TSH measurements can be affected by the TSH binding on to other proteins

[diogenes]

A paper here shows the case of a man with unusual TSH giving falsely high values and why. Another thing to look out for if TSH measurments go wrong

A case of macro-TSH consisting of IgA-bound TSH

May 2021

Endocrine Journal l

DOI: 10.1507/endocrj.EJ21-0021

Miho Fukushita, Natsuko Watanabe, Jaeduk Yoshimura Noh, et al

[SlowDragon Administrator]

Here link to the paper

pubmed.ncbi.nlm.nih.gov/340...

[vocalEK]

I sincerely wish that doctors would look up the definition of "sub-clinical" before deciding that a patient presenting with symptoms needs no treatment.

[radd]

diogenes,

Yes, we have seen hugely elevated TSH results that didn't match thyroid hormone levels previously on the forum and I read that because the macro-TSH is a larger molecule it's excretion is less likely to be dealt with by the kidneys and so accumulates in high levels in the blood stream.

Seeings as it largely inactive I guess it’s a case of educating those reading the results to avoid misdiagnosis but as they have troubles reading “normal” results that may not be a strong possibility. Interestingly macro-TSH can be transferred via placenta in newly born babies giving an elevated TSH which could prove fatal if interpreted incorrectly alongside “normal’ thyroid hormone levels.