系统性红斑狼疮与亚甲基四氢叶酸还原酶基因多态性的相关性

目的 探讨亚甲基四氢叶酸还原酶(MTHFR)基因第四外显子第677位C→T突变与系统性红斑狼疮(SLE)的相关性。方法 检测40例SLE患者和20例正常人对照组血浆同型半胱氨酸水平,用聚合酶链反应(PCR)-限制性片段长度多态性法作MTHFR基因分型。结果 SLE患者组血浆同型半胱氨酸水平明显高于正常人对照组.而活动期SLE患者与非活动期SLE患者之间血浆同型半胱氨酸水平差异无统计学意义。SLE患者组MTHFR基因TT型占62.5%,明显高于其他两种基因型和正常人对照组(15%)。MTHFR基因677位发生C→T突变可导致血浆同型半胱氨酸水平明显升高,且TT型的效应要明显强于CT型的效应。结论 MTHFR基因多态性是影响SLE患者同型半胱氨酸水平的主要因素之一。MTHFR基因第677位TT型是SLE的易感基因或与易感基因紧密连锁。

Relationship between methylene tetrahydrofolate reductase gene polymorphism and systemic lupus erythematosus

Objective To investigate the relationship between methylene tetrahydrofolate reductase （MTHFR） gene polymorphism and systemic lupus erythematosus. Methods Forty patients with SLE and 20 normal human controls were enrolled into this study. Plasma levels of homocysteine （Hcy） were mea-sured by fluorescence polarization immunization assay, and MTHFR 677 polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP）. Results The plasma Hcy level was significantly higher in SLE patients than in the controls, but was of no difference between the patients with active SLE and those with inactive SLE. The frequency of MTHFR 677 TT genotype was 62.5% in SLE groups, significantly higher than the frequencies of other two genotypes, CC and CT in SLE patients, and than that in the normal controls （62.5% vs 15%, P < 0.001）. The MTHFR 677 C→T mutation was associated with a significant increase of Hcy plasma evels in SLE patients, and the increase of Hcy was more significant in patients with TT genotype than those with CT genotype. Conclusions The polymor-phism of MTHFR gene is an important factor that influences the Hcy levels in SLE patients. The MTHFR 677 TT genotype may be a susceptibility factor of SLE, or be closely linked to the susceptibiliy genes of SLE.