[The immunochemical properties of thyroglobulin in human thyroid tumors in reaction to rabbit anti-human normal thyroglobulin-serum].

Interactions between antiserum (rabbit anti-human normal thyroglobulin-serum) and human thyroglobulin preparations (obtained from the tissues of the normal thyroid gland, thyroid adenoma, and carcinoma) were compared by inhibition effect with the binding between 131I-labeled standard thyroglobulin and antiserum, set up by a double antibody RIA. Thyroglobulins isolated from normal glands (designated as Nor-Tg) have a high affinity to the antiserum. In contrast, thyroglobulins in follicular adenoma or adenomatous goiter (designated as Ad-Tg) decrease the potency of the affinity to the antiserum. Furthermore, thyroglobulins in papillary or follicular carcinoma (designated as Ca-Tg) markedly decrease such a potency. With the t-test, the inhibition curves of Nor-Tgs are almost parallel to each other. Most of the inhibition curves of Ad-Tgs and Ca-Tgs are not parallel to the curve of Nor-Tg 1 (P-value for non-parallelism less than or equal to 0.05). Therefore, it seems that Tg preparations obtained from tumor tissue are heterogeneous in terms of specificity and/or affinity to antiserum, judging from the results of the non-parallel inhibition curves. The present results also show that the contribution of iodine content in Tg has little or no effect on the nature of Tg-immunogenicity.