Eosinophil cationic protein as a serological marker of disease activity in childhood bronchial asthma.

To study the value of eosinophil cationic protein (ECP) as a serological marker of disease activity in childhood bronchial asthma, ECP levels were measured in 20 healthy control children and 25 asthmatic children, during and 2 weeks after acute exacerbation. The mean serum ECP level of all asthmatic patients, during and after exacerbation, was significantly higher than the control group and was significantly higher during attacks than 2 weeks after their termination. ECP levels were highest in severe attacks, but did not differ between mild and moderate attacks. ECP levels in asthmatic patients 2 weeks after mild and moderate attacks were comparable to normal; after severe attacks levels remained higher than normal. Measurement of serum ECP will be helpful in determining asthma activity and deciding the use of anti-asthma drugs.