Department of Clinical Biochemistry, Northwick Park Hospital, North West London Hospitals NHS Trust, Harrow, Middlesex HA1 3UJ, UK.
Ann Clin Biochem. 2011 Nov;48(Pt 6):542-9. doi: 10.1258/acb.2011.010250. Epub 2011 Aug 16.
We report a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection of four commonly prescribed steroid drugs (prednisolone, dexamethasone, betamethasone and beclomethasone dipropionate) while simultaneously measuring 24-h urine free cortisol and cortisone in patients.
Two hundred and fifty microlitre aliquots of urine were spiked with internal standard and extracted with dichloromethane. The MS instrument was operated with positive electrospray and multiple reaction monitoring. Two transitions were monitored for each analyte of interest and the ratio of the intensities of the product ion fragments was established.
The LC-MS/MS method for the measurement of urine free cortisol and cortisone was established. The assay was linear up to 788 nmol/L for cortisol and 777 nmol/L for cortisone, with a limit of quantitation of 5.0 nmol/L for both. Analysis time per sample was seven minutes. Transitions for four synthetic glucocorticoids were included, and they were identified based on the ratio of the intensities of product ion fragments. Analysis of 219 samples collected from 154 patients (55 male and 99 female) revealed the presence of prednisolone in five samples from three patients. Dexamethasone was detected in samples from four patients, and betamethasone was detected in one sample.
This is the first LC-MS/MS method in routine use to combine quantification of urinary cortisol and cortisone and detection of synthetic glucocorticoids in patients being investigated for Cushing's syndrome. Since the most common quoted cause of Cushing's syndrome is steroid treatment, this is a valuable diagnostic tool.
我们报道了一种液相色谱-串联质谱（LC-MS/MS）方法，用于检测四种常用的甾体药物（泼尼松龙、地塞米松、倍他米松和丙酸倍氯米松），同时测量患者 24 小时尿液游离皮质醇和皮质酮。
将 250μl 尿液等分试样与内标物混合，用二氯甲烷提取。MS 仪器采用正电喷雾，进行多重反应监测。每个感兴趣分析物监测两个转换，建立产物离子碎片强度比。
建立了测量尿液游离皮质醇和皮质酮的 LC-MS/MS 方法。该测定方法在皮质醇的线性范围高达 788 nmol/L，皮质酮的线性范围高达 777 nmol/L，皮质醇和皮质酮的定量下限均为 5.0 nmol/L。每个样品的分析时间为七分钟。包括四个合成糖皮质激素的转换，根据产物离子碎片强度比进行鉴定。分析了 154 名患者（55 名男性和 99 名女性）收集的 219 个样本，发现 3 名患者的 5 个样本中存在泼尼松龙。在 4 名患者的样本中检测到地塞米松，在 1 名患者的样本中检测到倍他米松。
这是一种常规使用的 LC-MS/MS 方法，可用于同时定量检测皮质醇和皮质酮，以及检测怀疑库欣综合征患者的合成糖皮质激素。由于最常见的库欣综合征病因是类固醇治疗，因此这是一种有价值的诊断工具。
