Association between the interleukin-5 receptor alpha-subunit G-80A polymorphism and immunological parameters in asthmatic children

Abstract

Introduction: The expression of human interleukin-5 (IL-5) receptor alpha (Rα)-subunit presented on eosinophils, mast cells, and basophils. Hence, a polymorphism in IL-5 Rα may be implicated in the development of asthma and effect on immunological parameters (IL-5 level, absolute eosinophil count, and total serum immunoglobulin E [IgE]) production. Methods: A total of 85 children, including 59 males and 26 females with asthma with ages between 1 and 16 years, attended the Respiratory Clinic at Karbala Pediatric Hospital, with a nonasthmatic children group who had the same age and gender. Restriction fragment length polymerase chain reaction was performed to determine IL-5 Rα G-80A genetic polymorphisms. The total 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: There were no statistically significant differences in GG, AG, and AA genotypes frequency of IL-5 Rα G-80A between asthmatic patients and controls (P = 0.437, 0.160, and 0.106, respectively). The results showed no statistically significant correlation between immunological parameters (IL-5 level, absolute eosinophil count, and total serum IgE) and IL-5 Rα G-80A genotypes (P = 0.649, 0.06, and 0.552 respectively). Conclusions: Asthma in children is not associated with IL-5 Rα G-80A polymorphism. IL-5 Rα G-80A polymorphism has not any impact on IL-5 levels, eosinophil count, and total serum IgE.