THYROID ANTIBODIES IN ASSOCIATION WITH THYROID MALIGNANCY .2. QUALITATIVE PROPERTIES OF THYROGLOBULIN ANTIBODIES

Qualitative properties of thyroglobulin (Tg) antibodies, in associatio n with thyroid malignancy, suspected malignancy or other thyroid disea ses, were studied in 177 patients. Retrospective clinical analysis rev ealed 137 patients to have thyroid carcinoma and 40 to have other thyr oid diseases. Serum Tg was assayed by an immunoradiometric method. Thy roid microsomal (AMC) and Tg antibodies were measured by the particle agglutination method and the avidity of Tg antibodies by enzyme immuno assay (ELA). Assessment of the qualitative properties of Tg antibodies revealed that the high-avidity antibodies especially seem to bind cir culating Tg. Thus any Tg value from a sample with detectable Tg antibo dies is unreliable and should be interpreted with caution.