Interleukin-1 gene cluster polymorphisms and risk of coronary artery disease

Background and Objectives. The pro-inflammatory cytokine interleukin (IL)-1 has been suggested to play a role in atherosclerosis. Several genetic polymorphisms have been described in the genes of the IL-1 cluster and associations with coronary artery disease (CAD) have been reported, although with contrasting results. Design and Methods. The associations of a variable number tandem repeat (86bp) polymorphism in intron 2 of interleukin-1 receptor antagonist (IL1-RA) and of the -511 C/T polymorphism of IL-1β with the risk of CAD were studied. Three hundred and thirty-five case (CAD+) patients with angiographically documented CAD (stenosis >50% in at least one major coronary artery) were compared with 205 unrelated individuals free of CAD signs at angiogram (CAD-controls). One hundred and two (30.5%) CAD+ patients had single-vessel disease (SVD) and 233 (69.5%) multiple-vessel disease (MVD). Results. There was no statistically significant difference in either genotype distribution or allele frequency of both IL-1 RA and IL-1β -511 C/T polymorphisms between CAD⁺ cases and CAD-controls. Moreover in multivariate analysis, adjusting for multiple comparisons and confounding factors, no difference was found in IL-1 RA genotype distribution between patients with SVD or MVD. Interpretation and Conclusions. Our study does not support the association between IL-1 RA intron 2 VNTR and IL-1β -511 C/T polymorphisms and the risk of CAD in individuals undergoing coronary angiography.