Ketosteroid profiling using Girard T derivatives and electrospray ionization tandem mass spectrometry: direct plasma analysis of androstenedione, 17-hydroxyprogesterone and cortisol

A function of concentrations of three ketosteroids, [(androstenedione + 17alpha-hydroxyprogesterone)/cortisol], has been shown to provide better discrimination than the concentration of 17alpha-hydroxyprogesterone alone, for the diagnosis of the inherited disease congenital adrenal hyperplasia (CAH). A rapid, direct infusion electrospray ionization tandem mass spectrometry (ESI-MS/MS) method has been developed to measure this ratio in plasma (100 muL). Sensitivity and specificity result from the preparation of mono-Girard T derivatives. Androstenedione, 17alpha-hydroxyprogester-one and cortisol are individually quantitated by isotope dilution. Excellent statistical correlation with radioimmunoassay (RIA) results for the analysis of 17alpha-hydroxyprogesterone is demonstrated. The value of the ratio function of the three ketosteroids is 0.01-0.16 for normal controls (n = 26) and 1.83-18.7 for patients with severe CAH (n = 4). Profiles of ketosteroids derivatized with Girard T from the plasma of a child with severe CAH, generated by ESI-MS/MS analysis, are shown. Neutral loss scans for 29.5 and 59 Da assist in the identification of the ketosteroids. Copyright (C) 2004 John Wiley Sons, Ltd.