Stability of steroid hormones in dried blood spots (DBS)

Abstract

Objectives: Steroid hormone levels of patients may be monitored via dried blood spot (DBS) sampling at home. Stability of steroid hormones in DBS samples, however, needs to be established. Methods: DBS samples from healthy volunteers were collected and stored at various temperatures. Steroid hormone concentrations in DBS were measured directly, at day 2, day 7 and day 14 following storage at 37°C and after 7 days, 14 days, 3 months and 6 months following storage at -20°C, 4°C and room temperature (RT). Cortisol, cortisone, corticosterone, testosterone, androstenedione, and 17-hydroxyprogesterone (17-OHP) were assessed using LC-MS/MS. Results: All steroids were stable (±15%) up to 14 days when stored at 37°C, except for cortisone (only stable until 2 days). All steroids were stable up to 6 months when stored at -20°C, 4°C and RT. However, there were some exceptions, for androstenedione at RT (only stable until 7 days), for 17-OHP when stored at -20°C (only stable until 3 months), for cortisone at RT and 4°C (only stable until 14 days), and cortisol at RT (only stable until 3 months). Conclusions: Overall, we demonstrated stability of steroid hormone concentrations in DBS under various conditions which may be encountered during shipping to the diagnostic laboratory and during long-term storage before analysis.