Polymorphisms of interleukin 4 and interleukin 4 receptor genes and bronchial asthma risk among Egyptian children

Interleukin 4 (IL4) is a key cytokine that regulates the inflammatory cascade in bronchial asthma. We investigated the association between the IL4 and IL4R polymorphisms and the susceptibility for bronchial asthma among Egyptian children. IL4 VNTR and IL4R c.1902 A>G p.(Q576R) polymorphisms were investigated among 100 children with bronchial asthma and 100 healthy controls using PCR method. Serum levels of IL4 and immunoglobulin E (IgE) were assessed by ELISA. The frequencies of (A1A2 + A2A2) genotypes and A2-allele of the IL4 VNTR variant were significantly higher among asthmatic patients than controls (p = 0.01, OR = 2.34, 95% CI = 1.24–4.44; p = 0.01, OR = 2.27, 95% CI = 1.29–3.99, respectively). The frequencies of (AG + GG) genotypes and G-allele of the IL4R (A1902G) variant were significantly higher among asthmatic patients than controls (p = 0.003, OR = 2.52, 95% CI = 1.39–4.58; p = 0.002, OR = 2.25, 95% CI = 1.35–3.76, respectively). There was a significant association between (A1A2 + A2A2) genotypes of the IL4 VNTR variant and high serum IL4 level among asthmatic patients (p