IL-1 cluster genes and occurrence of post-percutaneous transluminal coronary angioplasty restenosis: a prospective, angiography-based evaluation

A polymorphic marker of the gene encoding the interleukin-1 (IL-1) receptor antagonist has been recently reported to be associated with risk of coronary artery disease. However, no prospective studies of the IL-1 gene cluster in relation to the occurrence of restenosis, a major complication of percutaneous transluminal coronary angioplasty (PTCA), have so far been conducted. We had the opportunity to investigate this question in a large, prospective cohort characterized by quantitative coronary angiography in all subjects. The IL1A A114S, IL1B −511C>T, IL1B 3953T>C, IL1RI exon1B T>C, and IL1RN VNTR (intron 2) polymorphisms were characterized in a cohort of 779 patients of whom 342 (“cases”) had developed restenosis (as defined by >50% loss of lumen compared to immediate post-procedure results) at repeat angiography at 6 months post-PTCA. All observed genotype frequencies were in Hardy–Weinberg equilibrium. Frequencies for the rare alleles were: IL1A S, 0.29 (cases), 0.28 (controls); IL1B T, 0.31 (cases), and 0.33 (controls); IL1B C, 0.23 (cases), 0.24 (controls); IL1RI C, 0.34 (cases), 0.35 (controls); and IL1RN 2, 0.29 (cases), 0.29 (controls), respectively. There was no evidence for an association between genotype and restenosis or degree of lumen loss (adjusted for covariables). Our data indicate that the common variants in the IL-1 cluster genes are not associated with incidence of restenosis after PTCA.