Association of Toll-like receptor 4 polymorphisms with the risk of coronary artery disease in the ethnic Zhuang population of the Guangxi Province of China.

Objectives: Toll-like receptor 4 (TLR4) is known to be involved in the innate immunity and inflammatory responses that plays a crucial role in the pathogenesis of coronary artery disease (CAD). This study aimed to examine the potential relationship of TLR4 polymorphisms and serum TLR4 protein levels and the risk of CAD in the ethnic Zhuang population of China.

Methods: 1171 serum samples were collected from Zhuang patients, including 556 CAD cases (≥50% luminal stenosis of any coronary vessel) and 615 normal healthy controls (subjects with no luminal stenosis in coronary arteries). Detection of TLR4 polymorphisms was by single base extension polymerase chain reaction (Snapshot PCR) and DNA sequencing (rs11536879A/G and rs11536889G/C) gene sequence in all subjects. Serum TLR4 protein concentrations was measured by ELISA.

Results: There are significant differences in the allele and genotype frequencies of TLR4 gene rs11536889 between Chinese Zhuang CAD patients and controls, especially in the males. Male carriers of rs11536879 andrs11536889 variant alleles show an increased risk of CAD compared to non-carriers. Serum TLR4 protein levels of CAD patients are higher than controls and the levels tended to increase with the number of coronary artery lesions. Serum TLR4 protein levels of CAD patients showed no correlation with rs11536879 and rs11536889 polymorphisms.

Conclusions: The rs11536879 and rs11536889 polymorphisms of TLR4 gene and serum TLR4 protein levels may contribute to the occurrence and development of CAD. However, the rs11536879 and rs11536889 polymorphisms have no significant effects on the expression of serum TLR4 protein in Zhuang patients with CAD.