Serum thyroglobulin measurement in various thyroidal disorders.

A specific double antibody radioimmunoassay for human serum thyroglobulin was established. Serum thyroglobulin concentrations were measured in euthyroid non-goitrous subjects and in patients with various specific pathologies of the thyroid gland. Thyroglobulin was detectable in the serum of most euthyroid non-goitrous subjects studied. The serum thyroglobulin concentrations obtained in patients with hyper or hypofunctioning thyroid glands seem to mirror gland activity in terms of hormone production, being high in thyrotoxicosis and low in hypothyroidism. Elevation of serum thyroglobulin concentrations were observed in patients with non-toxic goitres. There was a great deal of overlap in the values obtained in patients with benign goitres and those with malignant lesions making serum thyroglobulin concentration an unreliable discriminant. However, it would seem that once histological diagnosis is established serum thyroglobulin measurements could be useful in the management and follow-up of patients with differentiated primary thyroid malignancies. The likely mechanism(s) of release of thyroglobulin in different thyroidal states and the clinical potential of this new entry into thyroidology are extensively discussed.