Abstract
Several studies have reported an association between the 9p21 region in the human genome and atherosclerosis. The rs1333049 polymorphism is a single nucleotide polymorphism (SNP) in CDKN2B-AS1, located in the 9p21 region. The aim of our study was to investigate the association between the rs1333049 polymorphism and advanced carotid atherosclerosis, as well as its effect on CDKN2B expression in endarterectomy sequesters. In our case-control study, we included 881 participants, divided into two groups. The case group comprised 308 participants with advanced atherosclerosis of the internal or common carotid artery (stenosis > 75 %) who underwent a revascularization procedure. The control group included 573 participants without hemodynamically significant carotid atherosclerosis. We analyzed the rs1333049 polymorphism using the StepOne real-time polymerase chain reaction (PCR) and TaqMan SNP genotyping assay. We found a statistically significant association according to the co-dominant (P=0.014, OR=3.29, 95% CI: 1.32-8.91, and P=0.015, OR=2.50, 95% CI: 1.22-5.37) and dominant (P=0.006, OR=2.74, 95% CI: 1.36-5.71) models. We performed immunohistochemical analysis of CDKN2B expression on 26 endarterectomy sequesters. The C allele of rs1333049 was associated with a lower numerical area density of CDKN2B-positive cells in atherosclerotic plaques. In conclusion, the C allele of the rs1333049 SNP is associated with an increased risk of developing advanced carotid atherosclerosis and lower CDKN2B expression in the plaques.