PTPN22 Gene Polymorphisms Are Associated with Susceptibility to Large Artery Atherosclerotic Stroke and Microembolic Signals

Large artery atherosclerotic stroke (LAAS) is the most common ischemic stroke (IS) subtype, and microemboli may be clinically important for indicating increased risk of IS. The inflammatory process of atherosclerosis is well known, and lymphoid phosphatase (Lyp), which is encoded by the protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene, plays an important role in the inflammatory response. Our study was intended to evaluate the relationship between PTPN22 gene and LAAS and microembolic signals (MES). Three loci of the PTPN22 gene (rs2476599, rs1217414, and rs2488457) were analyzed in 364 LAAS patients and 369 control subjects. A genotyping determination was performed using the TaqMan assay. The G allele of rs2488457 might be related to a higher risk for developing LAAS and MES (odds ratio OR = 1 456, 95% confidence interval (CI) 1.156-1.833, P = 0 001; OR = 1 652, 95% CI 1.177-2.319, P = 0 004, respectively). In the LAAS group, the prevalence of the GTG haplotype was higher (P < 0 001) and the prevalence of the GCC haplotype was lower (P = 0 001). An interaction analysis of rs2488457 with smoking showed that smokers with the CG/GG genotypes had a higher risk of LAAS, compared to nonsmokers with the rs2488457 CC genotype (OR = 2 492, 95% CI 1.510-4.114, P < 0 001). Our research indicated that the PTPN22 rs2488457 might be related to the occurrence of LAAS and MES in the Han Chinese population. In addition, the rs2488457 polymorphism and the environmental factor of smoking jointly influenced the susceptibility of LAAS.