title: Comparison of three commercial assays for the measurement of 17alpha-hydroxyprogesterone (17alpha-OHPR): limitations of the quality control system.
abstract: The measurement of 17alpha-hydroxyprogesterone (17alpha-OHPR) is of value for the diagnosis and management of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. In the central laboratory from 2000 to 2002, we observed, using the assay from the manufacturer DSL, an elevation of the moving average of 17alpha-OHPR concentrations and a number of adrenocorticotropic hormone (ACTH) stimulation tests despite the lack of any changes to the internal and external quality control, of which the criteria were continuously fulfilled. We studied a population of n=49 patients for the measurement of 17alpha-OHPR, with and without extraction, to evaluate the quality of different commercially available radioimmunoassays. The internal and external quality controls were successful in determining 17alpha-OHPR. An excellent measurement and correlation of 17alpha-OHPR was expressed with the assay from the manufacturer IBL without extraction and from the manufacturer DSL with extraction. The quantitative determination of 17alpha-OHPR requires adequate specificity and accuracy of the 17alpha-OHPR radioimmunoassays. The results show that internal and external quality control systems are not sufficient to resolve analytical problems described in this study.
authors.affiliation: Institute of Clinical Chemistry and Pathobiochemistry and Central Laboratory, RWTH-University Hospital Aachen, Aachen, Germany. umeier@ukaachen.de
authors.forename: Ursula
authors.initials: U
authors.lastname: Meier
authors.forename: Claudia
authors.initials: C
authors.lastname: Schnabel
authors.forename: Dagmar
authors.initials: D
authors.lastname: Kunz
authors.forename: Reinhard
authors.initials: R
authors.lastname: Driesch
authors.forename: Axel M
authors.initials: AM
authors.lastname: Gressner
mesh_terms: D019326:17-alpha-Hydroxyprogesterone / Q000097:blood*; D000312:Adrenal Hyperplasia, Congenital / Q000097:blood* / Q000175:diagnosis; D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D011786:Quality Control; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D019326:17-alpha-Hydroxyprogesterone; D000324:Adrenocorticotropic Hormone