Abstract
Very few studies have been reported on the isolation of hydatidiform mole thyrotrophins (hmT) from patients exhibiting flagrant thyrotoxicosis. This report describes preliminary studies on endometrial tissue from a 50 year old woman with suspected molar pregnancy and associated thyrotoxicosis. Thyrotrophic activity was identified by the TSH mouse bioassay (Adams). Neutralisation of thyrotrophic activity was attempted by the addition of 10% (v/v) rabbit anti human pituitary TSH antisera or control rabbit sera to the samples. Subsequent histologic examination confirmed the tissue to be a hydatidiform mole with moderate trophoblastic proliferation. The responses of the mice show that the extract contained a thyroid stimulator with biologic response properties which are substantially different from either pituitary TSH or thyroid stimulating autoantibodies like LATS. Furthermore, the mole extract showed insignificant neutralisation with antisera to human pituitary proteins, as has been observed with other hormones derived from tumors. The gel filtration of the extract indicated that the thyrotrophic material was a mixture of at least two, and possibly more, molecular entities and had a substantially larger molecule weight and size than pituitary thyrotrophin, but smaller than any known thyroid stimulating autoantibody. The results thus confirm that the thyroid stimulator detected in the hydatidiform mole differs from other, and more common, human thyroid stimulators.