An Evaluation of Serum Thyroxine Binding Globulin as a Routine Test of Thyroid Function

High serum thyroxine-binding globulin--an important cause of hyperthyroxinaemia.

Four patients are described who had a significant elevation of serum thyroxine-binding globulin (TBG). Review of these patients indicated that inappropriate therapy for thyrotoxicosis had been given in three cases. A study of our laboratory records revealed that significant TBG elevation was a relatively common phenomenon which occurred in approximately 0.45% of our hospital population. Patient...

Binding of thyroid hormones and their analogues to thyroxine-binding globulin in human serum.

The present study was undertaken to study the binding of several thyroid hormones and structurally related compounds to human serum thyroxine-binding alpha-globulin (TBG). The source of TBG was normal human serum diluted 1:100 in 0.035 M barbital buffer, pH 7.4. In the binding assays, 125I-thyroxine, unlabeled thyroxine, and diluted serum were incubated for 20 h at 37 degrees in Plexiglas equil...

A Study of Thyroid Function in Partial Thyroxine-Binding Globulin Deficiency

Objective: It is generally thought that thyroxine-binding globulin (TBG)-deficient individuals are euthyroid and do not require treatment. However, there have been case reports of TBG deficiency combined with hypothyroidism. The purpose of this study was to investigate the relationship between TBG deficiency and thyroid function. Methods: We reviewed the medical records of 32 patients diagnosed...

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 ...

Primary thyroid failure with concomitant thyroxine binding globulin deficiency.