Association analysis of CD40 gene polymorphism with acute coronary syndrome

Current evidence shows that the CD40–CD40 ligand (CD40–CD40L) system plays a crucial role in the development, progression and outcome of acute coronary syndrome (ACS). The aim of this study is to investigate whether a CD40 gene (−1C/T) single nucleotide polymorphism (SNP) is associated with ACS and CD40 expression. We included controls (n = 163) and patients with either ACS (n = 210) or stable angina (SA, n = 189) in the study. The gene polymorphism was measured using polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) and identified by sequencing. CD40 expression on platelets was detected by flow cytometry. The results showed that the frequency of the CC genotype of CD40 gene in the ACS group was significantly higher than in the SA and control groups (P < 0.001), while the TT genotype frequency in the ACS group was significantly lower than that of the SA and control groups (P < 0.001). The C-allele frequency of the ACS group was higher than that of the SA and control groups (P < 0.001). The C allele increased the risk of ACS when compared with the SA group (OR = 1.841, 95% CI: 1.390–2.437) and the control groups (OR = 1.877, 95% CI: 1.402–2.515). No significant differences in genotypes or allele frequencies were found between the SA and control groups. CD40 expression on platelets in patients with C-allele carriers was significant higher than in the T-allele carriers in each group. In conclusion, our results suggested that the CD40 gene (−1C/T) polymorphism was associated with ACS in Chinese people. The −1C-allele gene carriers had a higher expression of CD40 and an increased risk of suffering from ACS.