Time-dependent changes in FT4 and FT3 levels measured using mass spectrometry after an acute ingestion of excess levothyroxine in a case with hypothyroidism.

ABSTRACT:

Background

Thyrotoxicosis is common disorder among endocrine dysfunctions. It is not rare that the free thyroid hormone level exceeds the measurement range of immunoassay. Such extreme high concentration of free thyroid hormone is generally considered to be impossible to measure correctly because of changes in the balance between free hormones and binding proteins by dilution of serum. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), however, higher concentrations are able to be determined.

Case presentation

We present a case of a 21-year-old female with congenital hypothyroidism who had taken a total of 5 mg levothyroxine over three consecutive days following discontinuance of the medication for a month. Immunoassay performed 3 hours after the last ingestion

SUBMITTER: Ito Y 

PROVIDER: S-EPMC7193347 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature