血浆叶酸、同型半胱氨酸水平及亚甲基四氢叶酸还原酶基因突变与静脉血栓栓塞症

目的 探讨血浆叶酸、同型半胱氨酸(Hcy)水平及亚甲基四氢叶酸还原酶(MTHFR)基因突变与静脉血栓栓塞症(VTE)的关系及MTHFR基因突变对血浆叶酸、Hcy水平的影响。方法 采用病例对照研究,对58例既往确诊为VTE(VTE组)的患者及与其性别、年龄相匹配的58例健康对照者(健康对照组)行流行病学调查,高效液相色谱分析法测血浆中Hcy、蛋氨酸和半胱氨酸水平,放射免疫法测血浆中叶酸水平,PCR-限制性片段长度多态性(RFLP)法测MTHFR C677T基因型。结果吸烟、高血压、糖尿病等危险因素均与VTE无关。血浆Hcy和叶酸浓度在2组间有明显差异(P<0.05)。多变量logistic回归分析显示,Hcy和叶酸浓度是影响VTE的独立因素(OR=1.5,95％CI为1.216～2.213;OR=0.396,95％CI为0.149-0.709)。MTHFR C667T基因突变在2组间差异无显著性(P>0.05)。血浆叶酸浓度与血浆Hcy浓度有明显关联(偏相关系数为-2.061,P<0.05)。MTHFR C667T。基因突变虽然与血浆Hcy浓度无关,但与血浆叶酸浓度相关(偏相关系数为0.5856,P<0.01)。结论 高同型半胱氨酸血症和叶酸缺乏是VTE独立的危险因素,叶酸缺乏是造成高同型半胱氨酸血症的原因之一,MTHFlR C667T基因突变可能是造成叶酸缺乏的遗传因素之一。

Relationship of plasma homocysteine and folic acid levels and 5,10-methylenetetrahydrofolate reductase gene mutation with venous thromboembolism

Objective To investigate the association between concentrations of plasma homocysteine and folic acid, 5, 10-methylenetetrahydrofolate reductase ( MTHFR) C667T mutation and venous thromboembolism (VTE) and to analyze the effect of MTHFR C667T mutation on concentrations of plasma homocysteine and folic acid Methods In 58 patients with VTE and 58 sex and age matched controls, epidemiological risk factors were surveyed. The concentration of plasma homocysteine was measured by high performance liquid chromatography, and the concentration of plasma folic acid was measured by radioimmunoassay. MTHFR C667T genotype was measured by PCR-RFLP. Results The concentrations of plasma homocysteine and folic acid showed significant difference between the case group and the control group (OR = 1.5, 95% CI; 1.216-2.213 and OR =0.396, 95% CI: 0. 149-0.709, respectively). There was no significant difference in the frequency of mutant alleles in site 667 of MTHFR gene between the cases and the controls ( P > 0. 05). The concentration of plasma folic acid was associated with the concentration of plasma homocysteine ( multiple correlation coefficient = - 2. 061, P < 0. 05 ) . The MTHFR C667T polymorphism was associated with the concentration of plasma folic acid but not with the concentration of plasma homocystein in both the case group and the control group. The multiple correlation coefficient between the MTHFR C667T polymorphism and the concentration of plasma folic acid is 0. 5856 (P < 0. 01). Conclusions The results of our study demonstrate that hyperhomocystinemia and folic acid deficiency are independent risk factors for VTE. Folic acid deficiency is a cause of hyperhomocystinemia while the MTHFR C667T mutation is one of the possible genetic factors causing folic acid deficiency in this Chinese population.