(R)-2-hydroxyglutarate (R-2-hg) is a metabolite produced under physiologic conditions but also by tumors harboring isocitrate dehydrogenase (IDH) mutations. Detection is challenging as it must be distinguished from its enantiomer (S)-2-hydroxyglutarate (S-2-hg), which is also produced in the body but can increase under hypoxic conditions. A chiral gas chromatography-tandem mass spectrometry (GC–MS/MS) assay was developed, which separated enantiomers using a chiral column and quantified levels using a stable-isotope internal standard. The assay improves upon current methods by avoiding chiral derivatization and implementing a simplified sample extraction procedure. The assay was validated and serum 2-hg levels from healthy patients were measured, establishing a new, comprehensive reference range for normal levels of each enantiomer. Differences in basal levels were observed between races, but not sex. Age also correlated with S-2-hg levels, but not R-2-hg levels. Finally, serum levels of 2-hg enantiomers were measured in a pilot study of 11 patients with and without IDH mutant gliomas. An increase in R-2-hg levels was observed in 2/3 patients with actively growing IDH mutant gliomas. S-2-hg levels were increased in 4/11 patients, irrespective of IDH status. The results presented demonstrate the feasibility of a GC–MS/MS assay for measurement of 2-hg enantiomer levels for clinical use.

（R）-2-羟基戊二酸酯（R-2-hg）是在生理条件下产生的代谢物，也是由携带异柠檬酸脱氢酶（IDH）突变的肿瘤产生的。检测具有挑战性，因为必须将其与对映异构体（S）-2-羟基戊二酸（S-2-hg）区分开，对映体（S）-2-羟基戊二酸也可能在体内产生，但在低氧条件下会增加。建立了手性气相色谱-串联质谱（GC-MS / MS）分析方法，该方法使用手性色谱柱分离对映异构体，并使用稳定同位素内标对定量水平进行分离。通过避免手性衍生化并实施简化的样品提取程序，该测定法改进了当前方法。该测定方法得到验证，并测量了健康患者的血清2-hg水平，为每种对映体的正常水平建立了新的全面参考范围。种族之间观察到基础水平的差异，但没有性别差异。年龄也与S-2-hg水平相关，但与R-2-hg水平无关。最后，在一项对11名患有和未患有IDH突变型神经胶质瘤的患者进行的初步研究中，测定了2-hg对映体的血清水平。在2/3活跃生长的IDH突变型神经胶质瘤患者中，观察到R-2-hg水平升高。不论IDH状态如何，4/11患者的S-2-hg水平均升高。提出的结果证明了用GC-MS / MS测定临床上使用的2 hg对映异构体水平的可行性。在2/3活跃生长的IDH突变型神经胶质瘤患者中，观察到R-2-hg水平升高。不论IDH状态如何，4/11患者的S-2-hg水平均升高。提出的结果证明了用GC-MS / MS测定临床上使用的2 hg对映异构体水平的可行性。在2/3活跃生长的IDH突变型神经胶质瘤患者中，观察到R-2-hg水平升高。不论IDH状态如何，4/11患者的S-2-hg水平均升高。提出的结果证明了用GC-MS / MS测定临床上使用的2 hg对映异构体水平的可行性。