M. Platzer

PREDICTION OF THERAPEUTIC RESPONSE TO RADIOACTIVE IODINE IN GRAVES’DISEASE USING TSH-RECEPTOR ANTIBODIES AND HLA-STATUS

We have examined the combined usefulness of TSH‐receptor antibody detection and HLA status on the therapeutic response to standard doses of radioactive iodine (RAI) in forty‐three hyperthryoid Graves’patients. Twenty‐three patients had detectable TSH‐receptor antibodies as measured by 125I‐TSH binding‐inhibition (TBI) prior to administration of 7 mCi RAI. Eighteen (78%) of these patients were rendered euthyroid within 3 months. In contrast, twenty patients were TBI negative prior to RAI and sixteen (80%) of these individuals remained hyperthyroid at 3 months and required two, or more, doses of RAI to control their thyroid function. DR3 status alone was not strongly associated with resistance to RAI. However, of sixteen patients without detectable TBI activity and who required two or more doses of RAI, ten patients were DR3 positive (62%) compared with 25% in a control population. Only one patient who was both TBI and DR3 negative required more than one dose of RAI.

THYROGLOBULIN SECRETION BY HUMAN THYROID CELLS AFTER MONOLAYER CULTURE–COMPARISON OF NORMAL AND ADENOMATOUS CELLS

We have analysed immunoassayable thyroglobulin (hTg) secretion from both normal and abnormal isolated human thyroid cells after short‐term monolayer culture. All cells were sensitive to more than 10 μU/ml bTSH when assessed by intracellular cyclic AMP accumulation in the presence of a phosphodiesterase inhibitor. hTg release was stimulated in all cells by bTSH in a dose related manner and with a detectable response within 24 h. Basal hTg secretion rates were greater in cells derived from benign follicular adenomata (range 1‐1–2‐2 ng/105 cells/h, n=4) than in normal human thyroid cells (range 0‐1‐0‐65 ng). Therefore it appears likely that hTg secretion by adenomatous thyroid cells was a likely contributor to increased serum hTg in patients with single follicular adenomata. We conclude that simple human thyroid cell monolayers have potential for the further study of hTg secretion and its control by TSH.