Contribution of IL9, IL2RA and IL2RB genetic polymorphisms in coronary heart disease in Chinese Han population

Background: Coronary heart disease (CHD) is one of the leading causes of disability and death worldwide. In the pathogenesis of CHD, inflammatory cytokines take an essential part. This study was designed to detect the potential association between IL-9, IL-2RA and IL-2RB variants and CHD in Chinese Han population. Methods: This case-control study conducted 499 CHD patients and 496 healthy controls. Seven selected SNPs were genotyped to investigate the possible association between the polymorphisms and the CHD risk. The interaction of SNP-SNP in the CHD risk was analyzed by Multifactor dimensionality reduction (MDR). Results: We observed an association between IL-9 rs55692658 (OR = 1.72, p = 0.003) and the increased CHD risk. The stratification analysis by age indicated that no matter participants who were older or younger than 61 years, IL-9 rs55692658 and IL-2RB rs1573673 contributed to the CHD susceptibility significantly (p < 0.05, respectively). IL-9 rs55692658 showed an increasing-risk effect (OR = 2.32, p = 0.003), while IL-2RA rs12722498 was correlated with the decreased susceptibility of CHD (OR = 0.54, p = 0.033) in female. Furthermore, IL-2RA rs12569923 was related to the diabetes risk in the CHD patients (OR = 1.50, p = 0.028). MDR analysis revealed a positive interaction between the SNPs. Conclusion: The present study firstly demonstrated that IL-9 rs55692658，IL-2RA rs12569923, rs12722498 and IL-2RB rs3218264 polymorphisms might be related to CHD. The results required further validation by larger studies.