A Sensitive and Specific Liquid Chromatography-Tandem Mass Spectrometry Assay for Simultaneous Quantification of Salivary Melatonin and Cortisol: Development and Comparison With Immunoassays

• Published in: Annals of laboratory medicine Vol. 41; no. 1; pp. 108 - 113
• Main Authors: Shin, Sunghwan, Oh, Hyeonju, Park, Hea Ree, Joo, Eun Yeon, Lee, Soo-Youn
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Society for Laboratory Medicine 01.01.2021; 대한진단검사의학회
• Subjects: Brief Communication; 병리학; Immunoassay; Melatonin; Cortisol; Performance; Saliva; Liquid chromatography-tandem mass spectrometry (LC-MS/MS)
• ISSN: 2234-3806; 2234-3814; 2234-3814
• DOI: 10.3343/alm.2021.41.1.108

Melatonin and cortisol are clinically important for diagnosing sleep and mood disorders. We developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for simultaneous measurement of salivary melatonin and cortisol concentrations according to the Clinical and Laboratory Standards Institute guidelines. Additionally, we compared the LC-MS/MS assay with immunoassays, ELISA (Direct Salivary Melatonin Elisa EK-DSM, Bühlmann Laboratories AG, Schönenbuch, Switzerland) and electrochemiluminescence immunoassay (Cortisol II, Roche, Mannheim, Germany), using 121 saliva samples. The LC-MS/MS assay exhibited good performance in terms of linearity, precision, accuracy, limit of detection, lower limit of quantification, extraction recovery, carry-over, and matrix effect. The LC-MS/MS assay and immunoassays showed strong correlation (Pearson's r=0.910 for melatonin, r=0.955 for cortisol), but demonstrated a significant mean bias of 23.2% (range 54.0-143.7%) for melatonin and 48.9% (range 59.7-184.7%) for cortisol. Our LC-MS/MS assay provided more sensitive and reliable salivary melatonin and cortisol quantification results compared with immunoassays.