CONCENTRATIONS OF MYELOPEROXIDASE IN NASAL SECRETIONS OF ATOPIC PATIENTS AFTER NASAL ALLERGEN CHALLENGE AND DURING NATURAL ALLERGEN EXPOSURE

A quantitativ determination of myeloperoxidae (MPO) concentration was performed in the nasal secretions of atopic patients (challenged group , n=17) after nasal allergen challenge outside the pollen season, and of patients with ongoing seasonal (seasonal group, n = 40) and with pe rennial (perennial group, n = 30) allergic rhinitis. The concentration s of MPO obtained from 10 nonallergic healthy volunteers (control grou p) were used as a normal control. Results showed that there was no sta tistical difference between the normal controls (median: 2.0 mu g/g) a nd the atopic patients (median: 1.7 mu g/g) outside the pollen season. After nasal allergen challenge (challenged group), there was no signi ficant difference of MPO at 5 min (median: 1.0 mu g/g), 8 h (median: 1 .7 mu g/g), and 24 h (median: 3.1 mu g/g) after challenge as compared to the baseline values. Also, there was no significant difference betw een patients with ongoing seasonal (median: 1.3 mu g/g) or perennial ( median: 1.8 mu g/g) rhinitis, and atopic patients outside the pollen s eason. In conclusion, this study showed that MPO is not locally elabor ated in measurable quantities in nasal secretions after nasal allergen challenge and during natural allergen exposure. Further studies will be needed to elucidate the role of neutrophils in the pathophysiologic al processes of allergic rhinitis.