The dynamics of a serum steroid profile after stimulation with intravenous ACTH.

BACKGROUND: Stimulation with intravenous adrenocorticotropic hormone (ACTH) is a widely used diagnostic procedure to characterize the adrenocortical function. Currently, the response of serum cortisol, mainly quantified by immunoassays, is the only established read-out of this test. By using liquid chromatography coupled with mass spectrometry (LC-MS/MS) simultaneous determination of several steroids that respond to ACTH stimulation is now possible. The aim of this study was to further characterize the typical effect of exogenous ACTH (250 mg) on a LC-MS/MS-serum steroid profile. METHODS: A set of 36 paired samples (pre-/post-IV-ACTH) was investigated (age range 22-58, 26 female and 10 male individuals). Serum steroid profiling was performed using a LC-MS/MS method covering cortisol, cortisone, corticosterone, 11-deoxycortisol, 17-OH-progesterone and 11-deoxycorticosterone. RESULTS: The concentrations of all measured steroids increased after stimulation with ACTH, except for cortisone. Serum corticosterone, 11-deoxycorticosterone and 11-deoxycortisol showed markedly more pronounced relative increases compared to cortisol. The strongest response was observed for corticosterone (15-fold median relative increase, compared to 1.4-fold median increase of cortisol). CONCLUSION: Serum steroid profiling using LC-MS/MS after stimulation with IV ACTH demonstrates highly dynamic response patterns. Further studies should address in particular serum corticosterone as a potential novel marker of biochemical stress response.