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 microL). Sensitivity and specificity result from the preparation of mono-Girard T derivatives. Androstenedione, 17alpha-hydroxyprogesterone 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.
Johnson
David W
DW
Department of Genetic Medicine, Women's and Children's Hospital, 72 King William Rd, North Adelaide, South Australia, 5006 Australia. david.johnson@adelaide.edu.au
D019326:17-alpha-Hydroxyprogesterone / Q000097:blood*; D000312:Adrenal Hyperplasia, Congenital / Q000097:blood / Q000175:diagnosis; D000735:Androstenedione / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D011863:Radioimmunoassay; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D000735:Androstenedione; D019326:17-alpha-Hydroxyprogesterone; D006854:Hydrocortisone