Eosinophil cationic protein (ECP), eosinophil chemotactic activity (ECA), neutrophil chemotactic activity (NCA) and tryptase in serum before and during bronchial challenge in cat-allergic children with asthma

In order to study ECP, ECA, NCA and tryptase levels in serum in 18 cat-allergic children with asthma scrum samples were obtained before and during an allergen bronchial challenge. All children were on regular treatment with inhaled steroids (200-800 μg/day) and bronchodilators. Peak expiratory flow (PEF) was recorded twice daily for at least a week before the challenge. The baseline ECP levels were significantly higher in the children who had a baseline PEF 80-95% of pred. compared to those who had PEF >95% of pred. (mean 24. 3 μg/l and 14. 3 μg/l respectively, p <0.02). ECP in serum before the ehallenge correlated significantly to PEF in % of the expected optimal PEF obtained from the PEF curve (r= 0. 48, p <0.05). During the challenge ECA and NCA increased significantly from mean 96. 2% and 97. 9% to 122. 7% and 118. 7% (p <0.05 for both), while ECP did not change significantly, mean 20. 4 μg/l before and 17. 5 μg/l after the challenge. Tryptase levels in serum were not detectable (<0. 5 ng/ml) before or during the asthmatic attack. We eoncludc that there are significantly raised ECP levels in serum in symptom-free asthmatic children on long-term treatment with topical steroids possibly indicating remaining airway inflammation. Acute asthma results in an increase of ECA and NCA while ECP levels seem to reflect the chronic rather than the acute phase of asthma in children.