Influence of 5,10-methylenetetrahydrofolate reductase polymorphism on whole-blood folate concentrations measured by LC-MS/MS, microbiologic assay, and bio-rad radioassay
Influence of 5,10-methylenetetrahydrofolate reductase polymorphism on whole-blood folate concentrations measured by LC-MS/MS, microbiologic assay, and bio-rad radioassay
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DOI：
10.1373/clinchem.2007.096545
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发表时间：
2008-01-01
影响因子：
9.3
通讯作者：
Koontz, Deborah
中科院分区：
文献类型：
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作者：
Fazili, Zia;Pfeiffer, Christine M.;Koontz, Deborah
背景技术背景：5，10-亚甲基四氢叶酸还原酶（NADPH）（MTHFR）C677 T多态性可能影响液相色谱-串联质谱法测定的全血叶酸模式（LC-MS/MS）和通过LC-MS/MS、微生物测定和Bio-Rad放射性测定（BR）测量总叶酸。方法：我们用这三种方法分析了2个血库的171份全血溶血产物的叶酸模式和总叶酸浓度，并确定了MTHFR基因型。在美国组中，通过LC-MS/MS测定的中位（范围）总叶酸浓度[378（228-820）nmol/L; n=96]高于欧洲组[250（122582）nmol/L; n=75]。C/C（n=73）和C/T（n=66）基因型个体的全血叶酸模式[中位数（范围）]相似：分别为88%（71%-91%）和86%（50%-91%），5-甲基四氢叶酸（5CH（3）THF）的含量为12%（9%-29%），而5-甲基四氢叶酸以外的形式（非5CH（3）THF）的含量为14%（9%-51%）。T/T（n=32）基因型个体5CH 3 THF阳性率为58%（22%-87%），非5CH（3）THF阳性率为42%（13%-78%）。与微生物测定结果相比，LC-MS/MS（r=0.94）和BR（r=0.87）结果显著较低（分别为-10%和-45%）;然而，BR测定的这些差异具有浓度依赖性和基因型依赖性（C/C+C/T为-48%，T/T为-31%）。除四氢叶酸（THF）[46.4%（8.1%）]外，微生物学试验完全回收了添加至全血溶血产物中的叶酸[平均值（SD）]。BR法对5CH（3）THF回收率不足[51%（4.1%）]和5-甲酰四氢叶酸回收率不足[18%（0.1%）]，对THF回收率过高[152%（19%）]。LC-MS/MS法和微生物法测定的总叶酸之间的一致性，与MTHFR基因型无关，允许使用一个回归方程。由于BR结果是基因型依赖性的，因此应使用不同的回归方程。
BACKGROUND: The 5,10-methylenetetrahydrofolate reductase (NADPH) (MTHFR) C677T polymorphism may affect whole-blood folate pattern measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and total folate measured by LC-MS/MS, microbiologic assay, and Bio-Rad radioassay (BR).METHODS: We analyzed 171 whole blood hemolysates from 2 blood banks for folate pattern and total folate concentrations using these 3 methods and determined MTHFR genotype.RESULTS: The median (range) total folate concentration by LC-MS/MS was higher in the US set [378 (228-820) nmol/L; n=96] than in the European set [250 (122582) nmol/L; n=75]. The whole-blood folate pattern [median (range)] was similar for individuals with C/C (n=73) and C/T (n=66) genotype: 88% (71%-91%) and 86% (50%-91%), respectively, for 5-methyltetrahydrofolic acid (5CH(3)THF) vs 12% (9%-29%) and 14% (9%-51%) for forms other than 5-methyltetrahydrofolic acid (non-5CH(3)THF). Individuals with T/T (n=32) genotype had 58% (22%-87%) 5CH3THF vs 42% (13%-78%) non-5CH(3)THF. Compared with microbiologic assay results, LC-MS/MS (r=0.94) and BR (r=0.87) results were significantly lower (-10% and -45%, respectively); however, these differences were concentration dependent and also genotype dependent for the BR assay (-48% for C/C+C/T and -31% for T/T). The microbiologic assay completely recovered [mean (SD)] folates added to a whole blood hemolysate, except for tetrahydrofolic acid (THF) [46.4% (8.1%)]. The BR assay underrecovered 5CH(3)THF [51% (4.1%)] and 5-formyltetrahydrofolic acid [18% (0.1%)], and overrecovered THF [152% (19%)].CONCLUSION: MTHFR C677T polymorphism influences the folate pattern in whole blood. The agreement between total folate by LC-MS/MS and microbiologic assay, independent of the MTHFR genotype, allows the use of one regression equation. Because BR results are genotype dependent, different regression equations should be used.