Interleukin- 18 gene polymorphism in patients with and without atherosclerotic coronary artery disease

ABSTRACT

Several studies have revealed that inflammation plays an important role in development of Coronary Artery Disease [CAD] and its other manifestations. IL-18 is a pleiotropic cytokine that enhances Th1 [T helper 1] or Th2 [T helper 2] immune response depending on its cytokine milieu and genetic background. It strongly induces formation of plaques in patients with CAD. Variation in the Il-18 gene found to influence both levels of IL-18 and clinical outcomes in individuals with history of heart disease. To investigate the association of two IL-18 promoter gene polymorphisms at -607C/A and - 137 G/D positions with CAD, and some CAD risk factors such as diabetes, arterial hypertension, hypercholesterolemia, cigarette smoking and obesity. Genomic DNA was extracted by the salting out method from the peripheral arterial blood of 280 patients with CAD documented by coronary angiography [143 with a documented history of myocardial infarction termed positive MI and 137 without myocardial infarction designated negative MI] and 140 age- sex matched persons with a normal coronary angiography [control group]. The genotype of both CAD and control groups were assessed by ASP-PCR method. Arlequin program was used for gametic phase estimation and haplotype analysis. There was no significant difference between patient and control groups either allelic, genotypic, and haplotypic for both variants[p>0.05]. Furthermore, no significant correlation was found between IL-18 genotypes and CAD risk factors in the patient group [P>0.05]. There results suggest that the investigated IL-18 gene promoter polymorphisms at -607 C/A and -137G/C positions are not associated with genetic susceptibility to CAD in southern Iran