Lee Anna, Jang Sooah, Lee Sanghoo, Park Hyun-Kyung, Kim In-Young, Ahn Ryunsup, Seok Jeong-Ho, Lee Kyoung-Ryul
Department of Laboratory Medicine, Seoul Clinical Laboratories, Yong-In, Republic of Korea.
Research Institute of Minds.AI, Co. Ltd., Seoul, Republic of Korea.
Pract Lab Med. 2024 Apr 9;40:e00393. doi: 10.1016/j.plabm.2024.e00393. eCollection 2024 May.
Salivary cortisol reflects the biologically active form of serum cortisol, offering a noninvasive evaluation method for the diurnal rhythm of the hypothalamic-pituitary-adrenal (HPA) axis. While liquid chromatography-tandem mass spectrometry (LC-MS/MS) is known for its specificity, immunoassays (IA) are commonly used because of their simplicity. This study aimed to assess the performance of salivary cortisol measurement using both IA and LC-MS/MS in comparison to serum-free cortisol measurement.
Assay results for 188 saliva and 94 serum samples from 47 participants were analyzed. Salivary samples collected at different time points were analyzed using IA and LC-MS/MS. Serum samples were analyzed for cortisol, cortisol-binding globulin, and free cortisol. The statistical analyses included correlations and method comparisons.
The diurnal salivary cortisol profiles exhibited a comparable circadian rhythm pattern; however, the concentrations measured using IA were consistently higher than those measured using LC-MS/MS. The correlation analysis revealed robust associations among salivary cortisol (IA), salivary cortisol (LC-MS/MS), and serum-free cortisol levels (LC-MS/MS). However, the method comparison revealed a systematic bias between IA and LC-MS/MS in salivary cortisol measurement.
This study contributes to the ongoing debate on assay techniques by affirming the suitability of IA and LC-MS/MS for salivary cortisol measurement to assess dynamic changes in HPA axis activity. The identified systematic bias emphasizes the importance of selecting methods based on specific research or clinical requirements.
唾液皮质醇反映血清皮质醇的生物活性形式，为下丘脑-垂体-肾上腺（HPA）轴的昼夜节律提供了一种非侵入性评估方法。虽然液相色谱-串联质谱法（LC-MS/MS）以其特异性著称，但免疫分析法（IA）因其操作简便而被广泛使用。本研究旨在比较免疫分析法和液相色谱-串联质谱法在测量唾液皮质醇方面与测量血清游离皮质醇相比的性能。
分析了47名参与者的188份唾液样本和94份血清样本的检测结果。使用免疫分析法和液相色谱-串联质谱法对不同时间点采集的唾液样本进行分析。对血清样本进行皮质醇、皮质醇结合球蛋白和游离皮质醇的分析。统计分析包括相关性分析和方法比较。
唾液皮质醇的昼夜变化曲线呈现出相似的昼夜节律模式；然而，使用免疫分析法测得的浓度始终高于使用液相色谱-串联质谱法测得的浓度。相关性分析显示唾液皮质醇（免疫分析法）、唾液皮质醇（液相色谱-串联质谱法）和血清游离皮质醇水平（液相色谱-串联质谱法）之间存在密切关联。然而，方法比较显示免疫分析法和液相色谱-串联质谱法在测量唾液皮质醇时存在系统偏差。
本研究通过确认免疫分析法和液相色谱-串联质谱法适用于测量唾液皮质醇以评估HPA轴活性的动态变化，为正在进行的检测技术辩论做出了贡献。所发现的系统偏差强调了根据特定研究或临床需求选择方法的重要性。
