The range for the TSH Receptor Antibodies in my daughter's blood results at the beginning of Dec 2020 was 0-2 IU/L and her result was 3.51 (so high).
Tested again on 30/6/21. Different lab, but both in England. Range 0 - 0.4. Her result 2.77 IU/L. Still high.
My question is about the upper limit in the range, 0.4 instead of 2. Big difference. All the other ranges (platelets, free T3, etc.) were the same. Why is there such a wide variation only for the TSH Receptor Antibodies?
Different machines, calibrated differently.
So how can we compare results? I thought that the calibration was based on the average results of the healthy population, to determine the ranges. How can they vary so much in the same country? Why only for the TSH Receptor Antibodies? Maybe they use a different machine for this particular test, while the rest of the blood results are from a different machine? The Receptor Antibodies test was the only one where there was a variation in the range.
So how can we compare results?
With FT4 and FT3 when a result is within the range, and the ranges are different from previous ones, we use this calculator to get the percentage through range to compare:
When it's over range it doesn't really matter, it's over range whatever the range.
I thought that the calibration was based on the average results of the healthy population, to determine the ranges.
To a certain extent the range is based on local healthy population but different machines are calibrated differently and that has nothing to do with the local population, it's to do with how the manufacturers set the machine.
How can they vary so much in the same country?
Different labs use different machines.
Why only for the TSH Receptor Antibodies?
Maybe at that lab they're using the same machines as other labs for the other tests.
If you go back to the very early twentieth century, individual labs, even individual scientists did tests themselves. Whilst they were often highly skilled at laboratory work, achieving consistency from one run the the next was challenging. And from one lab to another, towards impossible.
Gradually, companies started to produce highly standardised reagents for performing tests. And, due to massively increasing workloads, automation was introduced.
Nowadays, you can buy big computer-controlled analysers and pre-packs of the various reagents required. They have extremely high levels of automation and manage things like reporting to the medical staff.
Alongside that, for some tests, a lot of work went into ensuring that the tests were consistent from one lab to another. One way this was achieved was producing reference samples. These are used to check the calibration of the machine. For those tests which have been standardised, results can be pretty well standardised.
But with some tests, such as many antibodies, Free T4 and Free T3, and ferritin, that has not been achieved. A test done at one lab might have a very different result to what is nominally the same test run at another lab. And sometimes the tests are reported in different units (e.g. pmol/L versus pg/mL).
I don't think anyone is happy with these variations but they do exist. And while they exist, the reference intervals will also vary.
I think there must be a lot of variation between labs. Mine from Glasgow RI were 16U/L with under 1 being negative, between 1 and 2 borderline positive and over 2U/L TrAb positive.
Thanks. This sounds more similar to the range used in the first test. 0.4 as the upper limit in the second test seems a bit strange, very low.Do you have Graves?
Diagnosed 5years ago. Graves and TED. On block and replace. It's been a rocky road but feeling really well at the moment. Has your daughter a diagnosis of Graves ?
Not a firm one. They say that blood results are indicative of it. They want to put her on Carbimazole, but her free T4 is not raised, not out of range. What do you do to treat the actual Graves rather than the symptoms (overactive thyroid, low TSH). What can you do to lower the antibodies?
What can you do to lower the antibodies?Wish I knew. Stress is often mentioned but I am very laid back and yet AB's still high. I looked back your daughter's history and all the good advice you have received from members of the forum. I would only add that if your daughter isn't suffering hyper symptoms and her thyroid levels aren't high I can't see why she would be started on Carbimazole as it is very likely to make her hypothyroid. This happened to me and worsened my thyroid eye disease. You will naturally be worried for her but you are doing the right thing learning all you can to enable you to understand what is going on and when treatment might be needed.
Thanks for the advice. I've looked at the Elaine Moore's website. She is talking about research on a type of mushrooms which seems to help. Have you tried? Does Carbimazole have any effect on the actual Graves? Unfortunately the GP is just sticking to what the hospital told her to do. Have you ever had your antibodies tested privately? Have you had the scan with contrast to confirm that you had Graves?
Not tried the mushrooms. E Moore also recommends L carnitine. I find it all a bit overwhelming and since I feel well don't have incentive to experiment. Carbimazole reduces production of thyroid hormone but is also believed to have an immunomodulatory effect.pubmed.ncbi.nlm.nih.gov/752...
Endo did AB testing so no need for private test. I only have TrAB not TPO or TG. I use medichecks to monitor Vitamins which are low although I eat healthy diet.
Scan showed diffuse uptake typical of Graves.
My daughter had an ultrasound, but not the one with contrast, so the only thing indicating Graves is the blood test (high antibodies, low TSH, slightly high T3).Good to know that carbimazole can also help with autoimmune diseases. I'm still worried that 20 mg might be too high if free T4 is within range. They said that they are going to monitor the blood though, so they should be able to readjust the dosage if 20 mg is too high and makes her hypo. Any possible long-term side-effects from taking carbimazole?
Maybe I should read about l-carnitine and consider trying it.
Thanks for all the info
From my own experience I would worry that 20mg C is " taking a sledgehammer to crack a nut ".What is the rationale behind treating a patient whose thyroid hormones are within range ?
My TSH was below 0.01 and fT4 29 ( range 9 -21) when started on 20mg. C. Within 4 weeks TSH 1.25 and fT4 14.2 . Over the next few months I was titrated down as I was becoming very hypothyroid. TSH 39 and fT4 8. The TED started. I was put on block and replace because my TrAb was high at 16 and remission therefore unlikely. My endo told me if TrAb under 5 I could work towards stopping meds. Your daughter therefore probably has a high chance of remission under a watch and wait approach. I wish you both the best.
The GP wants to test her again a few weeks after starting the carbimazole, so I assume that they'd reduce the dose if thyroid levels were too low. I agree with you though.Do you think that your Ted would have started anyway or that it was triggered by having become hypo?
Glad to hear that your current treatment (block and replace) is working for you. Thanks so much for all your advice.
I think my TED was triggered by becoming hypo. It is good your GP will retest every few weeks I think it will be needed ! I would be interested to follow how your daughter reacts to the Carbimazole. Keep us posted.
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