Thyroxine- binding globulin physiology
TBG is a high affinity, low concentration TBP that binds 80% of T3 and
75% of T4. Transthyretin (TTR) and serum albumin are the other TBPs.
TBG has a distributive as well as buffering role to stabilise free
thyroid hormone concentration supply to target
tissues.22 Abnormalities in the TBG can be inherited
or acquired, and drugs remain a common cause of acquired alteration.