Simultaneous measurement of endogenous cortisol, cortisone, dehydroepiandrosterone, and dehydroepiandrosterone sulfate in nails by use of UPLC-MS-MS

Steroid hormone concentrations are mostly determined by using different body fluids as matrices and applying immunoassay techniques. However, usability of these approaches may be restricted for several reasons, including ethical barriers to invasive sampling. Therefore, we developed an ultra-performance LC-MS-MS method for high-throughput determination of concentrations of cortisol, cortisone, dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEAS) in small quantities of human nails. The method was validated for linearity, limits of detection and quantification, recovery, intra and interassay precision, accuracy, and matrix effect. Samples from 10 adult women were analyzed to provide proof-of-principle for the method's applicability. Calibration curves were linear (r (2) > 0.999) in the ranges 10-5000 pg mg(-1) for cortisol, cortisone, and DHEAS, and 50-5000 pg mg(-1) for DHEA. Limits of quantification were 10 pg mg(-1) for cortisol, cortisone, and DHEAS, and 50 pg mg(-1) for DHEA. The sensitivity and specificity of the method were good, and there was no interference with the analytes. Mean recovery of cortisol, cortisone, DHEA, and DHEAS was 90.5%, 94.1%, 84.9%, and 95.9%, respectively, with good precision (coefficient of variation < 14% for all analytes) and accuracy (relative error (%) -8.3% to 12.2% for all analytes). The median (pg mg(-1), range) hormone concentrations were 69.5 (36-158), 65 (32-133), 212 (50-1077), and 246 (115-547) for cortisol, cortisone, DHEA, and DHEAS, respectively. This method enables measurement of cortisol, cortisone, DHEA, and DHEAS in small quantities of human nails, leading to the development of applications in endocrinology and beyond.