Endocrinology, Diabetes and Metabolism, Department of Medical Sciences, City of Health and Science University Hospital, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy.
Clinical Biochemistry Laboratory, City of Health and Science University Hospital, Turin, Italy.
J Endocrinol Invest. 2020 Dec;43(12):1797-1806. doi: 10.1007/s40618-020-01388-1. Epub 2020 Aug 9.
International guidelines recommend salivary cortisol for the diagnosis of Cushing's syndrome. Despite mass spectrometry-based assays are considered the analytical gold-standard, there is still the need to define reference intervals and diagnostic accuracy of such methodology.
100 healthy volunteers and 50 consecutive patients were enrolled to compare LC-MS/MS and electrochemiluminescence assay for the determination of late-night salivary cortisol and cortisone. Moreover, we aimed to determine reference intervals of salivary steroids in a population of healthy individuals and diagnostic accuracy in patients with suspected hypercortisolism and in a population including also healthy individuals.
Method comparison highlighted a positive bias (51.8%) of immunoassay over LC-MS/MS. Reference intervals of salivary cortisol (0.17-0.97 µg/L), cortisone (0.84-4.85 µg/L) and ratio (0.08-0.30) were obtained. The most accurate thresholds of salivary cortisol for the diagnosis of hypercortisolism were 1.15 µg/L in the population with suspected hypercortisolism (AUC 1) and 1.30 µg/L in the population including also healthy individuals (AUC 1). Cut-off values of salivary cortisone (7.23 µg/L; Se 92.9%, Sp 97.2%, AUC 0.960 and Se 92.9%, Sp 99.1%, AUC 0.985 in suspected hypercortisolism and in overall population, respectively) and cortisol-to-cortisone ratio (0.20; Se 85.7%, Sp 80.6%, AUC 0.820 and Se 85.7%, Sp 85.5%, AUC 0.855 in suspected hypercortisolism and in overall population, respectively) were accurate and similar in both populations.
LC-MS/MS is the most accurate analytical platform for measuring salivary steroids. Obtained reference intervals are coherent with previously published data and diagnostic accuracy for diagnosis of overt hypercortisolism proved highly satisfactory.
国际指南推荐唾液皮质醇用于库欣综合征的诊断。尽管基于质谱的检测被认为是分析的金标准，但仍需要定义这种方法的参考区间和诊断准确性。
纳入 100 名健康志愿者和 50 名连续患者，比较 LC-MS/MS 和电化学发光法测定唾液皮质醇和皮质酮的午夜值。此外，我们旨在确定健康人群唾液类固醇的参考区间，并评估其在疑似库欣综合征患者和包括健康人群在内的人群中的诊断准确性。
方法比较显示免疫测定法比 LC-MS/MS 有正偏倚（51.8%）。获得唾液皮质醇（0.17-0.97μg/L）、皮质酮（0.84-4.85μg/L）和比值（0.08-0.30）的参考区间。用于诊断库欣综合征的唾液皮质醇最准确的阈值为疑似库欣综合征人群中的 1.15μg/L（AUC 1）和包括健康人群在内的人群中的 1.30μg/L（AUC 1）。唾液皮质酮的截断值（7.23μg/L；在疑似库欣综合征人群中的 Se 为 92.9%、Sp 为 97.2%、AUC 为 0.960 和在包括健康人群在内的总体人群中的 Se 为 92.9%、Sp 为 99.1%、AUC 为 0.985）和皮质醇/皮质酮比值（0.20；在疑似库欣综合征人群中的 Se 为 85.7%、Sp 为 80.6%、AUC 为 0.820 和在包括健康人群在内的总体人群中的 Se 为 85.7%、Sp 为 85.5%、AUC 为 0.855）在两种人群中均准确且相似。
LC-MS/MS 是测量唾液类固醇最准确的分析平台。获得的参考区间与先前发表的数据一致，并且对显性库欣综合征的诊断准确性非常令人满意。
