INHIBITORY EFFECT OF CETIRIZINE ON THE BRONCHIAL EOSINOPHIL RECRUITMENT INDUCED BY ALLERGEN INHALATION CHALLENGE IN ALLERGIC PATIENTS WITH ASTHMA

In patients with asthma there is a recruitment of eosinophils in bronchoalveolar lavage fluid (BALF) after the late asthmatic reaction (LAR). Cetirizine is a selective H-1 antagonist that inhibits the eosinophil recruitment induced by allergen in the skin. The aim of this study was to evaluate whether cetirizine was able to inhibit the LAR-induced inflammatory reaction. Twelve allergic asymptomatic subjects with asthma (aged 18 to 58 years) without any treatment were enrolled in the study; FEV1 was >83% predicted in each case. An allergen inhalation-challenge test was performed to assess the presence of an LAR. In a double-blind, randomized, placebo-controlled study, the patients were treated for 8 days with either cetirizine, 15 mg twice a day (six patients, group 1), or placebo (six patients, group 2). On day 8, a second allergen inhalation-challenge test with the same allergen was performed, and BAL was realized 24 hours later; as usual 250 ml of saline was instilled by 50 ml aliquots, and the first recovery was analyzed separately. In each case, the LAR observed after treatment was similar to the first one. In placebo-treated patients, an increased number of cells, mainly eosinophils, was observed in the first recovery of BALF compared with the number in subsequent recoveries. These numbers were significantly higher than numbers observed in cetirizine-treated patients. Cetirizine did not modify significantly the allergen inhalation-challenge test, but it inhibited the recruitment of inflammatory cells, mainly eosinophils.