammatory neuropeptides in NAL and suppression of their release after allergen challenge caused by a topical corticosteroid suggest a role for neuropeptides in allergic inflammation. Diminished release of neuropeptides induced b fluticasone propionate was accompanied by an improvement in the clinical symptoms of patients with persistent allergic rhinitis.