Abstract
To determine whether IL-4, IL-4Rα and STAT6 polymorphisms are associated with susceptibility to dermatitis in Egyptian children.
We genotyped three groups of children, consisting of 106 atopic dermatitis (AD) children, 95 non-AD children, and 100 of healthy controls, for IL-4 (−590 C/T), (−33 C/T), IL-4Rα (I50V), (Q576R) and STAT6 (2964 G/A), (2892 C/T) gene polymorphisms using PCR-RFLP assay. Total serum IgE and serum IL-4 levels were detected by ELISA.
There was a non-significant association of IL-4 −590 C/T, −33 C/T polymorphisms in the children with non-AD or those with AD when compared with the controls. We identified a significant association between IL-4Rα I50V, Q576R polymorphisms and dermatitis susceptibility in AD (p=0.002, <0.001 respectively), whereas no such association was observed in non-AD group (p=0.52, 0.99 respectively). A significant association between STAT6 polymorphisms and both types of dermatitis was found. Patients who were carriers of IL4 −590C, IL-4Rα I50V G, STAT6 2964 A and STAT6 2892 T had an increased risk of AD [OR and 95% CI: 3.2 (2.5–4.2), p=0.005]. Furthermore, there was no relation between each polymorphism and serum IL-4 level (p>0.05 for each) while homozygosity for the risk alleles of IL-4, IL-4Rα and STAT6 SNPs were significantly associated with increased total IgE levels in all subjects.
In Egyptian children, the IL-4Rα and the STAT6 polymorphism may play a role in susceptibility to AD. In addition, gene–gene interaction between the IL-4, the IL-4Rα and the STAT6 significantly increases an individual's susceptibility to AD.
•IL-4Rα and STAT6 SNPs may play a role in atopic dermatitis in Egyptian children.•Lack of association of IL4 −590 C/T and −33 C/T polymorphisms with dermatitis•Evidence of gene interactions between IL4, IL4Rα and STAT6 polymorphisms was found.•No effect of IL4, IL4Rα and STAT6 variants on IL4 levels in all subjects•IL4, IL4Rα and STAT6 SNPs may be involved in the control of IgE production.