Endocrine Abstracts

Introduction: Free thyroxine (FT4) assays are available on different commercial platforms where manufacturers provide different reference ranges. The lower limit of normal varies considerably between 8 and 13.9 pmol/l depending on the FT4 assay being used. There is concern about the validity of these reference ranges in paediatric populations, especially for the Roche FT4 assay; here there is a tendency for FT4 results to be below age-related lower limits of 13.9 or 13.6 pmol/...

Tyrosine kinase inhibitors (TKIs) are relatively new therapy drugs used for the treatment of metastatic cancers including Renal cell carcinoma (RCC), gastrointestinal stromal tumours, thyroid and neuroendocrine tumours. They block vascular endothelial growth factor and other growth factors Thyroid dysfunction is often a side effect of this treatment. A close monitoring of thyroid hormone levels is a necessity.We have a case of a 69-year-old lady with RCC...

Positive interference in free thyroxine (fT4) and free triiodothyronine (fT3) immunoassays is well known, however we report a rare case of negative interference in the Roche fT4 and fT3 immunoassays in a 3-year-old girl with undetectable fT4 and fT3. She presented with increasing tiredness, abdominal pain, pain in her lower limbs and constipation. Examination was unremarkable. Thyroid func...