Role of Eosinophil Cationic Protein in Asthma and Confounding Factors.

Background: It has been found that activated eosinophils play an important role in the pathogenesis of bronchial asthma.Objective: To clarify the validity of serum Eosinophil Cationic Protein (ECP) as parameter in assessment of asthma since it reflects the pulmonary inflammation in bronchial asthma. Patients and Methods: Serum ECP was determined in 139 asthmatic patients by using enzyme linked immunosorbent assay and compared to control .Results: Serum ECP was very highly significant higher (P<0.00001) in asthmatic patients than in control. There was no overlap between the lower asthmatic limit and higher limit of the control group. In addition, the ECP variation between asthmatic and control was correlated to variations in FEV1 percent predicted (P<0.0001) between both groups. There was an association between serum ECP levels and asthma severity and pattern. A cut – off of 20 μg/l for serum ECP was with sensitivity of 89% and specificity of 88% in detection asthma cases. The area under curve was found to be 0.805, meaning that determination of serum ECP was with a predictive value in detection of asthmatic cases.Conclusion: Serum ECP level may help in discrimination between asthmatic and non asthmatic individuals, also between symptomatic and asymptomatic asthmatic individuals. The residence does not influence serum ECP in our asthmatic patients.