Interleukin-18 promoter polymorphisms and risk of ischemic stroke

Ischemic stroke (IS) is a major cause of morbidity and mortality around the world. Interleukin-18 (IL-18) plays an important role in the pathogenesis of IS and IL-18 promoter polymorphisms have been shown to be associated with levels of expression of IL-18. We investigated the association of two functional polymorphisms in IL-18 promoter, −607C/A (rs1946518) and −137G/C (rs187238), with the risk of ischemic stroke in a Han Chinese population of 423 patients and 384 healthy controls matched for sex and age. The results revealed that the −607C allele was associated with an increased risk of IS with an odds ratios (OR) of 1.358 (P = 0.002, power = 100%) and the presence of the −137G allele was correlated with increased the risk of IS in the subtype of patients with large artery atherosclerosis (LAA) (OR = 1.583, P = 0.02, power = 94%). Patients with the −607C/−137G haplotype also had significantly increased risk of IS compared to controls (OR = 1.341, P = 0.005, power = 100%). Our findings suggest that these functional polymorphisms in the IL-18 promoter are involved in development of IS in the Han Chinese population.