Comparison of three commercial assays for the measurement of 17α-hydroxyprogesterone (17α-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.

17-Hydroxyprogesterone in children, adolescents and adults

“…Methods have been compared, confirminng lower results by LC-MS/MS. 90 EQA samples were analysed with LC-MS/MS 91 to investigate high results with one kit in stimulation tests. Quality control (QC) samples performed acceptably, so this was not helpful to resolve the analytical problems that were presumably due to cross-reactions.…”