Has anyone faced an issue with TSH measurements

[Blueskyyy]

Hi all,

Has anyone while being treated faced issues such as assay interference with TSH measurement, which led to falsely raised TSH?

Thx

[diogenes Remembering]

It is actually quite common. The detection device in most TSH tests is by what is called a monoclonal antibody (an antibody originally developed in mice but now manufactured independently of the animal). A proportion of people have antibodies in their blood which recognise and bind onto the TSH antibodies and prevent the test from working. The test fails and artificially high estimates of TSH then come about. However, it can be that the exact details of the antibodies are different in different tests from different manufacturers and failure in one test could also be a success in another. Thus if a false high result is found in one test, another may not suffer from this problem. This is a very unstated ongoing problem with TSH tests.

[SilverAvocado]

There are always possibilities of error. This is part of why it's best to see a full thyroid panel, and a history of thyroid panels going back months or years is even better.