An Intact ACTH LC-MS/MS Assay as an Arbiter of Clinically Discordant Immunoassay Results

Measurement of plasma adrenocorticotropic hormone, or ACTH, is key in the differential diagnosis of hypothalamic pituitary adrenal disorders. Two-site sandwich immunoassay dominate clinical testing of ACTH in North America. However, discordant results among different assays have been repeatedly reported. To help resolve this discrepancy, a multicenter effort developed a liquid chromatography tandem mass spectrometry assay for the intended measurand, that is the biologically active intact ACTH. A report on that initiative appears in the November 2019 issue of Clinical Chemistry. We are pleased to have the senior author of that paper , Dr. Mari DeMarcoas our guest in this podcast.