Radioimmunoassay of serum thyroglobulin

A RIA for serum thyroglobulin has been developed. Normal subjects had a mean globulin level of 30.4 ng/ml. The values were higher in women (33.5 ng/ml) than in men (26.4 ng/ml). In 13 patients with hyperthyroidism, levels were above normal. In 31 patients with autonomous thyroid adenoma, the mean thyroglobulin value was 156.3 ng/ml. In 5 patients observed after externally applied radiotherapy, thyroglobulin levels increased with the radiation dose to 1.5 to 7 times the initial value. In 15 patients with autonomous adenoma treated with radioiodine, thyroglobulin levels were 4 to 10 times as high as before the treatment. In 24 patients, thyroglobulin levels increased after thyroid operation. In 74 patients with differentiated thyroid carcinoma without metastases, thyroglobulin was either not detected at all or in concentrations up to 17 ng/ml. In 23 of 24 patients with metastases, thyroglobulin levels were higher than 39 ng/ml. The sensitivity of the thyroglobulin method in the detection of metastases can thus be defined as being 96% with 100% specificity. Course control showed that thyroglobulin curves had a linear relationship with the tumour course. (orig./MG)