Abstract
Background and Aim: Eosinophils are a key player in allergic inflammation. ECP and IL-4 are essential mediators of allergic inflammation in the lungs and therefore can be used to help in the diagnosis and follow-up of allergic asthma. This study aimed to evaluate whether ECP and IL-4 levels in the plasma of asthmatic patients may reflect the clinical status of asthma exacerbations during sandstorms.

Methods: Thirty patients had allergic asthma, and sixteen normal controls were enrolled in this study. These subjects were divided into two groups. The first group included seventeen patients who had chronic symptoms of asthma but were controlled, and the second group included thirteen patients with chronic symptoms who developed exacerbations during sandstorms. Total IgE, ECP, and IL-4 levels were measured in the plasma of asthmatic patients and normal controls by using specific ELISAs.

Results: Total IgE levels were significantly higher in patients with asthma (mean= 467 IU/ml, P = 0.0001) than in controls (113 IU/ml). IL-4 was not detected in patients with asthma or in controls. ECP levels were elevated significantly in patients with severe symptoms of asthma (mean= 3.28 ng/ml, P=0.0006) in comparison to those in normal controls or patients with controlled asthma (1.9 ng/ml, P=0.02). In addition, there was no significant increase in ECP levels in patients with controlled asthma relative to those
in normal controls.

Conclusions: These findings suggest that ECP but not IL-4 may be a useful marker to evaluate the severity of asthma, follow and predict a response to steroid treatment.

Key words: Asthma, IgE, ECP, IL-4, Eosinophils