Endocrine Abstracts

Increased cortisol production (Cushing’s syndrome) is a rare disease that is sometimes very difficult to diagnose. Cyclical Cushing’s syndrome in particular is a major challenge. In this case of hypercortisolism, which is not always present, longitudinal diagnostic methods are advantageous. In the past, it has already been shown several times that the measurement of cortisol in the scalp hair shows significantly increased values in patients with Cushing’s syndrome. However, the measurement of cortisol in hair is not yet widely available. Our aim was therefore to use a commercially available assay for the determination of cortisol in saliva for the determination of cortisol in hair. Our study introduces a cutting-edge method for quantifying cortisol levels in scalp hair through the utilization of an commercially available automated Enzyme-Linked-Immunosorbent Assay (ELISA). For the analysis of cortisol in hair, 25 mg of washed and milled scalp hair were extracted within 3 hours using methanol and ultrasound-assisted extraction. The supernatant was transferred to a glass vial and evaporated to dryness at 50 °C under a constant stream of nitrogen. The dry residue was redissolved in deionized water and vortexed for 30 seconds. Cortisol concentrations were determined using a commercially available cortisol-saliva ELISA from IBL International GmbH. The test protocol was modified for this purpose by reducing the sample volume used and adjusting the calibration points to a range of 40 pg/mg to 600 pg/mg to meet the expected concentrations of cortisol in hair. Processing and analysis were performed on a fully automated ELISA processor (Analyzer 1 from Euroimmun). For further development, individual reference values for healthy individuals, mild autonomous cortisol secretion and Cushing’s syndrome still need to be determined. Our study outlines the successful adaptation and optimization of a saliva cortisol measurement protocol for assessing cortisol level in scalp hair. Unlike existing techniques primarily restricted to research applications, we aim for commercial viability of an automated processed protocol, providing an efficient and reproducible means for routine analysis, paving the way for broader applications in clinical and diagnostic setting.