Serum tryptase in allergic rhinitis: effect of cetirizine and fluticasone propionate treatment.

PURPOSE

A specific reaction against several kinds of inhalant allergens characterizes allergic rhinitis. Mast cells play a crucial role in the allergic inflammation releasing histamine and other mediators. Tryptase is considered to be a specific marker of mast cell activation. This study was devoted to evaluate the serum tryptase in allergic rhinitis and to evaluate the effect of cetirizine and fluticasone propionate on mast cell activation. 13 subjects, suffering from perennial allergic rhinitis induced by Dermatophagoides pteronyssinus, were studied.

MATERIALS AND METHODS

Tryptase serum levels were detected by the fluoroenzymeimmunoassay (Pharmacia & Upjohn AB, Uppsala, Sweden). Blood samples were taken four times: before starting the study, after two weeks of 10 mg cetirizine treatment once a day, after two weeks of wash-out, and again after 15 days of 100 micrograms intranasal fluticasone propionate therapy twice a day.

RESULTS

In allergic rhinitis, the basal values of serum tryptase (M +/- SD: 6.1 +/- 2.4 micrograms/l) were significantly higher than in controls (M +/- SD: 3.0 +/- 1.2 micrograms/l). After the antihistamine treatment, tryptase values (M +/- SD: 4.4 +/- 1.8 micrograms/l) decreased significantly (p < 0.001). After the stop of antihistamine treatment, tryptase levels increased (M +/- SD: 5.5 +/- 2.6 micrograms/l, p < 0.001). After the topical corticosteroid treatment, tryptase values decreased again significantly (M +/- SD: 4.5 +/- 3.1 micrograms/l, p < 0.04).

CONCLUSIONS

All these data seem to confirm the effective action of cetirizine and fluticasone propionate on tryptase serum levels. While the action of corticosteroid is well known, the action of cetirizine is still to define, considering the recent reports on anti-inflammatory effect of the second generation of H1 receptor antagonists. Further studies are necessary to understand if the pharmacological effect on tryptase is a specific one of cetirizine, or if it is common to other anti-H1 molecules.