I wanted to write to share my recent experience, which I'm afraid I don't think will raise your spirits given the singular focus of many of our doctors on lab results.
My endocrinologist ordered two sets of blood tests: the regular one done at the hospital lab (not sure what it's called) and one from a lab that uses the Abbott assay which he believes is superior.
I had just one blood draw for both samples (8am and fasting) so it was a perfect comparison. The results from the two labs were as follows:
Hopsital lab:
TSH: 0.02 (0.27 - 4.2)
T3: 4.4 (3.1 - 6.8) - 35% through range
T4: 22.4 (12 - 22) - 104% (over range)
Conversion: 5.09
Abbott:
TSH: 0.02 (0.27 - 4.2)
T3: 4.5 (2.4 - 6.0) - 58% through range
T4: 15.3 (9 - 23) - 45% through range
Conversion 3.40
This is the second time I've had this exact pattern from the same sample sent to the same two labs. Last time, annoyingly, my medication was adjusted down because only the hospital lab results had come back and they showed 'high T4' and an apparent conversion problem. Several weeks later, the Abbott ones turned up and showed mid-range T4 and no conversion issue. I find this quite shocking and wanted to share.
He thinks eventually all labs will move to Abbott but who knows if that's true (and it's not much help in the meantime).
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London3891
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Nice to see a proper comparison with the 'variables' removed .. thanks London .
Tagging diogenes in case he's interested as i had a previous discussion with him a coupple of yrs ago re. differing fT4 ranges and how comparable their results truly are .
I was questioning an fT4 range of [7.9-14] which at the time of the discussion i thought was an Abbott plarform , but i'm not certain it was actually Abbott ,,, it may have been Beckmann -Coulter ,as they make a platform with similar range.
was surprised to see that lab range of 9-23 for the abbott machine ..i wonder if that is quite an old machine ? my NHS lab had an fT4 range very similar to that in about 2011,,, but now has 7.9-14 , which i believe is very similar to some of the newer ? abbott platforms .
It's quite hard to find out what the' factory setting' ranges are for all the different manufacturers platforms are though .. or more likely ,i'm just rubbish at searching using the right terms lol )
(i mean 'factory setting' as in ~ before the local lab who buy it then adjust it slightly to take their local population samples into account)
It says "Manufacturer-provided reference ranges included 0.35 to 4.94 mIU/L and 9.0 to 19.0 pmol/L for the Abbott TSH and fT4 assays, respectively, and 0.27 to 4. 2 mIU/L and 12.0 to 22.0 pmol/L for Roche’s assays."
It also jogged my memory and I'm 99% sure the first 'hospital' lab result that I posted was Roche.
A podcast series has been made about a woman who made a blood test machine that didn’t work… (finger prick not a draw) I won’t spoil the ending but it’s shocking how long the machines that have totally spurious results were up and running in the US.
I'm in the process of writing a chapter in an ebook we are going to write dealing with this very subject. Making the best FT4 and FT3 tests isn't as easy a task as making total T4 and T3 tests. In fact, I have come to believe that such a task is beyond most manufacturers' capability. The remarkable situation is that there are tests that obey all the rules governing valid FT4 and FT3 tests, but they appear rarely in usage. For all those who think that big pharma, can be malign: this is the area of assay platforms being bought by cost rather than quality (and the medical users preferring to hold their noses). The whole thing smells of finance over quality with the confusion that results.
I imagine most manufacturers provide a wide range of tests on their platform.
Do we see one company being awful for some tests but good at others? And another company the other way round? Or do they tend to be at least relatively poor across the board?
It really is a patchwork. But FT4 and FT3 tests are much more likely to be poor. As an example, in 1983, when we had launched our own tests (Amersham) another company quickly scratched up a rival assay. However, it was no good because the blood binding protein-T4 also contributed to the results when it shouldn't have. So then they put in a "blocker" which they finagled so the results looked good - though everywhere else they weren't. Since then, this company was taken over by another who simply rejigged the test to become detected by nonradioactive rather than radioactive marker. So, the result is that the poor test of 1983 is simply reflected in a test widely used today - shan't name the manufacturer for libel possibilities.
In my area a couple of years ago I saw a footnote about the Siemens' assay meaning a drop in the bottom of the reference range for serum calcium. GPs already appear loathe to help patients with mild (but symptomatic) hypocalcaemia, and can now point at the reference range and claim results are normal, and avoid expensive vitamin D and PTH testing.
One of my results from the old days: Corrected serum calcium level 2.13 mmol/L, range 2.2 - 2.6 mmol/L.
New range: 2.12~2.51 mmol/L.
My results vary between 2.13 and 2.19 mmol/L and my surgery's GPs have the viewpoint that anything over 1.9 mmol/L can be dismissed. I've only been tested once since 2020, instead of several times a year, so cannot say whether my results have dropped due to the new assay.
With conflicting results, big question marks over quality vs cost etc, one has to keep coming back to what about symptoms?
By all means use tests as a (rough) guide but symptoms are unequivocally the best calibration to our individual wellness.
When an instrument is calibrated that is to ensure it produces consistent results that can be compared to each other. It doesn’t mean calibration to the individual should be ignored.
Symptoms are bespoke. to us. There will never be a test that accurately predicts the dose of replacement hormones each individual person requires.
The test has to be calibrated to the person. A doctor should be noting an individual’s response to treatment and comparing the test results, thus treating the patient. Not dosing according to the test results and ignoring symptoms, or putting it down to something the patient is, or is not doing ie gaslighting and doggedly treating the lab work (not the patient).
The more the holy grail of accurate reproducible tests is sought the closer we get to symptoms being ‘made redundant’ by ignorance and laziness. If the interpretation of tests and the inherent limitations are not properly explained to doctors and endocrinologists alike we will see no improvement in treatment.
Currently we have the ‘Your Normal’ (when in range) paradigm for blood test results. To give you a feel for how inadequate this method of ‘interpretation’ is :
I was ‘Normal’ at 75ug of Levothyroxine- though severely symptomatic. My 6 1/2 stone friend is fine on 75ug.
I was ‘Normal’ at 100ug - but still symptomatic
I was ‘Normal’ at 125 ug - but still symptomatic
I became well at 150 ug of Levothyroxine and at 5’ 8” tall and just over 15 stone that may not come as a surprise, but I had to FIGHT for every dose increase.
Improving testing for the most part will make no difference if the 🤡 reading off the lab sheets don’t know $*ite from pudding.
This is a systemic problem with actually a not so massive knowledge gap that needs plugging. The problem is it is a widespread knowledge gap.
Science and medicine have long since parted company and basic scientific principles have been lost. New methodology has been introduced and doctors have not been trained to understand it.
Even putting ‘normal’ on a lab test printout is abhorrent - it goes to reinforce the current paradigm.
I have a very similar situation going on and the radioiodine treatment made me incredibly ill as my blood results were followed on the wrong platform. I was ‘healthy’ before and incredibly hypothyroid (although still in the norm) for my standards.
Sadly enough my menopausal symptoms were all blamed on the thyroid… and the blood test results did not help at all.
Today my endo would go much more by symptoms again - thankfully.
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