Effect of inhaled glucocorticoid on the cellular profile and cytokine levels in induced sputum from asthmatic patients

Cytokines are considered to play a role in the airway inflammation of bronc hial asthma. We examined the cellular profile and cytokine levels in induce d sputum samples obtained before and after treatment with beclomethasone di propionate (BDP, 800 mu g/day, for 4 weeks) in 12 mild to moderate asthmati c subjects who had not previously received inhaled glucocorticosteroids. Sp utum was induced with a 20-min inhalation of 3% saline by an ultrasonic neb ulizer. The freshly expectorated sputum separated from the saliva was analy zed fur cell counts, for the concentration of interleukin-8 (IL-8), and for the concentration of granulocyte macrophage colony-stimulating factor (GM- CSF). The mean percentage of eosinophils in the sputum samples decreased si gnificantly after BDP treatment, but no significant change in the percentag e of neutrophils was observed. The mean IL-8 and GM-CSF levels also decreas ed significantly after treatment. The BDP treatment was associated with an increase in the mean peak expiratory flow (PEF) and with a decrease in the diurnal variation of PEF. These results suggest that inhaled steroids impro ve airway inflammation and lung function in asthmatics, presumably in part by inhibiting the synthesis of inflammatory cytokines such as IL-X and GM-C SF.