Simultaneous measurement of testosterone (T) and 5α-dihydrotestosterone (DHT) is important for diagnosing androgen deficiency states and hyperandrogenism in males and females, respectively. However, immunoassays used for T and DHT determination suffer from inadequate specificity and sensitivity, while tandem mass spectrometry is expensive and demanding in use.
We developed a selective gas chromatography-mass spectrometry (GC-MS) method for parallel T and DHT measurement. The assay showed a linear response up to 46.5nmol/L, intra- and interassay imprecision and inaccuracy <15% and recoveries in spiked samples >90% for both analytes. The limit of quantitation was 0.117nmol/L for T and 0.168nmol/L for DHT. Comparison with immunoassays revealed good agreement for T in males, but a bias in favour of immunoassays at low concentrations for T in females and DHT in both sexes. We established reference ranges for T and DHT and suggest interval partitioning for T according to age in men and menstrual cycle in women. Assay validation in a clinical setting suggests that measuring DHT or T/DHT ratio may help identify patients with polycystic ovary syndrome.
We developed a selective, simple and inexpensive GC-MS method for parallel measurement of T and DHT with potential use in the clinical laboratory.
Clinica chimica acta; international journal of clinical chemistry. 2017 Nov 06 [Epub ahead of print]
Frank Kannenberg, Manfred Fobker, Erhard Schulte, Grzegorz Pierściński, Reinhard Kelsch, Michael Zitzmann, Jerzy-Roch Nofer, Andreas N Schüring
Center for Laboratory Medicine, University Hospital Münster, Münster, Germany., Institute for Transfusion Medicine and Transplantation Immunology, University Hospital Münster, Münster, Germany., Center for Reproductive Medicine and Andrology, Department of Clinical Andrology, University Hospital Münster, Münster, Germany., Center for Laboratory Medicine, University Hospital Münster, Münster, Germany. Electronic address: ., UKM Kinderwunschzentrum, Department of Gynaecology and Obstetrics, University Hospital Münster, Münster, Germany.