NASAL HYPERREACTIVITY AND ITS EFFECT ON EARLY AND LATE SEQUELAE OF NASAL CHALLENGE WITH HOUSE-DUST MITE EXTRACT

For a study on the relationship between nasal hyperreactivity to hista mine and the nasal response to allergen, 14 rhinitis patients allergic to house-dust mites were challenged with histamine and 5 days later w ith a house-dust mite (HDM) extract. According to symptom scores, afte r allergen challenge two groups of patients were distinguished, i.e., isolated early and dual responders. The nasal response to histamine wa s significantly correlated with the amount of secretion (r = 0.71; p = 0.0039) and the number of sneezes (r = 0.78; p = 0.0016) induced by t he HDM extract during the early reaction. The amount of allergen-induc ed secretion could be predicted from the response to histamine, skin r eactivity to allergen, and blood eosinophils (multiple r = 0.90; p < 0 .0001). Late-phase symptoms appearing between 3.5 and 9.5 hour after a llergen challenge could be predicted from histamine responsiveness and skin reactivity (multiple r = 0.67, p = 0.004). Compared with early r esponders (LAR-) (n = 8), patients with early and late symptoms (LAR+) (n = 6) were characterized by a higher secretory responsiveness to hi stamine (p = 0.033), increased production of leukotrienes determined i n nasal lavage fluid during the early response (p = 0.033), and elevat ed albumin levels occurring between 3.5 and 9.5 hours after challenge (p = 0.043). Late-phase symptoms were significantly correlated with al bumin influx (r = 0.73; p = 0.001) and leukotrienes production (r = 0. 60; p = 0.011) during the early reaction. In summary, nasal responsive ness to HDM extract was found to be closely associated with pre-existe nt nasal hyperreactivity. The degree of mediator involvement during th e early reaction seems to be of importance for the development of late -phase symptoms.