ExcelMale
Menu
Home
What's new
Latest activity
Forums
New posts
Search forums
What's new
New posts
Latest activity
Videos
Lab Tests
Doctor Finder
Buy Books
About Us
Men’s Health Coaching
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Navigation
Install the app
Install
More options
Contact us
Close Menu
Forums
Testosterone Replacement, Low T, HCG, & Beyond
Blood Test Discussion
Direct Measurements of Free Hormones Using Mass Spectrometry-Based Methods
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="madman" data-source="post: 260331" data-attributes="member: 13851"><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/cdc-standardized-total-t-and-estradiol-tests-and-soon-to-be-free-testosterone.17329/[/URL]</p><p></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/when-binding-proteins-interfere-with-immunoassays.25729/[/URL]</p><p></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/free-testosterone-harmonize-diagnostic-efforts-in-steroid-hormonology.27247/[/URL]</p><p></p><p>[URL unfurl="true"]https://www.excelmale.com/forum/threads/testosterone-assays.27661/[/URL]</p><p></p><p></p><p>Regarding labs, FT assays/reference ranges.</p><p></p><p>For the time being, if you have access to such then stick to testing your FT using what would be considered the most accurate assays such as the gold standard Equilibrium Dialysis or Equilibrium Ultrafiltration (next best), especially in cases of ALTERED SHBG!</p><p></p><p>Forget getting caught up in the different reference ranges for the same assays (ED, UF) used by different labs.</p><p></p><p>Let alone trying to compare the results of ED vs UF, or ED/UF vs the cFT methods.</p><p></p><p>Test using the same lab/same assay (most accurate).</p><p></p><p>Compare your blood work using the same lab/same assay (most accurate).</p><p></p><p>Top it all off that the calculated methods even have flaws!</p><p></p><p>We need accurate and standardized free testosterone assays with harmonized reference ranges!</p><p></p><p></p><p></p><p></p><p><strong>Take home points:</strong></p><p><strong></strong></p><p><strong><em>*Because FHs are present in biological samples in trace concentrations, <u>highly sensitive and specific methods are required for accurate measurement of FH concentrations</u></em></strong></p><p><strong><em></em></strong></p><p><strong><em>*A limitation of calculation-based methods is in the <u>assumption of uniform hormone affinity to binding proteins among individuals</u>. <u>However, binding protein variants, posttranslational modifications, and other factors may alter binding affinity, causing erroneous results and biases</u> (10). Direct immunoassay methods show discrepancy among methods of different manufacturers and <u>often perform poorly when binding protein concentrations are very elevated or decreased</u>, with some methods suffering from biotin interference (9)</em></strong></p><p><strong><em></em></strong></p><p><strong><em>*When a binding protein abnormality is suspected (15). <u>Equilibrium dialysis (ED) followed by LC–MS/MS is considered the gold standard methodology</u>, with a number of LC–MS/ MS methods developed and introduced in routine patient testing (12, 16–22)</em></strong></p><p><strong><em></em></strong></p><p><strong><em><em><strong>*<u>FH concentrations measured by UF-based methods often do not agree with ED-based methods because of UF conditions</u> (temperature, time, centrifugation speed), <u>the type of the UF device</u> (MWC membrane material, material of the of the housing, seal around the membrane, etc.), and <u>inconsistencies in the filtration rate</u>. <u>Therefore, reference intervals are typically not interchangeable across methods for measurement of the same FH</u></strong></em></em></strong></p><p></p><p></p><p></p><p></p><p></p><p><a href="https://www.excelmale.com/forum/threads/cdc-standardized-total-t-and-estradiol-tests-and-soon-to-be-free-testosterone.17329/" target="_blank">CDC STANDARDIZED TOTAL T AND ESTRADIOL TESTS and soon-to-be FREE TESTOSTERONE!</a></p><p></p><p><strong>Key Points:</strong></p><p><strong></strong></p><p><strong><em>* Limitations of using free testosterone by equilibrium dialysis and calculated free testosterone concentrations in practice are the <u>lack of assay standardization, an accuracy-based quality control program, and a harmonized reference range</u>. Until these <u>limitations are addressed</u>, free testosterone by equilibrium dialysis and calculated free testosterone should use <u>reference ranges established by individual laboratories or their specific assay method</u></em></strong></p><p><strong><em></em></strong></p><p><strong><em>*Currently, the CDC is developing a<u> <u>harmonized method for free T based on calculated free T using REVISED FORMULAE</u>.</u> This may bring the measurement of free T to a referable standard in clinical laboratories and common reference intervals that all clinicians can use</em></strong></p><p><strong><em></em></strong></p><p><strong><em>*Assays that are <u>standardized are designed to provide accurate results, traceable to “true” value-assigned certified reference materials and gold-standard reference methods</u>. <u>Results obtained using standardized methods can be compared across assays, institutions, populations, and past and future test results, thereby improving diagnosis, treatment, and outcomes of patients</u></em></strong></p><p><strong></strong></p><p><strong></strong></p><p><strong></strong></p><p><strong></strong></p><p><strong>The Need to Harmonize Clinical Laboratory Test Results-----</strong></p><p><strong></strong></p><p><strong><em>Laboratory test results are a critical component of patient care. These values help physicians diagnose disease and are critical to developing clinical guidelines that direct treatment options and are instrumental in ongoing efforts to improve and measure the quality of patient care. <u>Most tests report a numeric value for healthcare providers to interpret and the range of numbers reported for a test for a certain condition may vary depending on the method used</u></em></strong></p><p><strong><em><u></u></em></strong></p><p><strong><em><u>Different test methods, however, may report different numeric values for the same condition</u>. <u>Although these test results may be accurate within the context of its own method, this variation can create confusion for physicians and patients</u>. Clinical laboratory test results need to be <u>harmonized</u> so that healthcare providers and the public receive the <u>same numeric result regardless of the method or instrument used or the setting where it was performed</u></em></strong></p></blockquote><p></p>
[QUOTE="madman, post: 260331, member: 13851"] [URL unfurl="true"]https://www.excelmale.com/forum/threads/cdc-standardized-total-t-and-estradiol-tests-and-soon-to-be-free-testosterone.17329/[/URL] [URL unfurl="true"]https://www.excelmale.com/forum/threads/when-binding-proteins-interfere-with-immunoassays.25729/[/URL] [URL unfurl="true"]https://www.excelmale.com/forum/threads/free-testosterone-harmonize-diagnostic-efforts-in-steroid-hormonology.27247/[/URL] [URL unfurl="true"]https://www.excelmale.com/forum/threads/testosterone-assays.27661/[/URL] Regarding labs, FT assays/reference ranges. For the time being, if you have access to such then stick to testing your FT using what would be considered the most accurate assays such as the gold standard Equilibrium Dialysis or Equilibrium Ultrafiltration (next best), especially in cases of ALTERED SHBG! Forget getting caught up in the different reference ranges for the same assays (ED, UF) used by different labs. Let alone trying to compare the results of ED vs UF, or ED/UF vs the cFT methods. Test using the same lab/same assay (most accurate). Compare your blood work using the same lab/same assay (most accurate). Top it all off that the calculated methods even have flaws! We need accurate and standardized free testosterone assays with harmonized reference ranges! [B]Take home points: [I]*Because FHs are present in biological samples in trace concentrations, [U]highly sensitive and specific methods are required for accurate measurement of FH concentrations[/U] *A limitation of calculation-based methods is in the [U]assumption of uniform hormone affinity to binding proteins among individuals[/U]. [U]However, binding protein variants, posttranslational modifications, and other factors may alter binding affinity, causing erroneous results and biases[/U] (10). Direct immunoassay methods show discrepancy among methods of different manufacturers and [U]often perform poorly when binding protein concentrations are very elevated or decreased[/U], with some methods suffering from biotin interference (9) *When a binding protein abnormality is suspected (15). [U]Equilibrium dialysis (ED) followed by LC–MS/MS is considered the gold standard methodology[/U], with a number of LC–MS/ MS methods developed and introduced in routine patient testing (12, 16–22) [I][B]*[U]FH concentrations measured by UF-based methods often do not agree with ED-based methods because of UF conditions[/U] (temperature, time, centrifugation speed), [U]the type of the UF device[/U] (MWC membrane material, material of the of the housing, seal around the membrane, etc.), and [U]inconsistencies in the filtration rate[/U]. [U]Therefore, reference intervals are typically not interchangeable across methods for measurement of the same FH[/U][/B][/I][/I][/B] [URL='https://www.excelmale.com/forum/threads/cdc-standardized-total-t-and-estradiol-tests-and-soon-to-be-free-testosterone.17329/']CDC STANDARDIZED TOTAL T AND ESTRADIOL TESTS and soon-to-be FREE TESTOSTERONE![/URL] [B]Key Points: [I]* Limitations of using free testosterone by equilibrium dialysis and calculated free testosterone concentrations in practice are the [U]lack of assay standardization, an accuracy-based quality control program, and a harmonized reference range[/U]. Until these [U]limitations are addressed[/U], free testosterone by equilibrium dialysis and calculated free testosterone should use [U]reference ranges established by individual laboratories or their specific assay method[/U] *Currently, the CDC is developing a[U] [U]harmonized method for free T based on calculated free T using REVISED FORMULAE[/U].[/U] This may bring the measurement of free T to a referable standard in clinical laboratories and common reference intervals that all clinicians can use *Assays that are [U]standardized are designed to provide accurate results, traceable to “true” value-assigned certified reference materials and gold-standard reference methods[/U]. [U]Results obtained using standardized methods can be compared across assays, institutions, populations, and past and future test results, thereby improving diagnosis, treatment, and outcomes of patients[/U][/I] The Need to Harmonize Clinical Laboratory Test Results----- [I]Laboratory test results are a critical component of patient care. These values help physicians diagnose disease and are critical to developing clinical guidelines that direct treatment options and are instrumental in ongoing efforts to improve and measure the quality of patient care. [U]Most tests report a numeric value for healthcare providers to interpret and the range of numbers reported for a test for a certain condition may vary depending on the method used Different test methods, however, may report different numeric values for the same condition[/U]. [U]Although these test results may be accurate within the context of its own method, this variation can create confusion for physicians and patients[/U]. Clinical laboratory test results need to be [U]harmonized[/U] so that healthcare providers and the public receive the [U]same numeric result regardless of the method or instrument used or the setting where it was performed[/U][/I][/B] [/QUOTE]
Insert quotes…
Verification
Post reply
Share this page
Facebook
Twitter
Reddit
Pinterest
Tumblr
WhatsApp
Email
Share
Link
Sponsors
Forums
Testosterone Replacement, Low T, HCG, & Beyond
Blood Test Discussion
Direct Measurements of Free Hormones Using Mass Spectrometry-Based Methods
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top