Radioelectrophoresis for determination of thyroid hormone binding abnormalities in human serum.

This paper describes a rapid and accurate method for determining binding abilities of thyroid hormones to their corresponding serum proteins: prealbumin, albumin and thyroxine binding globulin. A tube cell agarose gel electrophoresis is used with radioactive labelled triiodothyronine or thyroxine. The distribution curve shows characteristic peaks for prealbumin, albumin and thyroxine binding globulin. A collective of 60 euthyroid thyroid-healthy persons was examined, and the following reference values for the binding of thyroxine to its binding proteins were found: The percentage binding of thyroxine to the prealbumin fraction is 21 to 33%, to the albumin fraction 10 to 15% and to the thyroxine binding globulin fraction 54 to 66%. In a group of 220 patients with suspected thyroid hormone binding abnormalities there were 42 cases of albumin-associated hyperthyroxinaemia, 5 cases of prealbumin-associated hyperthyroxinaemia and 2 cases of thyroxine binding globulin deficiency. In another group of 35 patients with suspected antibodies against thyroid hormones one patient showed antibodies against triiodothyronine.