Institute for Interdisciplinary Salivary Bioscience Research, University of California Irvine, California.
Johns Hopkins University School of Medicine, Baltimore, Maryland.
Ther Drug Monit. 2023 Dec 1;45(6):813-816. doi: 10.1097/FTD.0000000000001094. Epub 2023 Mar 27.
Lithium medication is considered to be the first-line treatment for bipolar disorder as a monotherapy, and for treatment-resistant depression with lithium augmentation. However, because of potential toxicity, lithium levels must be monitored frequently. Recent studies have demonstrated a significant correlation between lithium levels measured in serum and those detected in oral fluid, suggesting that oral fluid analysis may represent an easy, noninvasive means to monitor lithium levels. The aim of this study was to evaluate the analytical performance of rapid assays for lithium measurements in oral fluid.
Levels of lithium in oral fluid from psychiatric patients (n = 108 in total) taking lithium medications were quantified using 2 rapid techniques: an automated clinical chemistry analyzer and a novel, commercially available colorimetric lithium assay. These results were compared with those obtained using inductively coupled plasma optical emission spectrometry (ICP-OES).
The mean and median oral fluid lithium levels in this cohort were 1.43-1.61 mM and 1.32-1.52 mM, respectively, depending on the method, with the overall range, across all methods, being 0.213-4.42 mM. Linear regression analysis showed excellent agreement between the oral fluid values measured using ICP-OES and the colorimetric method (r 2 value = 0.926; P < 0.0001; slope = 1.084 ± 0.038). Similarly, excellent agreement was observed between ICP-OES and the automated method (r 2 = 0.872; P < 0.0001; slope = 1.019 ± 0.057).
These results demonstrate that lithium levels in oral fluid can be rapidly and reliably quantified using colorimetric approaches. These findings may facilitate the development of point-of-care lithium monitoring systems for use in oral fluid.
锂药物被认为是治疗双相情感障碍的一线药物，作为单一疗法，对于锂增效治疗抵抗性抑郁症也是如此。然而，由于潜在的毒性，必须频繁监测锂水平。最近的研究表明，血清中测量的锂水平与口腔液中检测到的锂水平之间存在显著相关性，这表明口腔液分析可能代表一种简单、非侵入性的监测锂水平的方法。本研究旨在评估口腔液中锂测量的快速分析方法的分析性能。
使用两种快速技术：自动临床化学分析仪和新型商业可用比色锂测定法，定量测定服用锂药物的精神科患者（共 108 例）的口腔液中的锂水平。将这些结果与电感耦合等离子体发射光谱法（ICP-OES）的结果进行比较。
该队列的平均和中位数口腔液锂水平分别为 1.43-1.61mM 和 1.32-1.52mM，具体取决于方法，所有方法的总体范围为 0.213-4.42mM。线性回归分析显示，ICP-OES 和比色法测量的口腔液值之间具有极好的一致性（r2 值=0.926；P<0.0001；斜率=1.084±0.038）。同样，也观察到 ICP-OES 和自动方法之间的极好一致性（r2=0.872；P<0.0001；斜率=1.019±0.057）。
这些结果表明，可以使用比色法快速可靠地定量口腔液中的锂水平。这些发现可能有助于开发用于口腔液的即时护理锂监测系统。
