Association between thrombomodulin (THBD) gene polymorphism and pulmonary thromboembolism in a Chinese population

Objective: Thrombomodulin (TM) is an essential component of the anticoagulant protein C system. Polymorphism 1418C>T of the thrombomodulin gene (THBD) that encodes TM is associated with venous thrombosis in both American and Japanese populations; however, the effect of this polymorphism in Chinese populations is unknown. Therefore this study aimed to investigate the relationship between the THBD polymorphisms 1418C>T and/or -151G>T, and pulmonary thromboembolism (PTE) in a Chinese population. Patients and methods: The current study assessed 111 PTE patients (PTE group) and 100 healthy patients (control group). These patients were screened for 1418C>T and -151G>T polymorphisms using high-resolution melt (HRM) analysis, and their plasma TM concentration was examined by ELISA. Results were statistically analysed to evaluate a possible relationship between THBD 1418C>T and/or -151G>T polymorphism, plasma TM concentration, and PTE incidence. Results: Patients were identified as having one of the three genotypes at THBD position 1418: C/C, C/T, or T/T. The frequency of the T allele was higher in the control group than in PTE group; however, this difference was not statistically significant (P>0.05). Patients were shown to have either a G/G or a G/T genotype at THBD position -151. The frequency of the T allele at this locus was significantly higher in PTE patients than in the control group (P<0.05). The results of the patient screening at the THBD 1418 and -151 loci demonstrate that 1418C>T polymorphism is associated with a decreased risk of PTE (OR=0.373, P<0.05). Similarly, -151G>T polymorphism appears to significantly reduce the plasma concentration of soluble TM (sTM) compared to the standard G/G genotype at this locus (P<0.05). Conclusion: THBD 1418C/T genotype is a protective factor against the development of PTE, and the THBD -151G/T genotype reduces expression of plasma sTM.