Existence of anti-thyroglobulin IgG in healthy subjects

An autoantibody, anti-thyroglobulin IgG, was detected in a large proportion of healthy subjects. Sera were collected from 232 healthy subjects aged 7-83 yr, who had no apparent symptoms with normal serum levels of thyroid-stimulating hormone, confirming the absence of Graves' disease and chronic thyroiditis. Anti-thyroglobulin IgG in serum was measured by a novel enzyme immunoassay, the principle of which has been shown to provide 3,000 to 10,000-fold higher sensitivity than the conventional methods. Anti-thyroglobulin IgG was demonstrated in 38% of the healthy subjects (15% of those aged 7-19 yr and 69% of those aged 20-39 yr), and the serum concentration of anti-thyroglobulin IgG was assessed to be 2 micrograms/l - 38 mg/l.