Association of interleukin-1 alpha gene polymorphism with cerebral infarction.

Interleukin-1 (IL-1) has pleiotropic actions in the central nervous system. During the last decade, a growing corpus of evidence has indicated an important role of this cytokine in the development of brain damage following cerebral ischemia. The expression of IL-1 in the brain is dramatically increased during the early and chronic stage of infarction. The IL-1 gene cluster on chromosome 2q14 contains three related genes (IL1alpha, IL1beta, and IL1 receptor antagonist) located within a 430-kb region. T and C alleles exist for the IL-1alpha-889 regulatory region and the TT genotype has been reported to increase the production of the protein in lipopolysaccharide (LPS)-stimulated mononuclear cells from IL-1alpha-889 TT carriers. We examined whether the IL-1alpha polymorphism affects the probability of cerebral infarction (CI). We genotyped 360 CI patients and 519 healthy controls for the same polymorphism. A significant increase was found for the IL-1alpha T allele in CI patients compared with controls (chi2=5.026, P=0.025). We conclude that the IL-1alpha-889 polymorphism is a major risk factor for CI in Koreans.