Development of automated GC/MS data profiling and disease-detection sytems for organic acidemia screening.

GC/MS在临床检验医学，特别是有机酸的化学诊断中越来越受欢迎。然而，在日本，GC/MS目前还不够普及，可能是因为GC/MS设备的维护或GC/MS数据解释的困难，或者对遗传性代谢紊乱的知识要求。我们开发了一个自动化的GC/MS数据分析和疾病检测系统，使用个人计算机，并确认其在以下实验室测试的有用性。1）标准有机酸血症筛查：有机酸血症筛查的溶剂提取是最流行的制备方法。预先收集了诊断所需的约120种尿代谢物。经溶剂提取和GC/MS分析后，我们证实了数据可以自动处理和分析尿液代谢产物，并通过该系统在个人计算机上进行可能的诊断。2）全面的新生儿筛查：在制备过程中，尿液样品直接干燥和衍生化。样品的制备使得能够分析氨基酸、碳水化合物或其他以及有机酸。我们将该系统应用于筛选方法，并证实该系统可以自动分析这些化合物的GC/MS数据，并成功地诊断疾病。3）稳定同位素稀释分析：稳定同位素稀释法是一种非常灵敏的GC/MS分析方法，特别是对于量太小的代谢物。我们将该系统应用于稳定同位素法测定尿中酰基甘氨酸，设置了多个内标，证实了该系统的实用性。

GC/MS is becoming popular for clinical laboratory medicine, in particular, chemical diagnosis of organic acidemias. In Japan, however, GC/MS is not enough popular still now, probably because of difficulties in maintenance of GC/MS equipments or GC/MS data interpretation, or requirements of knowledge on the inherited metabolic disorders. We developed an automated GC/MS data profiling and disease detection system using a personal computer, and confirmed its usefulness in the following laboratory tests.1) Standard organic acidemia screening : The solvent extraction of urinary organic acids is a most popular preparation method for organic acidemia screening. About 120 kinds of urinary metabolites that are necessary for the diagnosis were enrolled in advance. We confirmed after the solvent extraction and GC/MS analysis that the data could be automatically processed and profiled urinary metabolites, and that the possible diagnosis was made by this system on a personal computer.2) Comprehensive neonatal mass screening : In preparation, urinary samples were directly dried up and derivatized. Preparation of the samples enable the analysis of amino acids, carbohydrates or others as well as organic acids. We apllied this system for the screening method and confirmed that this system could automatedly profile GC/MS data of these compounds preset and successfully diagnose the diseases.3) Stable isotope dilution analysis : The stable isotope dilution method is an extremely sensitive GC/MS analytical method, in particular, for metabolites whose amount is too small. We applied this system to the stable isotope method to determine urinary acylglycines, setting multiple internal standards, and confirmed the usefulness of this system.