Effect of a single dose of a topical glucocorticoid and a cyclo-oxygenase inhibitor on allergen-induced changes in nasal reactivity

The inflammatory response of airway mucosa to allergen exposure is a complex phenomenon featuring symptoms, the influx of inflammatory cells, the release of mediators, and changes in local reactivity. These features and their pharmacological modifications can be successfully studied in nasal challenge models. We performed a nasal allergen challenge followed by a rechallenge with allergen 24 h later in order to monitor changes in specific reactivity due to the initial allergen challenge. Symptoms were monitored, as was the generation of TAME-esterase activity in nasal lavage fluids. Prior to each challenge a nasal brush specimen was taken. In a double blind, cross-over, double-dummy manner the patients were pretreated with placebo, a single dose of 200 μg of budesonide (topical corticosteroid) given 2 h prior to rechallenge with allergen or 600 mg ibuprofen (cyclooxygenase inhibitor) given per os t.i.d. to steady state starting 24 h prior to the initial allergen challenge. Treatment with ibuprofen induced a slightly lower composite symptom score (P < 0.05) at the initial allergen challenge when compared with placebo. No differences were noted in the relevant TAMF-esterase activities. The allergen challenge resulted in significantly increased proportions of eosinophils in the brush specimens 24 h after the initial allergen challenge (P < 0.001) with no differences between the different treatment alternatives. At rechallenge there was a reduction in the symptoms of secretion and nasal blockage in both groups receiving active treatment compared with placebo (P < 0.05), whereas the number of sneezes was not affected and no differences were noted m TAME-esterase activity. We conclude that allergen-induced changes in reactivity appear to involve cyclooxygenase metabolites to some extent and that a reduction in eosinophil numbers is not a prerequisite when it comes to demonstrating an inhibition of the change in reactivity.