Purpose

The current cut-offs for the diagnosis of adrenal insufficiency (AI) have been established using outdated immunoassays. We compared the cortisol concentrations measured with Roche Cortisol I (R1), the newly available Roche Cortisol II (R2), and liquid chromatography tandem mass spectrometry (LC-MS/MS), the gold standard procedure to measure steroids in patients undergoing the corticotropin (ACTH) test.

Methods

We enrolled 30 patients (age 47 ± 21 years) referred to undergo the ACTH test (1 or 250 μg). Cortisol was measured at 0, 30, and 60 min after stimulation with R1, R2, and LC-MS/MS. AI was diagnosed for R1-stimulated peak cortisol concentrations < 500 nmol/L.

Results

Mean cortisol concentrations measured with R2 and LC-MS/MS were comparable, while mean cortisol concentrations measured by R1 were higher than those of both R2 and LC-MS/MS (respectively, basal 411 ± 177, 287 ± 119, and 295 ± 119 nmol/L; at 30 min, 704 ± 204, 480 ± 132, and 500 ± 132 nmol/L; at 60 min, 737 ± 301, 502 ± 196, and 519 ± 201 nmol/L, p ≤ 0.01 for R1 vs. both R2 and LC-MS/MS at each point). Considering the 500 nmol/L cortisol peak cut-off, AI was diagnosed in 5/30 patients using R1 and in 12/30 using R2 (+ 140%). Based on the correlation between R1 and R2, the threshold of 500 nmol/L became 351 nmol/L (12.7 μg/dL) when cortisol was measured with R2, and 368 nmol/L (13.3 μg/dL) with LC-MS/MS.

Conclusions

The use of more specific cortisol assays results in lower cortisol concentrations. This could lead to misdiagnosis and overtreatment when assessing AI with the ACTH test if a different cut-off for cortisol peak is not adopted.

中文翻译：

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记住用第二代测定法测量的皮质醇水平与目前诊断肾上腺功能不全的诊断阈值之间的差距：单中心经验。

目的

目前已经使用过时的免疫测定方法来确定肾上腺功能不全（AI）的诊断标准。我们比较了用Roche Cortisol I（R1），最新可用的Roche Cortisol II（R2）和液相色谱串联质谱法（LC-MS / MS）进行的皮质醇浓度测量，液相色谱串联质谱法是在接受促肾上腺皮质激素的患者中测量类固醇的金标准程序（ACTH）测试。

方法

我们招募了30名患者（年龄47±21岁）进行ACTH测试（1或250μg）。用R1，R2和LC-MS / MS刺激后0、30和60分钟测量皮质醇。诊断为AI受R1刺激的皮质醇峰值浓度<500 nmol / L。

结果

用R2和LC-MS / MS测量的平均皮质醇浓度具有可比性，而用R1测量的平均皮质醇浓度则高于R2和LC-MS / MS（分别为411±177、287±119和295± 119 nmol / L的;在30分钟，704±204，480±132和500±132 nmol / L的;在60分钟，737±301，502±196和519±201纳摩尔/ L，p  ≤0.01 R1相对于R2和LC-MS / MS在每个点）。考虑到500 nmol / L的皮质醇峰值截止值，在使用R1的5/30患者和使用R2的12/30患者中诊断出AI（+ 140％）。根据R1和R2之间的相关性，用R2测定皮质醇时，500 nmol / L的阈值变为351 nmol / L（12.7μg/ dL），而使用LC-MS / MS的阈值变为368 nmol / L（13.3μg/ dL）。多发性硬化症。

结论

使用更具体的皮质醇测定可降低皮质醇浓度。如果未采用不同的皮质醇峰值截止值，则在通过ACTH测试评估AI时可能导致误诊和过度治疗。