Eosinophil markers in seasonal allergic rhinitis

Background The purpose was to study activation markers of the eosinophil granulocytes in seasonal allergic rhinitis, and the impact of topical steroid therapy thereupon.
Methods Sixty-three rhinitis patients with monoallergy to grass were examined before and at peak pollen season. Blood eosinophil count, eosinophil cationic protein (ECP), and eosinophil peroxidase (EPO) in serum and nasal lavage fluid were measured. During the season, patients were randomized to treatment with intranasal fluticasone propionate 0.1 mg o.d. ( n =26), 0.2 mg o.d. ( n =25), or placebo (n = 12). Six healthy persons served as controls.
Results During the season, all parameters, except nasal lavage ECP, increased in the placebo group (P<0.001 – P<0.05). Significant differences were seen between the steroid grotips and the placebo group for all parameters (P<0.001–F<0.05). Higher eosinophil count (P<0.05), serum EPO (F<0.02), and nasal lavage EPO (P<0.05) were found in patients before season than in controls. The following winter, 44 patients returned for repeated measurement. Lower levels of nasal lavage EPO were observed for patients than levels at the beginning of the season (P<0.0001).
Conclusions Intranasal fluticasone propionate reduced inflammation of the nasal mucosa, demonstrated locally by nasal lavage ECP and EPO, and systemically by blood eosinophils, serum ECP, and serum EPO. EPO seemed more sensitive than ECP as indicator of allergic inflammation. EPO demonstrated some perennial eosinophil activity in hay fever patients, increasing locally during spring.