Impaired binding properties of thyroxine‐binding globulin in hepatocellular carcinoma and chronic liver disease

To determine the factors underlying the apparent reduction in binding ability of thyroxine-binding globulin in hepatocellular carcinoma, hormonebinding characteristics were further examined in patients with this disease and in control subjects. No differences in affinity constants with respect to triiodothyronine or serum thyroxine-binding globulin from hepatocellular carcinoma, cirrhotic and normal subjects were found. The affinity for thyroxine was significantly reduced in hepatocellular carcinoma (0.41 ± 0.13 × 1010 mol−1) and cirrhotic (0.65 ± 0.1 × 1010 mol−1) patients compared with normal subjects (0.94 ± 0.7 × 1010 mol−1). Investigations carried out on liver tissue obtained from patients with hepatocellular carcinoma and chronic liver disease showed that thyroxine-binding globulin within tumor tissue was elevated and bound less exogenous tracer hormone compared with that obtained from nontumor tissue. Tumor-derived thyroxine-binding globulin with altered binding properties is, at least partly, responsible for the abnormal behavior of the serum protein in patients with hepatocellular carcinoma. (HEPATOLOGY 1991;14:116–120.)