[Association of ABCB1 gene polymorphisms with aspirin resistance in patients with ischemic stroke]

Objective: To investigate the relationship of single nucleotide polymorphisms of Multi-drug resistance (ABCB1/MDR1) gene with Aspirin resistance (AR) in patients with ischemic stroke. Methods: Three hundred ischemic stroke patients from Department of Neurology, Affiliated Hospital of Qingdao University were collected from September 2014 to May 2016. According to the results of Thromboelastogram (TEG), the patients were divided into aspirin resistance (AR) group and aspirin sensitive (AS) group. The genotypes of ABCB1 gene (C1236T, G2677T/A, C3435T) were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct sequencing. Result: Linkage disequilibrium was found among the three loci (D'=0.8; r²=0.9). The T allele frequency of C3435T in AR group and AS group was 57.3% and 43.1% respectively, and the difference was statistically significant (χ²=9.143, P=0.002). The frequency of genotypes CT+ TT in AR group was higher than AS group, and the difference was also significant (χ²=4.369, P=0.037). But there was no difference in allele frequency and genotype distribution of C1236T and G2677T/A between the two groups.Haplotypes constituted by the three loci were analyzed, and the OR value of haplotype (C-T-T) was 1.602 (χ²=5.374, P=0.02), the OR value of haplotype (C-G-C) was 0.495 (χ²=8.775, P=0.003), the OR value of haplotype (T-G-C) was 3.010 (χ²=5.846, P=0.015), while the OR value of haplotype (T-T-T) was 3.308 (χ²=4.650, P=0.031). Conclusions: The polymorphisms of C3435T in the ABCB1 gene have a relationship with AR in the patients with ischemic stroke. The haplotypes (C-T-T, T-G-C, T-T-T) are also related to the AR in the patients with ischemic stroke.