NITRIC-OXIDE METABOLITES IN NASAL LAVAGE FLUID OF PATIENTS WITH HOUSE-DUST MITE ALLERGY

Background - The role of nitric oxide in the early and late phase of t he allergic process was investigated in patients with allergic rhiniti s against house dust mite and the effect of fluticasone propionate aqu eous nasal spray was determined. Methods - Production of nitric oxide (measured as nitrite + nitrate) in vivo in nasal mucosa was examined i n 24 patients with rhinitis allergic to the house dust mite. In a doub le blind placebo controlled crossover study fluticasone propionate 200 mu g aqueous nasal spray was administered twice daily for two weeks. In response to provocation with house dust mite extract (after four ba sal nasal lavages) nasal lavages were performed every hour for 9.5 hou rs by washing the nose with saline. In addition, a similar lavage prot ocol was performed in healthy volunteers with or without challenge wit h phosphate buffered saline. Results - Nitric oxide is present in nasa l lavage fluid in detectable amounts (range 10-50 mu M), the level gra dually increasing with time in both patients and controls after a decr ease during the four basal lavages. Treatment with fluticasone propion ate aqueous nasal spray did not affect initial basal production of nit ric oxide nor production following provocation with house dust mite ex tract. Conclusions - Production of nitric oxide in nasal mucosa determ ined in sequential nasal washings is not affected by therapeutic doses of intranasal steroids.