Serum Thyroglobulin in Patients With Toxic and Non-Toxic Goitres Compared to Sex- And Age-Matched Control Subjects

Abstract

To study serum thyroglobulin (Tg) levels in patients with thyroid disorders compared to sex-and age-matched control subjects and to correlate the Tg levels to the thyroid function, 71 patients were investigated before treatment was started. Serum Tg, measured by a double antibody radioimmunoassay, was elevated in all groups with thyroid disorders, as compared to their controls, but the values showed large overlaps between groups. The highest median values were seen in the two groups of patients with toxic goitres (toxic adenoma and Graves' disease). The Tg values in patients with non-toxic goitres (diffuse and nodular) and in controls showed a log normal distribution, whereas the distribution of values from patients with toxic goitres was different. No correlation was found between serum Tg and serum thyroxine, serum triiodothyronine and serum TSH, respectively. It is concluded that determination of serum Tg is of little diagnostic value in thyroid diseases. Several previous studies have demonstrated varying degrees of elevated levels of serum thyroglobulin (Tg) in thyroid disease (Torrigiani et al. 1969;Hjort 1963;Van Herle et al. 1973; Ochi el al. 1975;Schneider et al. 1977). The actual levels have been shown to be dependent on goitre size and thyroid surgery (Torrigiani et al. 1969) as well as radioiodine therapy (Ochi et al. 1975) and thyroid stimulating hormone (Van Herle et al. 1976; Viler et al. 1973).

Serum Thyroglobulin and Thyroglobulin Autoantibodies in Thyroid Diseases

“…By injection of radioactively labelled T g into rats and monkeys T4 was shown to appear in plasma (15). In patients, however, high levels of T g are not necessarily associated with hyperthyroidism (29,98,101,119,120). I t is therefore unlikely that the T3 and T4 contents of T g should contribute substantially to the thyronine effects in man.…”

“…There was a tendency towards higher values in women at all age groups as compared to men, but this was not significant. The prac-tical consequence of these studies is that a sexand age-matched reference sample group should be used for comparison with results from patients (29,37).…”

“…There are overlaps between normal persons and patients with thyroid diseases, and between various types of thyroid diseases, limit- ing the use of serum Tg as an aid in differential diagnosis (29,98, reviewed in 120). Most pronounced elevations are seen after damage to the thyroid gland, e.g.…”

“…A number of other thyroid autoantibodies are present in Graves' disease (29,76,94,125). By radioimmunological methods TgAb are found present in 50430% of the patients (reviewed in 129), which is about the same incidence as reported for MAb (1,70).…”

Thyroid hyperactivity with high thyroglobulin in serum despite sufficient iodine intake in chronic cold adaptation in an Arctic Inuit hunter population

“…Small amounts of TG are released from the thyroid into the blood (13), and measurement of TG in serum has found its greatest use as an indicator of thyroid tissue remnants in patients treated for differentiated thyroid carcinoma (14). However, serum TG is raised in patients with goitre (13,15), in pregnancy (16,17) and hyperthyroidism (18,19,20) where thyroid hormone production is increased. Moreover, elevated serum TG is a sign of iodine deficiency in population studies (21,22).…”