ALTERATIONS OF THYROXINE-BINDING PROTEIN IN CLINICALLY HYPO- AND HYPERTHYROID PATIENTS WITH NORMAL PBI LEVEL

Publisher Website
Google Scholar
Abstract
6 patients, clinically hypothyroid in spite of a normal or elevated protein-bound iodine (PBI) level, and 6 hyperthyroid patients with a low level of PBI are described. In these patients, a probable modification of the transport of the thyroid hormones is revealed by means of in vitro uptake of T3 by erythrocytes (Hamolsky''s test) and by the determination of the binding capacity of the thyroxine-binding protein (TBP or TBG). In the first group, the labelled triiodothyronine uptake by the erythrocytes is low and the TBP-binding capacity is higher than normal. In the second group, the elevated percentage of free hormones and the low TBP-binding capacity may partly explain the hyperthyroidism despite the low PBI level. PBI concentration in the thyrotoxic range with high TBP binding capacity, is also demonstrated in infectious hepatitis. The meaning of these results is discussed.