AUG 24, 2017 10:00 AM PDT

WEBINAR: Testosterone Testing: Total, Free, and Bioavailable

C.E. CREDITS: P.A.C.E. CE | Florida CE
  • Prof & Med Dir Clinical Chemistry, Co-Director ATL/SPA & Pathology Core Reference Lab, Dir Postdoctoral Clinical Chemistry Fellowship Program, Penn State Univ Hershey Medical Center
      Dr. Zhu is Professor and Medical Director of Clinical Chemistry, Co-Director of ATL/SPA and Pathology Core Reference Laboratory, and Director of Postdoctoral Clinical Chemistry Fellowship Program at Penn State University Hershey Medical Center. Prior to this position, he served as a Tenured Professor and Medical Director of Clinical Chemistry and Toxicology, Director of Postdoctoral Clinical Chemistry Fellowship Program at the Medical University of South Carolina for over 10 years. He is board certified by the American Board of Clinical Chemistry (ABCC) in Clinical Chemistry, Toxicological Chemistry, and Molecular Diagnostics and a Fellow of the National Academy of Clinical Biochemistry (NACB) since 2007. He served as the President of the North American Chinese Clinical Chemists Association (2012), President of the Commission on Accreditation in Clinical Chemistry (ComACC), Chair of American Association for Clinical Chemistry (AACC) Southeast Section in 2015, Chair of Clinical Translational Science Division (2015-2016), and Secretary of Proteomics & Metabolomics Division (2013-15) of AACC. Currently, he is the Board Director of ABCC, Treasurer of Mass Spectrometry & Separation Science Division, and serves on Global Laboratory Quality Initiative Asia-Pacific Working Group and Mass Spectrometry Conference Organizing Committee of AACC. Yusheng is on the Editorial Boards of three medical journals and an invited reviewer of seven international medical journals. He has given many presentations at national and international conferences. He is interested in clinical and translational research in clinical chemistry, toxicology, hemoglobinopathy, pharmacogenetics, proteomics, and clinical application of mass spectrometry. He has over 100 publications including peer-reviewed papers, editorials, book chapters, and abstracts. He has received 31 awards from AACC, NACB, and other organizations.


    DATE: August 24, 2017
    TIME: 10:00am PT, 1:00pm ET

    Testosterone is a steroid hormone that stimulates development of male secondary sexual characteristics, but it is also synthesized in female at a much lower level. Testosterone circulates in blood system in different forms: bound to sex-hormone binding globulin (SHBG)/albumin and free. Free testosterone and albumin-bound testosterone are collectively known as bioavailable testosterone. Clinically, testosterone test is used for evaluation of men with possible hypogonadism, women with hirsutism, virilization, oligomenorrhea, and possible testosterone deficiency in women. In children, testosterone test is used to evaluate boys with delayed or precocious puberty and infants with ambiguous genitalia or virilization. In addition, it is useful for monitoring testosterone replacement and antiandrogen therapy as well as diagnosis of androgen-secreting tumor. Currently, the commonly used method is automated direct immunochemiluminescent assays because of ease of use, wide availability, and high throughput. The limitations of immunochemiluminescent assays are insufficient sensitivity and specificity as well as substantial inter-method variability. Lately there has been a trend towards switching to liquid chromatography-tandem mass spectrometry (LC-MS/MS) due to its high sensitivity and specificity. Limitation of total testosterone test is that it may not closely reflect the level of androgenism in individuals who have altered amount of SHBG. For those individuals, free or bioavailable testing are recommended. The methods for free testosterone testing include equilibrium dialysis, ultracentrifugation, analog analysis, and calculation based on SHBG.  Bioavailable testosterone can be measured after ammonium sulfate precipitation to remove SHBG-bound testosterone or calculated based on serum total testosterone, SHBG, and albumin concentrations. Since multiple methods are available for serum testosterone testing and substantial inter-method variability, U.S. Centers for Disease Control and Prevention has established a Laboratory/Manufacturer Hormone Standardization Program to standardize serum total testosterone measurements. Many professional organizations including American Association of Clinical Endocrinologists, Endocrine Society, and Canadian Men’s Health Foundation have published practice guidelines and position statements on appropriate use of testosterone test. It is generally recommended that a reliable total testosterone assay can be used for initial testing for men. If initial values are low, free or bioavailable testosterone should be used for confirmation. Direct immunoassays cannot accurately measure the low serum testosterone levels found in women, children, and hypogonadal men. The Endocrine Society recommends testosterone methods that use extraction and purification prior to measurement. LC-MS/MS methods meet these recommendations. Because of increased sensitivity and specificity, LC-MS/MS has emerged as the method of choice in women, children, and hypogonadal men for testosterone testing.

    Learning Objectives:

    • Describe different forms of testosterone in serum and clinical applications of serum testosterone test;
    • Select appropriate methods for serum testosterone testing;
    • Follow recommended guidelines to correctly use testosterone test in different patient population.

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