Don't understand my results

[RickHow]

I am 72 y.o. male. I am on immunotherapy for kidney cancer that has spread to my bones (2 places). Immunotherapy is know to possibly affect Thyroid. Every 3 weeks my thyroid is tested. On average my TSH has been in the 3.01 to 3.57 range, typically about 3.3x. The highest ever (since Januayy or 2020) was 3.57. My T4 has ranged from 8.8 to 12.5. (this lab say the normal range is 5.5 to 11.0) Typically my T4 .s 9.7. Since January of 2020 I was only above 11 2 times, and that happened this past September and last week at 12.5 (my highest yet). My oncologist says nothing about hitting the 12.5 T4 and says all is fine because my TSH is 3.13. But I have noticed recently I sometimes have slight, but evident, tremors in the index fingers of both hands, chills in my arms. It seems odd to me that we test T4 so often but when we get a HIGH result (12.5 when 11 is limit) we just ignore it. Further I am confused, would this be hyperthyroidism or hypo if my TSH is in normal range of 3.13.

[PurpleNails Administrator]

Welcome to thyroid forum.

Do you have an existing thyroid issue or is your thyroid closely monitored because of treatment? It’s very good you are being very frequent monitored. Most with a thyroid issues are monitored every few months.

A normal range for TSH is usually eg (0.35 - 3.5). It rises signalling the thyroid to make new hormone when thyroid levels are low. 1 is healthy the higher it is the more the thyroid is struggling.

Often medics don’t treat unless TSH reaches 10 (overt hypothyroidism)

Was the free T4 or Total T4 tested? FT4 is what you need a range of (5.5 to 11.0) is not typically what we see it’s very low for FT4 range. Can you double check if Total or Free T4 & the lab range. As a free FT4 between 8.8 to 12.5 would be very low by most ranges we see.

Has FT3 ever been tested this is the active thyroid hormone.

If your FT4 & FT3 are low it might be a good idea to test thyroid antibodies. TPO & TG. Also important to test folate, ferritin B12 & vitamin D.

[greygoose]

Hi RickHow, welcome to the forum.

The reason they ignore your over-range FT4 is because the result isn't really that important.

T4 is basically a storage hormone, which doesn't do very much until it is converted into T3. It's the FT3 level that says if you are hypo or hyper.

However, with a TSH of over 3, you cannot be hyper. In fact, your TSH is probably saying that you are hypo, and your FT3 is low - although they really, really ought to be testing that! But, I expect that, if you ask, they will come up with all sorts of silly reasons why the don't. The truth being that they wouldn't understand the results if they did!

A euthyroid (normal) TSH is around 1, never over 2, and you are hypo when it gets to 3. You don't say where you are, but in some countries you would be prescribed thyroid hormone replacement when your TSH gets to 3.

I have no idea how immunotherapy affects the thyroid, but have you had your anti-thyroid antibodies tested - TPO and Tg antibodies? The way your FT4 appears to jump around, it is possible that you have developed autoimmune thyroiditis - aka Hashi's. It's important to know, so if they haven't been tested, I would suggest that you get them tested. Plus very important to test nutrients: vit D, vit B12, folate and ferritin.

[radd]

RickHow,

Welcome to our forum, and sorry to hear of your condition.

Renal cancer therapy is sometimes associated with hypothyroidism by altering thyroid physiology from how thyroid hormones are made to behaviours in the cell nucleus and cytoplasm. Equally dependant upon our genetic makeup, thyroid hormones can exert influence on how cancers develop, and their regulation & proliferation.

In hyperthyroidism TSH drops low + thyroid hormones raise high, and in hypothyroidism TSH raises high + thyroid hormones drop low. For those medicating thyroid hormone replacement meds the aim is usually for a TSH of around 1 and middle to high-in-range thyroid hormone levels but is is variable upon meds and individuals.

However, if you are not medicating thyroid hormone replacement (most commonly Levothyroxine) your aims would be different, and the influence immunotherapy can exert on thyroid function could make your labs present as skewed.

FT4 seems to be jumping about which in hypothyroidism usually indicates Hashimotos attacks (thyroid autoimmune disease). I do not know the effects of suppressed or heightened immune therapy on Hashimotos but it is commonly triggered by shock/stress and immune change. Ask to have TPOAb & TGAb tested. Also FT3 which is the active hormone so important in keeping metabolism correctly regulated.

[RickHow]

Thanks to all who wrote a response. I should have been a bit clearly and will now to provide better information based upon your questions. I am in the United States and the units of measure may be different than the UK.--My Thyroid is tested every 3 weeks (due to cancer immunotherapy). They test the TSH and T4.

--The T4 test is marked as TOTAL T4. It was 12.5 ug/dl. It says the normal range is 5.5 to 11 ug/dl.

--The TSH test was 3.130 ulu/ml. It says the normal range is .467 to 4.680 ulu/ml.

To answer specific questions asked I have no specific thyroid issue, the frequent testing is monitoring because of my cancer treatments.

The normal TSH for this lab is not .35 to 3.5 but rather .467 to 4.6 ulu/ml.

As I mentioned the oncologist is not concerned about the total T4 of 12.5 ug/dl which is high, because the TSH is normal at 3.13 ulu/ml for whom the normal range is .465 to 4.580 Ulu/ml. I know that "hyper" is usually low TSH with elevate T4, and that "hypo" is a high TSH and low T4. But i am the oddball here because my TSH is in "normal" but my T4 is HIGH!

[PurpleNails Administrator in reply to RickHow]

Your TT4 might be high but Total T4 measurement doesn’t give you the information you need. You need to know the unbound or Free T4, and the FT3 as that’s what available for your body to use.

A normal TSH Is usually 1 but doctors aren’t concerned until it goes very high. Here in UK many use direct private companies to obtain full set of thyroid results.

I’m sure there would be similar options in US.

[radd in reply to RickHow]

RickHow,

TSH & thyroid hormones should inversely correlate, but given you are not medicating thyroid hormone replacement meds but immunotherapy a skewed result would not be unusual as many different hormones will be involved and influencing these results.

I am sorry to hear about about your condition, and a slightly elevated thyroid hormone is really not necessarily a cause for concern.

[RickHow in reply to radd]

Thanks for your note and information. It means a lot to me.