INFLUENCE OF SALMETEROL ON CHRONIC AND ALLERGEN-INDUCED AIRWAY INFLAMMATION IN MILD ALLERGIC-ASTHMA - A PILOT-STUDY

Salmeterol xinafoate, a potent, long-acting, selective beta(2)-agonist , inhibits allergen-induced asthmatic responses. To evaluate if this b ronchoprotection was also associated with anti-inflammatory effects, m ild asthmatic patients presenting a dual asthmatic response to allerge ns were randomized in a double-masked, placebo-controlled, parallel-gr oup study to take either salmeterol 50 mu g twice daily (n = 7) or pla cebo (n = 6) for 2 months. At the end of the treatment period, airway inflammation was assessed by bronchoalveolar lavage and bronchial biop sies, both before and after allergen challenge. After treatment, aller gen-induced responses were decreased in the salmeterol group and, to a lesser degree, in the placebo group. Postallergen and preallergen cha llenge, lavage total, and differential cell counts mere similar in the two groups. Before allergen challenge, bronchial biopsies of both gro ups indicated extensive airway inflammation with similar total inflamm atory cell counts but with a higher percentage of epithelial desquamat ion in the salmeterol group. The allergen challenge did not modify the inflammatory variables measured except for an increase in eosinophil counts in connective tissue. Comparison of the postchallenge data of t he two groups showed that counts of AA1-, HLA-DR-, and CD45ro-positive cells were reduced in the salmeterol group. When prechallenge and pos tchallenge data were pooled to compare the two treatments, the salmete rol group had lower numbers of CD3-, CD25-, HLA-DR-, AA1-, CD45-, and CD45ro-positive cells. In conclusion, these results confirmed the bron chodilator and bronchoprotective effects of salmeterol. They also sugg ested that; even though salmeterol did not modify lavage and overall b ronchial biopsy cellular infiltrate, the drug apparently reduced expre ssion of some bronchial mucosa activation cell markers. This study, ho wever, was mainly exploratory, and the reproducibility and clinical si gnificance of these observations require further clarification.