汉族人凝血酶活化的纤溶抑制物编码区的基因多态性与冠状动脉粥样硬化性心脏病相关性研究

Study on the association of the gene polymorphism of thrombin activatable fibrinolysis inhibitor with coronary heart disease in Han population

目的研究汉族人血浆中凝血酶活化的纤溶抑制物水平及编码区的基因多态性分布特征与冠状动脉粥样硬化性心脏病之间的相关性。方法应用 ELISA 及发色底物法分别检测了126例冠状动脉粥样硬化性心脏病患者和45名健康对照组血浆中的 TAFI 抗原及活性水平,同时应用PCR 结合限制性片段长度多态性技术研究了浙江地区156名汉族健康人与126例冠状动脉粥样硬化性心脏病患者 TAFI 基因编码区 Thr325Ile、Thr147Ala 多态性分布特点,并分析这两个多态性位点与冠状动脉粥样硬化性心脏病之间的关系。结果急性心肌梗死组患者血浆中 TAFI 抗原与活性水平分别为(106.82±24.51)%和(6.32±1.58)μg/ml,心绞痛组患者血浆中 TAFI 抗原与活性水平分别为(100.73±30.39)%和(6.92±1.78)μg/ml,经方差分析,二者之间及其与对照组之间的差异无统计学意义(P>0.05);在浙江汉族人群中 TAFI Thr325Ile 的基因多态性分布中 Thr325Thr(1040C/C)占0.667 0,Thr325Ile(1040C/T)占0.262 0,Ile325Ile(1040T/T)占0.071 0;104 0位 C 与 T 等位基因频率的分别为0.798 0与0.202 0,TAFI Thr147Ala 的基因型分布中 Ala147Ala(505G/G)为0.603 0,Ala 147 Thr(505G/A)为0.278 0,Thr147Thr(505A/A)为0.119 0,505位 G 与 A 等位基因频率分别为0.742 0与0.258 0,冠状动脉粥样硬化性心脏病组与对照组中基因型的分布频率和等位基因频率之间的差异也无统计学意义(P>0.05);另外,在 Thr325Ile 基因多态性中,纯合子 Thr325Thr(1040C/C)者血浆 TAFI 抗原水平为(114.89±22.53)%,较其他两型(1040C/T、1040T/T)高,差异有统计学意义(P<0.05),而后两型之间差异无统计学意义(P>0.05);纯合子 Ile325Ile(1040T/T)的 TAFI 活性为(3.08±3.63)μg/ml,较其他两型(1040C/T、1040T/T)低,差异有统计学意义(P<0.05),而后两者之问的差异无统计学意义(P>0.05);而 Thr147Thr(505AZA)、Thr147Ala(505C/T)、AIa147Ala(505G/C)3种基因型血浆中 TAFI 水平(抗原与活性)之间的差异均无统计学意义(P>0.05)。结论TAFI 编码区 Thr325Ile 基因多态性对血浆中 TAFI 抗原与活性水平有明显的影响,但 TAFI Ala147Thr与 Thr325Ile 两种基因多态性与冠状动脉粥样硬化性心脏病的发生无明显的相关性。

Objective To investigate the gene polymorphism at amino acids 147 and 325 in TAFI of Chinese Han population and to analyze the relationships among the two gene polymorphism in thrombin activatable fibrinolysis inhibitor（TAFI） , plasma levels of TAFI and coronary heart disease. Methods The TAFI antigen and activity in 171 samples were determined by sandwich enzyme link immunoabsorbent assay specific for human TAFI and chromogenic assay for activated human TAFI in plasma, respectively. And the gene polymorphism in TAFI of 282 samples （ Ala147Thr and Thr325Ile） were detected by the polymerase chain reaction and restrict fragment length polymorphism assay （PCR-RFLP）, Results The TAFI antigen and activity levels in plasma of patients with acute myocardial infarction and acute angina pectoris were （ 106. 82±24. 51）% ,（6. 32±1.58）μg/ml and （ 100. 73±0. 39）%, （6. 92±1.78） μg/ml,there were no significantly different among them （ P 〉 0. 05 ）. At the 325 position, the frequencies for Thr325Thr, Thr325Ile and Ile325Ile were 0. 667 0, 0. 262 0,0. 071 0, respectively, the frequencies of C allele was 0. 798 0, and that of the T allele was 0. 202 0;at the 147 position, frequencies for Ala147Ala, Thr147Ala and Thr147qhr were 0. 603 0, 0. 278 0 and 0. 119 0, respectively, the frequencies of G allele was 0. 742 0, and that of A allele was 0. 258 0. No statistical significance was found （ P 〉 0. 05 ） in the frequency of alleles and genotypes between controls and coronary heart disease. In additional, at the 325 position, the TAFI antigen of the Thr325Thr was higher [ （ 114. 89 ±2. 53 ）% ] than that of the other genotype （Thr325Ile and Ile325Ile）, there was significant difference between the TAFI antigen of the Thr325Thr and the others （ P 〈 0.05）, and no statistical significance between the TAFI antigen of the Thr325Ile and the lle325Ile（P 〉 0.05）. But the TAFI activity of the lle325Ile was lower（3.08±3.63 μg/ml） than that of the other genotypes （Thr325Ile and Thr325Thr）,there was significantly difference between the TAFI activity of the Thr325Thr and the other （ P 〈 0. 05 ）. At the 147 position, the plasma TAFI antigen and activity for the Ala147Ala, Thr147Ala and Thr147Thr were （ 103.72±26. 77）% and （6. 20 ± 1.38）μg/ml, （ 105.94±27.60） % and （6.47± 1.90 ） μg/ml, （ 111.76 ± 36. 10 ） % and （ 7.84 ±0. 74 ） μg/ml, respectively, No significantly difference was found among them. Conclusions Our study suggested there was obvious effect on TAFI levels in the gene polymorphism at amino acid Thr325Ile;the genotypes distribution of the Thr325Ile and Thr147Ala polymorphism in the CHD were no significant difference, and there were discrepancies on considering the TAFI gene polymorphism as the risk factor of the coronary heart disease in the Han population.