[Clinical value of human thyroglobulin measurement].

A direct radioimmunoassay for human serum thyroglobulin (TG) has been developed. The lower limit of detection of the assay was 7.5 ng/ml. The serum values in normal subjects were between 0 and 44 ng/ml (n = 34, 21 female subjects, 13 male subjects). In 22 of the 34 subjects, TG was not detectable. The mean value of TG in a group of 19 subjects with multinodular goiter was 115.8 +/- 62.7 ng/ml (mean +/- SD). A group of 16 thyrotoxic individuals also had an elevated TG concentration (107 +/- 71 ng/ml). The serum TG levels in 6 patients with differentiated thyroid carcinoma with metastases were much more elevated than in any other clinical situation (3430 +/- 1100 ng/ml). In patients with thyroid cancer in clinical remission (n = 9), the TG levels were normal. In 2 patients with non-differentiated thyroid tumors, TG was not detectable. The major methodological problem in TG determination is the presence of anti-TG autoantibodies which may interfere with the radioimmunoassay.