Glucocorticoid-induced attenuation of mucosal exudation of fibrinogen and bradykinins in seasonal allergic rhinitis.

The mucosal plasma exudate with its proteins, enzymes, derived peptides, and matrix molecules is an important factor in inflammatory airway diseases. This study investigated whether topical glucocorticosteroid treatment influences mucosal exudation of bulk plasma (fibrinogen) and the generation of plasma-derived mediators (bradykinins) in seasonal allergic rhinitis. Twenty-two patients with birch-pollen-induced allergic rhinitis participated in a double-blind, randomized, placebo-controlled study during the birch pollen season in 1989. After a 2-week run-in period, the participants received treatment with budesonide (200 micrograms per nasal cavity and day) or placebo. The patients kept a diary to record their daily nasal symptoms (itching, sneezing, nasal blockage, and secretion). The amount of birch pollen in the air was determined with the aid of a Burkhard pollen trap. A nasal lavage was performed once a week, and the levels of bradykinins and fibrinogen were determined in the lavage fluid samples. The birch pollen season was very mild, resulting in only minor nasal symptoms. In spite of the low pollen exposure, treatment with budesonide reduced the lavage fluid levels of both bradykinins and fibrinogen. The present results show that topical glucocorticosteroid treatment attenuates plasma exudation and the generation of plasma-derived mediators in seasonal allergic rhinitis. This action may not result from simple vascular antipermeability effects of the drug but may rather reflect the anti-inflammatory efficacy of topical glucocorticoids in the airway mucosa.