Concentration of thyroxine-binding globulin and the Thyopac-3 test.

Concentration of thyroxine-binding globulin: value of direct assay.

The concentration of thyroxine-binding globulin (TBG) in the serum can now be measured by direct assays that are simple and inexpensive. Comparison of a direct measurement of TBG concentration with a widely used indirect method (Thyopac-3) showed that the indirect method was inaccurate when TBG concentrations were high. This will result in an increase in the derived free thyroxine index (FTI), ...

Thyroxine-Binding Globulin Concentrations

Plasma thyroid hormone concentrations may be abnormal in non-thyroid disease and pose diagnostic problems. For example, concentrations of triiodothyronine (T3) in the blood decline in acute illness with a reciprocal increase in reverse triiodothyronine (reverse T3), but thyroxine (T4) concentrations are usually normal or only slightly decreased (1, 2). However, McLarty et al. (3) reported that ...

Familial thyroxine-binding globulin deficiency.

Genetically determined thyroxine-binding globulin deficiency is described in two families in the United Kingdom. All subjects in both pedigrees were euthyroid. Transmission was by sex-linkage; males showed low serum protein bound iodine and high thyroxine (T4) resin uptake due to complete absence of serum thryroxine-binding globulin; females were less severely affected. The distinctive biochemi...

Thyroxine-binding globulin, hyperthyroxinemia and hepatocellular carcinoma.

Growth retardation and thyroxine-binding globulin deficiency.