RE. Shocked about T3 blood test results

[Everdean]

after a very high T3 blood test result of;-

34 ( 3.1 - 6.8 )

Which I posted on this forum. I was advised by some of your members to get it checked. The surgery made an appointment for me to see the pharmacist to discuss it.

She was lovely , and she rang the lab and let me speak to Alison Jones - Consultant in Biochemistry. This is what Alison said to me;- "Because I am taking a non standard treatment (Thyroid S NDT). and becauset the content it not regulated it may react differently to the chemicals in the lab - She said "treat the patient not the figure so if patient is feeling fine so blood test may not be effective therefore not necessary to repeat."

After another blood test yesterday, my results now are;-

T3 Serum free triiodothyronine level 4 pmol/L [3.1 - 6.8]

FT3 now within normal limits. ?analytical error caused previous

high result, ?due to non-standard thyroid replacement.

Serum free T4 level 17.6 pmol/L [11 - 22]

Serum TSH level < 0.01 miu/L [0.27 - 4.2]

Below low reference limit

Further info at: british-thyroid-association...

I hope this helps someone else.

Thank you for all your help.

[diogenes Remembering]

It's more likely you had a short-term production of antibodies in your blood which reacted with the test ingredients to give a temporary high FT3 value. These episodes are known in patients taking T4 and/or T3 and often interfere with tests, giving silly results easily spotted. Its when the antibody levels are smaller to give only a small rise that misdiagnosis can come in..

[Everdean in reply to diogenes]

That is really interesting. Thank you.

[Everdean in reply to diogenes]

Could you tell me please what could cause the antibodies to rise so rapidly for a short time?

[diogenes Remembering in reply to Everdean]

No one really knows. With NDT there are so many potential stimulants, eg T4-thyroglobulin, T3-thyroglobulin where the hormones are bound on to proteins. These could give a momentary flux of T3/T4 antibodies owing to an immune response to a particular dose with particular ingredients. When that batch is finished, another one may not contain such things and the blood antibodies subside.

[Everdean in reply to diogenes]

Thank you. Diogenes

[ShootingStars in reply to diogenes]

What kind of antibodies?

[diogenes Remembering in reply to ShootingStars]

Antibodies against T4 or T3-protein conjugates when ingested T4 or T3 + the protein gives an immune response

[ShootingStars]

That sounds like it could have been a lab error if your previous results were normal and follow up results were normal. Did you retest immediately? If your FT3 was actually that high, you would have had extreme symptoms that would probably send you to the ER. Were you hot, sweating excessively, heart racing wildly, not sleeping, having hyperactive bowls? What was your previous result and how many weeks before the unusual result?

[Everdean in reply to ShootingStars]

I retested a week after the high reading.

My previous blood test results in January 2018, were T3 9.7 ( 3.5- 6.5.) This was above average but I had taken my thyroid meds only that morning. I was there for another blood test but even though I objected, the nurse insisted on doing the thyroid. I told her it wouldn't be an accurate reading.

Apart from that T3 have always been low or somewhere in range.

The very high reading of 34 was a one off, and I certainly didn't feel ill as you describe.

So yes I think it was a lab error too ShootingStars.

Thanks for your comments.