Department of Chemistry, Hong Kong Baptist University, Kowloon, Hong Kong, China.
Talanta. 2012 Jan 15;88:193-200. doi: 10.1016/j.talanta.2011.10.031. Epub 2011 Oct 29.
Urinary organic acids, plasma amino acids and acylcarnitine profile analyses are the main tools used to diagnose inborn errors of metabolisms (IEMs). However, without metabolic decompensation, these parameters are often not helpful. On the other hand, in cases of IEM, acylglycines are consistently raised even when patients appear to be in remission. This study aims to set-up a simple liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the determination of urine acylglycines, complementary to organic acid and acylcarnitine profiles, for the diagnosis of IEM. In addition, local reference intervals for various acylglycines are established by using this method. Acylglycines were isolated by solid-phase extraction, derivatized with n-butanol, separated by HPLC, and detected by ESI-MS/MS. Acylglycines were quantified with deuterated internal standards. Mean recoveries of acylglycines ranged from 90.2 to 109.3%. Within- and between-run imprecisions for all acylglycines have CVs less than 10%. Linear regression coefficients were greater than 0.99. Reference intervals were established according to CLSI guidelines by analyzing 204 samples from apparently healthy individuals less than 18 years of age. The distributions of AG in the "normal" urine were skewed towards the right. After log transformation, all the results were normally distributed. Partitioning into age group reference intervals was not indicated, according to the Harris and Boyd approach. In this context, a single reference interval for each acylglycine could be used. This method of urine acylglycines analysis is a powerful diagnostic tool, complementary to urine organic acids and plasma acylcarnitine profiling, for detecting certain inborn errors of metabolism.
尿有机酸、血浆氨基酸和酰基肉碱谱分析是诊断代谢性遗传病（IEM）的主要手段。然而，在没有代谢失代偿的情况下，这些参数通常没有帮助。另一方面，在 IEM 的情况下，即使患者看起来处于缓解期，酰基甘氨酸也会持续升高。本研究旨在建立一种简单的液相色谱-电喷雾串联质谱（LC-ESI-MS/MS）方法，用于测定尿液酰基甘氨酸，与有机酸和酰基肉碱谱分析互补，用于诊断 IEM。此外，还使用该方法建立了各种酰基甘氨酸的本地参考区间。酰基甘氨酸通过固相萃取分离，用正丁醇衍生化，用 HPLC 分离，用 ESI-MS/MS 检测。酰基甘氨酸用氘代内标定量。酰基甘氨酸的平均回收率在 90.2%至 109.3%之间。所有酰基甘氨酸的日内和日间精密度的 CV 值均小于 10%。线性回归系数均大于 0.99。根据 CLSI 指南，通过分析 204 份年龄小于 18 岁的健康个体的样本，建立了参考区间。“正常”尿液中 AG 的分布向右偏态。经对数转换后，所有结果均呈正态分布。根据 Harris 和 Boyd 方法，按年龄组划分参考区间的情况并不明显。在这种情况下，可以为每个酰基甘氨酸使用单一的参考区间。这种尿液酰基甘氨酸分析方法是一种强大的诊断工具，与尿液有机酸和血浆酰基肉碱谱分析互补，用于检测某些先天性代谢缺陷。
