In recent years, there has been wide interest in the use of dried blood spots (DBS) for research and diagnostic purposes. DBS sampling has major advantages over venous sampling. It is less invasive, easier to sample, and simpler to transport and store due to a reduced sample volume. Patients can, with the proper training, sample the bloodspots themselves at home and sent them to the lab. This makes it possible to have the test results available at the next appointment.

As steroid hormones require preferably specific timing of blood withdrawal, and are frequently measured to follow up therapy, these hormones are interesting candidates to measure using DBS sampling at home. To be able to facilitate DBS sampling for diagnostic purposes, the optimal conditions for storage and shipping of DBS need to be determined to guarantee the stability of the analytes to be measured in DBS. In this study, blood spots from 40 healthy volunteers (20 males, 20 females) were collected and stored at different temperatures (-20°C, 4°C, room temperature, 37°C). Directly after sampling and after 7- and 14-days, and 3- and 6-months storage under above mentioned conditions, steroid hormone concentrations of cortisol, cortisone, corticosterone, testosterone, androstenedione, and 17-hydroxyprogesterone were assessed using a validated LC-MS/MS method.

Currently, we performed the measurements up till 14 days of storage and compared these to baseline for all storage conditions. The mean changes of the analyte concentrations compared to their own baseline ranged from -5% to 9%, with one unexpected outlier (testosterone) at day 7 for DBS stored at -20⁰C, -17% to 7% for DBS stored at 4⁰C, -6% to 19% for DBS stored at room temperature, and -33% to 15% with two unexpected outliers (17-hydroxyprogesterone and corticosterone) at day 7 for DBS stored at 37⁰C. Analyses after 3 and 6 moths will be performed in December 2022 and March 2023. After the final measurements we can conclude whether DBS sampling for the measured steroid hormones can be implemented in routine diagnostics to improve patient care.