Cytokines gene polymorphisms have been implicated in susceptibility to ischemic stroke. This study aims to determine the influence of the polymorphism within the intron 2 of the interleukin- 1 receptor antagonist (IL-1Ra) gene on the susceptibility to stroke. A variable number of tandem repeats (VNTR) in intron 2 of the IL-1Ra gene was analyzed in 148 patients with stroke and 161 healthy volunteers from the same area. The carriage rate of allele 2 of IL-1Ra gene, low producer, was significantly higher in patients with stroke compared to the controls (29% vs 21% p = 0.02). Frequency of IL1RN1/IL1RN1 genotype in the patients was significantly lower than the controls (49% vs 66% p = 0.003). The distribution of homozygous genotypes of IL1RN2 was not different between the controls and stroke patients while the heterozygous genotype was more frequent among the patients. (39% vs 25%, respectively). Multiple logistic regression analysis demonstrated that individuals who carry allele 2 for IL-1Ra gene had a significantly higher risk for ischemic stroke with an odds ratio of 2.48 (95% CI, 1.67, 3.51, p = 0.006). These data suggest that allele 2 of the IL-1Ra intron 2 gene represents a susceptibility factor in the development of ischemic stroke.

The polymorphism of the E-selectin gene has been implicated in the pathogenesis of atherosclerosis. We sought to explore whether the allelic variants relate to ischemic stroke. We conducted a case-control study of 359 cases of ischemic stroke and 353 community controls. Participants were evaluated for known cerebrovascular risk factors, and the E-selectin S128R and L554F genotypes were established using the polymerase chain reaction (PCR) method. The frequency of minor allele (R) and heterozygous (RS) genotype of E-selectin S128R polymorphism was significantly higher in the stroke patients than in the controls. Evaluation of genetic variation for E-selectin L554F polymorphisms revealed that the frequency of minor allele (F) and its heterozygous genotype (LF) is almost 4 times higher in the stroke patients than the controls (16.7 vs. 4.3 and 33.4 vs. 8.5, respectively). Multivariable logistic regression analysis after adjustment for age, sex and conventional vascular risk factors demonstrated that alleles R of S128R and F of L554F polymorphisms are independent risk factors for ischemic stroke. The combination of 2 minor alleles of E-selectin genes appeared to be the strongest susceptibility factor for ischemic stroke (adjusted OR: 5.89, 95% CI: 2.84–12.21, p = 0.0001). Our study demonstrates that the E-selectin S128R and L554F polymorphisms are associated with susceptibility to ischemic stroke.