Association of IL4RA polymorphism in predicting susceptibility toward chronic obstructive pulmonary disease.

Background: The cytokine IL-4 plays vital role in the intercellular signalling network during immune responses to allergen exposure. Methods: This cross-sectional study involved 202 chronic obstructive pulmonary disease (COPD) patients and 203 healthy individuals. The genotyping of IL4RAQ576R gene polymorphism was determined using PCR restriction fragment length polymorphism analysis. Results: Significant association between mutant genotype (GG) and combined (AA+AG) genotype for the risk of COPD was found (odds ratio [OR]: 4.32; p = 0.04). A significant protective effect was observed between the IL4RAQ576R polymorphism and Global Strategy for Obstructive Lung Disease (GOLD) stage four patients in a recessive model (AA+AG vs GG; p = 0.002). In GOLD A, a substantial relationship was found between the AG and wild-type genotypes (AA) for COPD risk (OR: 2.38; p = 0.03). A strong association was found for COPD duration of 5-10 years (OR: 8.80; p = 0.01). Conclusion: IL4RAQ576R polymorphism is associated with COPD susceptibility.