The association of IL-17A polymorphisms with IL-17A serum levels and risk of ischemic stroke

The aim of our study was to investigate the association of interleukin-17A (IL-17A) polymorphisms with IL-17A serum levels and risk of ischemic stroke (IS) in a Chinese population. 392 IS patients and 443 controls were included in this study. The polymorphisms of IL-17A gene were determined by Snapshot SNP genotyping assay and DNA sequencing. Serum IL-17A levels were measured by enzyme-linked immunosorbent assay (ELISA). We found that the G allele, GA and GG genotypes, and GA/GG vs. AA model of rs2275913 polymorphism were associated with increased risk of IS even after adjusted by clinical characters such as age, gender and diabetes (G vs. A: OR=1.27, 95% CI, 1.05∼1.54, P=0.014; GA vs. AA: OR=1.72, 95% CI, 1.05∼2.81, P=0.032; GG vs. AA: OR=1.99, 95% CI, 1.08∼3.67, P=0.028; GA/GG vs. AA: OR=1.78, 95% CI, 1.11∼2.86, P=0.017). Serum IL-17A levels were increased in IS patients compared with controls (P<0.01). Individuals carrying rs2275913 GA or GG genotype present higher serum IL-17A levels compared with the rs2275913AA genotype in the IS group (P<0.01). In conclusion, this is the first study reporting the rs2275913 polymorphism as a risk factor for IS, which may be partly explained by influencing the levels of IL-17A cytokine.