Study of serum interleukin 5 level and factors that impact on this level in Iraqi asthmatic children

Background: Interleukin-5 (IL-5) is a cytokine associated with the cause of several allergic diseases such as asthma due to their function in growth, activation, and maturation of eosinophils and stimulates B-cell growth and increases immunoglobulin E (IgE) secretion. The study aims to measure the IL-5 level in asthmatic children and detect the relationship between IL-5 level with eosinophils, total serum IgE level, and asthma severity. Methods: Eighty asthmatic children, including 55 males and 25 females with asthma who aged between 1 and 16 years collected at Kerbala Teaching Hospital for Children, were measured IL-5 level using Elabscience ELISA kit and measured total IgE level using EUROIMMUN IgE ELISA kit. However, absolute eosinophils count was examined by peripheral blood smear. In addition, the clinical characteristics of the patients were recorded by a questionnaire. Results: There was a significant difference in IL-5 level in asthma patients depending on sex, absolute eosinophil count, and use of treatment (P = 0.046, 0.046, and 0.001, respectively). However, there was no effect on the IL-5 level at asthmatic children depending on the age, body mass index, resident, exposure to cigarette smoking, family history of asthma/allergic diseases, asthma severity, and total serum IgE (P = 0.936, 0.769, 0.154, 0.898, 0.614, 0.550, and 0.874, respectively). Conclusions: IL-5 level had a positive correlation with absolute eosinophils count but not with total serum IgE. In addition, IL-5 level was a poor indicator of asthma severity.