Analysis of the interleukin-1 receptor antagonist gene variable number tandem repeats in ischemic stroke.

Background: There is an increasing interest in the role of inflammatory mechanisms contributing to the development of stroke. Recent studies have reported an association between allele 2 of a variable number tandem repeat of the interleukin-1 receptor antagonist (IL1RN) gene in Caucasian patients with ischemic stroke. The purpose of this investigation is to independently confirm these results in our study population.

Methods: We recruited and genotyped 516 Caucasian patients with ischemic stroke and 380 matched controls. Tests of association were performed to estimate odds ratio (OR) for the IL1RN gene variable number tandem repeat polymorphism with case-control status. Genotype frequencies of IL1RN gene were compared by case-control and symptom status using χ2 contingency tables and logistic regression models.

Results: No significant association was observed between any of the IL1RN gene genotypes and ischemic stroke. The unadjusted association model a, and the fully saturated model e, adjusted for age, gender, and stroke risk factors demonstrated no significant increase in risk associated with the IL1RN gene 2/2 genotype (a: OR, 1.11; 95% confidence interval [CI], .67-1.89; P=.615; and e: OR, .95; 95% CI, .46-1.94; P=.574). Analyses of genotypic and allelic frequencies of each Trial of Org 10172 in Acute Stroke Treatment subtype with control and pairwise comparison between stroke subtypes did not show any significant differences in their distributions, and all P values were greater than the significance level of .05.

Conclusion: Our results do not confirm an association between the gene and ischemic stroke in Caucasian patients.