Authors: Mary A. Williamson Mt(ascp) Phd,L. Michael Snyder Md
Certain drugs (e.g., estrogens, birth control pills, perphenazine, clofibrate, heroin, methadone).
Estrogen-producing tumors.
Systemic illness is increased early.
Acute intermittent porphyria.
Acute or chronic active hepatitis.
Lymphocytic painless subacute thyroiditis.
Neonates.
Inherited.
Idiopathic.
An increased TBG is associated with increased serum T
4
and decreased T
3
resin uptake; a converse association exists for decreased TBG.
Decreased In
Nephrosis and other causes of marked hypoproteinemia such as liver disease, severe illness (late), stress (thyroxine-binding prealbumin [TBPA] also decreased)
Deficiency of TBG, genetic or idiopathic
Acromegaly (TBPA also decreased)
Severe acidosis