Serum levels of eosinophil cationic protein and eosinophils in asthmatic children during a course of prednisolone therapy

Eosinophils play an important role in the inflammatory events of allergic a sthma. Serum eosinophil cationic protein (ECP) is a marker of disease activ ity and of treatment efficacy in bronchial asthma. To understand the role o f ECP concentrations in disease activity of acute asthma, we determined cha nges in serum concentrations of ECP elaborated by activated eosinophil befo re and after prednisolone therapy. Circulating levels of ECP in 15 normal c ontrol subjects, and in sera of 20 asthmatic children who were allergic to house dust mites, were measured during an acute exacerbation and when the c hildren were in stable condition, using commercially available assay kits. The mean concentrations of serum ECP were significantly higher during an ac ute asthma exacerbation than when the children were stable (26.41 +/- 21.66 mug/L vs 15.74 +/- 11.36 mug/L P < 0.01) or when compared to control subje cts (7.50 +/- 1.42 <mu>g/L; P < 0.001). The mean eosinophil counts (EC) dur ing acute asthma attacks (575 +/- 286/mm(3)) and when stable (467 +/- 204/m m(3)) were higher than in the control group (181 +/- 164/mm(3)). The differ ences were statistically significant among the three groups (P < 0.05). A s ignificant correlation was found between serum levels of ECP and EC (r = 0. 788, P = 0.001) in asthmatic children, there were also significant correlat ions between ECP and EC in nonallergic normal control subjects (r = 0.662; P = 0.007). In conclusion, this study provides further evidence that changes in serum E CP may serve as an objective indicator for clinical activity and results of treatment in allergic asthmatics. Pediatr Pulmonol, 2001; 31:121-125. (C) 2001 Wiley-Liss, Inc.