Specific IL-5 snp is associated with high serum IL-5 levels and higher eosinophil counts among iraqi asthmatic children

Abstract

Objective: Interleukin-5 (IL-5) is a cytokine known to play major role in the regulation of eosinophil formation, maturation, recruitment, and survival. Hence, an increased production of IL-5 may be contributed to the pathogenesis of eosinophil-dependent inflammatory diseases such as asthma. Methods: A total of 85 children, including 59 males and 26 females with asthma with ages between 1 year and 16 years, attended the Respiratory Clinic at Karbala pediatric hospital, with a nonasthmatic children group which have the same age and gender. Restriction fragment length polymerase chain reaction was performed to determine IL-5 C-703T genetic polymorphisms. Total immunoglobulin E (IgE) level was measured using the EUROIMMUN IgE ELISA kit and serum IL-5 levels using Elabscience ELISA kit. The absolute eosinophil count was measured by five differential automated hematology analyzers and confirmed by the examination of peripheral blood smear. Results: The TT genotype of IL-5 C-703T polymorphism was associated with asthmatic children (P: 0.033). In addition, TT genotype was associated with increase of serum IL-5 levels and high absolute eosinophil count (P = 0.008 and 0.021, respectively). Whereas, CT genotype of IL-5 C-703T was found to be associated with high total serum IgE (P < 0.001). Conclusions: Asthma in children is associated with IL-5 C-703T polymorphism. In addition, IL-5 C-703T polymorphism has impact on IL-5 levels and eosinophil count. TT genotype of IL-5 C703T consider a risk factor for mild asthma in Iraqi asthmatic children.

Keywords

• Bronchial asthma
• eosinophil
• interleukin 5
• total IgE