Allergic rhinitis to grass pollen: Measurement of inflammatory mediators of mast cell and eosinophils in native nasal fluid lavage and in serum out of and during pollen season

Background: In allergic rhinitis, mast cells, activated by cross-linking of allergen to mast cell-bound specific IgE, release both vasoactive mediators related to the early nasal symptoms and chemotactic mediators that attract inflammatory cells, such as eosinophils, related to the late-phase response. Objective: We have analyzed, during and out of pollen season, in blood and nasal fluid from patients allergic to grass pollen, histamine and tryptase to monitor the early phase markers and eosinophil and eosinophil cationic protein (ECP) to monitor the late phase. Methods: Twenty patients were enrolled in the study. As a control, we studied 10 nonatopic subjects. Mediators and eosinophils were assessed in blood and nasal fluid. Histamine was tested only in nasal fluid. Results: During pollen season, tryptase but not histamine increased in nasal fluids from patients (2.96 vs 0.22 U/ml, p = 0.001) and correlated with symptom scores (r(s) = 0.63, p = 0.003). Tryptase was not detected in serum. Eosinophils increased in nasal cytology (17.0% vs 2.0%, p = 0.001) and in the blood (26.5 vs 12.7 x 10(6) L, p = 0.001) from patients, but they did not correlate with symptom scores. ECP increased only in the nasal lavage (16.33 vs 1.30 ng/ml, p = 0.001) and correlated with symptom scores (r(s) = 0.53, p = 0.016). Conclusions: Both ECP and tryptase increase in nasal secretion in natural disease. Therefore the measurement of tryptase and ECP levels in nasal fluid might be a useful clinical test for monitoring disease activity and the effects of therapeutic agents.