Noninvasive determination of human cortisol and dehydroepiandrosterone sulfate using liquid chromatography-tandem mass spectrometry

摘要

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) for measurements of steroids in human saliva has garnered increased interest in the area of clinical psychoneuroendocrinological research. However, performance characteristics of LC-MS/MS methods for the analysis of steroids in saliva are limited. Human saliva samples were collected via passive drool. Cortisol and dehydroepiandrosterone sulfate (DHEA-S) in the samples were extracted together, resolved on a C18-A column, and analyzed using tandem mass spectrometry. The LC-MS/MS method had limits of quantitation of 0.03 and 0.06ng/mL for DHEA-S and cortisol, respectively. Method evaluations showed coefficient variation (CV) of inter-assay ranging 4.6-17.9 for DHEA-S and cortisol, recoveries of 102.4-109.5 for DHEA-S and 94.6-98.3 for cortisol, and assay linearity with R-2=0.9964 for DHEA-S (1.0-25.0ng/mL) and R-2=0.997 (1.0-25.0ng/mL) for cortisol. No cross contamination among samples was observed. Human saliva showed 20 and 18 ion enhancement effect for DHEA-S and cortisol assay, respectively. No interference by ten common steroids was detected. Regression analysis of method comparisons with laboratory-developed test (LDT) method revealed R-2=0.9688 (LC-MS/MS=0.9665 LDT-LC-MS/MS-0.7355) for cortisol, and R-2=0.9039 (LC-MS/MS=1.0173 LDT-LC-MS/MS+3.6797) for DHEA-S. Reference ranges for young adults were determined to be 0.3-5.9ng/mL for females and 0.1-5.6ng/mL for males for salivary cortisol, and 0.6-7.4ng/mL for females and 0.6-10.1ng/mL for males for salivary DHEA-S. An LC-MS/MS method for quantifying cortisol and DHEA-S in human saliva was developed and validated for clinical and psychoneuroendocrinological research that require noninvasive means of measuring these hormones.