Hans Perrild

Thyroid function in patients with breast cancer

Thyroid function was evaluated in 58 patients with breast cancer and compared with data obtained from an age-matched control group of healthy women. Thyroid antibodies at low levels were present in 29 patients (50%): 21 patients (36%) had thyroid stimulating antibodies at low activity. Ten patients (17%) had thyroglobulin antibodies compared with 3 in the control group (P less than 0.05). Nine of 10 patients with thyroglobulin antibodies had microsomal antibodies as well. Two patients had only microsomal antibodies. Additionally 10 autoimmune antibodies were determined. These were, however, either absent or present in low concentrations in serum. Independent of the stage of disease, no differences were demonstrated between patients and controls in serum levels of triiodothyronine, thyroxine, free T3 index, free T4 index, thyroid stimulating hormone, and thyroglobulin. In conclusion, we found an increased frequency of thyroid autoantibodies in euthyroid patients with breast cancer compared with healthy controls suggesting a possible relation between this disease and autoimmune thyroid disease.

Acute in vitro thyrotropin regulation of lysosomal enzyme activity in the thyroid follicular cell

The acute effect of a physiological concentration (1 mU/l) of thyrotropin (TSH) on the activity of four lysosomal enzymes in the thyroid follicular lining cell has been studied by quantitative cytochemical techniques. N-acetyl-beta-glucosaminidase (NAG) activity was increased by 14% after 10 min TSH stimulation and NAG and beta-galactosidase activities were increased by 24% and 25% respectively (P less than 0.05) after 20 min stimulation and by 40% and 45% (P less than 0.05) respectively after 30 min stimulation with TSH, indicating an early processing of these carbohydrate residues in thyroglobulin. Acid phosphatase activity, an acid hydrolase unrelated to the hydrolysis of thyroglobulin, was unchanged 30 min after TSH stimulation. Leucyl-beta-naphthylaminidase (LNA) activity changed biphasically with peak activities of 7 and 25 min possibly representing an early fusion of endocytotic vesicles and lysosomes and later the release process of the thyroid hormones. The changes in LNA activity and thus membrane permeability were not reflected in the other enzyme activities studied. This may indicate that the TSH regulation of lysosomal enzyme activities could be independent to the endocytotic process, which is known to involve fusion of lysosomes and endocytotic vesicles. In conclusion we have demonstrated for the first time with physiological concentrations of TSH a specific acute regulation of some lysosomal enzyme activities which may be involved in thyroglobulin processing. Further, these effects may be independent of the changes in lysosomal membrane permeability due to formation of secondary lysosomes.