Labcorp E2 Test Results Comparison

[Steady]

There have been many discussions on the forum about the differences between the 2 Labcorp tests for Estradiol, the "Standard Estradiol" test #4515 and the "Sensitive Estradiol" test #140244. I hope we can use this thread to post actual results from these 2 tests when taken simultaneously. Perhaps then we can each evaluate how best to make use of these tests for our own circumstances.

I've searched the forum and only found one case with numbers from both these tests and today I have my own results to get us started. If you have results for simultaneous tests in the past that I've missed in my search please post them here. If you would like to include any symptoms you feel are related to E2 at the time of the tests that may be useful information also. Thanks in advance to anyone willing to contribute to this data collection.

March 19, 2014 JustAskin posted 4515 E2=33 & 140244 E2=19
July 28, 2014 Steady - 4515 E2=65.6 & 140244 E2= 46 Morning wood not as regular, but libido is good, minor water retention.
August 25, 2014 outside source - 4515 E2=30.1 & 140244 E2=34

[Sam]

Ideally you should compare these to the LCMS test.

Estradiol Free, Equilibrium Dialysis, With Total Estradiol, HPLC/MS-MS (Endocrine Sciences)
Test Number: 500649 CPT Code: 82670; 84999


Or

Estradiol, LCMS (Endocrine Sciences)
Test Number: 500108 CPT Code: 82670

[Steady]

Almost all of the discussions I've seen have been about the merits of those 2 tests from Labcorp, 4515 & 140244. So, that's what I proposed we evaluate. If you have data from the 3rd test include it also. What is the test number at Labcorp? Oh I see now test #500108.

[PeakT]

Almost all of the discussions I've seen have been about the merits of those 2 tests from Labcorp, 4515 & 140244. So, that's what I proposed we evaluate. If you have data from the 3rd test include it also. What is the test number at Labcorp? Oh I see now test #500108.

Steady, what you are doing is great cuzz it's good general knowledge and a lot of docs are using the above.  However, what Sam is pointing out I believe is that the LCMSMS is the latest and greatest test.  But great thread and lets see if anyone will post their results.

[Steady]

Bump
I was hoping to get some responses. Doesn't anyone have data to include. If you are about to get testing please consider taking both tests in order to help the members of this forum to better understand these tests.

[Steady]

I've added data from another source to the original post.

[Steady]

Bump

March 19 JustAskin          4515 E2=33 & 140244 E2=19
July 28 Steady                4515 E2=65.6 & 140244 E2=46
August 25 outside source 4515 E2=30.1 & 140244 E2=34

Not many data points. More are needed. Hasn't anyone else run the 2 tests and could share to help with the comparison?

[Kierkegaard]

So the first is regular and second ultrasensitive?

Do you know if both are RIA, ECLIA, or LC/MS?

[Steady]

So the first is regular and second ultrasensitive?

Do you know if both are RIA, ECLIA, or LC/MS?

The first test, #4515, is called "Estradiol" by Labcorp and is ECLIA.
The second test, #140244, is called "Estradiol, Sensitive" by Labcorp and is RIA.
Labcorp doesn't seem to have a test called ultrasensitive and their use of the word sensitive is misleading.

[Kierkegaard]

So the first is regular and second ultrasensitive?

Do you know if both are RIA, ECLIA, or LC/MS?

The first test, #4515, is called "Estradiol" by Labcorp and is ECLIA.
The second test, #140244, is called "Estradiol, Sensitive" by Labcorp and is RIA.
Labcorp doesn't seem to have a test called ultrasensitive and their use of the word sensitive is misleading.

God, what a mess.  RIA has the least amount of biometric validity and reliability.  Translation: its results are going to be more variable, and generally won't reflect the actual, objective value you have.  ECLIA is better but not best; that would be LC/MS. 

So I'd trust the 4515 most.

[Steady]

Yes, the 2 T clinics that I've been with both used the Labcorp #4515 and tried to stay between 20 & 30 on that test. That 20 to 30 range on that test always felt good to me. But there's been so much confusing talk that the #140244 is better or more reliable maybe just because Labcorp chose to mislead by calling it "sensitive" and charging more for it.

Labcorp does have 2 tests for E2 by LCMS. One for Total E2 and the other with E2 Total and Free. I haven't seen any way to order them thru PrivateMD.

[Kierkegaard]

This might actually explain why we see such a discrepancy between regular and sensitive assays.  One is one type of methodology (ECLIA) and another is a different type (RIA), hence the discrepancy.  You might even have more discrepancy on top of the different methodologies, given that the sensitive assay is *meant* to test for lower ranges, which could mean that using it when your E2 isn't low tends toward invalid/unreliable results. 

[Steady]

Quest has an Estradiol test they call ultra-sensitive. It is LCMS/MS. It is interesting to compare the reference ranges given for all these different tests.

Labcorp's ECLIA test #4515 has - Adult male: 7.6-42.6 pg/mL
Labcorp's RIA test #140244 has - Males age >15: 3-70 pg/mL
Quest's LCMS/MS Males: <29 pg/mL
Labcorp's LCMS tests do not have a reference range listed.

This might actually explain why we see such a discrepancy between regular and sensitive assays.  One is one type of methodology (ECLIA) and another is a different type (RIA), hence the discrepancy.  You might even have more discrepancy on top of the different methodologies, given that the sensitive assay is *meant* to test for lower ranges, which could mean that using it when your E2 isn't low tends toward invalid/unreliable results.

Of course, they are different tests. And they confuse the conversation. Consider a low E2 reading of 5 pg/mL. That is considered within range on 2 of the tests. We cannot talk about an E2 number without specifying which test was used. I was hoping to gather some data to help with a loose comparison on this thread.
Kierkegard, what tests have you been using and could you contribute some direct comparison data with simultaneous tests?

[Sam]

Remember ranges are set for these tests based on how "that test" performed on a certain set if samples they choose to develop a standard.   The ranges are set broad enough to capture both expected deviation and demographic variation unless otherwise specified. 

You cannot compare one methodology directly to another in most cases but you can draw broader comparisons if you have run them side by side for yourself at the same time and compared results.  LCMS is the good standard for accuracy because it separates the analysts of interest from the matrix it is in before measurement.  All the rest have potential interferences and there accuracy is a function of the conc of the analyte vs. conc of potentially interfering analytes.   

[Kierkegaard]

It depends on how impatient I am or how quickly I want data for my results.  If I just want a broad, not-so-reliable ballpark idea of whether my E2 is too high or too low, I'll order my local E2 RIA test.  If I want something more specific, I'll order through LEF (ECLIA) and go to the next town over to get blood drawn.  Never had the chance (or the money) for an LC/MS, which I would definitely get if I could, but at the same time it's all about symptoms in conjunction with bloodwork, so I'm (contrary perhaps to Sam, who knows more about this than me) not going to lose sleep over "just" getting the ECLIA to determine levels.  Whatever you use, just keep it consistent.