[Eosinophil cationic protein in serum from adults with asthma and with chronic obstructive pulmonary disease]

Levels of eosinophil cationic protein (ECP) in serum are abnormally high in bronchial asthma, and may reflect the degree of eosinophilic inflammation in the lung. The purposes of this study were to evaluate whether serum ECP levels are more closely related to the severity of asthma than are peripheral blood eosinophil counts, and whether these levels can be used to distinguich bronchial asthma from pulmonary emphysema and chronic bronchitis. Serum ECP levels were measured and blood eosinophil counts were obtained in 46 symptomatic adults with asthma (31 atopic and 15 non-atopic), 10 patients with pulmonary emphysema, 11 patients with chronic bronchitis, and 30 non-smoking healthy subjects. Both serum ECP levels and blood eosinophil counts were higher in patients with asthma than in those with pulmonary emphysema, chronic bronchitis and in healthy subjects. Neither serum ECP levels nor blood eosinophil counts differed between atopic and non-atopic patients with asthma. After therapy, serum ECP levels were found to have decreased to have decreased significantly (p < 0.025), but blood eosinophil counts were not. We conclude that both serum ECP levels and blood eosinophil counts are useful for distinguishing bronchial asthma from chronic obstructive pulmonary diseases. These data also indicate that in adults with asthma serum ECP levels may be more closely related to clinical severity than are blood eosinophil counts.