Endocrine Abstracts

Biotin is used in many hormone immunoassays as an immobilizing system as streptavidin binds biotin with high affinity. Recently, cases with spurious results from biotin interference have been increasing due to widespread use of vitamin supplements containing biotin. We report two cases of erroneously high total T3 levels caused by biotin interference.Case 1: A 88-year-old female who had total thyroidectomy for papillary thyroid cancer 10 years ago and ha...