Study of the correlation between total immunoglobulin-E levels and Interleukin-4 polymorphism in asthmatic children

Abstract

The aim of this study is to analyze the possible correlation between the single nucleotide polymorphisms (SNP) IL-4-590C/T with specific parameters in asthmatic children (blood eosinophils, total serum immunoglobulin-E (TSIgE) levels, and asthma severity). This study includes one hundred asthmatic patients as well as one hundred healthy unrelated age-matched controls from the same locality of Iraq. DNA is extracted and processed by the allele specific-PCR technique for characterization of genetic variants of IL-4- 590 C>T polymorphisms. TSIgE levels are determined by ELISA technique while blood eosinophils are determined by blood film staining. Iraqi cases with asthma show a higher frequency of the IL-4-590 CC homozygous genotype in comparison to controls (66% versus 7%) with a lower CT heterozygous genotype (17% versus 90%) respectively. IL-4-590 shows significantly positive associations with asthma in the dominant, co-dominant, and over- dominant models of inheritance. On the other hand, comparing genotypes of subgroups related to gender, asthma severity shows a non-significant difference (p > 0.05). Homozygous genotypes (IL-4-590 CC) can be considered as risk factors, while the homozygous wild types (-590 TT) might be regarded as protective of asthma and there is no association between TSIgE and IL-4-590 SNP.