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Background: Eosinophilic airway inflammation is thought to be associated with airflow limitation and airway hyperresponsiveness. Methods: Spirometry, peak expiratory flow (PEF) measurement, histamine challenge test, and sputum induction with hypertonic saline inhalation were performed in 70 asymptomatic patients with asthma who were treated with bronchodilators or an inhaled corticosteroid (beclomethasone dipropionate, 400–800 µg/day) or both for more than 2 months. The relationships between the sputum eosinophils, respiratory function, and airway responsiveness to histamine were investigated. Results: Induced sputum was obtained from 53 patients. Although significant correlations between sputum eosinophils and forced expiratory volume in 1 s/forced vital capacity × 100% (FEV1%) or maximum expiratory flow at 25% of the forced vital capacity (v̇25) divided by height (v̇25/Ht) were observed, no significant correlations were found between sputum eosinophils and percent predicted PEF (%PEF) or airway responsiveness to histamine. Furthermore, airway responsiveness to histamine was not correlated with FEV1%, v̇25/Ht or %PEF. Conclusion: Single-point measurements of FEV1% and v̇25/Ht but not PEF or airway responsiveness to histamine correlate with the degree of airway inflammation evaluated indirectly with induced sputum.

Background: A step-down therapy may be more beneficial for the management of asthma than a step-up therapy. Methods: Eighty-two asthmatic patients with moderate persistent asthma were enrolled in the study and randomized into three groups. One group of patients received 400 µg/day of beclomethasone dipropionate (BDP) for 4 weeks and then 800 µg/day for another 4 weeks (step-up group). The other two groups of patients received 1,200 µg/day of BDP for 4 weeks with or without short-term oral steroid (prednisolone, 0.5 mg/day for 1 week) and then 800 µg/day for another 4 weeks (step-down group). Severe exacerbation of asthma, asthma symptoms, respiratory function and rescue use of inhaled β2-agonists were monitored. If asthma was well controlled, the dose of BDP was decreased every 3 months and if asthma was exacerbated, the dose of BDP was increased until 8 months after the initial treatment. Results: Twenty-two patients during the run-in period, 4 patients in the step-up group, 2 patients in the step-down group treated with a high dose of BDP and no patients in the step-down group with oral steroids during first 4 weeks dropped out because of severe exacerbation of asthma. Although asthma symptoms and respiratory function significantly improved 8 weeks after the therapy in all groups, more significant and prompt improvements of these parameters were observed in patients of the step-down group than in patients of the step-up group after the first 2 weeks of treatment. Furthermore, step-down therapy with short-term oral steroid resulted in the lowest maintenance doses of BDP at 8 months of the three groups. Conclusions: These results suggest that step-down therapy starting with a high dose of inhaled steroid and short-term oral steroid is more effective in gaining prompt control of asthma and reducing the severe exacerbation of asthma and the maintenance dose of inhaled steroids than a step-up therapy starting with a low dose of inhaled steroids in patients with moderate persistent asthma.