We conducted a randomized, double-blind, parallel-group study to assess the effect of 6 weeks treatment with low-dose (100 microg twice a day) or high-dose (500 microg twice a day) inhaled fluticasone propionate (FP) on the vascular component of airway remodeling in 30 patients with mild to moderate asthma. We also studied the effect on the inflammatory cells and the basement membrane thickness, and we compared findings from bronchial biopsies taken in patients with asthma with those in eight control subjects. Bronchial responsiveness to methacholine and asthma symptom score were measured before and after treatments. Eight patients in the low-dose FP group and eight patients in high-dose FP group completed the study. At baseline, patients with asthma showed an increase in the number of vessels and in vascular area as compared with control subjects. In the subjects with asthma, number of vessels correlated with vascular area (p < 0.01) and with number of mast cells (p < 0.01). Bronchial responsiveness to methacholine, asthma symptom score, and inflammatory cells decreased significantly after both low- and high-dose FP (p < 0.05). However, the number of vessels, the vascular area, and the basement membrane thickness decreased only after high-dose FP (p < 0.05). In conclusion, this study shows that in patients with mild to moderate asthma, high dose of inhaled FP given over 6 weeks can significantly affect airway remodeling by reducing both submucosal vascularity and basement membrane thickness.

In a double-blind, parallel-group study, we examined the effect of short-term treatment with inhaled fluticasone propionate (FP) in a group of 20 nonsmoking asthmatic patients who required only beta2-agonists to control their symptoms. We administered FP (250 microg twice daily) or matched placebo for 6 wk. Methacholine challenge was performed before treatment, after 3 wk, and at the end of treatment. Each patient underwent bronchoscopy with bronchoalveolar lavage (BAL) and bronchial biopsy before and after treatment. Eight patients in the placebo group and nine patients in the FP group completed the study. Bronchial responsiveness to methacholine decreased significantly only after 6 wk of treatment with FP (p < 0.05). When we compared the FP group with the placebo group, we observed a significant decrease only in the number of cells expressing intracellular adhesion molecule-1 (ICAM-1) and MAC-1 (p < 0.04 and p < 0.03, respectively). Moreover, we saw that the tryptase level in BAL decreased (p < 0.001), whereas the eosinophil cationic protein (ECP) level did not change significantly. Additionally, the number of eosinophils and mast cells in the lamina propria in bronchial biopsies specimens was significantly smaller in the FP group than in the placebo group (p < 0.02 and p < 0.01, respectively). Additionally, in the FP group, we found that basement-membrane thickness was significantly decreased when compared with that of the placebo group (p < 0.05). In conclusion, our results show that short-term treatment with low-dose FP reduces inflammatory cell infiltration into the lamina propria in bronchial biopsy specimens. Moreover, short-term low-dose FP treatment might control the intensity of airway remodeling in mild asthma.

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