Measurement of serum testosterone in women; what should we do?

Abstract

AddressesAll immunoassays for female serum testosterone give falsely high results in some samples. The effect is variable and cannot be predicted for any given sample. Inaccurate calibration or interference by cross-reacting substances is almost certainly the cause of the problem, but for many immunoassays, the exact nature of the interferent is not known. Some of the interference can be removed by employing an extraction step prior to immunoassay. The advent of fast simple and sensitive liquid chromatography tandem mass spectrometry methods offers an exciting alternative to immunoassay for serum testosterone measurement. It is recommended that all high serum testosterone concentrations in women are checked, before reporting, by a method which is accurate (i.e. minimal bias to isotope dilution gas chromatography mass spectrometry [ID-GCMS] method) and is not subject to interference. Action should also be taken by assay users, manufacturers, regulators and professional bodies to ensure accurate standardization and comparability of assays. 2007; 44: 5-15 Ann Clin Biochem

Accuracy of First and Second Generation Testosterone Assays and Improvement through Sample Extraction

“…None of the immunoassays investigated (Table 1) used an extraction step, as a prescribed procedure, before analysis. We extracted testosterone using diethyl ether as described previously (4 ). The dried extracts were reconstituted in a matrix recommended by the manufacturer.…”

Standardization of testosterone measurements in humans

“…In other studies, the performance of selected immunoassays using sera from individual donors and mass spectrometrybased (MS) assays as a comparative method was investigated [30,35,[38][39][40]. For most assays, the investigators observed high correlations between the MS assay and the immunoassays.…”

“…Researchers concerns about the quality of testosterone measurements have initiated recommendations to repeat measurements with more reliable assays on already completed epidemiological studies and clinical trials [29]. Others have recommended not using certain assays such as free testosterone analog assays [2,[30][31][32]. However, despite these recommendations, tests are still used that are unsuitable for addressing clinical and public health questions [1].…”

Dehydroepiandrostenedione sulphate interferes in many direct immunoassays for testosterone

“…Testosterone assays have been 'under ¢re' for some time, 4--6 and concerted action is required to improve them. 7 …”