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 polymerase chain reaction 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.