Zhang Xiaochun, Tang Xiaoying, Gibson Bill, Daly Thomas M
Department of Laboratory Medicine, Robert Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH.
J Appl Lab Med. 2017 Nov 1;2(3):367-379. doi: 10.1373/jalm.2017.024349.
Two primary assays are routinely used for evaluating a patient's vitamin B1 status: plasma free thiamine and whole blood thiamine diphosphate (TDP). TDP is the bioactive form of vitamin B1 and best reflects body stores. Plasma free thiamine levels are driven by recent dietary intake. The objective of this study was to develop a simple HPLC method with an internal standard (IS) that simultaneously measures TDP and thiamine in whole blood, and to assess the use of this single-tube assay to provide comprehensive evaluation of vitamin B1 status.
The final assay used amprolium thiochrome as an IS, and the sample preparation procedure takes approximately 1 h. Whole blood thiamine and plasma thiamine were concurrently measured for 126 subjects.
The analytical measurement range was 1.7 to 442.3 nmol/L (TDP) and 1.7 to 375.4 nmol/L (thiamine), with interassay precisions of 4.0% to 4.8% (TDP) and 2.9% to 8.0% (thiamine), respectively. Method comparison with a reference laboratory HPLC method showed r = 0.9625, slope = 1.021, and intercept = 0.982 (n = 53) for TDP quantification. Whole blood thiamine correlated closely with plasma thiamine levels but were slightly higher with a mean difference of 1.0 nmol/L (range: -3.0 to 5.0 nmol/L). The reference interval for whole blood TDP and thiamine was 84.3 to 213.3 nmol/L and 1.7 to 21.9 nmol/L, respectively.
This assay provides a simple and reliable HPLC method with a suitable IS for quantification of both TDP and thiamine from whole blood. It also eliminates the need for separate samples for TDP and thiamine measurement, which will allow both short-term and long-term vitamin B1 status to be assessed from a single sample.
通常使用两种主要检测方法来评估患者的维生素B1状态：血浆游离硫胺素和全血硫胺素二磷酸酯（TDP）。TDP是维生素B1的生物活性形式，能最好地反映体内储备情况。血浆游离硫胺素水平受近期饮食摄入的影响。本研究的目的是开发一种带有内标（IS）的简单高效液相色谱法（HPLC），用于同时测定全血中的TDP和硫胺素，并评估使用这种单管检测法全面评估维生素B1状态的可行性。
最终检测使用氨丙啉硫色素作为内标，样品制备过程约需1小时。对126名受试者同时测定全血硫胺素和血浆硫胺素。
分析测量范围为1.7至442.3 nmol/L（TDP）和1.7至375.4 nmol/L（硫胺素），批间精密度分别为4.0%至4.8%（TDP）和2.9%至8.0%（硫胺素）。与参考实验室的HPLC方法进行方法比较，TDP定量分析显示r = 0.9625，斜率 = 1.021，截距 = 0.982（n = 53）。全血硫胺素与血浆硫胺素水平密切相关，但略高，平均差异为1.0 nmol/L（范围：-3.0至5.0 nmol/L）。全血TDP和硫胺素的参考区间分别为84.3至213.3 nmol/L和1.7至21.9 nmol/L。
该检测法提供了一种简单可靠的HPLC方法，带有合适的内标，可用于定量全血中的TDP和硫胺素。它还无需分别采集用于TDP和硫胺素测量的样品，这将使得能够从单个样品评估短期和长期的维生素B1状态。
