液相色谱-质谱联用法（LC-MS/MS）和酶联免疫法(ELISA)对体内25（OH）D3水平的测定

目的 同时用液相色谱-质谱联用法（LC-MS/MS）和酶联免疫法（ELISA）检测患者体内25（OH）D3水平，分析两者结果的差异。方法 随机选取50例住院患者，对同一血清样本分别用LC-MS/MS法和ELISA法测定25（OH）D3水平，同时用LC-MS/MS法测定25（OH）D2的水平。结果 LC-MS/MS法测定的维生素D3的均数为14.99±6.51ng/ml，酶联免疫法测定的均数为20.91±9.70ng/ml，两者的相关系数为0.725（P＜0.01），线性相关方程为维生素D3（LC-MS/MS法）=4.829+0.486×维生素D3(ELISA法)。LC-MS/MS法组25（OH）D3浓度高于20ng/ml的比例17%，酶联免疫法组为52%，LC-MS/MS法组的25（OH）D2和25（OH）D3总浓度高于20ng/ml的为24%。25（OH）D2占25（OH）D总量的8.4%。 结论 LC-MS/MS法测定的维生素D3的数值明显低于ELISA法，两者正相关性较高，可经方程互换。酶联免疫法低估了体内维生素D的缺乏，检测25（OH）D3的同时需测定25（OH）D2浓度。

The measurement of 25 (OH) D3 using liquid chromatography-tandem mass spectrometry and enzyme-linked immunosorbent assay

Objective To detect 25 (OH) D3 levels in patients using both liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA), and to analyze the difference between the two methods. Methods Fifty hospitalized patients were randomly selected. 25 (OH) D3 level in a same serum sample was detected using both LC-MS/MS method and ELISA method. Meanwhile, 25 (OH) D2 level was detected using LC-MS/MS method. Results The mean vitamin D3 level detected using LC-MS/MS method was 14.99 ± 6.51ng/ml, while the result using ELISA method was 20.91 ± 9.70ng/ml, and the correlation coefficient was 0.725 (P <0.01).The linear correlation equation was vitamin D3 (LC-MS/MS) = 4.829 +0.486×vitamin D3 (ELISA). 25 (OH) D3 level of 17% patients in LC-MS/MS group was higher than 20ng/ml, while it was 52% in ELISA group. The total concentration of 25 (OH) D2 and 25 (OH) D3 detected using LC-MS/MS method of 24% patients was higher than 20ng/ml, and 25 (OH) D2 accounted for 8.4% in the total 25 (OH) D concentration. Conclusion The result using LC-MS/MS method for the determination of vitamin D is significantly lower than that using ELISA method. The positive correlation between LC-MS/MS and ELISA is obvious, and they can convert using an equation. ELISA method underestimates the lack of vitamin D. When detecting the 25 (OH) D3 concentration, 25 (OH) D2 concentrations should be detected at the same time.