A chemiluminescent method for the measurement of pregnanetriol-3 alpha-glucuronide in human diluted urine

• Published in: Journal of bioluminescence and chemiluminescence Vol. 4; no. 1; p. 580
• Main Authors: Pinzani, P, Magini, A, Franceschetti, F, Messeri, G, Pazzagli, M
• Format: Journal Article
• Language: English
• Published: England 01.07.1989
• Subjects: 17-alpha-Hydroxyprogesterone; Adrenal Hyperplasia, Congenital - blood; Adrenal Hyperplasia, Congenital - diagnosis; Adrenal Hyperplasia, Congenital - urine; Adrenocorticotropic Hormone - pharmacology; Adult; Female; Humans; Hydroxyprogesterones - blood; Immunoassay - methods; Luminescent Measurements; Male; Middle Aged; Pregnanetriol - analogs & derivatives; Pregnanetriol - urine; Quality Control
• DOI: 10.1002/bio.1170040176
• ISSN: 0884-3996

Pregnanetriol-3 alpha-glucuronide (PTG) is the majority urinary metabolite of 17-hydroxyprogesterone (17OHP) and it typically increases in the commonest form of congenital adrenal hyperplasia (CAH), due to 21 hydroxylase deficiency. We developed a simple chemiluminescent immunoassay for the direct measurement of PTG in diluted urine in order to avoid the preliminary hydrolysis and extraction steps that are usually employed in gas-liquid chromatographic methods. The immunogenic complex PTG-bovine-serum-albumin was used to induce the formation of specific antibodies in New Zealand rabbits. In addition, PTG was conjugated to aminoethylethylisoluminol and the resulting tracer was characterized by mass spectrometry and used to monitor the immunological reaction. The characteristics of the antibody were determined with regard to specificity and sensitivity. The precision of the assay method was also established. PTG excretion was studied before and after the ACTH stimulation test (1 mg synthetic ACTH i.m.) in 11 normal women and in one subject affected by CAH due to 21-hydroxylase deficiency. PTG levels well correlated with 17OHP plasma concentrations both under basal and stimulated conditions, in normal women as well as in the patient affected by CAH.